Journal

Molecular Carcinogenesis

Papers (50)

Baohuoside I inhibits resistance to cisplatin in ovarian cancer cells by suppressing autophagy via downregulating HIF‐1α/ATG5 axis

AbstractSince chemotherapy's therapeutic impact is diminished by drug resistance, treating ovarian cancer is notably challenging. Thereafter, it is critical to develop cutting‐edge approaches to treating ovarian cancer. Baohuoside I (derived from Herba Epimedii) is reported to have antitumor properties in various malignancies. It is unknown, however, what role Baohuoside I plays in cisplatin (DDP)‐resistant ovarian cancer cells. 3‐(4,5)‐dimethylthiahiazo (‐z‐y1)‐3,5‐di‐phenytetrazoliumromide (MTT), colony formation, and flow cytometry assay were used to investigate the impact of Baohuoside I on ovarian cancer A2780 cells and DDP‐resistant A2780 (A2780/DDP) cells. The level of microtubule associated protein 1 light chain 3 (LC3) was determined using immunofluorescence staining. Utilizing the mRFP‐GFP‐LC3B tandem fluorescent probe allowed us to analyse the autophagy flux. Analysis of mRNA and protein level was performed using RT‐qPCR and Western blot analysis, respectively. The interaction between hypoxia inducible factor 1 subunit alpha (HIF‐1α) and autophagy related 5 (ATG5) promoter was investigated by dual luciferase and ChIP assay. Additionally, evaluation of Baohuoside I's role in ovarian cancer was performed using a nude mouse xenograft model. Baohuoside I decreased the viability and proliferation and triggered the apoptosis of both A2780 and A2780/DDP cells in a concentration‐dependent manner. Baohuoside I also increased the sensitivity of A2780/DDP cells to DDP. Concurrently, HIF‐1α could promote A2780/DDP cells resistance to DDP. In addition, HIF‐1α could induce the autophagy of A2780/DDP cells through transcriptionally activating ATG5, and Baohuoside I imporved the chemosensitivity of A2780/DDP cells to DDP by downregulating HIF‐1α. Moreover, Baohuoside I could inhibit the chemoresistance to DDP in ovarian cancer in vivo. Baohuoside I sensitizes ovarian cancer cells to DDP by suppressing autophagy via downregulating the HIF‐1α/ATG5 axis. Consequently, Baohuoside I might be evaluated as a new agent for enhancing the chemotherapeutic efficacy of drug treatment for ovarian cancer.

SNORD60 promotes the tumorigenesis and progression of endometrial cancer through binding PIK3CA and regulating PI3K/AKT/mTOR signaling pathway

AbstractEndometrial carcinoma is a common gynecological malignant tumor, small nucleolar RNAs (snoRNAs) are involved in cancer development. However, researches on the roles of snoRNAs in endometrial carcinoma are limited. The expression levels of snoRNAs in endometrial cancer tissues were analyzed using The Cancer Genome Atlas (TCGA) database. Antisense oligonucleotides (ASOs) and plasmids were used for transfection. Moreover, CCK‐8, EdU, wound‐healing assay, transwell, cell apoptosis, western blotting, and xenograft model were employed to examine the biological functions of related molecules. real‐time reverse transcription polymerase chain reaction and western blotting were performed to detect messenger RNA (mRNA) and protein levels. Including bioinformatics, fluorescence in situ hybridization, RNA pulldown, actinomycin D and RTL‐P assays were also carried out to explore the molecular mechanism. Analysis of data from TCGA showed that the expression level of small nucleolar RNA, C/D box 60 (SNORD60) in endometrial cancer tissues is observably higher than that in normal endometrial tissues. Further research suggested that SNORD60 played a carcinogenic role both in vitro and in vivo, and significantly upregulated the expression of PIK3CA. However, the carcinogenic effects can be reversed by knocking down fibrillarin (FBL) or PIK3CA. SNORD60 forms complexes by binding with 2′‐O‐methyltransferase fibrillarin, thus catalyzes the 2′‐O‐methylation (Nm) modification of PIK3CA mRNA and modulates the PI3K/AKT/mTOR signaling pathway, so as to promote the development of endometrial cancer. In short, SNORD60 might become a new biomarker for the therapy of endometrial cancer in the future and provide new strategies for diagnosis and treatment.

The Activation of miR‐203a by SFRP4 Micropeptides Targets Epithelial–Mesenchymal Transition and Autophagy in Ovarian Cancer Stem Cells

ABSTRACT Cancer stem cells (CSCs) are characterized by various properties such as hyperactive Wnt pathway, increased chemoresistance, angiogenesis, autophagy, EMT and decreased apoptotic activity. SFRP4 micropeptides, SC‐301 and SC‐401 derived from cysteine rich domain (CRD) and netrin like domain (NLD) domains respectively have shown to exhibit significant anti‐CSC properties. In this study, based on our preliminary investigation, which showed that miR‐203a was downregulated in ovarian CSCs and was subsequently activated by treatment with SFRP4 micropeptides, we investigated whether miR‐203a plays any part in SFRP4 micropeptide‐mediated ovarian CSC inhibition in PA‐1 and SKOV‐3 cell lines. SFRP4 micropeptide‐treated and miR‐203a mimic‐overexpressing ovarian CSCs were subjected to various assays, and the results showed that miR‐203a overexpression by the SFRP4 micropeptide treatment resulted in disruption of sphere‐forming capacity and induction of caspase activity in ovarian CSCs. Furthermore, miR‐203a expression upon micropeptide treatment resulted in the increased levels of E‐cad and decreased levels of N‐cad, Snail and Twist, indicating reversal of EMT along with the significant reduction in migratory potential of ovarian CSCs. Our findings for the first time indicated the possible role of miR‐203a in regulating autophagy in ovarian CSCs, and reactivation of miR‐203a by SFRP4 micropeptides was sufficient to halt the autophagic machinery in ovarian CSCs.

Insulin‐like growth factor (IGF) and hepatocyte growth factor (HGF) in follicular fluid cooperatively promote the oncogenesis of high‐grade serous carcinoma from fallopian tube epithelial cells: Dissection of the molecular effects

AbstractIncessant ovulation is believed to be a potential cause of epithelial ovarian cancer (EOC). Our previous investigations have shown that insulin‐like growth factor (IGF2) and hepatocyte growth factor (HGF) in the ovulatory follicular fluid (FF) contributed to the malignant transformation initiated by p53 mutations. Here we examined the individual and synergistic impacts of IGF2 and HGF on enhancing the malignant properties of high‐grade serous carcinoma (HGSC), the most aggressive type of EOC, and its precursor lesion, serous tubal intraepithelial carcinoma (STIC). In a mouse xenograft co‐injection model, we observed that FF co‐injection induced tumorigenesis of STIC‐mimicking cells, FE25. Co‐injection with IGF2 or HGF partially recapitulated the tumorigenic effects of FF, but co‐injection with both resulted in a higher tumorigenic rate than FF. We analyzed the different transformation phenotypes influenced by these FF growth signals through receptor inhibition. The IGF signal was necessary for clonogenicity, while the HGF signal played a crucial role in the migration and invasion of STIC and HGSC cells. Both signals were necessary for the malignant phenotype of anchoring‐independent growth but had little impact on cell proliferation. The downstream signals responsible for these HGF activities were identified as the tyrosine‐protein kinase Met (cMET)/mitogen‐activated protein kinase and cMET/AKT pathways. Together with the previous finding that the FF‐IGF2 could mediate clonogenicity and stemness activities via the IGF‐1R/AKT/mammalian target of rapamycin and IGF‐1R/AKT/NANOG pathways, respectively, this study demonstrated the cooperation of the FF‐sourced IGF and HGF growth signals in the malignant transformation and progression of HGSC through both common and distinct signaling pathways. These findings help develop targeted prevention of HGSC.

VDX‐111, a novel small molecule, induces necroptosis to inhibit ovarian cancer progression

AbstractEpithelial ovarian cancers that are nonhomologous recombination deficient, as well as those that are recurrent and in a platinum‐resistant state, have limited therapeutic options. The objectives of this study were to characterize the mechanism of action and investigate the therapeutic potential of a small molecule, VDX‐111, against ovarian cancer. We examined the ability of VDX‐111 to inhibit the growth of a panel of ovarian cancer cell lines, focusing on BRCA wild‐type lines. We found that VDX‐111 causes a dose‐dependent loss of cell viability across ovarian cancer cell lines. Reverse phase protein array (RPPA) analysis was used to identify changes in cell signaling in response to VDX‐111 treatment. An RPPA analysis performed on cells treated with VDX‐111 detected changes in cell signaling related to autophagy and necroptosis. Immunoblots of OVCAR3 and SNU8 cells confirmed a dose‐dependent increase in LC3A/B and RIPK1. Incucyte live cell imaging was used to measure cell proliferation and death in response to VDX‐111 alone and with inhibitors of apoptosis, necroptosis, and autophagy. Annexin/PI assays suggested predominantly nonapoptotic cell death, while real‐time kinetic imaging of cell growth indicated the necroptosis inhibitor, necrostatin‐1, attenuates VDX‐111‐induced loss of cell viability, suggesting a necroptosis‐dependent mechanism. Furthermore, VDX‐111 inhibited tumor growth in patient‐derived xenograft and syngeneic murine models. In conclusion, the cytotoxic effects of VDX‐111 seen in vitro and in vivo appear to occur in a necroptosis‐dependent manner and may promote an antitumor immune response.

Curcuminoid PBPD induces cuproptosis and endoplasmic reticulum stress in cervical cancer via the Notch1/RBP‐J/NRF2/FDX1 pathway

AbstractCurcumin has been shown to have antitumor properties, but its low potency and bioavailability has limited its clinical application. We designed a novel curcuminoid, [1‐propyl‐3,5‐bis(2‐bromobenzylidene)‐4‐piperidinone] (PBPD), which has higher antitumor strength and improves bioavailability. Cell counting kit‐8 was used to detect cell activity. Transwell assay was used to detect cell invasion and migration ability. Western blot and quantitative polymerase chain reaction were used to detect protein levels and their messenger RNA expression. Immunofluorescence was used to detect the protein location. PBPD significantly inhibited the proliferation of cervical cancer cells, with an IC50 value of 4.16 μM for Hela cells and 3.78 μM for SiHa cells, leading to the induction of cuproptosis. Transcriptome sequencing analysis revealed that PBPD significantly inhibited the Notch1/Recombination Signal Binding Protein for Immunoglobulin kappa J Region (RBP‐J) and nuclear factor erythroid 2‐related factor 2 (NRF2) signaling pathways while upregulating ferredoxin 1 (FDX1) expression. Knockdown of Notch1 or RBP‐J significantly inhibited NRF2 expression and upregulated FDX1 expression, leading to the inhibition of nicotinamide adenine dinucleotide phosphate activity and the induction of oxidative stress, which in turn activated endoplasmic reticulum stress and induced cell death. The overexpression of Notch1 or RBP‐J resulted in the enrichment of RBP‐J within the NRF2 promoter region, thereby stimulating NRF2 transcription. NRF2 knockdown resulted in increase in FDX1 expression, leading to cuproptosis. In addition, PBPD inhibited the acidification of tumor niche and reduced cell metabolism to inhibit cervical cancer cell invasion and migration. In conclusion, PBPD significantly inhibits the proliferation, invasion, and migration of cervical cancer cells and may be a novel potential drug candidate for treatment of cervical cancer.

M6A‐mediated hsa_circ_0061179 inhibits DNA damage in ovarian cancer cells via miR‐143‐3p/TIMELESS

AbstractOvarian cancer (OC) is among the most common and deadly solid malignancies in women. Despite many advances in OC research, the incidence of OC continues to rise, and its pathogenesis remains largely unknown. Herein, we elucidated the function of hsa_circ_0061179 in OC. The levels of hsa_circ_0061179, miR‐143‐3p, TIMELESS, and DNA damage repair‐related proteins in OC or normal ovarian tissues and cells were measured using real‐time quantitative polymerase chain reaction and immunoblotting. The biological effects of hsa_circ_0061179 and miR‐143‐3p on proliferation, clone formation, DNA damage, and apoptosis of OC cells were detected by the cell counting kit‐8 assay, 5‐methylethyl‐2′‐deoxyuridine, flow cytometry, the comet assay, and immunofluorescence staining combined with the confocal microscopy. The interaction among hsa_circ_0061179, miR‐143‐3p, and TIMELESS was validated by the luciferase reporter assay. Mice tumor xenograft models were used to evaluate the influence of hsa_circ_0061179 on OC growth in vivo. We found that human OC biospecimens expressed higher levels of hsa_circ_0061179 and lower levels of miR‐143‐3p. Hsa_circ_0061179 was found to bind with miR‐143‐3p, which directly targets TIMELESS. Hsa_circ_0061179 knockdown or miR‐143‐3p overexpression suppressed the proliferation and clone formation of OC cells and increased DNA damage and apoptosis of OC cells via the miR‐143‐3p/TIMELESS axis. Furthermore, we demonstrated that METTL3 could direct the formation of has_circ_0061179 through a specific m6A modification site. YTHDC1 facilitated the cytoplasmic transfer of has_circ_0061179 by directly binding to the modified m6A site. Our findings suggest that hsa_circ_0061179 acts as the sponge of miR‐143‐3p to activate TIMELESS signaling and inhibits DNA damage and apoptosis in OC cells.

A novel hypoxia‐stimulated lncRNA HIF1A‐AS3 binds with YBX1 to promote ovarian cancer tumorigenesis by suppressing p21 and AJAP1 transcription

AbstractHypoxia is characteristic of the ovarian tumor (OC) microenvironment and profoundly affects tumorigenesis and therapeutic response. Long noncoding RNAs (lncRNAs) play various roles in tumor progression; however, the characteristics of lncRNAs in pathological responses of the OC microenvironment are not entirely understood. Through high‐throughput sequencing, lncRNA expression in hypoxia (1% O2) and normoxia (21% O2) SKOV3 cells was explored and analyzed. The 5′‐ and 3′‐rapid amplification of complementary DNA ends was used to detect the full length of the novel HIF1A‐AS3 transcript. Real‐time quantitative polymerase chain reaction was used to assess HIF1A‐AS3 expression in OC cells and tissues. In vitro and in vivo evaluations of the biological functions of hypoxic HIF1A‐AS3 were conducted. To clarify the underlying mechanisms of HIF1A‐AS3 in hypoxic OC, a dual‐luciferase assay, chromatin immunoprecipitation, RNA pull‐down, RNA immunoprecipitation, and RNA‐sequencing were used. We used high‐throughput sequencing to investigate a novel lncRNA, HIF1A‐AS3, as a hypoxic candidate significantly elevated in OC cells/tissues. HIF1A‐AS3 was predominantly localized in the nucleus and promoted in vitro and in vivo OC growth and tumorigenesis. Hypoxia‐inducible factor 1α bound to hypoxia response elements in the HIF1A‐AS3 promoter region and stimulated its expression in hypoxia. Under hypoxia, HIF1A‐AS3 directly integrated with Y‐Box binding protein 1 and inhibited its ability to bind to the promoters of p21 and AJAP1 to repress their transcriptional activity, thereby promoting hypoxic OC progression. Our results revealed the crucial role and mechanism of the novel hypoxic HIF1A‐AS3 in the oncogenesis of OC. The novel HIF1A‐AS3 could be a crucial biomarker and therapeutic target for future OC treatments.

ITGA7 loss drives the differentiation of adipose‐derived mesenchymal stem cells to cancer‐associated fibroblasts

AbstractCancer‐associated fibroblasts (CAFs) represent a major cellular component of the tumor (pre‐)metastatic niche and play an essential role in omental dissemination of ovarian cancer. The omentum is rich in adipose, and adipose‐derived mesenchymal stem cells (ADSCs) have been identified as a source of CAFs. However, the molecular events driving the phenotype shift of ADSCs remain largely unexplored. In this research, we focus on integrins, transmembrane receptors that have been widely involved in cellular plasticity. We found that integrin α7 (ITGA7) was the only member of the integrin family that positively correlated with both overall survival and progression‐free survival in ovarian cancer through GEPIA2. The immunohistochemistry signal of ITGA7 was apparent in the tumor stroma, and a lower omental ITGA7 level was associated with metastasis. Primary ADSCs were isolated from the omentum of patients with ovarian cancer and identified by cellular morphology, biomarkers, and multilineage differentiation. The conditional medium of ovarian cancer cells induced ITGA7 expression decrease and phenotypic changes in ADSCs. Downregulation of ITGA7 in primary omental ADSCs led to decrease in stemness properties and emerge of characteristic morphology and biomarkers of CAFs. Moreover, the conditioned medium of ADSCs with ITGA7 depletion exhibited enhanced abilities to improve the migration and invasion of ovarian cancer cells in vitro. Overall, these findings indicate that loss of ITGA7 may induce the differentiation of ADSCs to CAFs that contribute to a tumor‐supportive niche.

SLC5A6 Regulates Lipid Metabolism and Lymph Node Metastasis in Cervical Cancer via FASN

ABSTRACT The solute carrier protein SLC5A6 is associated with multiple malignant tumors, while its role in cervical cancer (CC) remains unexplored. This study aimed to investigate the expression pattern, biological functions, and underlying mechanisms of SLC5A6 in cervical cancer. It was found that the expression of SLC5A6 was significantly upregulated in cervical cancer tissues, and its high expression was associated with poorer overall survival of patients. In vitro functional experiments conducted in HeLa and SiHa cell lines demonstrated that overexpression of SLC5A6 enhanced cell proliferation, colony formation, and migration abilities, while inhibiting cell apoptosis; conversely, knockdown of SLC5A6 suppressed these oncogenic phenotypes. Further in vivo experiments confirmed that knockdown of SLC5A6 could inhibit the growth of xenograft tumors. Through transcriptomic analysis and pathway enrichment analysis, this study identified lipid metabolism as a key downstream pathway of SLC5A6, in which fatty acid synthase (FASN) serves as a crucial effector molecule. Mechanistically, SLC5A6 is responsible for the transmembrane transport of biotin. Reduced expression of SLC5A6 leads to a decrease in the expression of biotin‐dependent acetyl‐CoA carboxylase (ACC), which in turn downregulates its downstream target gene FASN. Importantly, knockdown of FASN could reverse the promotional effect of SLC5A6 overexpression on the growth of cervical cancer cells, indicating that SLC5A6 promotes cervical cancer progression through FASN‐mediated reprogramming of lipid metabolism. In conclusion, this study identified SLC5A6 as a novel oncogenic factor in cervical cancer and reveals its mechanism of regulating lipid metabolism via FASN, suggesting that targeting the SLC5A6‐FASN axis may serve as a potential therapeutic strategy for cervical cancer.

Withaferin A Exerts Cytotoxicity in Single/Multidrug‐Resistant Gastric and Ovarian Cancer Cells and Tumor Xenografts Through the AKT–NF‐κB–STAT3–Survivin Axis

ABSTRACT Resistance to primary chemotherapeutics poses a significant challenge in treating solid tumors. The majority of the second‐line chemo and targeted therapeutics act moderately/less effectively in drug‐resistant tumors owing to the multicausal nature of drug resistance. Therefore, a single agent with pleiotropic effects would be beneficial in combating this adversity. Withania somnifera exhibits multifunctional anticancer properties, but its role in overcoming chemoresistance remains poorly understood. We evaluated the cytotoxic effect of Ashwamax TM ‐ W. somnifera (WS)—extract and Withaferin A (WFA), in intrinsically resistant (KATO‐III and SKOV3) and acquired chemoresistant gastric (AGS 5FU ) and ovarian (A2780 LR ) cancer cellular models. We examined their impact on autophagy and apoptosis pathways and elucidated the underlying molecular mechanism. In vivo efficacy of WFA on cisplatin‐paclitaxel‐resistant epithelial ovarian cancer (EOC) xenografts was assessed using noninvasive optical imaging. Mechanistically, WFA is more proficient in targeting chemoresistant cells than Ashwamax TM ‐WS extract and activates apoptosis by overriding the AKT–NF‐κB–STAT3–survivin axis. Preclinical imaging revealed dose‐dependent tumor regression (during and after treatment) in platinum‐taxol‐resistant EOC xenografts that were unresponsive to cisplatin challenge. WFA, at 3 mg kg −1 dosage, reduced tumor volume by 4.7‐fold compared to controls, with sustained antitumor effects persisting after treatment cessation. WFA effectively targets the AKT–NF‐κB–STAT3–survivin axis to overcome single and multidrug resistance in gastric and epithelial ovarian cancers, presenting a promising therapeutic alternative for chemoresistant malignancies.

Integrative Bioinformatics Analysis and Experimental Study of NLRP12 Reveal Its Prognostic Value and Potential Functions in Ovarian Cancer

ABSTRACTNLRP12 plays a significant role in cellular functional behavior and immune homeostasis, influencing inflammation, tumorigenesis, and prognosis. This study aimed to explore its specific effects on the tumor microenvironment (TME) and its contribution to heterogeneity in ovarian cancer (OV) through bioinformatics analysis and experimental verification. Utilizing various bioinformatics databases and clinical specimens, we investigated NLRP12 expression and its relationship with OV prognosis and immune infiltration. In vitro assays were conducted to assess the impact of NLRP12 on the proliferation and invasion of OV cells. Our findings indicate that NLRP12 is upregulated in OV, with high expression correlating with a negative prognosis. Furthermore, NLRP12 expression demonstrated a positive correlation with the infiltration of various immune cells and the expression of immune checkpoint molecules in OV. Analysis of The Cancer Immunome Atlas (TCIA) database revealed that OV patients with lower NLRP12 expression may exhibit an enhanced response to immunotherapy, particularly CTLA4 blockers, a finding validated in animal experiments. Additionally, the study emphasized the role of NLRP12 in influencing the prognosis of OV patients by promoting epithelial‐mesenchymal transition (EMT) in ovarian cancer cells. Finally, we identified a potential therapeutic compound, Schisandrin B (Schi B), which decreases NLRP12 expression in ovarian cancer cells by binding to the transcription factor SPI1 associated with NLRP12. Our findings suggest that NLRP12 serves as a crucial immune‐related biomarker predicting poor outcomes in OV, and targeting NLRP12 may represent a promising therapeutic approach for OV patients in the future.

Therapeutic Potential of IL‐37 in Cervical Cancer: Suppression of Tumour Progression and Enhancement of CD47‐Mediated Macrophage Phagocytosis

ABSTRACTAs a promising therapeutic approach, immunotherapy is being extensively investigated in cervical cancer. Although immunotherapy has been validated to improve progression‐free survival and overall survival in clinical trials, the overall response rate for cervical cancer remains inadequate, necessitating further improvement. Interleukin (IL)‐37, an emerging immunomodulator, exhibits antitumour potentials by inhibiting tumour progression and regulating tumour‐associated macrophage recognition. We found a significant downregulation of IL‐37 expression in cervical cancer, correlated with a poor prognosis. Moreover, the upregulation of IL‐37 expression exhibited a suppressive effect on various tumorigenic processes, suppressing the proliferation, invasion, migration, apoptosis and angiogenesis of tumour cells. We also found that the upregulation of IL‐37 suppressed cluster of differentiation 47 (CD47) expression in tumour cells via suppression of the signal transducer and activator of transcription 3 (STAT3) expression and phosphorylation, thereby enhancing macrophage recognition and phagocytosis to tumour cells, ultimately reducing immune evasion. Overall, our study highlighted the crucial role of IL‐37 in antitumour efficacy and downregulating the expression of CD47 in tumour cells to reduce immune evasion, suggesting the potential of IL‐37 as a prognostic biomarker in cervical cancer and offering innovative therapeutic strategies to improve cancer treatment outcomes.

KDM1A/LSD1 inhibition enhances chemotherapy response in ovarian cancer

AbstractOvarian cancer (OCa) is the deadliest of all gynecological cancers. The standard treatment for OCa is platinum‐based chemotherapy, such as carboplatin or cisplatin in combination with paclitaxel. Most patients are initially responsive to these treatments; however, nearly 90% will develop recurrence and inevitably succumb to chemotherapy‐resistant disease. Recent studies have revealed that the epigenetic modifier lysine‐specific histone demethylase 1A (KDM1A/LSD1) is highly overexpressed in OCa. However, the role of KDM1A in chemoresistance and whether its inhibition enhances chemotherapy response in OCa remains uncertain. Analysis of TCGA datasets revealed that KDM1A expression is high in patients who poorly respond to chemotherapy. Western blot analysis show that treatment with chemotherapy drugs cisplatin, carboplatin, and paclitaxel increased KDM1A expression in OCa cells. KDM1A knockdown (KD) or treatment with KDM1A inhibitors NCD38 and SP2509 sensitized established and patient‐derived OCa cells to chemotherapy drugs in reducing cell viability and clonogenic survival and inducing apoptosis. Moreover, knockdown of KDM1A sensitized carboplatin‐resistant A2780‐CP70 cells to carboplatin treatment and paclitaxel‐resistant SKOV3‐TR cells to paclitaxel. RNA‐seq analysis revealed that a combination of KDM1A‐KD and cisplatin treatment resulted in the downregulation of genes related to epithelial‐mesenchymal transition (EMT). Interestingly, cisplatin treatment increased a subset of NF‐κB pathway genes, and KDM1A‐KD or KDM1A inhibition reversed this effect. Importantly, KDM1A‐KD, in combination with cisplatin, significantly reduced tumor growth compared to a single treatment in an orthotopic intrabursal OCa xenograft model. Collectively, these findings suggest that combination of KDM1A inhibitors with chemotherapy could be a promising therapeutic approach for the treatment of OCa.

FAPhigh α‐SMAlow cancer‐associated fibroblast‐derived SLPI protein encapsulated in extracellular vesicles promotes ovarian cancer development via activation of PI3K/AKT and downstream signaling pathways

AbstractOvarian cancer is the most lethal gynecological malignancy worldwide with high metastasis and poor prognosis rates. Cancer‐associated fibroblasts (CAFs), a heterogeneous population of cells that constitutes a major component of the tumor microenvironment, secrete extracellular vesicles (EVs) loading with proteins, lipids, and RNAs to promote tumorigenesis. However, the specific roles of CAF‐derived proteins contained in EVs in ovarian cancer remain poorly understood at present. Using the gene expression microarray analysis, we identified a list of dysregulated genes between the α‐SMA+CAF and FAP+CAF subpopulations, from which secretory leukocyte protease inhibitor (SLPI) was chosen for further validation. Quantitative PCR, western blot, immunohistochemistry, and enzyme‐linked immunosorbent assays were used to assess SLPI expression in ovarian cancer cells, tissues, CAFs, and EVs. Additionally, we evaluated the effects of exogenous SLPI on proliferation, migration, invasion, and adhesion of ovarian cancer cells in vitro. Our results showed SLPI protein was upregulated in CAFs, particularly in the FAPhighα‐SMAlowCAF subpopulation, and associated with increased tumor grade and decreased overall survival (OS). Importantly, CAF‐derived SLPI protein could be encapsulated in EVs for delivery to ovarian cancer cells, thus facilitating cell proliferation, migration, invasion, and adhesion via activating the PI3K/AKT and downstream signaling pathways. Moreover, high plasma expression of SLPI encapsulated in EVs was closely correlated with tumor stage in ovarian cancer patients. Our collective results highlight an oncogenic role of plasma EV‐encapsulated SLPI secreted by CAFs in tumor progression for the first time, supporting its potential utility as a prognostic biomarker of ovarian cancer.

LINC00662 modulates cervical cancer cell proliferation, invasion, and apoptosis via sponging miR‐103a‐3p and upregulating PDK4

AbstractCervical cancer (CC) is one of the most common cancers among women with high recurrence rates all over the world. Recently, the molecular mechanism of CC has been gradually uncovered in accumulating reports. This study aimed to investigate the function and upstream regulation mechanism of pyruvate dehydrogenase kinase 4 (PDK4) in CC cells, which was verified as an oncogene in several cancers. Through RT‐qPCR assay, we discovered that PDK4 was highly expressed in CC cells. Then, it was demonstrated in function assays that PDK4 facilitated CC cell proliferation and invasion, but inhibited CC cell apoptosis. Next, we sought to determine the upstream genes of PDK4, and miR‐103a‐3p was identified to target PDK4. Then, through bioinformatics tools and a range of mechanism assays, long intergenic non‐protein coding RNA 662 (LINC00662) was verified as the sponge of miR‐103a‐3p. Moreover, LINC00662 positively modulated PDK4 expression via competitively binding to miR‐103a‐3p in CC cells. Subsequently, rescue assays demonstrated that LINC00662 accelerated CC cell proliferation and inhibited cell apoptosis through upregulating PDK4. Furthermore, forkhead box A1 (FOXA1) was verified to activate transcription of both LINC00662 and PDK4. Taken together, our study revealed a novel ceRNA pattern of LINC00662/miR‐103a‐3p/PDK4 with FOXA1 as a transcription factor of LINC00662 and PDK4 in CC cells.

The interaction between PDCD4 and YB1 is critical for cervical cancer stemness and cisplatin resistance

AbstractCancer multidrug resistance (MDR) is existence in stem cell‐like cancer cells characterized by stemness including high‐proliferation and self‐renewal. Programmed cell death 4 (PDCD4), as a proapoptotic gene, whether it engaged in cancer stemness and cisplatin resistance is still unknown. Here we showed that PDCD4 expressions in Hela/DDP (cisplatin resistance) cells were lower than in parental Hela cells. Moreover, the levels of drug resistance genes and typical stemness markers were markedly elevated in Hela/DDP cells. In vivo, xenograft tumor assay confirmed that knockdown of PDCD4 accelerated the grafted tumor growth. In vitro, colony formation and MTT assay demonstrated that PDCD4 overexpression inhibited cells proliferation in conditions with or without cisplatin. By contrast, PDCD4 deficiency provoked cell proliferation and cisplatin resistance. On mechanism, PDCD4 decreased the protein levels of pAKT and pYB1, accompanied by reduced MDR1 expression. Correspondingly, luciferase reporter assay showed PDCD4 regulated MDR1 promoter activity entirely relied on YB1. Furthermore, Ch‐IP, GST‐pulldown, and Co‐IP assays provided novel evidence that PDCD4 could directly bind with YB1 by the nucleolar localization signal (NOLS) segment, causing the reduced YB1 binding into the MDR1 promoter region through blocking YB1 nucleus translocation, triggering the decreased MDR1 transcription. Taken together, PDCD4‐pAKT‐pYB1 forms the integrated molecular network to regulate MDR1 transcription during the process of stemness‐associated cisplatin resistance.

HPV‐16/18 E6‐induced APOBEC3B expression associates with proliferation of cervical cancer cells and hypomethylation of Cyclin D1

AbstractOncogenic high‐risk human papillomavirus (HR‐HPV) infection causes a majority of cases of cervical cancer and pre‐cancerous cervical lesions. However, the mechanisms underlying the direct evolution from HPV‐16/18‐infected epithelium to cervical intraepithelial neoplasia (CIN) III, which can progress to cervical cancer, remain poorly identified. Here, we performed RNA‐seq after laser capture microdissection, and found that APOBEC3B was highly expressed in cervical cancer specimens compared with CIN III with HPV‐16/18 infection. Furthermore, immunohistochemical analysis confirmed that high levels of APOBEC3B were correlated with lymph node metastasis in cervical cancer. Subsequent experiments revealed that HPV‐16 E6 could upregulate APOBEC3B through direct binding to the promoter of APOBEC3B in cervical cancer cells. Silencing of APOBEC3B by stable short hairpin RNA‐mediated knockdown reduced the proliferative capacity of Caski and HeLa cells in vitro and in vivo, but had only a small effect on the migration and invasion of two cervical cancer cell lines. Finally, we identified the changes in gene expression following APOBEC3B silencing in Caski cells by microarray, demonstrating a biological link between APOBEC3B and CCND1 in cervical cancer cells. Importantly, through methyl‐capture sequencing and pyrosequencing, APOBEC3B was found to affect the levels of the downstream protein Cyclin D1 (which is encoded by the CCND1 gene) through hypomethylation of the CCND1 promoter. In conclusion, our study supports HPV‐16 E6‐induced APOBEC3B expression associates with proliferation of cervical cancer cells and hypomethylation of Cyclin D1. Thus, APOBEC3B may be a potential therapeutic target in human cervical cancer.

Splicing factor SRSF3 promotes the progression of cervical cancer through regulating DDX5

AbstractAberrant alternative splicing (AS) profoundly affects tumorigenesis and cancer progression. Serine/arginine‐rich splicing factor 3 (SRSF3) regulates the AS of precursor mRNAs and acts as a proto‐oncogene in many tumors, but its function and potential mechanisms in cervical cancer remain unclear. Here, we found that SRSF3 was highly expressed in cervical cancer tissues and that SRSF3 expression was correlated with prognosis after analyses of the The Cancer Genome Atlas and GEO databases. Furthermore, knockdown of SRSF3 reduced the proliferation, migration, and invasion abilities of HeLa cells, while overexpression of SRSF3 promoted proliferation, migration, and invasion of CaSki cells. Further studies showed that SRSF3 mediated the variable splicing of exon 12 of the transcriptional cofactor DEAD‐box helicase 5 (DDX5). Specifically, overexpression of SRSF3 promoted the production of the pro‐oncogenic spliceosome DDX5‐L and repressed the production of the repressive spliceosome DDX5‐S. Ultimately, both SRSF3 and DDX5‐L were able to upregulate oncogenic AKT expression, while DDX5‐S downregulated AKT expression. In conclusion, we found that SRSF3 increased the production of DDX5‐L and decreased the production of DDX5‐S by regulating the variable splicing of DDX5. This, in turn promoted the proliferation, migration, and invasion of cervical cancer by upregulating the expression level of AKT. These results reveal the oncogenic role of SRSF3 in cervical cancer and emphasize the importance of the SRSF3‐DDX5‐AKT axis in tumorigenesis. SRSF3 and DDX5 are new potential biomarkers and therapeutic targets for cervical cancer.

KDM6A Exhibits Antitumor Activities Toward Ovarian Cancer by Epigenetically Activating Transcription of ISG‐15

ABSTRACT Ovarian cancer (OC) is a leading cause of cancer‐related mortality among females worldwide. Lysine demethylase 6A (KDM6A) plays a crucial role in multiple physiological and pathological processes. However, its role in ovarian carcinogenesis remains unclear. The expression of KDM6A and survival analysis in OC were assessed utilizing GEPIA and Kaplan–Meier plotter databases. The expression of KDM6A was evaluated immunohistochemically in tissue samples from 55 OC patients. The CCK‐8, Colony formation, and Transwell assays were employed to assess the ability of OC cells in proliferation, migration, and invasion. Lung metastasis and subcutaneous tumor models were used to evaluate the function of KDM6A in vivo. RNA sequencing, Western blot, and quantitative polymerase chain reaction were conducted to investigate the molecular functions of KDM6A. A chromatin immunoprecipitation assay was employed to determine the effects of KDM6A on the promoters of ubiquitin‐like protein interferon‐stimulated gene 15 (ISG‐15). KDM6A expression was downregulated in OC and associated with poor progression‐free survival and overall survival. KDM6A inhibits OC cell proliferation, migration, and invasion in vitro. Xenograft models have also confirmed the antitumor role of KDM6A in OC growth and metastasis. The mechanistic study demonstrated that KDM6A exerted an antitumor effect in a histone‐demethylase‐dependent manner by epigenetically activating ISG‐15 transcription. KDM6A, a functional tumor suppressor, is frequently downregulated in OC. The KDM6A‐ISG‐15 axis is critical in restraining OC malignancy and may serve as a potential molecular target for novel therapies.

AN02, a Naovel Curcumin Derivative, Orchestrates APC‐SMAD4‐Mediated CTLA‐4 Degradation for Ovarian Cancer Therapy

ABSTRACT Curcumin is a natural polyphenolic compound extracted from the rhizomes of Curcuma longa , exhibiting a wide range of biological activities, including anti‐inflammatory, antioxidant, antitumor, antibacterial, antiviral, and neuroprotective effects. However, its low oral absorption rate and poor bioavailability limit its clinical application. To address this issue, this study synthesized a novel curcumin derivative, AN02, which significantly improves the absorption rate and bioavailability while enhancing its antitumor activity. This study focused on the antitumor mechanism of AN02 in ovarian cancer, particularly its ability to inhibit ovarian cancer cell proliferation, invasion, and migration by regulating the APC (Adenomatous Polyposis Coli)‐SMAD4 (SMAD family member 4)‐CTLA‐4 (Cytotoxic T‐Lymphocyte‐Associated Protein 4) molecular axis. Experimental results demonstrated that AN02 significantly inhibited ovarian cancer cell proliferation at very low concentrations, with its half‐maximal inhibitory concentration (IC 50 ) significantly lower than that of curcumin. Additionally, AN02 exerted its antitumor effects by activating the APC‐SMAD4 molecular axis and inhibiting the CTLA‐4 molecular axis. Silencing CTLA‐4 inhibits the proliferation and immune escape of ovarian cancer. Further molecular mechanism studies revealed that APC directly regulates the SMAD4‐CTLA‐4 molecular axis, while SMAD4 forms a chaperone relationship with CTLA‐4 and promotes CTLA‐4 degradation through the K48‐dependent ubiquitination pathway, thereby suppressing the malignant phenotype of ovarian cancer cells. These findings not only reveal the antitumor mechanism of AN02 but also provide new insights for the treatment of ovarian cancer. Animal experiments also demonstrated that AN02 significantly inhibits the proliferation of subcutaneous xenograft tumors in mice. As a novel curcumin derivative, AN02 exhibits significant antitumor activity and inhibits ovarian cancer progression by regulating the APC‐SMAD4‐CTLA‐4 molecular axis. This study lays an important theoretical foundation for the development of novel antitumor drugs based on AN02, with significant clinical application potential. However, the long‐term toxicity and safety of AN02 require further investigation to establish safe dosage standards for clinical use. Future studies will focus on exploring combination therapy strategies of AN02 in cisplatin‐resistant ovarian cancer to provide new directions for precision treatment of ovarian cancer.

Wogonin Inhibits Ovarian Cancer by Activating the AMPK‐TET2‐5hmC Axis

ABSTRACTOvarian cancer is one of the most common gynecologic cancers. In the quest for effective anti‐cancer agents, this study explores the effects of wogonin, a naturally occurring flavonoid, on the viability and migration of A2780 and Kuramochi ovarian cancer cells. A2780 and Kuramochi human ovarian cancer cell lines were utilized. Cytotoxicity and migration were evaluated using the CCK8 assay and the wound‐healing assay, respectively. The effect of wogonin on the growth of A2780 ovarian cancer cells in vivo was assessed using a nude mouse model. The phosphorylation and half‐life of AMPK were determined by western blot analysis. The level of 5hmC was assessed using dot blot analysis. The impact of wogonin on gene expression was examined through RNA‐Seq. Our results show that wogonin not only impedes cancer cell growth and mobility both in vitro and in vivo but also significantly increases the cytotoxicity of cisplatin. Investigations of the mechanism underlying these effects reveal that wogonin suppresses genes associated with cell proliferation and the EMT and upregulates metabolic pathways, particularly the AMPK signaling pathway, which is crucial for increasing 5hmC levels. These results indicate that wogonin promotes DNA demethylation by stabilizing TET2. In conclusion, our findings highlight not only the therapeutic potential of wogonin but also its preventative capability against ovarian cancer in individuals with metabolic disorders, such as diabetes, who are at increased risk of ovarian cancer.

SYT7 as a Potential Prognostic Marker Promotes the Metastasis of Epithelial Ovarian Cancer Cells by Activating the STAT3 Pathway

ABSTRACTThe study aimed to investigate the impact of synaptotagmin 7 (SYT7) on the metastasis of epithelial ovarian cancer (EOC) and its potential mechanisms. This was achieved through the analysis of SYT7 expression levels and clinical relevance in EOC using bioinformatics analysis from TCGA. Additionally, the study examined the influence of SYT7 on the migration and invasion of EOC cells, as well as explored its molecular mechanisms using in vitro EOC cell lines and in vivo mouse xenograft models. Our research revealed that human EOC tissues exhibit significantly elevated levels of SYT7 compared to normal ovarian tissues, and that SYT7 expression is inversely correlated with overall survival. Suppression of SYT7 effectively impeded the migratory and invasive capabilities of CAOV3 cells, whereas overexpression of SYT7 notably accelerated tumor progression in A2780 cells. Mechanistic investigations demonstrated that SYT7 upregulates p‐STAT3 and MMP2 in EOC cells. Importantly, treatment with the STAT3 inhibitor niclosamide effectively counteracted the oncogenic effects of SYT7 in EOC. The inhibition of SYT7 was found to significantly reduce in vivo tumor metastasis in a nude mouse xenograft model. Our findings suggest that the upregulation of SYT7 in EOC is associated with a negative prognosis, as it enhances tumor migration and invasion by activating the STAT3 signaling pathway. Thus, SYT7 might be utilized as a EOC prognostic marker and treatment target.

Novel Metabolic‐Prognostic Integration Reveals TCF21‐Mediated Mitochondrial Regulation in Endometrial Cancer

ABSTRACT Despite endometrial cancer (EC) being a malignancy linked to metabolic disorders such as diabetes and obesity, its prognostic markers and metabolic dysregulation remain incompletely understood. Gene expression profiles and clinical data were obtained from TCGA. Metabolism‐regulating genes (MRGs) were identified by intersecting genes linked to diabetes, obesity, and EC prognosis. A prognostic MRG‐model was developed using LASSO Cox regression. Functional pathway features of the MRG‐model were analyzed for prognostic signals, immune status, and antitumor therapy using methods such as gene set enrichment analysis, GSVA, ssGSEA, EPIC, CIBERSORT, and others. Machine learning algorithms identified the optimal MRG, TCF21, for in vivo and in vitro validation through experiments including colony formation, CCK8 assays, wound healing, Transwell assays, measurement of reactive oxygen species and ATP levels. We identified 72 candidate genes related to EC metabolism and progression. The MRG‐model effectively distinguished high‐risk from low‐risk EC patients and demonstrated strong prognostic predictive capacity. Significant differences were observed between the two groups in clinical factors, functional pathways, immune characteristics, mutation profiles, and treatment recommendations. TCF21, with optimal performance, was selected for further study. TCF21 expression was significantly downregulated in EC and correlated with DNA methylation. As a tumor suppressor, TCF21 regulates proliferation, migration, invasion, and mitochondrial metabolism in EC via PDE2A. The MRG‐model can serve as a robust tool for prognostic prediction and support personalized EC treatment, enhancing its clinical potential. TCF21 is methylated in EC, and its regulation of PDE2A governs the malignant phenotype and mitochondrial metabolism.

Inhibiting Wnt/beta‐catenin in CTNNB1‐mutated endometrial cancer

AbstractThe role of β‐catenin/TCF transcriptional activity in endometrial cancer (EC) recurrence is not well understood. We assessed the impact of Wnt/β‐catenin inhibition in EC models. In an analysis of the Cancer Genome Atlas, we confirmed that CTNNB1 mutations are enriched in recurrent low‐risk EC and showed that aberrant Wnt/β‐catenin pathway activation is associated with recurrence. We studied CTNNB1‐wildtype (HEC1B, Ishikawa) and CTNNB1‐mutant (HEC108, HEC265, HEC1B‐S33Y, Ishikawa‐S33Y) EC cell lines. Dose response curves were determined for 5 Wnt/β‐catenin pathway inhibitors (Wnt‐C59, XAV‐939, PyrPam, PRI‐724, SM04690). XAV939, Wnt‐C59 and PyrPam inhibited function upstream of β‐catenin transcriptional activity and were ineffective at inhibiting cell viability. In contrast, PRI724 and SM04690 indirectly inhibited β‐catenin transcriptional activity and significantly reduced cell viability in CTNNB1‐mutant cell lines. Treatment with SM04690 reduced cell viability (Licor Cell stain) in all EC cell lines, but viability was significantly lower in CTNNB1‐mutant cell lines (p < 0.01). Mechanistically, SM04690 significantly inhibited proliferation measured via 5′‐bromo‐2′‐deoxyuridine incorporation and reduced T cell factor (TCF) transcriptional activity. HEC1B, HEC1B‐S33Y and HEC265 tumor‐bearing mice were treated with vehicle or SM04690. Tumors treated with SM04690 had smaller mean volumes than those treated with vehicle (p < 0.001, p = 0.014, p = 0.06). In HEC1B‐S33Y and HEC265 tumors, SM04690 treatment significantly reduced Ki67 H‐scores compared to vehicle (p = 0.035, p = 0.024). Targeting the Wnt/β‐catenin pathway in CTNNB1‐mutant EC effectively inhibited proliferation and β‐catenin/TCF transcriptional activity and blunted tumor progression in in vivo models. These studies suggest β‐catenin transcriptional inhibitors are effective in EC and particularly in CTNNB1‐mutant EC, highlighting a potential therapeutic vulnerability for treatment of CTNNB1‐mutant EC.

The Role of SMAD7 in the Epigenetic Regulation of TGF‐β Targets in the Metastasis of Ovarian Cancer

ABSTRACTThe role of TGF‐β signaling in the epigenetic modifications involved in ovarian cancer is not fully understood. This study investigated the relationship between TGF‐β signaling, epigenetic modifications, and cellular behaviors in ovarian cancer. We found that E‐cadherin, a key cell adhesion molecule, underwent epigenetic silencing via promoter DNA hypermethylation in ovarian cancer cell lines and that this was accompanied by the upregulation of vimentin, which is indicative of a mesenchymal and invasive phenotype. DNA‐demethylating agents restored E‐cadherin expression, which suggests that TGF‐β signaling mediates this epigenetic silencing. Overexpression of SMAD7, an inhibitory component of TGF‐β signaling, reversed E‐cadherin silencing, which suggests a role of SMAD7 in modulating the epigenetic status. Functionally, SMAD7 overexpression inhibited the migration and invasion in ovarian cancer cells, which suggests its therapeutic potential for suppressing metastasis. Clinically, ovarian cancer patients with high SMAD7 expression had significantly longer disease‐free survival. Mechanistically, SMAD7 overexpression decreased the acetylation of H3K9 and the binding of the transcriptional repressor TWIST1 at the E‐cadherin promoter, which promoted its demethylation and reactivation. Disruption of TGF‐β signaling upregulated SMAD4 target genes, which are silenced by epigenetic mechanisms, a finding that suggests broader therapeutic implications. Overall, our results provide insights into the role of TGF‐β‐mediated epigenetic regulation in ovarian cancer metastasis and underscore the therapeutic potential of targeting TGF‐β signaling and its downstream effectors. Further research is needed to elucidate the underlying mechanisms and validate these therapeutic strategies.

HPV16 CpG Methylation Contributes to Cervical Carcinogenesis by Regulating HPV16 Tumorigenesis‐Related Genes

ABSTRACTHPV16 CpG methylation is associated with cervical carcinogenesis and the expression of HPV16 tumorigenesis‐related genes. However, the genome‐wide methylation profile of HPV16 CpG sites during cervical carcinogenesis has not been fully characterized, and the regulatory role of HPV16 CpG methylation in the expression of these genes in cervical carcinogenesis remains unclear. This study aims to comprehensively map HPV16 CpG methylation patterns across different cervical carcinogenesis stages and elucidate its regulatory effect on the expression of HPV16 tumorigenesis‐related genes as well as biological alterations in cervical cancer cells. A total of 341 participants diagnosed with various stages of cervical lesions and normal cervix were enrolled to evaluate the associations between HPV16 CpG methylation, expression of HPV16 tumorigenesis‐related genes, and cervical carcinogenesis. Demethylation of HPV16 CpG sites in Caski cells using 5‐Aza‐dC was performed to assess subsequent changes in the expression of HPV16 tumorigenesis‐related genes and cellular biological functions. HPV16 hypermethylation was associated with an increased risk of cervical cancer and precancerous lesions. Thirty‐six specific CpG sites across various regions of the HPV16 genome exhibited progressively elevated methylation levels correlating with lesion severity. Effects of HPV16 CpGs methylation on cervical carcinogenesis were partially mediated by HPV16 oncoproteins. Demethylation of HPV16 CpGs significantly suppressed HPV16 oncogene expression, promoted apoptosis, and inhibited proliferation, migration, and invasion in cervical cancer cells. This study provides novel insights into the role of HPV16 CpG methylation in cervical carcinogenesis through the modulation of HPV16 oncogenes. This might represent a promising therapeutic strategy for impeding cervical cancer progression.

Targeting BRPF3 moderately reverses olaparib resistance in high grade serous ovarian carcinoma

Abstract PARP inhibitors (PARPi) kill cancer cells by stalling DNA replication and preventing DNA repair, resulting in a critical accumulation of DNA damage. Resistance to PARPi is a growing clinical problem in the treatment of high grade serous ovarian carcinoma (HGSOC). Acetylation of histone H3 lysine 14 (H3K14ac) and associated histone acetyltransferases (HATs) and epigenetic readers have known functions in DNA repair and replication. Our objectives are to examine their expression and activities in the context of PARPi‐resistant HGSOC, and to determine if targeting H3K14ac or associated proteins has therapeutic potential. Using mass spectrometry profiling of histone modifications, we observed increased H3K14ac enrichment in PARPi‐resistant HGSOC cells relative to isogenic PARPi‐sensitive lines. By reverse‐transcriptase quantitative PCR and RNA‐seq, we also observed altered expression of numerous HATs in PARPi‐resistant HGSOC cells and a PARPi‐resistant PDX model. Knockdown of HATs only modestly altered PARPi response, although knockdown and inhibition of PCAF significantly increased resistance. Pharmacologic inhibition of HBO1 depleted H3K14ac but did not affect PARPi response. However, knockdown and inhibition of BRPF3, a bromodomain and PHD‐finger containing protein that is known to interact in a complex with HBO1, did reduce PARPi resistance. This study demonstrates that depletion of H3K14ac does not affect PARPi response in HGSOC. Our data suggest that the bromodomain function of HAT proteins, such as PCAF, or accessory proteins, such as BRPF3, may play a more direct role compared to direct HATs function in PARPi response.

Methylation, Gene Expression, and Risk Genotypes at the TERT‐CLPTM1L Locus in Cervical Cancer

ABSTRACTThe reverse transcriptase subunit of telomerase, TERT, is frequently activated in high‐grade dysplasia and invasive cancers of the uterine cervix. Telomerase activation through hypomethylation of the TERT promoter holds promise as a biomarker for cervical cancer progression, however, specific CpG sites involved in cervical cancer risk remain to be fully defined. A recent genome‐wide association study on cervical cancer identified genetic polymorphisms at 5p13.33 (close to TERT‐CLPTM1L) but the underlying mechanisms are undetermined. We investigated 529 CpG sites within the TERT promoter region and 3 CpG islands nearby, and 21 CpG sites within CLPTM1L in 190 bisulfite‐converted cervical tumor DNA samples from BioRAIDs (NCT02428842). We identified eight CpG sites within TERT intron 2 where methylation was significantly associated with the genotypes of cervical cancer risk variants rs27070 and rs459961 in cervical tumors after multiple testing correction (p < 9.4 × 10E−5). Hypermethylation at chr5:1289663 correlated with decreased TERT mRNA levels. In an independent series of 188 normal or dysplastic cervical tissues, rare alleles of rs27070 and rs459961 were associated with low basal CLPTM1L levels and with the absence of TERT mRNA in HPV‐negative samples, consistent with their proposed role as protective variants for cervical cancer. HPV infection was associated with increased CLPTM1L and TERT levels. Collectively, our results provide a link between cervical cancer risk variants, methylation, and gene expression and implicate both TERT and CLPTM1L as genes modulated by genomic background and HPV infection during cervical cancer development.

ICAT‐Mediated Crosstalk Between Cervical Cancer Cells and Macrophages Promotes M2‐Like Macrophage Polarization to Reinforce Tumor Malignant Behaviors

ABSTRACTInhibitor of β‐catenin and T‐cell factor (ICAT) is a classical inhibitor of the Wnt signaling pathway. Nonetheless, our previous work found that ICAT is overexpressed in cervical cancer (CC), resulting in the augmentation of migration and invasion capabilities of CC cells. It remains unclear what molecular mechanism underlies this phenomenon. The interaction between cancer cells and the tumor microenvironment (TME) promotes the outgrowth and metastasis of tumors. Tumor‐associated macrophages (TAMs) are a major constituent of the TME and have a significant impact on the advancement of CC. Consequently, our inquiry pertains to the potential of ICAT to facilitate tumor development through its modulation of the cervical TME. In this study, we first verified that ICAT regulated the secretion of cytokines interleukin‐10 (IL‐10) and transforming growth factor‐β (TGF‐β) in CC cells, leading to M2‐like macrophage polarization and enhancement of the migration and invasion of CC cells. Furthermore, the system of co‐culturing human umbilical vein endothelial cells (HUVECs) with macrophages revealed that depending on the CC cells' overexpression or inhibition of ICAT, the vascular tube formation by HUVECs can be either increased or decreased. Overall, our study indicates that ICAT stimulates M2‐like polarization of TAMs via upregulating IL‐10 and TGF‐β, which results in increased neovascularization, tumor metastasis, and immunosuppression in CC. In upcoming times, inhibiting crosstalk between CC cells and TAMs may be a possible strategy for CC therapy.

VPS45 Contributes to the Progression of Hepatocellular Carcinoma by Triggering the Wnt/β‐Catenin Signaling Pathway

ABSTRACTVacuolar protein sorting 45 (VPS45) has recently been implicated in the development of ovarian cancer and non‐small cell lung cancer. However, its role in the onset and progression of hepatocellular carcinoma (HCC) remains unclear. This study aims to elucidate the function of VPS45 in HCC. Bioassays were conducted to assess the prognostic significance of VPS45 in HCC. Techniques such as western blotting and real‐time quantitative polymerase chain reaction (qRT‐PCR) were used to confirm the expression levels of VPS45 in HCC tissues and cell lines, as well as to evaluate the expression of downstream effectors in its potential tumorigenic pathways. The impact of VPS45 on HCC cell invasion, proliferation, and migration was assessed using the Cell Counting Kit‐8 (CCK‐8), wound healing, and transwell assays. Furthermore, the effect of VPS45 on HCC tumorigenesis in vivo was evaluated through subcutaneous tumor formation assays in BALB/c nude mice. VPS45 is markedly overexpressed in both HCC tissues and cell lines. Its expression escalates with advancing tumor grade and clinical stage, and high VPS45 levels are indicative of poor prognosis. In vitro experiments revealed that VPS45 overexpression significantly boosts HCC cell proliferation, migration, and invasion. Conversely, VPS45 knockdown hindered HCC progression in vivo. Investigation into pathway protein expression suggests that VPS45 facilitates HCC progression through its involvement in the Wnt/β‐catenin signaling pathway. The overexpression of VPS45 contributes to the development of malignant phenotypes in HCC cells, resulting in a poor prognosis. Targeting VPS45 may offer a viable therapeutic strategy for managing HCC.

Human papillomavirus type 16 E6 promotes cervical cancer proliferation by upregulating transketolase enzymatic activity through the activation of protein kinase B

Abstract Over 99% of precancerous cervical lesions are associated with human papillomavirus (HPV) infection, with HPV types 16 and 18 (especially type 16) found in over 70% of cervical cancer cases globally. E6, a critical HPV gene, triggers malignant proliferation by degrading p53; however, this mechanism alone cannot fully explain the oncogenic effects of HPV16 E6. Therefore, we aimed to investigate new targets of HPV oncogenic mechanisms. Our results revealed significant changes in nonoxidative pentose phosphate pathway (PPP) metabolites in HPV16‐positive cells. However, the role of nonoxidative PPP in HPV‐associated cell transformation and tumor development remained unexplored. In this study, we investigated the impact and mechanisms of HPV16 E6 on cervical cancer proliferation using the HPV‐negative cervical cancer cell line (C33A). HPV16 E6 was found to promote cervical cancer cell proliferation both in vitro and in vivo, activating the nonoxidative PPP. Transketolase (TKT), a key enzyme in the nonoxidative PPP, is highly expressed in cervical cancer tissues and associated with poor prognosis. HPV16 E6 promotes cervical cancer cell proliferation by upregulating TKT activity through the activation of AKT. In addition, oxythiamine (OT), a TKT inhibitor, hindered tumor growth, with enhanced effects when combined with cisplatin (DDP). In conclusion, HPV16 E6 promotes cervical cancer proliferation by upregulating TKT activity through the activation of AKT. OT demonstrates the potential to inhibit HPV16‐positive cervical cancer growth, and when combined with DDP, could further enhance the tumor‐suppressive effect of DDP.

Circ_0001589/miR‐1248/HMGB1 axis enhances EMT‐mediated metastasis and cisplatin resistance in cervical cancer

AbstractCervical cancer is the fourth most common malignant tumors in female worldwide. Cirular RNAs (circRNA) represent a new class of regulatory RNA and play a pivotal role in the carcinogenesis and development of tumors. However, their functions have not been fully elucidated in cervical cancer. In this study, we identified an upregulated circRNA, circ_0001589, both in fresh clinical samples and tissue microarray of cervical cancer. Transwell assay and cell apoptosis assay by flow cytometry demonstrated circ_0001589 promotes epithelial–mesenchymal transition (EMT)‐mediated cell migration and invasion, and enhanced cisplatin resistance in vitro. In addition, in nude mice model, circ_0001589 increased the number of lung metastases and recovered xenograft growth from cisplatin treatment in vivo. Mechanistically, RNA pull‐down assay, RNA immunoprecipitation, and dual‐luciferase reporter assay disclosed that circ_0001589 function as an competing endogenous RNA to sponge miR‐1248, which directly target the 3′ untranslated region of high mobility group box‐B1 (HMGB1). Thereby, circ_0001589 upregulated HMGB1 protein expression and accelerate cervical cancer progression. The rescue experiments also revealed that miR‐1248 overexpression or HMGB1 knockdown partially reversed the regulatory functions of circ_0001589 on cell migration, invasion, and cisplatin resistance. In summary, our findings suggest the upregulation of circ_0001589 promoted EMT‐mediated cell migration and invasion, and enhanced cisplatin resistance via regulating miR‐1248/HMGB1 axis in cervical cancer. These results provided new evidence for understanding the carcinogenesis mechanism and finding new therapeutic target for cervical cancer.

Loss of CBX2 causes genomic instability and Wnt activation in high grade serous ovarian carcinoma cells

AbstractHigh grade serous ovarian carcinoma (HGSOC) is lethal with insidious onset, rapid progression, poor prognosis, and limited treatment options. Polycomb repressor complexes (PRC) 1 and 2 are intimately involved in progression of many types of cancer including HGSOC. Unlike the consistent constitution of PRC2, PRC1 consists of diverse components whose clinical significance in HGSOC are not entirely clear. Here, prognosis‐associated PRC1 components were identified through data‐mining. CBX2 promoted proliferation and reduced apoptosis of HGSOC cell lines OVCAR4, OVCAR3, and CAOV3. Complete loss of CBX2 by CRISPR‐cas9 editing (CBX2KO) destabilized genome stability with increased spontaneous chromosomal breaks and tendency to polyploidy accompanied by disrupted cell cycle especially stalled G2/M transition and caused severe cell death. Wnt/β‐catenin/LEF1/TCF7L1 was activated in surviving OVCAR4‐CBX2KO clones to bypass the crisis caused by loss of CBX2. The relieve of TCF7L1 core‐promoter region occupied by CBX2 might be one of the possible explanations to TCF7L1 increase in OVCAR4‐CBX2KO clones. Subcutaneous tumor model further validated that depletion of CBX2 repressed HGSOC cell line derived tumor growth. High immunohistochemistry score of CBX2 in primary ovarian cancer tissue associated with advanced clinical stage (p = 0.033), poor overall survival (HR = 3.056, 95% CI: 1.024−9.123), and progression free survival (HR = 4.455, 95% CI: 1.513−13.118) in HGSOC. Overall, our results suggested that CBX2 was a promising prognostic factor and therapeutic target in HGSOC.

MYC‐binding lncRNA EPIC1 promotes AKT‐mTORC1 signaling and rapamycin resistance in breast and ovarian cancer

AbstractAKT‐mTORC1 (mammalian target of rapamycin complex 1) signaling pathway plays a critical role in tumorigenesis and can be targeted by rapamycin. However, the underlying mechanism of how long noncoding RNA (lncRNAs) regulate the AKT‐mTORC1 pathway remains unclear. EPIC1 (epigenetically‐induced lncRNA 1) is a Myc‐binding lncRNA, which has been previously demonstrated to be overexpressed in multiple cancer types. In a pathway analysis including 4962 cancer patients, we observed that lncRNA EPIC1 expression was positively correlated with the AKT‐mTORC1 signaling pathway in more than 10 cancer types, including breast and ovarian cancers. RNA‐seq analysis of breast and ovarian cancer cells demonstrated that EPIC1‐knockdown led to the downregulation of genes in the AKT‐mTORC1 signaling pathway. In MCF‐7, OVCAR4, and A2780cis cell lines, EPIC1 knockdown and overexpression, respectively, inhibited and activated phosphorylated AKT and the downstream phosphorylation levels of 4EBP1 and S6K. Further knockdown of Myc abolished the EPIC1′s regulation of AKT‐mTORC1 signaling; suggested that the regulation of phosphorylation level of AKT, 4EBP1, and S6K by EPIC1 depended on the expression of Myc. Moreover, EPIC1 overexpressed MCF‐7, A2780cis, and OVCAR4 cells treated with rapamycin showed a significant decreasing in rapamycin mediated inhibition of p‐S6K and p‐S6 comparing with the control group. In addition, Colony Formation assay and MTT assay indicated that EPIC1 overexpression led to rapamycin resistance in breast and ovarian cancer cell lines. Our results demonstrated the lncRNA EPIC1 expression activated the AKT‐mTORC1 signaling pathway through Myc and led to rapamycin resistance in breast and ovarian cancer.

The anthraquinone derivative KA‐4s reduces energy metabolism and enhances the sensitivity of ovarian cancer cells to cisplatin

AbstractOvarian cancer is the leading cause of death from female gynecological cancers. Cisplatin (DDP) is a first‐line drug for ovarian cancer treatment. Due to DDP resistance, there is an urgent need for novel therapeutic drugs with improved antitumor activity. AMPK‐mediated metabolic regulatory pathways are related to tumor drug resistance. Our study aimed to determine the relationship between reversing DDP resistance with the anthraquinone derivative KA‐4s and regulating AMPK energy metabolism in ovarian cancer. The results showed that KA‐4s inhibited the proliferation of ovarian cancer cells. The combination of KA‐4s with DDP effectively promoted drug‐resistant ovarian cancer cell apoptosis and inhibited cell migration and invasion. Moreover, KA‐4s decreased the intracellular ATP level and increased the calcium ion level, leading to AMPK phosphorylation. Further studies suggested that the AMPK signaling pathway may be involved in the mechanism through which KA‐4s reduce drug resistance. KA‐4s inhibited mitochondrial respiration and glycolysis; downregulated the glucose metabolism‐related proteins GLUT1 and GLUT4; the lipid metabolism‐related proteins SREBP1 and SCD1; and the drug resistance‐related proteins P‐gp, MRP1, and LRP. The inhibitory effect of KA‐4s on GLUT1 was confirmed by the application of the GLUT1 inhibitor BAY‐876. KA‐4s combined with DDP significantly increased the expression of p‐AMPK and reduced the expression of P‐gp. In a xenograft model of ovarian cancer, treatment with KA‐4s combined with DDP reduced energy metabolism and drug resistance, inducing tumor apoptosis. Consequently, KA‐4s might be evaluated as a new agent for enhancing the chemotherapeutic efficacy of treatment for ovarian cancer.

TMED3 stabilizes SMAD2 by counteracting NEDD4‐mediated ubiquitination to promote ovarian cancer

AbstractOvarian cancer is a major cause of death among cancer patients. Recent research has shown that the transmembrane emp24 domain (TMED) protein family plays a role in the progression of various types of cancer. In this study, we investigated the expression of TMED3 in ovarian cancer tumors compared to nontumor tissues using immunohistochemical staining. We found that TMED3 was overexpressed in ovarian cancer tumors, and its high expression was associated with poor disease‐free and overall survival. To understand the functional implications of TMED3 overexpression in ovarian cancer, we conducted experiments to knockdown TMED3 using short hairpin RNA (shRNA). We observed that TMED3 knockdown resulted in reduced cell viability and migration, as well as increased cell apoptosis. Additionally, in subcutaneous xenograft models in BALB‐c nude mice, TMED3 knockdown inhibited tumor growth. Further investigation revealed that SMAD family member 2 (SMAD2) was a downstream target of TMED3, driving ovarian cancer progression. TMED3 stabilized SMAD2 by inhibiting the E3 ligase NEDD4‐mediated ubiquitination of SMAD2. To confirm the importance of SMAD2 in TMED3‐mediated ovarian cancer, we performed functional rescue experiments and found that SMAD2 played a critical role in this process. Moreover, we discovered that the PI3K‐AKT pathway was involved in the promoting effects of TMED3 overexpression on ovarian cancer cells. Overall, our study identifies TMED3 as a prognostic indicator and tumor promoter in ovarian cancer. Its function is likely mediated through the regulation of the SMAD2 and PI3K‐AKT signaling pathway. These findings contribute to our understanding of the molecular mechanisms underlying ovarian cancer progression and provide potential targets for therapeutic intervention.

HMGB1 Assists in Overcoming Cisplatin Resistance in Chemoresistant Human Ovarian Cancer Cells

ABSTRACT Cisplatin is one of the most effective chemotherapeutic agents used in the treatment of ovarian cancer. However, the frequent development of cisplatin resistance remains a significant limitation, leading to therapeutic failure and poor patient outcomes. Cisplatin cytotoxicity is attributed to the generation of toxic DNA lesions, which can be recognized and processed by a variety of proteins, including the high mobility group box 1 (HMGB1) protein. HMGB1 is a multifunctional protein, which is involved in chromatin remodeling and multiple DNA damage repair pathways. In this study, we investigated the role of HMGB1 in modulating cisplatin sensitivity in human ovarian cancer cells. Using cisplatin‐sensitive and cisplatin‐resistant human ovarian cancer cell lines, we employed siRNA‐mediated HMGB1 knockdown to assess its impact on the cellular responses to cisplatin treatment. In clonogenic survival assays, HMGB1 depletion resulted in a significant reduction in colony formation in cisplatin‐resistant cells upon cisplatin exposure, compared with nontargeting siRNA treated cells. Additionally, HMGB1 inhibition significantly enhanced cisplatin‐induced apoptosis in the cisplatin‐resistant cells. Mechanistically, HMGB1‐depleted cells exhibited altered DNA damage responses via modulation of ATM/CHK2 and ATR/CHK1 activity following cisplatin treatment. Notably, DNA immunoblot and modified alkaline comet assay results demonstrated that HMGB1 depletion stimulated cisplatin‐DNA adduct formation and impaired the removal of cisplatin‐DNA adducts, particularly in the cisplatin‐resistant cells. Collectively, these findings uncover novel functions of HMGB1 in mediating cisplatin sensitivity, emphasizing its potential as a therapeutic target to overcome cisplatin resistance in ovarian cancer.

Publisher

Wiley

ISSN

0899-1987