International Journal of Oncology

E6‑regulated overproduction of prostaglandin�E2 may inhibit migration of dendritic cells in human papillomavirus 16‑positive cervical lesions

Continuous human papillomavirus (HPV) infection is a critical cause of cervical lesions; however, the specific mechanism is currently not clear. E6 is one of the most important oncoproteins associated with HPV, which regulates synthases in the production of prostaglandin E2 (PGE2). Notably, PGE2 has been reported to be upregulated in cervical lesions. An insufficient number of mature dendritic cells (DCs), which is unable to cause an effective immune response, is an important cause of cervical lesions. Therefore, this study explored the possible causes of HPV16‑positive cervical lesions by identifying the relationship between E6, PGE2 and DCs. Firstly, the distribution and status of DCs in clinical biopsy specimens and animal models were analyzed with immunohistochemistry and flow cytometry, which demonstrated that the migratory ability of DCs was inhibited in HPV16‑positive cervical lesions. Furthermore, using immunohistochemistry, western blotting and ELISA, it was revealed that as the degree of cervical lesions increased, the expression of PGE2 and its synthases increased. Subsequently, as determined using Transwell and 3D migration assays, it was revealed that a high concentration of PGE2 inhibited the migration of DCs, which may explain the phenomenon observed in cervical lesions. Notably, E6 was identified to regulate PGE2 expression. The in vivo experiments indicated that E6 may increase the expression levels of PGE2 in cervical lesions, which could eventually induce inhibition of the migration of DCs. In conclusion, the present study suggested that E6 regulated overproduction of PGE2, which may induce inhibition of DC migration in HPV16‑positive cervical lesions.

Anti-Müllerian hormone concentration regulates activin receptor-like kinase-2/3 expression levels with opposing effects on ovarian cancer cell survival

Anti‑Müllerian hormone (AMH) type II receptor (AMHRII) and the AMH/AMHRII signaling pathway are potential therapeutic targets in ovarian carcinoma. Conversely, the role of the three AMH type I receptors (AMHRIs), namely activin receptor‑like kinase (ALK)2, ALK3 and ALK6, in ovarian cancer remains to be clarified. To determine the respective roles of these three AMHRIs, the present study used four ovarian cancer cell lines (COV434‑AMHRII, SKOV3‑AMHRII, OVCAR8, KGN) and primary cells isolated from tumor ascites from patients with ovarian cancer. The results demonstrated that ALK2 and ALK3 may be the two main AMHRIs involved in AMH signaling at physiological endogenous and supraphysiological exogenous AMH concentrations, respectively. Supraphysiological AMH concentrations (25 nM recombinant AMH) were associated with apoptosis in all four cell lines and decreased clonogenic survival in COV434‑AMHRII and SKOV3‑AMHRII cells. These biological effects were induced via ALK3 recruitment by AMHRII, as ALK3‑AMHRII dimerization was favored at increasing AMH concentrations. By contrast, ALK2 was associated with AMHRII at physiological endogenous concentrations of AMH (10 pM). Based on these results, tetravalent IgG1‑like bispecific antibodies (BsAbs) against AMHRII and ALK2, and against AMHRII and ALK3 were designed and evaluated.

Ex vivo assessment of cancer drug sensitivity in epithelial ovarian cancer and its association with histopathological type, treatment history and clinical outcome

Epithelial ovarian cancer (EOC) is divided into type I and type II based on histopathological features. Type I is clinically more indolent, but also less sensitive to chemotherapy, compared with type II. The basis for this difference is not fully clarified. The present study investigated the pattern of drug activity in type I and type II EOC for standard cytotoxic drugs and recently introduced tyrosine kinase inhibitors (TKIs), and assessed the association with treatment history and clinical outcome. Isolated EOC tumor cells obtained at surgery were investigated for their sensitivity to seven standard cytotoxic drugs and nine TKIs using a short‑term fluorescent microculture cytotoxicity assay (FMCA). Drug activity was compared with respect to EOC subtype, preoperative chemotherapy, cross‑resistance and association with progression‑free survival (PFS). Out of 128 EOC samples, 120 samples, including 21 type I and 99 type II, were successfully analyzed using FMCA. Patients with EOC type I had a significantly longer PFS time than patients with EOC type II (P=0.01). In line with clinical experience, EOC type I samples were generally more resistant than type II samples to both standard cytotoxic drugs and the TKIs, reaching statistical significance for cisplatin (P=0.03) and dasatinib (P=0.002). A similar pattern was noted in samples from patients treated with chemotherapy prior to surgery compared with treatment‑naive samples, reaching statistical significance for fluorouracil, irinotecan, dasatinib and nintedanib (all P<0.05). PFS time gradually shortened with increasing degree of drug resistance. Cross‑resistance between drugs was in most cases statistically significant yet moderate in degree (r<0.5). The clinically observed relative drug resistance of EOC type I, as well as in patients previously treated, is at least partly due to mechanisms in the tumor cells. These mechanisms seemingly also encompass kinase inhibitors. Ex vivo assessment of drug activity is suggested to have a role in the optimization of drug therapy in EOC.

ARID1A restrains EMT and stemness of ovarian cancer cells through the Hippo pathway

Genes encoding subunits of SWI/SNF (BAF) chromatin‑remodeling complexes are recurrently mutated in a broad array of tumor types, and among the subunits, ARID1A is the most frequent target with mutations. In the present study, it was reported that ARID1A inhibits the epithelial‑mesenchymal transition (EMT) and stemness of ovarian cancer cells, accompanied by reduced cell viability, migration and colony formation, suggesting that ARID1A acts as a tumor suppressor in ovarian cancer. Mechanistically, ARID1A exerts its inhibitory effects on ovarian cancer cells by activating the Hippo signaling pathway. Conversely, the overexpression of a gain‑of‑function transcriptional co‑activator with PDZ‑binding motif (TAZ) mutant (TAZ‑Ser89) effectively reverses the effects induced by ARID1A. In addition, activation of Hippo signaling apparently upregulates ARID1A protein expression, whereas ectopic expression of TAZ‑Ser89 results in the markedly decreased ARID1A levels, indicating a feedback of ARID1A‑TAZ in regulating ovarian cancer cell EMT and stemness. Thus, the present study uncovered the role of ARID1A through the Hippo/TAZ pathway in modulating EMT and stemness of ovarian cancer cells, and providing with evidence that TAZ inhibitors could effectively prevent initiation and metastasis of ovarian cancer cases where ARID1A is lost or mutated.

Activating transcription factor 3 inhibits endometrial carcinoma aggressiveness via JunB suppression

The function of activating transcription factor 3 (ATF3) in cancer is context‑dependent and its role in endometrial carcinoma (EC) is yet to be elucidated. In the present study, ATF3 was indicated to be downregulated, while one of the ATF3‑interacting proteins, JunB, was upregulated in ECs according to western blot analysis. After overexpression in ECs, ATF3 inhibited the proliferation and invasion of EC cells and enhanced apoptosis, as well as suppressed the expression of JunB. The properties of EC cells, including the expression of matrix metalloproteinases, tissue inhibitors of metalloproteinases, the cell cycle and apoptosis were all altered by overexpression of ATF3. Furthermore, luciferase activity assay, chromatin precipitation and DNA affinity assay results indicated that ATF3 exerted the aforementioned functions via JunB binding and activator protein‑1 signaling. However, the interaction between ATF3 and JunB did not occur in EC cells under basal conditions, but in ATF3‑overexpressing ECs, which was capable of mitigating EC proliferation, invasion and metastasis. Collectively, the present results suggested that the ATF3/JunB interaction may serve as a potential therapeutic target for ECs.

lncRNA LA16c‑313D11.11 modulates the development of endometrial cancer by binding to and inhibiting microRNA‑205‑5p function and indirectly increasing PTEN activity

The aim of the present study was to determine the competitive endogenous RNA (ceRNA) network associated with long‑coding RNA (lncRNA) LA16c‑313D11.11 in endometrial cancer (EC). Initially, the expression levels of LA16c‑313D11.11 in 60 EC tissues, 20 atypical hyperplasia endometrium (EAH) tissues and 20 normal endometrium tissues was determined. MicroRNA (miRNA/miR)‑205‑5p mimics and LA16c‑313D11.11 mimics were transfected into HEC‑1A and Ishikawa cells. The expression levels of miR‑205‑5p, LA16c‑313D11.11 and their target proteins were assessed using reverse transcription‑quantitative PCR or western blot analysis. Flow cytometry, Cell Counting kit‑8 assays, Transwell migration assays and wound healing assays were performed to assess the effects of LA16c‑313D11.11 and miR‑205‑5p on the migration and proliferation of tumor cells in vitro. The expression levels of LA16c‑313D11.11 and phosphatase and tensin homolog deleted on chromosome ten (PTEN) in human EAH and EC tissues were significantly decreased, whereas the expression levels of miR‑205‑5p in EAH and EC tissues were significantly increased, compared with the normal endometrium tissues. The expression of LA16c‑313D11.11 in human EC tissues negatively correlated with the expression of miR‑205‑5p. Additionally, the overexpression of LA16c‑313D11.11 significantly reduced the invasion, migration and viability of HEC‑1A and Ishikawa cells in vitro. LA16c‑313D11.11 was shown to regulate the expression of PTEN, and the invasion, migration and viability of HEC‑1A and Ishikawa cells, through its microRNA response element to compete for microRNA‑205‑5p. LA16c‑313D11.11 was also shown to modulate the PI3K/AKT signaling pathway. Therefore, LA16c‑313D11.11 acts as an effective ceRNA associated with a microRNA‑205‑5p‑PTEN axis. LA16c‑313D11.11 may inhibit the development and progression of EC by acting as a sponge of miR‑205‑5p, thus indirectly increasing the expression of PTEN.

Beyond tumor‑associated macrophages involved in spheroid formation and dissemination: Novel insights for ovarian cancer therapy (Review)

Ovarian cancer (OC) is the most common and deadly malignant tumor of the female reproductive system. When OC cells detach from the primary tumor and enter the ascitic microenvironment, they are present as individual cells or multicellular spheroids in ascites. These spheroids, composed of cancer and non‑malignant cells, are metastatic units and play a crucial role in the progression of OC. However, little is known about the mechanism of spheroid formation and dissemination. Tumor‑associated macrophages (TAMs) in the center of spheroids are key in spheroid formation and metastasis and provide a potential target for OC therapy. The present review summarizes the key biological features of spheroids, focusing on the role of TAMs in spheroid formation, survival and peritoneal metastasis, and the strategies targeting TAMs to provide new insights in treating OC.

17β‑estradiol‑induced mitochondrial dysfunction and Warburg effect in cervical cancer cells allow cell survival under metabolic stress

Mitochondria from different types of cancer show bioenergetics and dysfunction that favor cell proliferation. The mechanistic understanding of estrogen in cervical cancer is poorly understood. Therefore, the objective of this study was to determine how 17β‑estradiol (E2) affects mitochondrial function and the Warburg effect in SiHa, HeLa and C33A cervical cancer cells. Mitochondrial compromise was evaluated measuring changes in the membrane permeability by immunofluorescence, calcium concentration, redox status, iron and ferritin reserves. Glucose consumption and lactic acid assays were used to detect the metabolic activity. Results were confirmed at molecular level by analysis of the differential gene expression using RNA sequencing. E2 modified the mitochondrial permeability and produced an alteration in the calcium signaling pathway. In HeLa and SiHa, there was a significant decrease in nitric oxide levels and lipid peroxidation, and an increase in glucose consumption and lactic acid levels when stimulated with E2. Intracellular iron or ferritin reserves were not affected by the E2 treatment. Genes differentially modulated by E2 were involved in the mitochondrial electron transport chain, oxidative phosphorylation system, glycolysis, pentose phosphate pathway and the regulation of metabolic signaling pathways. Herein, we provide evidence for a primary effect of estrogen on mitochondrial function and the Warburg effect, favoring the metabolic adaptation of the cervical cancer cell lines and their survival.

Knockdown of lncRNA MALAT1 induces pyroptosis by regulating the miR‑124/SIRT1 axis in cervical cancer cells

The aim of the present study was to elucidate the role and downstream mechanism of long non‑coding RNA (lncRNA) metastasis‑associated lung adenocarcinoma transcript 1 (

miR‑126 regulates the progression of epithelial ovarian cancer in vitro and in vivo by targeting VEGF‑A

MicroRNA (miRNA/miR‑126) has been shown to be associated with ovarian cancer in previous studies. In ovarian cancer, however, the specific status of miR‑126 remains largely unknown. In the present study, to clarify its role in ovarian cancer, the levels of miR‑126 were first examined using laser microdissection and RT‑qPCR. It was found that the miR‑126 level was decreased in ovarian tissue samples and the restoration of miR‑126 inhibited cell proliferation, cell invasion and migration in vitro and suppressed tumor growth in vivo. A bioinformatics search revealed that the angiogenesis‑related gene, vascular endothelial growth factor (VEGF)‑A, was among the potential targets of miR‑126. The suppression of invasion and proliferation induced by ectopic miR‑126 expression was nullified by the ectopic expression of VEGF‑A, suggesting that these suppressive effects were largely attributable to the ability of miR‑126 to target VEGF‑A. Moreover, the restoration of miR‑126 suppressed the angiogenic potential of human umbilical vein endothelial cells (HUVECs). On the whole, these findings indicate that the loss of expression of miR‑126 contributes to the abnormal VEGF‑A accumulation and subsequent unchecked cell invasion and cell proliferation in epithelial ovarian cancer.

Bcl2l10 mediates the proliferation, invasion and migration of ovarian cancer cells

Bcl2l10, also known as Diva, Bcl‑b and Boo, is a member of the Bcl2 family of proteins, which are involved in signaling pathways that regulate cell apoptosis and autophagy. Previously, it was demonstrated that Bcl2l10 plays a crucial role in the completion of oocyte meiosis and is a key regulator of Aurora kinase A (Aurka) expression and activity in oocytes. Aurka is overexpressed in several types of solid tumors and has been considered a target of cancer therapy. Based on these previous results, in the present study, the authors aimed to investigate the regulatory role of Bcl2l10 in A2780 and SKOV3 human ovarian cancer cells. The protein expression of Bcl2l10 was examined in human cancer tissues and cell lines, including the ovaries, using a tissue microarray and various human ovarian cancer cell lines. It was found that Bcl2l10 regulated the protein stability and activities of Aurka in ovarian cancer cells. Although apoptosis was not affected, the cell cycle was arrested at the G0/G1 phase by Bcl2l10 knockdown. Of note, cell viability and motility were markedly increased by Bcl2l10 knockdown. On the whole, the findings of this study suggest that Bcl2l10 functions as tumor suppressor gene in ovarian cancer.

A FXYD5/TGF‑β/SMAD positive feedback loop drives epithelial‑to‑mesenchymal transition and promotes tumor growth and metastasis in ovarian cancer

Epithelial ovarian cancer is aggressive and lacks effective prognostic indicators or therapeutic targets. In the present study, using immunohistochemistry and bioinformatics analysis on ovarian cancer tissue data from The Obstetrics and Gynecology Hospital of Fudan University and The Cancer Genome Atlas database, it was identified that FXYD domain‑containing ion transport regulator 5 (FXYD5) expression was upregulated in the SKOV3‑IP cell line compared with its parental cell line, SKOV3, and in ovarian cancer tissues compared with in normal tissues. In addition, FXYD5 upregulation was predictive of poor patient survival. Furthermore, through various in vitro (Transwell assay, clonogenic assay and western blot analysis) and in vivo (nude mouse model) experiments, it was demonstrated that FXYD5 promoted the metastasis of ovarian cancer cells. Mechanistically, RNA sequencing, western blot analysis, a luciferase reporter assay and chromatin immunoprecipitation were performed to reveal that FXYD5 dispersed the SMAD7‑SMAD specific E3 ubiquitin protein ligase 2‑TGF‑β receptor 1 (TβR1) complex, deubiquitinated and stabilized TβR1, and subsequently enhanced transforming growth factor‑β (TGF‑β) signaling and sustained TGF‑β‑driven epithelial‑mesenchymal transition (EMT). The TGF‑β‑activated SMAD3/SMAD4 complex was in turn directly recruited to the FXYD5 promoter region, interacted with specific SMAD‑binding elements, and then promoted FXYD5 transcription. In brief, FXYD5 positively regulated TGF‑β/SMADs signaling activities, which in turn induced FXYD5 expression, creating a positive feedback loop to drive EMT in the process of ovarian cancer progression. Collectively, the findings of the present study suggested a mechanism through which FXYD5 serves a critical role in the constitutive activation of the TGF‑β/SMADs signaling pathways in ovarian cancer, and provided a promising therapeutic target for human ovarian cancer.

ATAD2 predicts poor outcomes in patients with ovarian cancer and is a marker of proliferation

The oncogene ATPase family AAA domain‑​containing protein 2 (ATAD2) has been demonstrated to promote malignancy in a number of different types of tumor; however, its expression and role in ovarian cancer (OC) remain unknown. In the present study, it was demonstrated that ATAD2 acts as both a marker and a driver of cell proliferation in OC. Immunohistochemistry (IHC) and bioinformatics analyses were used to evaluate ATAD2 expression in OC, and multi‑omics integrated analyses were used to dissect which factor resulted in its upregulation. Multiplex IHC assay was used to reveal the specific expression of ATAD2 in proliferating OC cells. CRISPR‑Cas9‑mediated gene editing was performed to investigate the effect of ATAD2 deletion on OC proliferation. The results demonstrated that ATAD2 is elevated in primary OC tissues compared with the adjacent normal tissue and metastases from the stomach. Genetic copy number amplification is a primary cause resulting in upregulation of ATAD2, and this was most frequently observed in OC. High ATAD2 expression was associated with advanced progression and predicted an unfavorable prognosis. ATAD2 could be used to identify cases of OC with a high proliferation signature and could label proliferating cells in OC. CRISPR‑Cas9‑mediated ATAD2 deletion resulted in a significant decrease in both cell proliferation and colony formation ability. Mechanistically, ATAD2‑knockdown resulted in deactivation of the mitogen‑activated protein kinase (MAPK) pathways, particularly the JNK‑MAPK pathway, resulting in suppression of proliferation. Collectively, the data from the present study demonstrated that the ATD2 gene was frequently amplified and protein expression levels were upregulated in OC. Therefore, ATAD2 may serve as an attractive diagnostic and prognostic OC marker, which may be used to identify patients with primary OC, whom are most likely to benefit from ATAD2 gene‑targeted proliferation intervention therapies.

Overcoming acquired doxorubicin resistance of ovarian carcinoma cells by verapamil‑mediated promotion of DNA damage‑driven cytotoxicity

The efficacy of anticancer therapeutics is limited by acquired drug resistance of tumor cells. The present study aimed to characterize and overcome resistance mechanisms to the anthracycline derivative doxorubicin (Doxo). To this end, comparative analyses of Doxo‑induced stress responses of parental A2780 ovarian carcinoma cells and Doxo‑resistant A2780ADR variants were performed. A2780ADR cells revealed cross‑resistance to multiple compounds, including anticancer drugs [cisplatin (CisPt) and etoposide (Eto)] and DNA repair/DNA damage response (DDR) inhibitors (olaparib, niraparib, entinostat, prexasertib and rabusertib). A2780ADR cells formed markedly fewer DNA double‑strand breaks (DSB) following Doxo exposure compared with parental A2780 cells, resulting in a mitigated DDR, reduced proliferation inhibition and attenuated apoptosis. Potential resistance mechanisms identified to contribute to Doxo resistance of A2780ADR cells include increased Doxo efflux due to increased multi‑drug resistance gene 1 (MDR1) expression and reduced topoisomerase IIα protein expression. Substantial resensitization of A2780ADR cells to Doxo was achieved by both the RAC1 GTPase inhibitor EHT1864, the histone deacetylase inhibitor entinostat (EST) and, most effectively, the calcium channel blocker verapamil (Ver). Notably, Ver‑mediated sensitization also pertains to Eto and CisPt. The synergistic effect of Ver in combination with Doxo, which is reflected by low combination index (CI<0.8), probably involves inhibition of MDR1‑mediated drug export, increased intracellular steady state levels of Doxo and elevated DSB formation, eventually promoting pro‑toxic mechanisms of the DDR. However, combination treatment with Doxo and Ver also increased the cytotoxic response of non‑malignant murine cardiomyocytes, murine embryonic stem cells and human induced pluripotent stem cells. Taken together, the present study suggested inhibition of MDR1‑mediated Doxo efflux by Ver a useful approach to overcome acquired drug resistance of A2780ADR cells by stimulating DDR‑related cytotoxicity, yet at the price of a potentially increased risk of normal tissue toxicity.

Identification of the most common BRCA alterations through analysis of germline mutation databases: Is droplet digital PCR an additional strategy for the assessment of such alterations in breast and ovarian cancer families?

Breast and ovarian cancer represent two of the most common tumor types in females worldwide. Over the years, several non‑modifiable and modifiable risk factors have been associated with the onset and progression of these tumors, including age, reproductive factors, ethnicity, socioeconomic status and lifestyle factors, as well as family history and genetic factors. Of note, BRCA1 and BRCA2 are two tumor suppressor genes with a key role in DNA repair processes, whose mutations may induce genomic instability and increase the risk of cancer development. Specifically, females with a family history of breast or ovarian cancer harboring BRCA1/2 germline mutations have a 60‑70% increased risk of developing breast cancer and a 15‑40% increased risk for ovarian cancer. Different databases have collected the most frequent germline mutations affecting BRCA1/2. Through the analysis of such databases, it is possible to identify frequent hotspot mutations that may be analyzed with next‑generation sequencing (NGS) and novel innovative strategies. In this context, NGS remains the gold standard method for the assessment of BRCA1/2 mutations, while novel techniques, including droplet digital PCR (ddPCR), may improve the sensitivity to identify such mutations in the hereditary forms of breast and ovarian cancer. On these bases, the present study aimed to provide an update of the current knowledge on the frequency of BRCA1/2 mutations and cancer susceptibility, focusing on the diagnostic potential of the most recent methods, such as ddPCR.

Targeting endogenous fatty acid synthesis stimulates the migration of ovarian cancer cells to adipocytes and promotes the transport of fatty acids from adipocytes to cancer cells

Despite significant advances in oncology, 1 of 108 female patients succumb to ovarian cancer (OC) each year. Improved novel treatments against this aggressive disease would be a major improvement. The growth of OC cells has been demonstrated to be highly dependent on lipids. OC cells are abundantly present in the abdominal cavity and omentum, the main sites of OC expansion. Accordingly, it has been attempted not only to block the hyperactive synthesis of fatty acids (FAs) in cancer cells, but also to disrupt lipid supply. While either strategy has yielded promising results as monotherapy, the induction of resistance pathways diminishing the anticancer effects is yet conceivable. The endogenous regulation of lipid biosynthesis in OC has been extensively studied. However, the role of stromal cells in the modulation of the effects of anti‑lipogenic drugs has not yet been well documented. The present study thus examined the interaction between OC cells and associated stromal cells, when

Ovarian tumor deubiquitinase 6A regulates cell proliferation via deubiquitination of nucleolin and caspase‑7

Most proteins maintain protein homeostasis via post‑translational modifications, including the ubiquitin‑proteasome system. Deubiquitinating enzymes (DUBs) have essential intercellular roles, such as responses to DNA damage, proteolysis and apoptosis. Therefore, it is important to understand DUB‑related diseases to identify DUBs that target abnormally regulated proteins in cells. Ovarian tumor deubiquitinase 6A (OTUD6A) was previously reported as a downregulated DUB in HCT116 cells with p53 knockdown. Therefore, it was expected that the relationship between OTUD6A and p53 would affect cell proliferation. In the present study, putative substrates of OTUD6A related to the p53 signaling pathway were identified. Application of liquid chromatography‑tandem mass spectrometry and proteomic analysis led to the identification of nucleolin (known to bind p53) as a binding protein. In addition, immunoprecipitation studies determined that caspase‑7, an apoptotic protein, is associated with p53 signaling and is regulated by OTUD6A. It was further identified that OTUD6A regulates the protein stability of nucleolin, but not caspase‑7. It was also demonstrated that OTUD6A acts as a respective DUB through the deubiquitination of K48‑linked polyubiquitin chain of nucleolin and the K63‑linked polyubiquitin chain of caspase‑7. Furthermore, overexpression of OTUD6A induced cell proliferation via enhancing cell cycle progression of MCF7 cells. Taken together, OTUD6A may be proposed as a target for anticancer therapy.

TRIM22 inhibits endometrial cancer progression through the NOD2/NF‑κB signaling pathway and confers a favorable prognosis

Endometrial cancer (EnC) is a malignant gynecological tumor commonly observed in developed countries, specifically among post‑menopausal women. Although numerous patients with EnC receive promising prognoses, those with advanced or metastatic disease often have a poor prognosis and an impaired quality of life. Tripartite motif‑containing 22 (TRIM22) has been confirmed to play many crucial roles in different biological processes, from inflammatory to tumorigenesis. However, the multifaceted roles of TRIM22 in EnC remain uncharacterized. Herein, comparing normal endometrial tissues with tumor tissues obtained from patients, it was concluded that TRIM22 expression was decreased in tumor tissues. However, the overexpression of TRIM22 served to inhibit the migratory, invasive, proliferative and cell cycle activity of EnC cells. Moreover, the knockdown of TRIM22 increased the migratory, invasive, and proliferative activity of the EnC cells. Furthermore, it was found that TRIM22 effectively suppressed EnC progression through the nucleotide binding oligomerization domain containing 2 (NOD2)/nuclear factor (NF)‑κB pathway. The data also demonstrated that TRIM22 functions as an inhibitor of EnC tumor xenograft growth in vivo. Overall, the findings of the present study define a novel regulatory role for TRIM22 in EnC progression. Moreover, TRIM22 may serve as an important prognostic predictor for EnC.

Claudin‑9 is a novel prognostic biomarker for endometrial cancer

The tight‑junction protein claudin‑9 (CLDN9) is barely distributed in normal adult tissues but is ectopically expressed in various cancer types. Although multiple databases indicated upregulation of CLDN9 in endometrial cancers at the mRNA level, its protein expression and biological roles remain obscure. In the present study, the prognostic significance of CLDN9 expression in endometrial cancer was evaluated by immunohistochemical staining and semi‑quantification using formalin‑fixed paraffin‑embedded specimens obtained from 248 endometrial carcinoma cases. A total of 43 cases (17.3%) had high CLDN9 expression, whereas 205 cases (82.7%) exhibited low CLDN9 expression. The 5‑year disease‑specific survival rates in the high and low CLDN9 expression groups were 62.8 and 87.8% (P<0.001), respectively. In addition, multivariate analysis revealed that high CLDN9 expression was an independent prognostic factor (hazard ratio, 4.99; 95% CI, 1.96‑12.70; P<0.001). Furthermore, CLDN9 expression was significantly correlated with the expression of CLDN6 (P<0.001), which is the closest CLDN member to CLDN9 and a poor prognostic factor for endometrial carcinoma. The 5‑year disease‑specific survival rate of cases with CLDN6‑high/CLDN9‑high, CLDN6‑high/CLDN9‑low and CLDN6‑low/CLDN9‑high status was 30.0, 37.5 and 72.7%, respectively, whereas that of CLDN6‑low/CLDN9‑low was 89.8% (P=0.004). In conclusion, aberrant CLDN9 expression is a predictor of poor prognosis for endometrial cancer and may be utilized in combination with CLDN6 to achieve higher sensitivity.

Genomic characterization of five commonly used endometrial cancer cell lines

Recently, the compilation of massive amounts of genetic and genomic information on a wide variety of human cancer types, collectively known as The Cancer Genome Atlas (TCGA), has revealed a wealth of descriptive classification schemes both within and between different types and sources of cancer. In endometrial cancer, TCGA analyses have produced a post hoc scheme composed of four clusters: DNA polymerase ε catalytic subunit A (POLE) ultra‑mutated (cluster 1), microsatellite instability (MSI) hypermutated (cluster 2), copy‑number low (endometrioid, cluster 3) and copy‑number high (serous‑like, cluster 4). Given that cultured cells are the pre‑clinical platform of cancer research, it was questioned how representative endometrial cancer cultured cell lines are in the context of TCGA‑driven classification scheme. To address this issue in endometrial cancer cell lines, the present study investigated five commonly used cell lines: Ishikawa, ECC‑1, Hec50co, KLE And RL95‑2. The histology, mutation profile, MutL homolog 1 promoter methylation, copy‑number variation, homologous recombination repair and microsatellite instability in each of these cell lines was assessed. The result of this characterization was that none of the cell lines fits neatly into any one of TCGA classes but are still useful models for groups of endometrial tumors. Furthermore, the contention that the ECC‑1 cell line is actually Ishikawa was addressed using additional data. It was confirmed that ECC‑1 cells likely no longer exist as ECC‑1 but that they are not exactly Ishikawa either. For this reason, ECC‑1 cells are suggested to be used in vitro but with this caveat in mind. Finally, we compiled a database of 127 endometrial cancer cell lines, including the five reported on here. The wide range of variation found in these cell lines highlights the need to further characterize these cells to select models that are more representative of the various histological and genomic aspects of endometrial cancer.

New insight into the role of PTCH1 protein in serous ovarian carcinomas

The Hedgehog (Hh) signaling pathway is essential for normal embryonic development, while its hyperactivation in the adult organism is associated with the development of various cancers. The role of the Hh signaling pathway in ovarian cancer has not been sufficiently investigated. Therefore, the present study investigated the role of protein patched homolog 1 (PTCH1), a component of the Hh signaling pathway, and changes in the promoter methylation status of the corresponding gene in a cohort of low‑(LGSC) and high‑grade serous ovarian carcinomas (HGSC) and HGSC cell lines (OVCAR8 and OVSAHO). PTCH1 protein expression level was analyzed using immunohistochemistry in tissue samples and immunofluorescence and western blotting in cell lines. DNA methylation patterns of the

Exposure to escalating olaparib does not induce acquired resistance to PARPi and to other chemotherapeutic compounds in ovarian cancer cell lines

Poly (ADP‑ribose) polymerase (PARP)‑inhibitors (PARPi) such as olaparib and niraparib are currently used as a treatment option for

Combined inhibition of IL‑6 and IL‑8 pathways suppresses ovarian cancer cell viability and migration and tumor growth

Ovarian cancer is the most lethal gynecological cancer type in the United States. The success of current chemotherapies is limited by chemoresistance and side effects. Targeted therapy is a promising future direction for cancer therapy. In the present study, the efficacy of co‑targeting IL‑6 and IL‑8 in human ovarian cancer cells by bazedoxifene (Baze) + SCH527123 (SCH) treatment was examined. ELISA, cell viability, cell proliferation, cell migration, cell invasion, western blotting and peritoneal ovarian tumor mouse model analyses were performed to analyze the expression levels of IL‑6 and IL‑8, tumor growth, tumor migration and invasion, and the possible pathways of human ovarian cancer cell lines (SKOV3, CAOV3 and OVCAR3) and patient‑derived OV75 ovarian cancer cells. Each cell line was treated by monotherapy or combination therapy. The results demonstrated that IL‑6 and IL‑8 were secreted by human ovarian cancer cell lines. Compared with the DMSO control, the combination of IL‑6/glycoprotein 130 inhibitor Baze and IL‑8 inhibitor SCH synergistically inhibited cell viability in ovarian cancer cells. Baze + SCH also inhibited cell migration and invasion, suppressed ovarian tumor growth and inhibited STAT3 and AKT phosphorylation, as well as survivin expression. Therefore, co‑targeting the IL‑6 and IL‑8 signaling pathways may be an effective approach for ovarian cancer treatment.

Efficacy of birinapant in combination with carboplatin in targeting platinum‑resistant epithelial ovarian cancers

Patients diagnosed with epithelial ovarian cancers (EOCs) often suffer from disease relapse associated with the emergence of resistance to standard platinum‑based chemotherapy. Treatment of patients with chemo‑resistant disease remains a clinical challenge. One mechanism of chemoresistance includes overexpression of pro‑survival proteins called inhibitors of apoptosis (IAP) which enable cancer cells to evade apoptosis. Due to their anti‑apoptotic activity, association with poor prognosis, and correlation with therapy resistance in multiple malignancies, IAP proteins have become an attractive target for development of anticancer therapeutics. Second mitochondrial activator of caspase (SMAC) mimetics are the most widely used IAP antagonists currently being tested in clinical trials as a monotherapy and in combination with different chemotherapeutic drugs to target different types of cancer. In the present study, the antitumor efficacy of combination therapy with birinapant, a bivalent SMAC mimetic compound, and carboplatin to target platinum‑resistant EOC cells was investigated. A 3D organoid bioassay was utilized to test the efficacy of the combination therapy in a panel of 7 EOC cell lines and 10 platinum‑resistant primary patient tumor samples. Findings from the

E7 oncoprotein from human papillomavirus 16 alters claudins expression and the sealing of epithelial tight junctions

Tight junctions (TJs) are cell‑cell adhesion structures frequently altered by oncogenic transformation. In the present study the role of human papillomavirus (HPV) 16 E7 oncoprotein on the sealing of TJs was investigated and also the expression level of claudins in mouse cervix and in epithelial Madin‑Darby Canine Kidney (MDCK) cells. It was found that there was reduced expression of claudins ‑1 and ‑10 in the cervix of 7‑month‑old transgenic K14E7 mice treated with 17β‑estradiol (E2), with invasive cancer. In addition, there was also a transient increase in claudin‑1 expression in the cervix of 2‑month‑old K14E7 mice, and claudin‑10 accumulated at the border of cells in the upper layer of the cervix in FvB mice treated with E2, and in K14E7 mice treated with or without E2. These changes were accompanied by an augmented paracellular permeability of the cervix in 2‑ and 7‑month‑old FvB mice treated with E2, which became more pronounced in K14E7 mice treated with or without E2. In MDCK cells the stable expression of E7 increased the space between adjacent cells and altered the architecture of the monolayers, induced the development of an acute peak of transepithelial electrical resistance accompanied by a reduced expression of claudins ‑1, ‑2 and ‑10, and an increase in claudin‑4. Moreover, E7 enhances the ability of MDCK cells to migrate through a 3D matrix and induces cell stiffening and stress fiber formation. These observations revealed that cell transformation induced by HPV16 E7 oncoprotein was accompanied by changes in the pattern of expression of claudins and the degree of sealing of epithelial TJs.

FAM83A exerts tumor‑suppressive roles in cervical cancer by regulating integrins

Family with sequence similarity 83 member A (FAM83A) has been recently observed to be upregulated in various types of cancer and hypothesized to be serve as an oncogene. The present study aimed to determine the functional roles and the underlying molecular mechanism of FAM83A in cervical cancer. The results demonstrated that although FAM83A expression was increased in cervical cancer compared with normal tissues, the expression levels of FAM83A were decreased in patients with advanced FIGO stage, deep stromal invasion, poor differentiation and/or lymph node metastasis and negatively associated with short survival time of patients with cervical cancer. FAM83A knockdown promoted cell proliferative, migratory and invasive abilities of CaSki and HeLa cells. A mouse xenograft model demonstrated that FAM83A knockdown promoted tumor growth in vivo. Mechanistically, RNA sequencing results revealed that knockdown of FAM83A increased the transcription of genes mainly associated with oncogenesis‑associated pathways. In addition, FAM83A knockdown increased the protein levels of α1, α3, α5, β4 and β5 integrins in vitro and in vivo, and the expression of FAM83A was also negatively associated with the levels of these proteins in human cervical cancer tissue samples. In conclusion, the results of the present study suggested that FAM83A may exert a tumor‑suppressive role in cervical cancer by suppressing the expression of integrins, which may offer new insight into the biological basis of cervical cancer.

HECTD1 regulates the expression of SNAIL: Implications for epithelial‑mesenchymal transition

As a transcription factor, SNAIL plays a crucial role in embryonic development and cancer progression by mediating epithelial‑mesenchymal transition (EMT); however, post‑translational modifications, such as ubiquitination, which control the degradation of SNAIL have been observed to affect its functional role in EMT. In a previous study by the authors, it was demonstrated that the HECT domain E3 ubiquitin ligase 1 (HECTD1) regulated the dynamic nature of adhesive structures. In the present study, HECTD1 was observed to interact with SNAIL and regulate its stability through ubiquitination, and the knockdown of HECTD1 increased the expression levels of SNAIL. HECTD1 was discovered to contain putative nuclear localization and export signals that facilitated its translocation between the cytoplasm and nucleus, a process regulated by epidermal growth factor (EGF). Treatment with leptomycin B resulted in the nuclear retention of HECTD1, which was associated with the loss of SNAIL expression. The knockdown of HECTD1 in HeLa cells increased cell migration and induced a mesenchymal phenotype, in addition to demonstrating sustained EGF signaling, which was observed through increased phosphorylated ERK expression levels. Under hypoxic conditions, HECTD1 expression levels were decreased by microRNA (miRNA or miR)‑210. Upon the observation of genetic abnormalities in the HECTD1 gene in cervical cancer specimens, it was observed that the decreased expression levels of HECTD1 were significantly associated with a poor patient survival. Thus, it was hypothesized that HECTD1 may regulate EMT through the hypoxia/hypoxia inducible factor 1α/miR‑210/HECTD1/SNAIL signaling pathway and the EGF/EGF receptor/HECTD1/ERK/SNAIL signaling pathway in cervical cancer. On the whole, the data of the present study indicated that HECTD1 serves as an E3 ubiquitin ligase to mediate the stability of SNAIL proteins.

Role of microRNAs in glycolysis in gynecological tumors (Review)

Gynecological malignancies are a leading cause of mortality among females worldwide, and difficulties in early diagnosis and acquired drug resistance constitute obstacles to effective therapies. Ovarian cancer causes more deaths than any other cancer of the female reproductive system. Specifically, in females aged 20 to 39 years, cervical cancer is the third leading cause of cancer‑related mortality, and the incidence rates of cervical adenocarcinoma are increasing. Endometrial carcinoma is the most common gynecological cancer in developed countries, such as the United States. Vulvar cancer and uterine sarcomas are considered rare, and therefore require further investigation. Notably, the development of novel treatment options is critical. Previous research has revealed metabolic reprogramming as a distinct feature of tumor cells, which includes aerobic glycolysis. In this instance, cells produce adenosine triphosphate and various precursor molecules through glycolysis, despite oxygen levels being sufficient. This is to meet the energy required for rapid DNA replication. This phenomenon is also known as the Warburg effect. The Warburg effect results in an increased glucose uptake, lactate production and reduced pH values in tumor cells. The results of previous studies have demonstrated that microRNAs (miRNAs/miRs) regulate glycolysis, and participate in tumorigenesis and tumor progression via interactions with glucose transporters, essential enzymes, tumor suppressor genes, transcription factors and multiple cellular signaling pathways that play critical roles in glycolysis. Notably, miRNAs affect the levels of glycolysis in ovarian, cervical and endometrial cancers. The present review article provides a comprehensive overview of the literature surrounding miRNAs in the glycolysis of gynecological malignant cells. The present review also aimed to determine the role of miRNAs as potential therapeutic options rather than diagnostic markers.

Advances in the role of GPX3 in ovarian cancer (Review)

Ovarian cancer (OC) is the 5th most common malignancy in women, and the leading cause of death from gynecologic malignancies. Owing to tumor heterogeneity, lack of reliable early diagnostic methods and high incidence of chemotherapy resistance, the 5‑year survival rate of patients with advanced OC remains low despite considerable advances in detection and therapeutic approaches. Therefore, identifying novel therapeutic targets to improve the prognosis of patients with OC is crucial. The expression of glutathione peroxidase 3 (GPX3) plays a crucial role in the growth, proliferation and differentiation of various malignant tumors. In OC, GPX3 is the only antioxidant enzyme the high expression of which is negatively correlated with the overall survival of patients. GPX3 may affect lipid metabolism in tumor stem cells by influencing redox homeostasis in the tumor microenvironment. The maintenance of stemness in OC stem cells (OCSCs) is strongly associated with poor prognosis and recurrence in patients. The aim of the present study was to review the role of GPX3 in OC and investigate the potential factors and effects of GPX3 on OCSCs. The findings of the current study offer novel potential targets for drug therapy in OC, enhance the theoretical foundation of OC drug therapy and provide valuable references for clinical treatment.

MicroRNA‑34b expression enhances chemosensitivity of endometrial cancer cells to paclitaxel

Aberrant DNA methylation is widely observed in various types of cancer, and expression of microRNAs (miRNAs/miRs) is suppressed by DNA methylation. The present study explored tumor suppressor miRNAs downregulated by DNA methylation in endometrial cancer cells, as the basis of a novel therapeutic approach for endometrial cancer. Among 821 candidate miRNAs, miR‑34b was identified as an upregulated miRNA after demethylation treatment in all four endometrial cancer cell lines (HEC‑108, SNG‑II, Ishikawa and HHUA) examined. miR‑34b expression with or without demethylation treatment in cancer cells was confirmed by TaqMan quantitative PCR. MYC and MET, the predicted target genes of miR‑34b, were downregulated at both the RNA and protein levels following miR‑34b overexpression. Following miR‑34b treatment, inhibition of cell growth and invasion, and cell cycle arrest were observed in HEC‑108 cells. Sensitivity to paclitaxel was increased in cancer cells with miR‑34b overexpression, compared with untreated cancer cells, but this difference was not identified for cisplatin or doxorubicin. In vivo, combination treatment with miR‑34b and paclitaxel markedly reduced tumor growth compared with treatment with negative control miRNA and paclitaxel. These data suggest that miR‑34b enhances paclitaxel sensitivity in endometrial cancer cells, and that miR‑34b and MET are key targets for treatment of endometrial cancer. The present results may contribute to the development of combination treatment with a demethylation agent, miR‑34b mimic or MET inhibitor and an anticancer drug.

RBM15‑mediating MDR1 mRNA m6A methylation regulated by the TGF‑β signaling pathway in paclitaxel‑resistant ovarian cancer

Ovarian cancer (OC) lacks effective biomarkers for diagnosis at an early stage and often develops chemoresistance after the initial treatment at an advanced stage. RNA‑binding motif protein 15 (RBM15) is an RNA m6A methylation mediator that serves an oncogenic role in some cancers. However, the function and molecular mechanisms of RBM15 in ovarian tumorigenesis and chemoresistance remain to be elucidated. The present study identified the overexpression of RBM15 in OC tissues and paclitaxel (PTX)‑resistant cells using reverse transcription‑quantitative (q)PCR, western blotting and immunohistochemistry. Clinical data analyses showed that high expression of RBM15 was associated with poor prognosis in patients with OC. Overexpression of RBM15 led to an increase in cell viability and colony formation and a decrease in cell sensitivity to PTX and apoptosis, whereas the knockdown of RBM15 resulted in the inhibition of cell viability and colony formation

Inhibition of protein arginine methyltransferase 6 activates interferon signaling and induces the apoptosis of endometrial cancer cells via histone modification

Histone modification, a major epigenetic mechanism regulating gene expression through chromatin remodeling, introduces dynamic changes in chromatin architecture. Protein arginine methyltransferase 6 (PRMT6) is overexpressed in various types of cancer, including prostate, lung and endometrial cancer (EC). Epigenome regulates the expression of endogenous retrovirus (ERV), which activates interferon signaling related to cancer. The antitumor effects of PRMT6 inhibition and the role of PRMT6 in EC were investigated, using epigenome multi‑omics analysis, including an assay for chromatin immunoprecipitation sequencing (ChIP‑seq) and RNA sequencing (RNA‑seq). The expression of PRMT6 in EC was analyzed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and immunohistochemistry (IHC). The prognostic impact of PRMT6 expression was evaluated using IHC. The effects of PRMT6‑knockdown (KD) were investigated using cell viability and apoptosis assays, as well as its effects on the epigenome, using ChIP‑seq of H3K27ac antibodies and RNA‑seq. Finally, the downstream targets identified by multi‑omics analysis were evaluated. PRMT6 was overexpressed in EC and associated with a poor prognosis. PRMT6‑KD induced histone hypomethylation, while suppressing cell growth and apoptosis. ChIP‑seq revealed that PRMT6 regulated genomic regions related to interferons and apoptosis through histone modifications. The RNA‑seq data demonstrated altered interferon‑related pathways and increased expression of tumor suppressor genes, including NK6 homeobox 1 and phosphoinositide‑3‑kinase regulatory subunit 1, following PRMT6‑KD. RT‑qPCR revealed that eight ERV genes which activated interferon signaling were upregulated by PRMT6‑KD. The data of the present study suggested that PRMT6 inhibition induced apoptosis through interferon signaling activated by ERV. PRMT6 regulated tumor suppressor genes and may be a novel therapeutic target, to the best of our knowledge, in EC.

Tripartite motif containing 33 demonstrated anticancer effect by degrading c‑Myc: Limitation of glutamine metabolism and proliferation in endometrial carcinoma cells

Tripartite motif containing 33 (TRIM33) has been reported to be involved in various tumor progression. However, its role in endometrial carcinoma (EC) remains to be elucidated. By mining the publicly available databases UALCAN and TIMER, low expression of TRIM33 was found in tumor tissues of EC patients. Clinically, downregulation of TRIM33 in EC tissues was positively correlated with the extensive muscle invasion and poor differentiation grade.

Ipatasertib exhibits anti‑tumorigenic effects and enhances sensitivity to paclitaxel in endometrial cancer in vitro and in vivo

Endometrial cancer is the most common gynecologic cancer and one of the only cancers for which incidence and mortality is steadily increasing. Although curable with surgery in the early stages, endometrial cancer presents a significant clinical challenge in the metastatic and recurrent setting with few novel treatment strategies emerging in the past fifty years. Ipatasertib (IPAT) is an orally bioavailable pan‑AKT inhibitor, which targets all three AKT isoforms and has demonstrated anti‑tumor activity in pre‑clinical models, with clinical trials emerging for many cancer types. In the present study, the MTT assay was employed to evaluate the therapeutic efficacy of IPAT or IPAT in combination with paclitaxel (PTX) in endometrial cancer cell lines and primary cultures of endometrial cancer. The effect of IPAT and PTX on the growth of endometrial tumors was evaluated in a transgenic mouse model of endometrial cancer. Apoptosis was assessed using cleaved caspase assays and cellular stress was assessed using ROS, JC1 and tetramethylrhodamine ethyl ester assays. The protein expression levels of markers of apoptosis and cellular stress, and DNA damage were evaluated using western blotting and immunohistochemistry. IPAT significantly inhibited cell proliferation, caused cell cycle G1 phase arrest, and induced cellular stress and mitochondrial apoptosis in a dose dependent manner in human endometrial cancer cell lines. Combined treatment with low doses of IPAT and PTX led to synergistic inhibition of cell proliferation and induction of cleaved caspase 3 activity in the human endometrial cancer cell lines and the primary cultures. Furthermore, IPAT effectively reduced tumor growth, accompanied by decreased protein expression levels of Ki67 and phosphorylation of S6 in the

O‑GlcNAcylation mediates endometrial cancer progression by regulating the Hippo‑YAP pathway

The incidence of endometrial cancer (EC) is rapidly increasing worldwide. The majority of endometrial cancers are diagnosed at an early stage and are associated with a good prognosis; however, patients with advanced‑stage EC have a poor prognosis and present with invasive metastasis. The mechanisms responsible for the invasion and metastasis of endometrial cancer remain unknown. Here, the present study aimed to examine the effects of

RNA m6A methylation regulators in endometrial cancer (Review)

As one of the three major malignant tumor types of the female reproductive system, endometrial cancer (EC) is the most prevalent gynecologic cancer in developed countries. In recent years, the incidence of EC has increased worldwide, threatening the health and well‑being of women. Recent research has indicated that the expression of multiple N6‑methyladenosine (m6A) regulators is up‑ or downregulated in EC and that abnormalities in m6A methylation and the expression of associated regulators are critical to the pathogenesis and progression of EC. m6A is the most abundant internal modification of mRNA. Several studies have demonstrated a close association between the development and progression of malignant tumors and the epigenetic phenomenon of m6A methylation. In the present study, the current status of research on m6A methylation in EC was reviewed. The mechanisms of methyltransferase, demethylase and m6A binding protein in regulating the development and progression of EC by modifying mRNA were introduced. The related research results will provide novel methods and approaches for the prevention and treatment of EC.

Therapeutic implications of targeting cancer testis antigen MAGEA1 in cervical cancer

MAGE family member A1 (MAGEA1), a cancer‑testis antigen (CTA), is aberrantly expressed in several malignancies such as lung and liver cancers. However, its role in cervical cancer remains to be elucidated. The present study investigated the functional significance and therapeutic potential of MAGEA1 in cervical cancer using lentiviral short hairpin RNA‑mediated knockdown, a series of functional assays, RNA sequencing (RNA‑seq), and nude mouse xenograft models. It was found that MAGEA1 was upregulated in cervical cancer cells and its knockdown substantially suppressed cell proliferation, migration, invasion, and

AUP1 transcriptionally activated by KDM5B reprograms lipid metabolism to promote the malignant progression of cervical cancer

Cervical cancer is one of the reproductive malignancies threatening women's lives worldwide. In the present study, it was aimed to explore the role and mechanism of ancient ubiquitous protein 1 (AUP1) in cervical cancer. Through bioinformatics analysis, AUP1 expression in cervical cancer tissues and the correlation between AUP1 and the prognosis of patients were analyzed. AUP1 expression in several cervical cancer cell lines was detected. Following the co‑transfection of short hairpin RNA specific to AUP1 with or without lysine demethylase 5B (KDM5B) overexpression plasmids in SiHa cells, the proliferation and apoptosis of SiHa cells were detected. Additionally, wound healing and Transwell assays were used to detect SiHa cell migration and invasion. Cellular lipid droplets level was detected using the Oil red O staining. Meantime, the levels of triglyceride, cholesterol, oxygen consumption rates and expression of lipid metabolism‑related proteins were detected to assess the lipid metabolism in SiHa cells. Then, the luciferase reporter assay and ChIP assay were used to verify the binding between KDM5B and AUP1. Finally, the effects of AUP1 and KDM5B on the growth and lipid metabolism in SiHa tumor‑bearing mice were measured. AUP1 was significantly upregulated in cervical cancer tissues and cells. AUP1 interference inhibited the malignant biological behaviors and lipid metabolism reprogramming of SiHa cells, which was blocked by KDM5B overexpression. Moreover, KDM5B could transcriptionally activate AUP1 and upregulate AUP1 expression. Furthermore, AUP1 knockdown transcriptionally regulated by KDM5B limited the tumor growth and suppressed the lipid metabolism reprogramming

Calcium signals and potential therapy targets in ovarian cancer (Review)

Ovarian cancer (OC) is a deadly disease. The poor prognosis and high lethality of OC are attributed to its high degrees of aggressiveness, resistance to chemotherapy and recurrence rates. Calcium ion (Ca

miR‑508‑3p suppresses the development of ovarian carcinoma by targeting CCNA2 and MMP7

Ovarian cancer is the most lethal gynecological tumor, and the 5‑year survival rate is only ~40%. The poor survival rate is due to cancer diagnosis at an advanced stage, when the tumor has metastasized. A better understanding of the molecular pathogenesis of tumor growth and metastasis is needed to improve patient prognosis. MicroRNAs (miRs) regulate carcinogenesis and development of cancers. However, the role of miR‑508‑3p in ovarian cancer remains largely unknown. Thus, the present study aimed to investigate the possible functions of miR‑508‑3p in the modulation of development of ovarian cancer. The results of the present study demonstrated that miR‑508‑3p mimics inhibited ovarian cancer cell proliferation, migration and invasion. Reporter gene assay results demonstrated that miR‑508‑3p suppressed cancer cell proliferation by directly targeting the 3'‑untranslated region (UTR) of cyclin A2 (CCNA2) and suppressed migration and invasion by directly targeting the 3'‑UTR of matrix metalloproteinase 7 (MMP7). In addition, high CCNA2 and MMP7 expression levels were associated with low miR‑508‑3p expression in ovarian cancer tissues. Furthermore, miR‑508‑3p and CCNA2 were independent predictors for overall survival in patients with ovarian cancer. To the best of our knowledge, this is the first study to demonstrated that miR‑508‑3p suppressed ovarian cancer development by directly targeting CCNA2 and MMP7. The results of this study suggested the potential value of miR‑508‑3p and CCNA2 as prognostic indicators and therapeutics for ovarian cancer.

Overexpression of PRC1 indicates a poor prognosis in ovarian cancer

Protein regulator of cytokinesis‑1 (PRC1) is a microtubule‑associated factor involved in cytokinesis. Recent studies have indicated that PRC1 overexpression is involved in tumorigenesis in multiple types of human cancer. However, the expression, biological functions and the prognostic significance of PRC1 in ovarian cancer have not yet been clarified. In this study, it was confirmed that the PRC1 mRNA and protein expression levels were upregulated in high‑grade serous ovarian carcinoma (HGSOC) tissues, particularly in patients without breast cancer susceptibility gene (BRCA) pathogenic mutations. PRC1 overexpression contributed to drug resistance, tumor recurrence and a poor prognosis. The findings also indicated that PRC1 knockdown decreased the proliferation, metastasis and multidrug resistance of ovarian cancer cells in vitro. It was also demonstrated that forkhead box protein M1 (FOXM1) regulated the mRNA and protein expression of PRC1. Dual‑luciferase reporter assay and rescue assay confirmed that PRC1 was a direct crucial downstream target of FOXM1. On the whole, the findings of this study confirmed that PRC1 was a major prognostic factor of HGSOC and a promising therapeutic biomarker for the treatment of ovarian cancer.

PAX2 promotes epithelial ovarian cancer progression involving fatty acid metabolic reprogramming

Ovarian cancer is the fifth most common type of cancer afflicting women and frequently presents at a late stage with a poor prognosis. While paired box 2 (PAX2) expression is frequently lost in high‑grade serous ovarian cancer, it is expressed in a subset of ovarian tumors and may play a role in tumorigenesis. This study investigated the expression of PAX2 in ovarian cancer. The expression of PAX2 in a murine allograft model of ovarian cancer, the RM model, led to a more rapidly growing cell line both in vitro and in vivo. This finding was in accordance with the shorter progression‑free survival observed in patients with a higher PAX2 expression, as determined in this study cohort by immunohistochemistry. iTRAQ‑based proteomic profiling revealed that proteins involved in fatty acid metabolism and oxidative phosphorylation were found to be upregulated in RM tumors expressing PAX2. The expression of two key fatty acid metabolic genes was also found to be upregulated in PAX2‑expressing human ovarian cancer samples. The analysis of existing datasets also indicated that a high expression of key enzymes in fatty acid metabolism was associated with a shorter progression‑free survival time in patients with serous ovarian cancer. Thus, on the whole, the findings of this study indicate that PAX2 may promote ovarian cancer progression, involving fatty acid metabolic reprograming.

A multidisciplinary approach remains the best strategy to improve and strengthen the management of ovarian cancer (Review)

Ovarian cancer represents one of the most aggressive female tumors worldwide. Over the decades, the therapeutic options for the treatment of ovarian cancer have been improved significantly through the advancement of surgical techniques as well as the availability of novel effective drugs able to extend the life expectancy of patients. However, due to its clinical, biological and molecular complexity, ovarian cancer is still considered one of the most difficult tumors to manage. In this context, several studies have highlighted how a multidisciplinary approach to this pathology improves the prognosis and survival of patients with ovarian cancer. On these bases, the aim of the present review is to present recent advantages in the diagnosis, staging and treatment of ovarian cancer highlighting the benefits of a patient‑centered care approach and on the importance of a multidisciplinary team for the management of ovarian cancer.

Interleukin‑8 released by cancer‑associated fibroblasts attenuates the autophagy and promotes the migration of ovarian cancer cells

The tumor microenvironment composed of a mixture of stromal cells and their secretions has a marked impact on cancer progression. In particular, soluble factors and metabolites contribute to malignancy through the dysregulation of autophagy in cancer cells. The present study investigated the effects of ovarian cancer‑associated fibroblasts (OVCAFs) with their secretory substances on the autophagy and migration of ovarian cancer cells. The conditioned‑medium (CM) of OVCAFs isolated from fresh human ovarian cancer tissues was analyzed for the levels of 27 common cytokines/chemokines using a cytokine array. Autophagy in cancer cells was assessed by determining the expression of the vacuolar form of LC3 by western blot analysis and immunofluorescence. Cancer cell migration was assessed by Transwell migration assay. Interleukin (IL)‑8 was found to be the most highly upregulated cytokine among the cytokines/chemokines found in the OVCAF‑CM. The role of IL‑8 in ovarian cancer cell migration and its mechanistic link with autophagy was investigated. Recombinant human IL‑8 (rhIL‑8) stimulated the migration of SKOV3 and Kuramochi ovarian cancer cells, and concurrently downregulated basal autophagy, in concentration‑dependent manner. Compared to the CM of control counterpart normal fibroblasts isolated from benign ovaries (OVNF‑CM), the CM from 3 OVCAF isolates (namely, OVCAF‑9, ‑20 and ‑43) exerted effects similar to rhIL‑8 on both cancer cell lines. The pharmacological induction of autophagy with rapamycin or metformin attenuated the pro‑migratory effects of IL‑8. Neutralizing anti‑IL‑8 antibody counteracted the inhibitory effect of OVCAF‑CM on basal autophagy. On the whole, the present study highlights the involvement of IL‑8 released by CAFs in the ovarian tumor microenvironment in promoting cancer cell migration through the suppression of autophagy.

Receptor for activated C kinase 1 promotes cervical cancer lymph node metastasis via the glycolysis‑dependent AKT/mTOR signaling

Cervical cancer (CC), an aggressive form of squamous cell carcinoma, is characterized by early‑stage lymph node metastasis and an extremely poor prognosis. The authors have previously demonstrated that patients with CC have aberrant glycolysis. The upregulation of receptor for activated C kinase 1 (RACK1) is associated with CC lymph node metastasis (LNM). However, its role in mediating aerobic glycolysis in CC LNM remains unclear. In the present study,

Regulation and reversal of paclitaxel resistance via the STAT1‑mediated apoptotic pathway in ovarian cancer

Ovarian cancer (OC) is the most lethal disease in women. Resistance to paclitaxel (PTX) is the main cause of treatment failure in patients with OC. The STAT1 protein is a transcription factor implicated in a variety of cellular processes. The present study explored the function and regulatory mechanism of STAT1 in the reversal of PTX resistance

RAD51 and PALB2 in precision oncology: Clinical implications for HRD associated breast and ovarian cancers (Review)

Maintaining genomic stability is essential for reducing the risk of carcinogenesis. Homologous recombination (HR) is a high‑fidelity DNA repair mechanism that addresses double‑strand breaks and interstrand crosslinks. The present review examined two key components of HR:

Function of microRNA‑124 in the pathogenesis of cancer (Review)

Non‑coding RNAs with a length of 22‑24 nt are known as microRNAs (miRNAs or miRs), which are critical regulators of protein translation. Over the past 10 years, the roles of miRNAs have been extensively investigated in several human cancer types. There is evidence to indicate that miRNAs regulate gene expression by concentrating on a number of substances that have an impact on the physiology and development of cancer cells. Thus, miRNAs as regarded as effective targets for further studies on the design of novel therapeutic strategies. Hepatocellular carcinoma, breast, prostate, and ovarian cancer are only a few of the cancers that miR‑124 suppresses. Furthermore, it has been shown that miR‑124 is linked to the development and aggressive spread of malignancies. The aim of the present review was to clarify and highlight the role of miR‑124 in the development and progression of cancer, emphasizing recent research illustrating how miR‑124 has been used as a therapeutic agent against cancer, as well as the diagnostic potential, regulatory mechanisms and clinical application of miR‑124.

Digitoxin inhibits HeLa cell growth through the induction of G2/M cell cycle arrest and apoptosis in vitro and in vivo

Cervical cancer is the fourth most common gynecological malignancy affecting the health of women worldwide and the second most common cause of cancer‑related mortality among women in developing regions. Thus, the development of effective chemotherapeutic drugs for the treatment of cervical cancer has become an important issue in the medical field. The application of natural products for the prevention and treatment of various diseases, particularly cancer, has always attracted widespread attention. In the present study, a library of natural products composed of 78 single compounds was screened and it was found that digitoxin exhibited the highest cytotoxicity against HeLa cervical cancer cells with an IC50 value of 28 nM at 48 h. Furthermore, digitoxin exhibited extensive antitumor activities in a variety of malignant cell lines, including the lung cancer cell line, A549, the hepatoma cell line, MHCC97H, and the colon cancer cell line, HCT116. Mechanistically, digitoxin caused DNA double‑stranded breaks (DSBs), inhibited the cell cycle at the G2/M phase via the ataxia telangiectasia mutated serine/threonine kinase (ATM)/ATM and Rad3‑related serine/threonine kinase (ATR)‑checkpoint kinase (CHK1)/checkpoint kinase 2 (CHK2)‑Cdc25C pathway and ultimately triggered mitochondrial apoptosis, which was characterized by the disruption of Bax/Bcl‑2, the release of cytochrome c and the sequential activation of caspases and poly(ADP‑ribose) polymerase (PARP). In addition, the in vivo anticancer effect of digitoxin was confirmed in HeLa cell xenotransplantation models. On the whole, the findings of the present study demonstrate the efficacy of digitoxin against cervical cancer in vivo and elucidate its molecular mechanisms, including DSBs, cell cycle arrest and mitochondrial apoptosis. These results will contribute to the development of digitoxin as a chemotherapeutic agent in the treatment of cervical cancer.

CDH1 and SNAI1 are regulated by E7 from human papillomavirus types 16 and 18

A common characteristic of cancer types associated with viruses is the dysregulated expression of the CDH1 gene, which encodes E‑cadherin, in general by activation of DNA methyltransferases (Dnmts). In cervical cancer, E7 protein from high risk human papillomaviruses (HPVs) has been demonstrated to interact with Dnmt1 and histone deacetylase type 1 (HDAC1). The present study proposed that E7 may regulate the expression of CDH1 through two pathways: i) Epigenetic, including DNA methylation; and ii) Epigenetic‑independent, including the induction of negative regulators of CDH1 expression, such as Snail family transcriptional repressor Snai1 and Snai2. To test this hypothesis, HPV16‑ and HPV18‑positive cell lines were used to determine the methylation pattern of the CDH1 promoter and its expression in association with its negative regulators. Different methylation frequencies were identified in the CDH1 promoter in HeLa (88.24%) compared with SiHa (17.65%) and Ca Ski (0%) cell lines. Significant differences in the expression of SNAI1 were observed between these cell lines, and an inverse association was identified between the expression levels of SNAI1 and CDH1. In addition, suppressing E7 not only increased the expression of CDH1, but notably decreased the expression of SNAI1 and modified the methylation pattern of the CDH1 promoter. These results suggested that the expression of CDH1 was dependent on the expression of SNAI1 and was inversely associated with the expression of E7. The present results indicated that E7 from HPV16/18 regulated the expression of CDH1 by the two following pathways in which Snai1 is involved: i) Hypermethylation of the CDH1 promoter region and increasing expression of SNAI1, as observed in HeLa; and ii) Hypomethylation of the CDH1 promoter region and expression of SNAI1, as observed in SiHa. Therefore, the suppression of CDH1 and expression of SNAI1 may be considered to be biomarkers of metastasis in uterine cervical cancer.

CD38 is involved in cell energy metabolism via activating the PI3K/AKT/mTOR signaling pathway in cervical cancer cells

In contrast to normal cells, cancer cells typically undergo metabolic reprogramming. Studies have shown that oncogenes play an important role in this metabolic reprogramming. CD38 is a multifunctional transmembrane protein that is expressed abnormally in a variety of tumor types. To investigate the effect and possible mechanism of CD38 in cervical cancer cells and to provide a new therapeutic target for the treatment of cervical cancer, the present study identified that CD38 is involved in regulating cell metabolism in cervical cancer cells. Liquid chromatography‑tandem mass spectrometry and bioinformatic analyses revealed that differentially abundant proteins in CD38‑overexpressed cervical cancer cells (CaSki‑CD38 and HeLa‑CD38) are predominantly involved in glycolytic pathways, oxidative phosphorylation and the NAD/NADH metabolic process. Further experiments using an ATP test kit and lactate test kit revealed that CD38 promotes glucose consumption, increases lactate accumulation and increases ATP production. In addition, CD38 increases the phosphorylation of phosphatidylserine/threonine kinase (AKT), mechanistic target of rapamycin (mTOR) and phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K), which play a key role in tumor metabolism. Furthermore, it was found that the energy metabolism of cervical cancer cells was inhibited following treatment with the mTOR inhibitor rapamycin. In conclusion, the results of the present study suggested that CD38 regulates the metabolism of cervical cancer cells by regulating the PI3K/AKT/mTOR pathway, which may be a candidate target for the treatment of cervical cancer.

Cx32 promotes autophagy and produces resistance to SN‑induced apoptosis via activation of AMPK signalling in cervical cancer

The roles of gap junctions (GJs) and its components, connexins, in the autophagy of cervical cancer cells have been rarely investigated. Our previous study demonstrated that connexin 32 (Cx32) exerted an anti‑apoptotic effect on cervical cancer. However, as an important regulator of apoptosis, whether the autophagy is involved in the function of Cx32 on cervical cancer cells is not well defined. The present study aimed to investigate the role of Cx32 on autophagy and apoptosis inhibition in cervical cancer cells. The expression levels of Cx32 and the autophagy‑associated protein LC3‑Ⅱ in paracancerous cervical tissues (n=30) and cervical cancer (n=50) tissues were determined via western blotting. In total, 45 cervical cancer specimens were used to evaluate the clinical relevance of Cx32 and LC3‑Ⅱ. It was found that both Cx32 and LC3‑Ⅱ were upregulated in cervical cancer tissues compared with those in paracancerous cervical tissues. The effect of Cx32 on autophagy was examined by detecting the change of LC3‑Ⅱ using western blotting, transfection with enhanced green fluorescent protein‑LC3 plasmid and transmission electron microscopy analysis. Overexpression of Cx32 significantly enhanced autophagy in HeLa‑Cx32 cells, whereas knockdown of Cx32 suppressed autophagy in C‑33A cells. The flow cytometry results demonstrated that Cx32 inhibited the apoptosis of cervical cancer cells by promoting autophagy. Moreover, Cx32 triggered autophagy via the activation of the AMP‑activated protein kinase (AMPK) signalling, regardless of the presence or absence of GJs. Collectively, it was identified that Cx32 exerted its anti‑apoptotic effect by activating autophagy via the AMPK pathway in cervical cancer, which demonstrates a novel mechanism for Cx32 in human cervical cancer progression.

Current data and future perspectives on DNA methylation in ovarian cancer (Review)

Ovarian cancer (OC) represents the most prevalent malignancy of the female reproductive system. Its distinguishing features include a high aggressiveness, substantial morbidity and mortality, and a lack of apparent symptoms, which collectively pose significant challenges for early detection. Given that aberrant DNA methylation events leading to altered gene expression are characteristic of numerous tumor types, there has been extensive research into epigenetic mechanisms, particularly DNA methylation, in human cancers. In the context of OC, DNA methylation is often associated with the regulation of critical genes, such as BRCA1/2 and Ras‑association domain family 1A. Methylation modifications within the promoter regions of these genes not only contribute to the pathogenesis of OC, but also induce medication resistance and influence the prognosis of patients with OC. As such, a more in‑depth understanding of DNA methylation underpinning carcinogenesis could potentially facilitate the development of more effective therapeutic approaches for this intricate disease. The present review focuses on classical tumor suppressor genes, oncogenes, signaling pathways and associated microRNAs in an aim to elucidate the influence of DNA methylation on the development and progression of OC. The advantages and limitations of employing DNA methylation in the diagnosis, treatment and prevention of OC are also discussed. On the whole, the present literature review indicates that the DNA methylation of specific genes could potentially serve as a prognostic biomarker for OC and a therapeutic target for personalized treatment strategies. Further investigations in this field may yield more efficacious diagnostic and therapeutic alternatives for patients with OC.

Guanosine monophosphate synthase upregulation mediates cervical cancer progression by inhibiting the apoptosis of cervical cancer cells via the Stat3/P53 pathway

Guanosine monophosphate synthase (GMPS) participates in chromatin and gene regulation in multiple types of organisms, and is highly expressed in a variety of human malignancies. The purpose of the present study was to explore the expression of GMPS and its role in cervical cancer (CC), and to provide ideas for improving the clinical efficacy of CC treatment. In the present study, immunohistochemistry, reverse transcription‑quantitative PCR analysis, Cell Counting Kit‑8 assay, 5‑ethynyl‑2'‑deoxyuridine assay, flow cytometry, western blotting and immunofluorescence assays were conducted to detect the expression of GMPS in normal cervical tissues, CC tissues, para‑cancerous tissues and CC cell lines. Moreover, the present study detected the effect of GMPS knockdown on CC cell proliferation, clonal formation ability, aging and apoptosis, as well as on the expression levels of apoptosis‑related proteins in tumor cells. The present results demonstrated that the expression level of GMPS in CC was significantly higher compared with that of adjacent tissues; the expression rate of GMPS in CC was 57.36%. GMPS expression was found to successively and gradually increase from that in normal cervical tissues, to that in cervical intraepithelial neoplasia and CC tissues. The abnormal expression of GMPS was positively associated with the degree of CC differentiation and the depth of early invasion. Small interfering (si)RNA knockdown of GMPS inhibited proliferation and colony formation, and promoted aging and apoptosis of CC cells. Furthermore, subcutaneous injection of GMPS‑knockdown tumor cells in nude mice resulted in a decrease in the proliferative ability of the tumor. The animal experimental results showed that the tumor growth rate of the short hairpin (sh)RNA‑GMPS group was significantly slower than that of the HeLa sh‑negative control group. It was identified that GMPS may inhibit CC cell senescence and apoptosis via the Stat3/P53 molecular pathway. Collectively, the present results suggested that GMPS may be a marker of unfavorable prognosis of CC, and it may also be a potential therapeutic target for CC.