Oxidative Medicine and Cellular Longevity

Suppression of Paclitaxel‐Induced Neuropathy and Ovarian Tumor Growth by Mn Porphyrin, MnTnBuOE‐2‐PyP 5+ (BMX‐001)

Numerous cellular and animal studies demonstrated the ability of redox‐active Mn(III) N ‐alkyl‐ and N ‐alkoxyalkylpyridyporphyrins (MnPs) to protect normal tissue while suppressing tumor growth. The mechanism primarily involves the modulation of NF‐кB and Nrf2 signaling pathways via catalysis of MnP/H 2 O 2 ‐driven protein thiol oxidation. Such differential protection/suppression effects have paved the way of Mn porphyrins (commonly known as mimics of superoxide dismutase) into clinical trials, therefore introducing new line of therapeutics that are affecting cellular redox status/oxidative stress, rather than specific proteins. The most clinically advanced Mn porphyrin, Mn(III) meso ‐tetrakis( N ‐n‐butoxyethyl‐2‐pyridyl) porphyrin (MnTnBuOE‐2‐PyP 5+ , BMX‐001) has progressed into five Phase II clinical trials, two of those related to the injuries of central nervous system. Currently, no efficient treatment for chemotherapy‐induced neuropathy is available in clinics. We therefore employed BMX‐001 to assess its effect on paclitaxel (PTX)‐induced neuropathy. Mechanical (Von‐Frey filaments) and thermal (hot plate) stimulation, toxicity (body weight), muscular coordination and general physical condition (rotarod) of female CD‐1 mice were evaluated over 3 weeks with 2 mg/kg daily dosing and also at clinically relevant dosing of 0.8 mg/kg given subcutaneously (SC) twice weekly after 1.6 mg/kg loading dose. Data revealed a significant ability of BMX‐001 to suppress peripheral neuropathy and neuroinflammation. Importantly, while protecting peripheral tissue, BMX‐001 suppressed the tumor growth of CAOV2 high‐grade serous ovarian cancer in a mouse subcutaneous xenograft model. Previously, the strong anticancer effect was only seen when Mn porphyrins were combined with radiation, chemotherapy, and ascorbate (Asc). Our data further demonstrate that high‐grade serous ovarian cancer is the first in vivo cancer thus far studied where redox‐active Mn porphyrin, as a single agent, exhibits strong anticancer effect, comparable to that of PTX. The effect is presumably due to high tumor levels of BMX‐001 and high oxidative stress specific to the aggressive chemoresistant CAOV2 cell line. Such a strong anticancer effect of BMX‐001 would allow for lowering the dosing of PTX and reducing the neuropathy. The combined neuropathy protection and anticancer efficacy demonstrate, therefore, strong therapeutic potential of BMX‐001 for gynecological cancers. Moreover, the ability of BMX‐001 to suppress neuropathy may be relevant for all types of cancer where chemotherapeutics that induce neuropathy are used as a standard‐of‐care.

XPO1‐Mediated EIF1AX Cytoplasmic Relocation Promotes Tumor Migration and Invasion in Endometrial Carcinoma

Dysregulation of eukaryotic translation initiation factor 1A, X‐linked (EIF1AX), has been implicated in the pathogenesis of some cancers. However, the role of EIF1AX in endometrial carcinoma (EC) remains unknown. We investigated the EIF1AX expression in EC patients and assessed its tumorigenesis‐associated function and nucleocytoplasmic transport mechanism in vitro and in vivo. The results indicated that the cytoplasmic EIF1AX expression showed a gradual increase when going from endometrium normal tissue, simple endometrial hyperplasia, complex endometrial hyperplasia, and endometrial atypical hyperplasia to EC, while vice versa for the nuclear EIF1AX expression. In addition, the cytoplasmic EIF1AX expression was positively correlated with histologic type, high International Federation of Gynecology and Obstetrics (FIGO) grade, advanced FIGO stage, deeper infiltration, high Ki67 index, and shorter recurrence‐free survival in EC patients. In vitro, short hairpin RNA‐mediated EIF1AX depletion or SV40NLS‐mediated EIF1AX import into the nucleus in multiple human EC cells potently suppressed cell migration and invasion, epithelial‐mesenchymal transition, and lung metastasis. Moreover, exportin 1 induced the transport of EIF1AX from the nucleus to the cytoplasm that could be inhibited by leptomycin B treatment or the mutation in the EIF1AX location sequence. These results demonstrate that cytoplasmic EIF1AX may play a key role in the incidence and promotion of EC, and thus, targeting EIF1AX or its nucleocytoplasmic transport process may offer an effective new therapeutic approach to EC.

[Retracted] Systematic Analysis of Tumor Microenvironment Patterns and Oxidative Stress Characteristics of Endometrial Carcinoma Mediated by 5‐Methylcytosine Regulators

As a widely distributed RNA methylation modification, m5C is involved in the regulation of tumorigenesis. Nevertheless, its fundamental process is not clear. This research sought to examine the genetic properties of the 5‐methylcytosine (m5C) regulator in endometrial carcinoma, as well as the prognostic significance and impact of m5C regulators on oxidative stress. Therefore, the TCGA‐UCEC data set was used to explore the characteristics of 17 RNAm5C‐related genes in the transcriptome, genome, and regulatory network. The subtypes of RNAm5C in UCEC were identified based on the expression levels of 17 RNAm5C‐related genes. The prognosis of RNAm5C‐2 was significantly better than that of RNAm5C‐1. Then, we examined the differences (variations) across various subtypes in terms of immune cell infiltration (ICI) as well as the expression of immune‐related signal markers. The findings demonstrated that there were distinct variations in the infiltration level of immune cells in each subtype, which may be the reason for the differences in the prognosis of each subtype. In addition, the differentially expressed genes (DEGs) among RNAm5C subtypes of different UCEC tumors were identified, and the DEGs significant for survival were screened. After obtaining 34 prognostic genes, the dimensionality was reduced to construct an RNA methylation score (RS). As per the findings, RS is a more accurate marker for determining the prognosis for patients with endometrial cancer. The RS was used to categorize UCEC tumor samples, and these results led to the formation of high‐score and low‐score groups. The patients in the group with a high‐RNA methylation score exhibited a survival time that was considerably longer in contrast with those in the group with a low‐RNA methylation score. The capacity of RS to predict whether or not immunotherapy would be beneficial was explored further. In the group with a high‐RNA methylation score, the objective response rate to the anti‐PD‐L1 therapy was substantially greater compared to that observed in the subgroup with a low‐RNA methylation score. Additionally, there were variations across various RS groups in terms of clinical features, tumor mutation burden, and the infiltration level of immune cells. After binary tree analysis and PCR verification of 34 prognostic genes, it is finally found that the six genes of MAGOH3P, TRBJ2_3, YTHDF1P1, RP11_323D18.5, RP11_405M12.2, and ADAM30 are significantly overexpressed in cancer tissues. These genes can be used as potential biomarkers of endometrial cancer and provide data support for precise immunotherapy in UCEC tumors.

N1‐Methyladenosine‐Related lncRNAs Are Potential Biomarkers for Predicting Prognosis and Immune Response in Uterine Corpus Endometrial Carcinoma

Uterine corpus endometrial carcinoma (UCEC) is a malignant disease that, at present, has no well‐characterised prognostic biomarker. In this study, two clusters were identified based on 28 N1‐methyladenosine‐ (m1A‐) related long noncoding RNAs (lncRNAs), of which cluster 1 was related to immune pathways according to the results of an enrichment analysis. We further observed better prognosis in patients with higher levels of immune cell infiltration, tumor mutation burden, microsatellite instability, and immune checkpoint gene expression. In addition, through Cox regression analysis and least absolute shrinkage and selection operator regression analysis, 10 m1A‐related lncRNAs (mRLs) were employed to build a prognosis model. We found that people in higher risk categories had a poorer survival probability than those in lower risk. Low‐risk samples were enriched with immune‐related pathways, while the high‐risk group was similar to the definition of the “immune desert” phenotype, which was associated with decreased immune infiltration, T cell failure, and decreased tumor mutation burden, while also being insensitive to immunotherapy and chemotherapy. This mRL‐based model has the ability to accurately predict the prognosis of UCEC patients, and the mRLs could become promising therapeutic targets in enhancing the response of immunotherapy.

Significance of TP53 Mutational Status‐Associated Signature in the Progression and Prognosis of Endometrial Carcinoma

Background. TP53 mutations are associated with poor outcome for patients with endometrial carcinoma (EC). However, to date, there have been no studies focused on the construction of TP53 mutational status‐associated signature in EC. In this study, we aim to conduct a TP53 mutation‐associated prognostic gene signature for EC. Methods. Hence, we explored the mutational landscape of TP53 in patients with EC based on the simple nucleotide variation data downloaded from The Cancer Genome Atlas (TCGA) database. Differential expression analysis and least absolute shrinkage and selection operator (LASSO)–Cox analysis was used to establish TP53 mutation‐associated prognostic gene signature. The overall survival rate between the high‐risk and low‐risk groups was compared by the Kaplan–Meier (K‐M) method. Results. We found that the TP53 mutation was associated with poor outcome, older age, lower BMI, and higher grade and stage of EC in patients. A TP53 mutational status‐associated signature was established based on transcriptome profiling data. Moreover, the patients in TCGA database were categorized into high‐ and low‐risk groups. Kaplan–Meier (K‐M) analysis indicated that the patients in the high‐risk group have poor survival outcome. Furthermore, receiver operating characteristic (ROC) curves confirmed the robust prognostic prediction efficiency of the TP53 mutational status‐associated signature. Finally, the prognostic ability was successfully verified in the other two datasets from cBioPortal database as well as in 60 clinical specimens. Univariate (hazard ratio (HR) = 1.041, 95%CI = 1.031–1.051, p < 0.001) and multivariate (hazard ratio (HR) = 1.029, 95%CI = 1.018–1.040, p < 0.001) Cox regression analyses indicated that the TP53 mutational status‐associated signature could be used as an independent prognostic factor for EC patients. Conclusion. In summary, our research constructed a powerful TP53 mutational status‐associated signature that could be a potential novel prognostic biomarker and therapeutic target for EC.

Significance of a PTEN Mutational Status‐Associated Gene Signature in the Progression and Prognosis of Endometrial Carcinoma

Background. PTEN mutations have been reported to be involved in the development and prognosis of endometrial carcinoma (EC). However, a prognostic gene signature associated with PTEN mutational status has not yet been developed. In this study, we generated a PTEN mutation‐associated prognostic gene signature for EC. Methods. We obtained the single‐nucleotide variation and transcriptomic profiling data from The Cancer Genome Atlas database as training data and implemented the least absolute shrinkage and selection operator (LASSO) Cox regression algorithm to establish a PTEN mutation‐associated prognostic gene signature. The overall survival rates of the high‐risk and low‐risk groups were determined with the Kaplan‐Meier (K‐M) method, and the accuracy of risk score prediction was tested by using the receiver operating characteristic (ROC) curve. Results. The K‐M curves revealed that the EC patients with PTEN mutations augured favorable survival outcomes. Differential expression analysis between the EC patients with PTEN mutation and wild‐type PTEN identified 224 differentially expressed genes (DEGs). Eighty‐four DEGs that manifested prognostic value were fitted into the LASSO‐Cox analysis, and a PTEN gene signature with seven mutation‐associated prognostic genes that showed robust prognostic ability was constructed; this signature was then successfully validated in the other two datasets from the cBioPortal database as well as with 60 clinical specimens. Furthermore, the PTEN mutation‐associated prognostic gene signature proved to be an independent prognostic predictor of EC. Remarkably, the EC patients in the high‐risk group were characterized by higher tumor stages and grades as well as lower tumor mutation burden with respect to EC, with a poor survival outcome. Collectively, the PTEN mutation‐associated prognostic gene signature that we developed could now be used as a favorable prognostic biomarker for EC. Conclusion. In summary, we developed and validated a prognostic predictor for EC associated with PTEN mutational status that may be used as a favorable prognostic biomarker and therapeutic target for EC.

Elevated LINC00909 Promotes Tumor Progression of Ovarian Cancer via Regulating the miR‐23b‐3p/MRC2 Axis

Ovarian cancer (OC), the third common gynecologic malignancy, contributes to the most cancer‐caused mortality in women. However, 70% of patients with OC are diagnosed at an advanced stage, of which the 5‐year survival is less than 30%. Long noncoding RNAs (long ncRNAs or lncRNA), a type of RNA with exceeding 200 nucleotides in length but no protein‐coding capability, have been demonstrated to involve the pathogenesis of various cancers and show considerable potential in the diagnosis of OC. In this study, we found that the LINC00909 expression in tumor and serum specimens of OC patients was elevated, determined by real‐time quantitative, and droplet digital PCR. In receiver operating characteristic (ROC) analysis, our results revealed that serum LINC00909 distinguished cancers from normal ovarian tissue with 87.8% of sensitivity and 69.6% of specificity (AUC, 81.2%) and distinguished serous ovarian cancer from normal ovarian tissue with 90.0% of sensitivity and 75.9% of specificity (AUC, 84.5%). Furthermore, we observed that the tumor and serum LINC00909 level was positively associated with the International Federation of Gynecology and Obstetrics (FIGO) stage and the Eastern Cooperative Oncology Group (ECOG) score (reflecting patients’ performance status). Also, patients with low serum LINC00909 level showed a longer overall (hazard ratio, HR = 1.874, p = 0.0004) and progression‐free (HR = 1.656, p = 0.0017) survival. Functional assays indicated that the elevation of LINC00909 expression contributes to cell proliferation, migration, and invasion capability of ovarian cancer cells. Besides, we demonstrated that LINC00909 functions as a competing endogenous RNA (ceRNA) of MRC2 mRNA by sponging miR‐23‐3p, and thereby promotes epithelial‐to‐mesenchymal transition (EMT) of ovarian cancer cells. Therefore, we highlight that the LINC00909/miR‐23b‐3p/MRC2 axis is implicated in the pathogenesis of ovarian cancer, and serum LINC00909 may be a promising biomarker for the diagnosis of OC.

Mitochondrial Dysfunction Pathway Alterations Offer Potential Biomarkers and Therapeutic Targets for Ovarian Cancer

The mitochondrion is a very versatile organelle that participates in some important cancer‐associated biological processes, including energy metabolism, oxidative stress, mitochondrial DNA (mtDNA) mutation, cell apoptosis, mitochondria‐nuclear communication, dynamics, autophagy, calcium overload, immunity, and drug resistance in ovarian cancer. Multiomics studies have found that mitochondrial dysfunction, oxidative stress, and apoptosis signaling pathways act in human ovarian cancer, which demonstrates that mitochondria play critical roles in ovarian cancer. Many molecular targeted drugs have been developed against mitochondrial dysfunction pathways in ovarian cancer, including olive leaf extract, nilotinib, salinomycin, Sambucus nigra agglutinin, tigecycline, and eupatilin. This review article focuses on the underlying biological roles of mitochondrial dysfunction in ovarian cancer progression based on omics data, potential molecular relationship between mitochondrial dysfunction and oxidative stress, and future perspectives of promising biomarkers and therapeutic targets based on the mitochondrial dysfunction pathway for ovarian cancer.

HSP90AB1 as the Druggable Target of Maggot Extract Reverses Cisplatin Resistance in Ovarian Cancer

Cisplatin resistance is a crucial factor affecting ovarian cancer patient’s survival rate, but the primary mechanism underlying cisplatin resistance in ovarian cancer remains unclear, and this prevents the optimal use of cisplatin therapy. Maggot extract (ME) is used in traditional Chinese medicine for patients with comas and patients with gastric cancer when combined with other drug treatments. In this study, we investigated whether ME enhances the sensitivity of ovarian cancer cells to cisplatin. Two ovarian cancer cells—A2780/CDDP and SKOV3/CDDP—were treated with cisplatin and ME in vitro. SKOV3/CDDP cells that stably expressed luciferase were subcutaneously or intraperitoneally injected into BALB/c nude mice to establish a xenograft model, and this was followed by ME/cisplatin treatment. In the presence of cisplatin, ME treatment effectively suppressed the growth and metastasis of cisplatin-resistant ovarian cancer in vivo and in vitro. RNA-sequencing data showed that HSP90AB1 and IGF1R were markedly increased in A2780/CDDP cells. ME treatment markedly decreased the expression of HSP90AB1 and IGF1R, thereby increasing the expression of the proapoptotic proteins p-p53, BAX, and p-H2AX, while the opposite effects were observed for the antiapoptotic protein BCL2. Inhibition of HSP90 ATPase was more beneficial against ovarian cancer in the presence of ME treatment. In turn, HSP90AB1 overexpression effectively inhibited the effect of ME in promoting the increased expression of apoptotic proteins and DNA damage response proteins in SKOV3/CDDP cells. Inhibition of cisplatin-induced apoptosis and DNA damage by HSP90AB1 overexpression confers chemoresistance in ovarian cancer. ME can enhance the sensitivity of ovarian cancer cells to cisplatin toxicity by inhibiting HSP90AB1/IGF1R interactions, and this might represent a novel target for overcoming cisplatin resistance in ovarian cancer chemotherapy.

Necroptosis-Related Modification Patterns Depict the Tumor Microenvironment, Redox Stress Landscape, and Prognosis of Ovarian Cancer

Necroptosis is one of programmed cell death discovered recently, which involves in tumorigenesis, cancer metastasis, and immune reaction. We studied the necroptosis-related genes (NRGs) in ovarian cancer (OV) tissues using data from public databases, which separated into two NRGclusters. Patients in cluster A would have severe clinical characteristics, poor prognosis, and worse tumor microenvironment infiltration characteristics. The NRG score was achieved through the Cox analysis, along with a construction of a prognostic model. People with lower risk score would have better prognosis, lower expression of redox related genes, higher immunogenicity, and better effect on immunotherapy. In addition, the NRG score was closely related to cancer stem cell index, copy number variations, tumor mutation load, and chemosensitivity. We built a nomogram to enhance clinical application of the signature. These outcomes can help use know the function of NRGs in OV and provide new ideas for evaluating clinical outcome and developing more effective treatment protocols.

Oxidative Stress Response Biomarkers of Ovarian Cancer Based on Single-Cell and Bulk RNA Sequencing

Background. The occurrence and development of ovarian cancer (OV) are significantly influenced by increased levels of oxidative stress (OS) byproducts and the lack of an antioxidant stress repair system. Hence, it is necessary to explore the markers related to OS in OV, which can aid in predicting the prognosis and immunotherapeutic response in patients with OV. Methods. The single-cell RNA-sequencing (scRNA-seq) dataset GSE146026 was retrieved from the Gene Expression Omnibus (GEO) database, and Bulk RNA-seq data were obtained from TCGA and GTEx databases. The Seurat R package and SingleR package were used to analyze scRNA-seq and to identify OS response-related clusters based on ROS markers. The “limma” R package was used to identify the differentially expressed genes (DEGs) between normal and ovarian samples. The risk model was constructed using the least absolute shrinkage and selection operator (LASSO) regression analysis. The immune cell infiltration, genomic mutation, and drug sensitivity of the model were analyzed using the CIBERSORT algorithm, the “maftools,” and the “pRRophetic” R packages, respectively. Results. Based on scRNA-seq data, we identified 12 clusters; OS response-related genes had the strongest specificity for cluster 12. A total of 151 genes were identified from 2928 DEGs to be significantly correlated with OS response. Finally, nine prognostic genes were used to construct the risk score (RS) model. The risk score model was an independent prognostic factor for OV. The gene mutation frequency and tumor immune microenvironment in the high- and low-risk score groups were significantly different. The value of the risk score model in predicting immunotherapeutic outcomes was confirmed. Conclusions. OS response-related RS model could predict the prognosis and immune responses in patients with OV and provide new strategies for cancer treatment.

HSP60 Regulates Lipid Metabolism in Human Ovarian Cancer

Accumulating evidence demonstrates that cancer is an oxidative stress‐related disease, and oxidative stress is closely linked with heat shock proteins (HSPs). Lipid oxidative stress is derived from lipid metabolism dysregulation that is closely associated with the development and progression of malignancies. This study sought to investigate regulatory roles of HSPs in fatty acid metabolism abnormality in ovarian cancer. Pathway network analysis of 5115 mitochondrial expressed proteins in ovarian cancer revealed various lipid metabolism pathway alterations, including fatty acid degradation, fatty acid metabolism, butanoate metabolism, and propanoate metabolism. HSP60 regulated the expressions of lipid metabolism proteins in these lipid metabolism pathways, including ADH5, ECHS1, EHHADH, HIBCH, SREBP1, ACC1, and ALDH2. Further, interfering HSP60 expression inhibited migration, proliferation, and cell cycle and induced apoptosis of ovarian cancer cells in vitro. In addition, mitochondrial phosphoproteomics and immunoprecipitation‐western blot experiments identified and confirmed that phosphorylation occurred at residue Ser70 in protein HSP60, which might regulate protein folding of ALDH2 and ACADS in ovarian cancers. These findings clearly demonstrated that lipid metabolism abnormality occurred in oxidative stress‐related ovarian cancer and that HSP60 and its phosphorylation might regulate this lipid metabolism abnormality in ovarian cancer. It opens a novel vision in the lipid metabolism reprogramming in human ovarian cancer.

The Nrf2/PGC1α Pathway Regulates Antioxidant and Proteasomal Activity to Alter Cisplatin Sensitivity in Ovarian Cancer

Drug resistance remains a barrier in the clinical treatment of ovarian cancer. Proteasomal and antioxidant activities play important roles in tumor drug resistance, and increasing evidence suggests the existence of an interaction between antioxidant and proteasomal activities. However, the mechanism of the synergistic effects of proteasomal activity and antioxidation on tumor drug resistance is not completely clear. In this study, we compared two ovarian cancer cells, A2780 and SKOV3 cells. Among them, SKOV3 cell is a human clear cell carcinoma cell line that is resistant to platinum. We found that compared with the findings in A2780 cells, SKOV3 cells were less sensitive to both proteasomal inhibitor and cisplatin. Proteasomal inhibition enhanced the sensitivity of A2780 cells, but not SKOV3 cells, to cisplatin. Notably, the Nrf2-mediated antioxidant pathway was identified as a resistance mechanism in proteasome inhibitor-resistant cells, but this was not the only factor identified in our research. In SKOV3 cells, PGC1α regulated the antioxidant activity of Nrf2 by increasing the phosphorylation of GSK3β, and in turn, Nrf2 regulated the transcriptional activity of PGC1α. Thus, Nrf2 and PGC1α synergistically participate in the regulation of proteasomal activity. Furthermore, the Nrf2/PGC1α pathway participated in the regulation of mitochondrial function and homeostasis, further regulating proteasomal activity in SKOV3 cells. Therefore, exploring the roles of PGC1α and Nrf2 in the regulation of proteasomal activity by antioxidant and mitochondrial functions may provide new avenues for reversing drug resistance in ovarian cancer.

Apatinib, a Novel Tyrosine Kinase Inhibitor, Promotes ROS-Dependent Apoptosis and Autophagy via the Nrf2/HO-1 Pathway in Ovarian Cancer Cells

Apatinib, a new-generation oral tyrosine kinase inhibitor targeting the vascular endothelial growth factor receptor 2 (VEGFR2) signaling pathway, shows favorable therapeutic effects in various malignant tumors. However, its effect on ovarian cancer has not yet been characterized. Here, we demonstrated that apatinib inhibited ovarian cancer cell growth and migration in a concentration-dependent manner. Further, we found that apatinib could directly act on tumor cells and promote ROS-dependent apoptosis and autophagy. Mechanistically, we showed that apatinib suppressed glutathione to generate ROS via the downregulation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway and maintained an antitumor effect at a low level of VEGFR2 in ovarian cancer, suggesting that combination of apatinib with Nrf2 inhibitor may be a promising therapy strategy for patients with ovarian cancer.

Moderate Static Magnet Fields Suppress Ovarian Cancer Metastasis via ROS‐Mediated Oxidative Stress

Metastasis is the leading cause of cancer patient death, which is closely correlated with reactive oxygen species (ROS) levels. It is well known that the effects of ROS on tumors are diverse, depending on ROS concentration and cell type. We found that ovarian cancer cells have significantly lower levels of ROS than normal ovarian cells. Moreover, increased ROS levels in ovarian cancer cells can substantially inhibit their migration and invasion ability. Furthermore, the results show that moderate static magnetic field (SMF) can inhibit ovarian cancer cell migration, invasion, and stemness in a ROS‐dependent manner. RNA sequencing results confirm that SMFs increased the oxidative stress level and reduced the stemness of ovarian cancer cells. Consistently, the expressions of stemness‐related genes were significantly decreased, including hyaluronan receptor (CD44), SRY‐box transcription factor 2 (Sox2), and cell myc proto‐oncogene protein (C‐myc). Furthermore, moderate SMFs provided by a superconducting magnet and permanent magnet have good biosafety and can both inhibit ovarian cancer metastasis in mice. Therefore, our study demonstrates the effects of SMFs on oxidative stress and metastasis in the ovarian cancer cells, which reveals the potential of applying SMF as a physical method in cancer therapy in the future.

Insights into the Role of Oxidative Stress in Ovarian Cancer

Oxidative stress (OS) arises when the body is subjected to harmful endogenous or exogenous factors that overwhelm the antioxidant system. There is increasing evidence that OS is involved in a number of diseases, including ovarian cancer (OC). OC is the most lethal gynecological malignancy, and risk factors include genetic factors, age, infertility, nulliparity, microbial infections, obesity, smoking, etc. OS can promote the proliferation, metastasis, and therapy resistance of OC, while high levels of OS have cytotoxic effects and induce apoptosis in OC cells. This review focuses on the relationship between OS and the development of OC from four aspects: genetic alterations, signaling pathways, transcription factors, and the tumor microenvironment. Furthermore, strategies to target aberrant OS in OC are summarized and discussed, with a view to providing new ideas for clinical treatment.

Identifying the Role of Oxidative Stress‐Related Genes as Prognostic Biomarkers and Predicting the Response of Immunotherapy and Chemotherapy in Ovarian Cancer

Background. Ovarian cancer (OC) is one of the most frequently seen and fatal gynecological malignancies, and oxidative stress (OS) plays a critical role in the development and chemoresistance of OC. Materials and Methods. OS‐related genes (OSRGs) were obtained from the Molecular Signatures Database. Besides, gene expression profiles and clinical information from The Cancer Genome Atlas (TCGA) were selected to identify the prognostic OSRGs. Moreover, univariate Cox regression, LASSO, and multivariate Cox regression analyses were conducted sequentially to establish a prognostic signature, which was later validated in three independent Gene Expression Omnibus (GEO) datasets. Next, gene set enrichment analysis (GSEA) and tumor mutation burden (TMB) analysis were performed. Afterwards, immune checkpoint genes (ICGs) and the tumor immune dysfunction and exclusion (TIDE) algorithm, together with IMvigor210 and GSE78220 cohorts, were applied to comprehensively explore the role of OSRG signature in immunotherapy. Further, the CellMiner and Genomics of Drug Sensitivity in Cancer (GDSC) databases were also applied in investigating the significance of OSRG signature in chemotherapy. Results. Altogether, 34 prognostic OSRGs were identified, among which 14 were chosen to establish the most valuable prognostic signature. The Kaplan‐Meier (KM) analysis suggested that patients with lower OS‐related risk score had better prognosis. The area under the curve (AUC) values were 0.71, 0.76, and 0.85 in 3, 5, and 7 years separately, and the stability of this prognostic signature was confirmed in three GEO datasets. As revealed by GSEA and TMB analysis results, OC patients in low‐risk group might have better immunotherapeutic response, which was consistent with ICG expression and TIDE analyses. Moreover, both IMvigor210 and GSE78220 cohorts demonstrated that patients with lower OS‐related risk score were more likely to benefit from anti‐PD‐1/L1 immunotherapy. In addition, the association between prognostic signature and drug sensitivity was explored. Conclusion. According to our results in this work, OSRG signature can act as a powerful prognostic predictor for OC, which contributes to generating more individualized therapeutic strategies for OC patients.

Dietary Vitamin A Intake and Circulating Vitamin A Concentrations and the Risk of Three Common Cancers in Women: A Meta‐Analysis

Background. According to relevant clinical research, dietary and circulating antioxidants vitamin A are connected with the risk of breast, cervical, and ovarian cancer in women. However, there was inconsistency between the findings. We completed this meta‐analysis at the right moment to address this contradiction of the problem. Methods. Web of Science, Embase, and PubMed databases were searched using the proposed search strategy and filtered using the inclusion and exclusion criteria as well as the NOS quality score. As of May 2022, low intake or low concentration was used as a control, and odds ratio (OR) or relative risk (RR) and ninety‐five percent confidence intervals (95% CI) were extracted for high intake. Stata 12.0 was used to process the data. Results. Our meta‐analysis included a total of 49 studies, 29 on breast cancer, 10 on ovarian cancer, and 10 on cervical cancer. There were 38 case‐control studies included, with 25,363 cases and 42,281 controls; there were 11 cohort studies included, 1,334,176 individuals were followed up, and finally 9496 obtained cancer. The pooled OR value results were as follows: diet or supplements (OR = 0.83, 95% CI 0.76‐0.90, I2 = 56.1%) and serum or plasma (OR = 0.96, 95% CI 0.86‐1.09, I2 = 29.5%). Subgroup analyses were performed according to cancer type, diet or supplements, serum or plasma, study type, and geographic regions. Conclusions. In North American and Asian populations, high dietary consumption of vitamin A or supplements decreases the incidence of three cancers in women, with breast and ovarian cancers being more significant. However, high circulating vitamin A concentrations were not significantly connected with the risk of the three malignancies.

[Retracted] Automatic Detection and Segmentation of Ovarian Cancer Using a Multitask Model in Pelvic CT Images

Ovarian cancer is one of the most common malignant tumours of female reproductive organs in the world. The pelvic CT scan is a common examination method used for the screening of ovarian cancer, which shows the advantages in safety, efficiency, and providing high‐resolution images. Recently, deep learning applications in medical imaging attract more and more attention in the research field of tumour diagnostics. However, due to the limited number of relevant datasets and reliable deep learning models, it remains a challenging problem to detect ovarian tumours on CT images. In this work, we first collected CT images of 223 ovarian cancer patients in the Affiliated Hospital of Qingdao University. A new end‐to‐end network based on YOLOv5 is proposed, namely, YOLO‐OCv2 (ovarian cancer). We improved the previous work YOLO‐OC firstly, including balanced mosaic data enhancement and decoupled detection head. Then, based on the detection model, a multitask model is proposed, which can simultaneously complete the detection and segmentation tasks.

PHGDH Inhibitor CBR‐5884 Inhibits Epithelial Ovarian Cancer Progression via ROS/Wnt/β‐Catenin Pathway and Plays a Synergistic Role with PARP Inhibitor Olaparib

PHGDH attaches importance to serine biosynthesis in cancer cells and maintaining mitochondrial redox homeostasis. However, the role of PHGDH inhibitor CBR‐5884 in cell ROS level and its downstream pathways has not been explored in epithelial ovarian cancer. Thus, we investigated the function and possible mechanism of PHGDH inhibitor CBR‐5884 on epithelial ovarian cancer in vitro and in vivo. A2780, OVCAR3, and ES‐2 were treated with CBR‐5884 at different concentrations or different time points. Results showed that CBR‐5884 inhibited epithelial ovarian cancer cell proliferation, migration, and invasion and increases cell ROS level. Meanwhile, CBR‐5884 exerts antitumor effect through activating ROS/Wnt/β‐catenin pathway. Besides, CBR‐5884 exerts antitumor effect in vivo. What’s more, we explored the effect of CBR‐5884 with or without PARP inhibitor Olaparib, which showed that the two together had a larger effect. In conclusion, PHGDH inhibitor CBR‐5884 inhibits epithelial ovarian cancer proliferation, migration, and invasion through activating ROS/Wnt/β‐catenin pathway and plays a synergistic role with PARP inhibitor olaparib, which provided a theoretical basis for PHGDH inhibitor CBR‐5884 in clinical treatment.

[Retracted] Network Pharmacology, Molecular Docking, and Experimental Validation to Unveil the Molecular Targets and Mechanisms of Compound Fuling Granule to Treat Ovarian Cancer

Background. Compound fuling granule (CFG) is a traditional Chinese medicine formula that is used for more than twenty years to treat ovarian cancer (OC) in China. However, the underlying processes have yet to be completely understood. This research is aimed at uncovering its molecular mechanism and identifying possible therapeutic targets. Methods. Significant genes were collected from Therapeutic Target Database and Database of Gene‐Disease Associations. The components of CFG were analyzed by LC‐MS/MS, and the active components of CFG were screened according to their oral bioavailability and drug‐likeness index. The validated targets were extracted from PharmMapper and PubChem databases. Venn diagram and STRING website diagrams were used to identify intersection targets, and a protein–protein interaction network was prepared using STRING. The ingredient‐target network was established using Cytoscape. Molecular docking was performed to visualize the molecule–protein interactions using PyMOL 2.3. Enrichment and pathway analyses were performed using FunRich software and Reactome pathway, respectively. Experimental validations, including CCK‐8 assay, wound‐scratch assay, flow cytometry, western blot assay, histopathological examination, and immunohistochemistry, were conducted to verify the effects of CFG on OC cells. Results. A total of 56 bioactive ingredients of CFG and 185 CFG‐OC‐related targets were screened by network pharmacology analysis. The potential therapeutic targets included moesin, glutathione S‐transferase kappa 1, ribonuclease III (DICER1), mucin1 (MUC1), cyclin‐dependent kinase 2 (CDK2), E1A binding protein p300, and transcription activator BRG1. Reactome analysis showed 51 signaling pathways (P < 0.05), and FunRich revealed 44 signaling pathways that might play an important role in CFG against OC. Molecular docking of CDK2 and five active compounds (baicalin, ignavine, lactiflorin, neokadsuranic acid B, and deoxyaconitine) showed that baicalin had the highest affinity to CDK2. Experimental approaches confirmed that CFG could apparently inhibit OC cell proliferation and migration in vitro; increase apoptosis; decrease the protein expression of MUC1, DICER1, and CDK2; and suppress the progression and distant metastasis of OC in vivo. DICER1, a tumor suppressor, is essential for microRNA synthesis. Our findings suggest that CFG may impair the production of miRNAs in OC cells. Conclusion. Based on network pharmacology, molecular docking, and experimental validation, the potential mechanism underlying the function of CFG in OC was explored, which supplies the theoretical groundwork for additional pharmacological investigation.

A Redox‐active Mn Porphyrin, MnTnBuOE‐2‐PyP5+, Synergizes with Carboplatin in Treatment of Chemoresistant Ovarian Cell Line

We have employed a redox‐active MnP (MnTnBuOE‐2‐PyP5+, Mn(III) meso‐tetrakis (N‐n‐butoxyethylpyridinium‐2‐yl) porphyrin) frequently identified as superoxide dismutase mimic or BMX‐001, to explore the redox status of normal ovarian cell in relation to two ovarian cancer cell lines: OV90 human serous ovarian cancer cell and chemotherapy‐resistant OV90 cell (OVCD). We identified that OVCD cells are under oxidative stress due to high hydrogen peroxide (H2O2) levels and low glutathione peroxidase and thioredoxin 1. Furthermore, OVCD cells have increased glycolysis activity and mitochondrial respiration when compared to immortalized ovarian cells (hTER7) and parental cancer cells (OV90). Our goal was to study how ovarian cell growth depends upon the redox state of the cell; hence, we used MnP (BMX‐001), a redox‐active MnSOD mimetic, as a molecular tool to alter ovarian cancer redox state. Interestingly, OVCD cells preferentially uptake MnP relative to OV90 cells which led to increased inhibition of cell growth, glycolytic activity, OXPHOS, and ATP, in OVCD cells. These effects were further increased when MnP was combined with carboplatin. The effects were discussed with regard to the elevation in H2O2 levels, increased oxidative stress, and reduced Nrf2 levels and its downstream targets when cells were exposed to either MnP or MnP/carboplatin. It is significant to emphasize that MnP protects normal ovarian cell line, hTER7, against carboplatin toxicity. Our data demonstrate that the addition of MnP‐based redox‐active drugs may be used (via increasing excessively the oxidative stress of serous ovarian cancer cells) to improve cancer patients’ chemotherapy outcomes, which develop resistance to platinum‐based drugs.

Glycosylation‐Related Genes Predict the Prognosis and Immune Fraction of Ovarian Cancer Patients Based on Weighted Gene Coexpression Network Analysis (WGCNA) and Machine Learning

Background. Ovarian cancer (OC) is a malignancy exhibiting high mortality in female tumors. Glycosylation is a posttranslational modification of proteins but research has failed to demonstrate a systematic link between glycosylation‐related signatures and tumor environment of OC. Purpose. This study is aimed at developing a novel model with glycosylation‐related messenger RNAs (GRmRNAs) to predict the prognosis and immune function in OC patients. Methods. The transcriptional profiles and clinical phenotypes of OC patients were collected from the Gene Expression Omnibus and The Cancer Genome Atlas databases. A weighted gene coexpression network analysis and machine learning were performed to find the optimal survival‐related GRmRNAs. Least absolute shrinkage and selection operator regression (LASSO) and Cox regression were carried out to calculate the coefficients of each GRmRNA and compute the risk score of each patient as well as develop a prognostic model. A nomogram model was constructed, and several algorithms were used to investigate the relationship between risk subtypes and immune‐infiltrating levels. Results. A total of four signatures (ALG8, DCTN4, DCTN6, and UBB) were determined to calculate the risk scores, classifying patients into the high‐and low‐risk groups. High‐risk patients exhibited significantly poorer survival outcomes, and the established nomogram model had a promising prediction for OC patients’ prognosis. Tumor purity and tumor mutation burden were negatively correlated with risk scores. In addition, risk scores held statistical associations with pathway signatures such as Wnt, Hippo, and reactive oxygen species, and nonsynonymous mutation counts. Conclusion. The currently established risk scores based on GRmRNAs can accurately predict the prognosis, the immune microenvironment, and the immunotherapeutic efficacy of OC patients.

Inhibition of Uncoupling Protein 2 Enhances the Radiosensitivity of Cervical Cancer Cells by Promoting the Production of Reactive Oxygen Species

Objective . The mechanism of enhanced radiosensitivity induced by mitochondrial uncoupling protein UCP2 was investigated in HeLa cells to provide a theoretical basis as a novel target for cervical cancer treatment. Methods . HeLa cells were irradiated with 4 Gy X-radiation at 1.0 Gy/min. The expression of UCP2 mRNA and protein was assayed by real-time quantitative polymerase chain reaction and western blotting. UCP2 siRNA and negative control siRNA fragments were constructed and transfected into HeLa cells 24 h after irradiation. The effect of UCP2 silencing and irradiation on HeLa cells was determined by colony formation, CCK-8 cell viability, γ H2AX immunofluorescence assay of DNA damage, Annexin V-FITC/PI apoptosis assay, and propidium iodide cell cycle assay. The effects on mitochondrial structure and function were investigated with fluorescent probes including dichlorodihydrofluorescein diacetate (DCFH-DA) assay of reactive oxygen species (ROS), rhodamine 123, and MitoTracker Green assay of mitochondrial structure and function. Results . Irradiation upregulated UCP2 expression, and UCP2 knockdown decreased the survival of irradiated HeLa cells. UCP2 silencing sensitized HeLa cells to irradiation-induced DNA damage and led to increased apoptosis, cell cycle arrest in G2/M, and increased mitochondrial ROS. Increased radiosensitivity was associated with an activation of P53, decreased Bcl-2, Bcl-xl, cyclin B, CDC2, Ku70, and Rad51 expression, and increased Apaf-1, cytochrome c, caspase-3, and caspase-9 expression. Conclusions . UCP2 inhibition augmented the radiosensitivity of cervical cancer cells, and it may be a potential target of radiotherapy of advanced cervical cancer.

The Cyr61 Is a Potential Target for Rotundifuran, a Natural Labdane‐Type Diterpene from Vitex trifolia L., to Trigger Apoptosis of Cervical Cancer Cells

Cervical cancer is a common female malignant tumor that seriously threatens human health. This study explored the anticervical cancer effects and potential mechanisms of Rotundifuran (RTF), a natural product isolated from Vitex trifolia L. In this study, we found that RTF can suppress the proliferation of cervical cancer cell lines, including HeLa and SiHa cells (with the IC50 less than 10 μM), via induction of apoptosis in vitro, and the antitumor effect of RTF is further confirmed on the HeLa cell‐inoculated xenograft model. In addition, our results proved that the antitumor effects of RTF might be related with the reactive oxygen species‐ (ROS‐) induced mitochondrial‐dependent apoptosis through MAPK and PI3K/Akt signal pathways. Using proteomics analysis and the drug affinity responsive target stability‐ (DARTS‐) combined mass spectrometry (DARTS‐MS), Cyr61 was indicated as a potential target for RTF in cervical cancer cells. Our present study would be beneficial for the development of RTF as a candidate for treatment of cervical cancer in the future.

[Retracted] Identification of Oxidative Stress‐Associated Molecular Subtypes and Signature for Predicting Survival Outcome of Cervical Squamous Cell Carcinoma

Background . Cervical squamous cell carcinoma (CESC) is the gynecologic malignancy with high incidence rate and high mortality rate. Oxidative stress participates in gene regulation and malignant tumor progression, including CESC. Methods . RNA‐seq, clinical information, and genomic mutation were from The Cancer Genome Atlas‐ (TCGA‐) CESC and GSE44001 datasets. Oxidative stress‐related genes were obtained from the gene set enrichment analysis (GSEA) website. ConsensusClusterPlus was used for clustering, which was assessed by the Kaplan‐Meier (KM) survival curve analysis, mutation analysis, immunocharacteristic analysis, and therapy. Prognostic signatures were built by combining weighted correlation network analysis (WGCNA), least absolute shrinkage and selection operator (LASSO) algorithm, and stepAIC. The prognostic power of this model was evaluated using the KM survival curve analysis, receiver operating characteristic (ROC) curve analysis, nomogram, and decision curve analysis (DCA). Results . 218 of the 291 CESC cases (74.91%) presented oxidative stress‐related gene mutation, especially FBXW7. Three clusters were determined based on oxidative stress‐related genes, among which cluster 3 (C3) presented low‐frequency mutation and hyperimmune state and was sensitive to immunotherapy. This research developed a 5‐gene oxidative stress‐related prognostic signature and a RiskScore model. As shown by ROC analysis, in the TCGA and GSE44001 datasets, the RiskScore model showed a high prediction accuracy for 1‐, 3‐, and 5‐year CESC overall survival. High RiskScore was associated with enhanced immune status. The nomogram model was greatly predictive of the overall survival of CESC patients. Conclusion . Our prognostic model was based on oxidative stress‐related genes in CESC, potentially aids in CESC prognosis, and provides potential targets against CESC.

Human Papillomavirus Type 16 Early Protein E7 Activates Autophagy through Inhibition of Dual‐Specificity Phosphatase 5

Consistent high‐risk human papillomavirus (HPV) infection leads to various malignant cancers. Autophagy can promote cancer progression by helping cancer cells survive under stress or induce oncogenic effects when mutations or abnormalities occur. Mitogen activated protein kinases (MAPKs) can transduce various external or intrinsic stimuli into cellular responses, including autophagy, and dual‐specificity phosphates (DUSPs) contribute to the direct regulation of MAPK activities. Previously, we showed that expression of DUSP5 was repressed in HPV16 E7‐expressing normal human epidermal keratinocytes (NHEKs). Here we show that clinical HPV16 E7‐positive precancerous and cancerous tissues also demonstrate low DUSP5 levels compared with control tissues, indicating that the inverse correlation between HPV16 E7 and DUSP5 is clinically relevant. We furthermore investigated the autophagy response in both DUSP5‐deficient and HPV16 E7‐expressing NHEKs. Confocal microscopy and Western analysis showed induction of LC3‐II levels, autophagosome formation and autophagy fluxes in DUSP5‐deficient NHEKs. Furthermore, Western analysis demonstrated specific induction of phosphorylated ERK in DUSP5‐deficient and HPV16 E7‐expressing NHEKs, indicating that HPV16 E7‐mediated repression of DUSP5 results in induced MAPK/ERK signaling. Finally, phosphorylated mTOR and ULK (S757) were reduced in DUSP5‐deficient NHEKs, while phosphorylated ULK (S555) and AMPK were increased, thereby inducing canonical autophagy through the mTOR and AMPK pathways. In conclusion, our results demonstrate that HPV16 E7 expression reduces DUSP5 levels, which in turn results in active MAPK/ERK signaling and induction of canonical autophagy through mTOR and MAPK regulation. Given its demonstrated inverse correlation with clinical cancerous tissues, DUSP5 may serve as a potential therapeutic target for cervical cancer.

HNF4A Regulates the Proliferation and Tumor Formation of Cervical Cancer Cells through the Wnt/β‐Catenin Pathway

Hepatocyte nuclear factor 4 alpha (HNF4A) is a transcriptional factor which plays an important role in the development of the liver, kidney, and intestines. Nevertheless, its role in cervical cancer and the underlying mechanism remain unknown. In this study, both immunohistochemistry and western blotting revealed that the expression of HNF4A was downregulated in cervical cancer. Xenograft assays suggested that HN4A could inhibit tumorigenic potential of cervical cancer in vivo. Functional studies illustrated that HNF4A also inhibited the proliferation and viability of cervical cancer cells in vitro. In addition, FACS analysis implied that HNF4A could induce cell cycle arrest from the G0/G1 phase to S phase. Further studies suggested that HNF4A downregulated the activity of the Wnt/β‐catenin pathway. Altogether, our data demonstrated that HNF4A inhibited tumor formation and proliferation of cervical cancer cells through suppressing the activity of the Wnt/β‐catenin pathway.

lncRNA SNHG15 Induced by SOX12 Promotes the Tumorigenic Properties and Chemoresistance in Cervical Cancer via the miR‐4735‐3p/HIF1a Pathway

Cervical cancer (CC) is one of the most common malignancies in females, with high prevalence and mortality globally. Despite advances in diagnosis and therapeutic strategies developed in recent years, CC is still a major health burden worldwide. The molecular mechanisms underlying the development of CC need to be understood. In this study, we aimed to demonstrate the role of lncRNA SNHG15 in CC progression. Using qRT‐PCR, we determined that lncRNA SNHG15 is highly expressed in CC tumor tissues and cells. lncRNA SNHG15 knockdown also reduces the tumorigenic properties of CC in vitro, as determined using the MTT, EdU, flow cytometry, and transwell assays. Using bioinformatics analysis, RNA pull‐down, ChIP, and luciferase reporter assays, we verified the molecular mechanisms of lncRNA SNHG15 in CC progression and found that lncRNA SNHG15 expression in CC cells is transcriptionally regulated by SOX12; moreover, lncRNA SNHG15 promotes CC progression via the miR‐4735‐3p/HIF1a axis. This study can provide a potential target for CC diagnosis or therapeutic strategies in the future.

Glaucocalyxin B Attenuates Ovarian Cancer Cell Growth and Cisplatin Resistance In Vitro via Activating Oxidative Stress

Ovarian cancer is one of the fatal gynecological cancers around the world. Cisplatin is the first‐line chemotherapy drug for the clinical treatment of ovarian cancer. However, many patients with ovarian cancer are still suffering from resistance to cisplatin. Therefore, the new drug combinations or treatment strategies for ovarian cancer are urgently needed. Glaucocalyxin B (GLB), a diterpenoid isolated from the aerial parts of Rabdosia japonica, has shown antitumor activity in some tumors. However, the mechanisms by which GLB inhibits ovarian cancer remain unclear. In the present study, we showed that GLB potently inhibits ovarian cancer cell growth in a dose‐dependent manner. Furthermore, we found that GLB has a notably synergistic antitumor effect with cisplatin. Mechanistically, we found that GLB enhances the sensitivity of ovarian cancer cells to cisplatin via increasing reactive oxygen species (ROS) levels, the phosphorylation of c‐Jun N‐terminal kinase (JNK), and DNA damage. Interestingly, a synergistic inhibitory effect of GLB with cisplatin was also observed in the cells which were resistance to cisplatin. Together, these data suggest that GLB can sensitize ovarian cancer cells to cisplatin by increasing ROS levels.