The FASEB Journal

METTL3 's role in cervical cancer development through m 6 A modification

Abstract N6‐methylated adenosine (m 6 A) is a crucial RNA modification in eukaryotes, particularly in cancer. However, its role in cervical cancer (CC) is unclear. We aimed to elucidate the part of m 6 A in CC by analyzing methyltransferase‐like 3 (METTL3) expression, identifying downstream targets, and exploring the underlying mechanism. We assessed METTL3 expression in CC using western blotting, quantitative polymerase chain reaction (qPCR), and immunohistochemistry. In vitro and in vivo experiments examined METTL3's role in CC. We employed RNA sequencing, methylated RNA immunoprecipitation sequencing, qPCR, and RNA immunoprecipitation qPCR to explore METTL3's mechanism in CC. METTL3 expression was upregulated in CC, promoting cell proliferation and metastasis. METTL3 knockdown inhibited human cervical cancer by inactivating AKT/mTOR signaling pathway. METTL3‐mediated m 6 A modification was observed in CC cells, targeting phosphodiesterase 3A (PDE3A). METTL3 catalyzed m 6 A modification on PDE3A mRNA through YTH domain family protein 3 (YTHDF3). Our study indicated the mechanism of m 6 A modification in CC and suggested the METTL3/YTHDF3/PDE3A axis as a potential clinical target for CC treatment.

Cuproptosis inhibits tumor progression and enhances cisplatin toxicity in ovarian cancer

Abstract Cuproptosis is a novel form of regulated cell death triggered by copper ion and copper ionophore. While cuproptosis has been actively explored as a potential target for cancer therapy, its role in ovarian cancer (OC) still remains unclear. In this study, we demonstrate that cuproptosis inhibits OC cell proliferation, migration, and invasion through FDX1 regulation and suppresses tumor growth in a mouse model. We also confirm that cuproptosis enhances OC sensitivity to cisplatin treatment both in vivo and in vitro. Moreover, our findings reveal that cuproptosis affects cholesterol biosynthesis in OC cells, with cholesterol playing a crucial role in its cytotoxic effect. Taken together, our results elucidate the effect of cuproptosis in OC and suggest it as a promising therapeutic strategy.

Targeting KRAS in gynecological malignancies

Abstract Cervical, endometrial, and ovarian cancers stand prominently as the leading gynecological malignancies of the female reproductive system. The conventional therapeutic modalities for gynecological malignancies have predominantly encompassed surgery, chemotherapy, and radiotherapy. However, efficacy of these approaches remains limited in cases of relapse or drug resistance. KRAS is one of the most frequently mutated oncogenes in human cancers. The KRAS gene encodes a small guanosine triphosphatase protein that acts as a molecular switch for crucial intracellular signaling pathways. KRAS mutations are deeply involved in the occurrence and development of gynecological malignancies. The present review aims to expound upon the role of oncogenic KRAS as a biomarker, elucidating various therapeutic approaches under investigation targeting the KRAS pathway in gynecological tumors.

Ceramide synthase 2‐C 24:1 ‐ceramide axis limits the metastatic potential of ovarian cancer cells

Abstract Regulation of sphingolipid metabolism plays a role in cellular homeostasis, and dysregulation of these pathways is involved in cancer progression. Previously, our reports identified ceramide as an anti‐metastatic lipid. In the present study, we investigated the biochemical alterations in ceramide‐centered metabolism of sphingolipids that were associated with metastatic potential. We established metastasis‐prone sublines of SKOV3 ovarian cancer cells using an in vivo selection method. These cells showed decreases in ceramide levels and ceramide synthase (CerS) 2 expression. Moreover, CerS2 downregulation in ovarian cancer cells promoted metastasis in vivo and potentiated cell motility and invasiveness. Moreover, CerS2 knock‐in suppressed the formation of lamellipodia required for cell motility in this cell line. In order to define specific roles of ceramide species in cell motility controlled by CerS2, the effect of exogenous long‐ and very long‐chain ceramide species on the formation of lamellipodia was evaluated. Treatment with distinct ceramides increased cellular ceramides and had inhibitory effects on the formation of lamellipodia. Interestingly, blocking the recycling pathway of ceramides by a CerS inhibitor was ineffective in the suppression of exogenous C 24:1 ‐ceramide for the formation of lamellipodia. These results suggested that C 24:1 ‐ceramide, a CerS2 metabolite, predominantly suppresses the formation of lamellipodia without the requirement for deacylation/reacylation. Moreover, knockdown of neutral ceramidase suppressed the formation of lamellipodia concomitant with upregulation of C 24:1 ‐ceramide. Collectively, the CerS2‐C 24:1 ‐ceramide axis, which may be countered by neutral ceramidase, is suggested to limit cell motility and metastatic potential. These findings may provide insights that lead to further development of ceramide‐based therapy and biomarkers for metastatic ovarian cancer.

Lysophosphatidic acid induces tumor necrosis factor‐alpha to regulate a pro‐inflammatory cytokine network in ovarian cancer

Abstract Epithelial ovarian carcinoma tissues express high levels of tumor necrosis factor‐alpha (TNF‐α) and other inflammatory cytokines. The underlying mechanism leading to the abnormal TNF‐α expression in ovarian cancer remains poorly understood. In the current study, we demonstrated that lysophosphatidic acid (LPA), a lipid mediator present in ascites of ovarian cancer patients, induced expression of TNF‐α mRNA and release of TNF‐α protein in ovarian cancer cells. LPA also induced expression of interleukin‐1β (IL‐1β) mRNA but no significant increase in IL‐1β protein was detected. LPA enhanced TNF‐α mRNA through NF‐κB‐mediated transcriptional activation. Inactivation of ADAM17, a disintegrin and metalloproteinase, with a specific inhibitor TMI‐1 or by shRNA knockdown prevented ovarian cancer cells from releasing TNF‐α protein in response to LPA, indicating that LPA‐mediated TNF‐α production relies on both transcriptional upregulations of the TNF‐α gene and the activity of ADAM17, the membrane‐associated TNF‐α‐converting enzyme. Like many other biological responses to LPA, induction of TNF‐α by LPA also depended on the transactivation of the epidermal growth factor receptor (EGFR). Interestingly, our results revealed that ADAM17 was also the shedding protease responsible for the transactivation of EGFR by LPA in ovarian cancer cells. To explore the biological outcomes of LPA‐induced TNF‐α, we examined the effects of a TNF‐α neutralizing antibody and recombinant TNF‐α soluble receptor on LPA‐stimulated expression of pro‐tumorigenic cytokines and chemokines overexpressed in ovarian cancer. Blockade of TNF‐α signaling significantly reduced the production of IL‐8, IL‐6, and CXCL1, suggesting a hierarchy of mechanisms contributing to the robust expression of the inflammatory mediators in response to LPA in ovarian cancer cells. In contrast, TNF‐α inhibition did not affect LPA‐dependent cell proliferation. Taken together, our results establish that the bioactive lipid LPA drives the expression of TNF‐α to regulate an inflammatory network in ovarian cancer.

LncRNA TMPO‐AS1 promotes LCN2 transcriptional activity and exerts oncogenic functions in ovarian cancer

Abstract Ovarian cancer remains the sixth most frequently occurring cancer in women worldwide. Long noncoding RNAs (lncRNAs) are capable of regulating gene expression, and thus, participating in a wide range of biological functions and disease processes including cancer development. Our work suggests that lncRNA TMPO antisense RNA 1 (TMPO‐AS1) represents an oncogenic lncRNA in ovarian cancer and presents a novel mechanism involving transcription factor E2F transcription factor 6 (E2F6) and lipocalin‐2 (LCN2). We identified upregulated lncRNA TMPO‐AS1 in ovarian cancer tissues and cells. siRNA‐mediated silencing of lncRNA TMPO‐AS1 restrained the aggressiveness of ovarian cancer cells and their pro‐angiogenic ability, and reduced the expression of LCN2. LncRNA TMPO‐AS1 was found to interact with E2F6, a transcriptional repressor that could bind to the promoter region of LCN2 gene. In addition, silencing of E2F6 or overexpression of LCN2 restored the aggressiveness of ovarian cancer cells and their pro‐angiogenic ability following siRNA‐mediated silencing of lncRNA TMPO‐AS1. Taken together, we demonstrated lncRNA TMPO‐AS1 could potentially promote LCN2 transcriptional activity by binding to transcription factor E2F6, and thus, stimulated the progression of ovarian cancer. These findings underscore a possible alternative therapeutic strategy for ovarian cancer treatment.

Reduced rDNA transcription diminishes skeletal muscle ribosomal capacity and protein synthesis in cancer cachexia

Abstract Muscle wasting in cancer is associated with deficits in protein synthesis, yet, the mechanisms underlying this anabolic impairment remain poorly understood. The capacity for protein synthesis is mainly determined by the abundance of muscle ribosomes, which is in turn regulated by transcription of the ribosomal (r)RNA genes (rDNA). In this study, we investigated whether muscle loss in a preclinical model of ovarian cancer is associated with a reduction in ribosomal capacity and was a consequence of impaired rDNA transcription. Tumor bearing resulted in a significant loss in gastrocnemius muscle weight and protein synthesis capacity, and was consistent with a significant reduction in rDNA transcription and ribosomal capacity. Despite the induction of the ribophagy receptor NUFIP1 mRNA and the loss of NUFIP1 protein, in vitro studies revealed that while inhibition of autophagy rescued NUFIP1, it did not prevent the loss of rRNA. Electrophoretic analysis of rRNA fragmentation from both in vivo and in vitro models showed no evidence of endonucleolytic cleavage, suggesting that rRNA degradation may not play a major role in modulating muscle ribosome abundance. Our results indicate that in this model of ovarian cancer‐induced cachexia, the ability of skeletal muscle to synthesize protein is compromised by a reduction in rDNA transcription and consequently a lower ribosomal capacity. Thus, impaired ribosomal production appears to play a key role in the anabolic deficits associated with muscle wasting in cancer cachexia.

Advances in natural products modulating autophagy influenced by cellular stress conditions and their anticancer roles in the treatment of ovarian cancer

Abstract Autophagy is a conservative catabolic process that typically serves a cell‐protective function. Under stress conditions, when the cellular environment becomes unstable, autophagy is activated as an adaptive response for self‐protection. Autophagy delivers damaged cellular components to lysosomes for degradation and recycling, thereby providing essential nutrients for cell survival. However, this function of promoting cell survival under stress conditions often leads to malignant progression and chemotherapy resistance in cancer. Consequently, autophagy is considered a potential target for cancer therapy. Herein, we aim to review how natural products act as key modulators of autophagy by regulating cellular stress conditions. We revisit various stressors, including starvation, hypoxia, endoplasmic reticulum stress, and oxidative stress, and their regulatory relationship with autophagy, focusing on recent advances in ovarian cancer research. Additionally, we explore how polyphenolic compounds, flavonoids, alkaloids, terpenoids, and other natural products modulate autophagy mediated by stress responses, affecting the malignant biological behavior of cancer. Furthermore, we discuss their roles in ovarian cancer therapy. This review emphasizes the importance of natural products as valuable resources in cancer therapeutics, highlighting the need for further exploration of their potential in regulating autophagy. Moreover, it provides novel insights and potential therapeutic strategies in ovarian cancer by utilizing natural products to modulate autophagy.

RPN1 Is Associated With Immunosuppression in Pan‐Cancer and Affects the Malignant Phenotype of Tumor

ABSTRACT Ribophorin 1 (RPN1), a key component of the oligosaccharyltransferase complex, is implicated in tumor progression through glycosylation‐mediated pathways, yet its pan‐cancer roles remain unexplored. This study presents a comprehensive multi‐omics analysis of RPN1 across 33 cancers such as sarcoma (SARC), integrating genomic, transcriptomic, and proteomic data from TCGA, GTEx, and CPTAC. RPN1 was significantly overexpressed in 14 malignancies and correlated with advanced tumor stages and poor prognosis in glioblastoma (GBM), lower‐grade glioma, SARC and hepatocellular carcinoma, validated in an independent glioma cohort ( n  = 151). Genomically, RPN1 amplification linked to homologous recombination deficiency and elevated tumor mutational burden, suggesting a role in genomic instability. Critically, multiplex immunofluorescence demonstrates RPN1 overexpression colocalizes with CD206 + M2 macrophages in tumor microenvironments, while in vitro coculture experiments confirm RPN1‐dependent microglial recruitment and M2 polarization. RPN1 expression negatively correlates with CD8 + T cell infiltration and predicts resistance to chemotherapy (GBM, ovarian cancer) and immunotherapy (GBM, esophageal carcinoma), though it associates with PD‐1 inhibitor sensitivity in bladder cancer. Functional validation shows RPN1 knockdown suppresses proliferation, migration, and invasion in GBM cells. Pathway enrichment connects RPN1 to endoplasmic reticulum stress, glycosylation, DNA repair, and immune checkpoint regulation. These findings position RPN1 as a multimodal oncogenic driver promoting genomic instability, immunosuppressive microenvironment remodeling, and context‐dependent therapeutic vulnerabilities across cancers.

The in vivo effects of knockdown of long non‐coding RNA XIST on fibroid growth and gene expression

Abstract The role of long non‐coding RNAs in fibroid pathogenesis remains largely unexplored. In a previous study, we found elevated XIST (X‐inactive specific transcript) levels in fibroids, which sponged miR‐29c and miR‐200c, leading to the overexpression of their target genes. This study aimed to assess the therapeutic potential of XIST downregulation in fibroid treatment. Ovariectomized SCID (severe combined immunodeficiency) mice were implanted with fibroid tumors transduced with XIST siRNA or a control via lentivirus. After 1 month, animals were sacrificed and the xenografts were removed for further analysis. XIST knockdown reduced tumor weight by 15% and increased miR‐29c and miR‐200c expression by 3.9‐fold and 2.2‐fold, respectively. The mRNA expression of miR‐29c targets ( COL3A1 , TGF‐β3 , CDK2 , SPARC ) and miR‐200c targets ( CDK2 , FN1 , TDO2 ), as well as PRL , E2F1 , and EZH2 , was significantly decreased. Protein abundance of collagen, COL3A1, FN1, CDK2, SPARC, and EZH2 was also reduced. IHC analysis of xenograft sections using the markers of Ki67 for cell proliferation and cleaved caspase 3 for apoptosis showed decreased cell proliferation and no changes in apoptosis in the XIST knockdown xenografts. This analysis also revealed decreased collagen and E2F1 staining nuclei in the XIST knockdown xenografts. These results indicate that downregulation of XIST in fibroids has beneficial therapeutic effects, by reducing tumor growth and the expression of genes involved in cell proliferation, inflammation, and extracellular matrix regulation.

Spatially restricted ecto‐5′‐nucleotidase expression promotes the growth of uterine leiomyomas by modulating Akt activity

Abstract Found in as many as 80% of women, uterine leiomyomas are a frequent cause of abnormal uterine bleeding, pelvic pain, and infertility. Despite their significant clinical impact, the mechanisms responsible for driving leiomyoma growth remain poorly understood. After obtaining IRB permission, expression of ecto‐5′‐nucleotidase ( NT5E, CD73 ) was assessed in matched specimens of myometrium and leiomyoma by real‐time qPCR, Western blot, and immunohistochemistry (IHC). Adenosine concentrations were measured by enzyme‐linked assay. Primary cultures were used to assess the impact of adenosine and/or adenosine receptor agonists on proliferation, apoptosis, and patterns of intracellular signaling in vitro. When compared to matched specimens of healthy myometrium, uterine leiomyomas were characterized by reduced CD73 expression. Largely limited to thin‐walled vascular structures and the pseudocapsule of leiomyomas despite diffuse myometrial distribution. Restricted intra‐tumoral CD73 expression was accompanied by decreased levels of intra‐tumoral adenosine. In vitro, incubation of primary leiomyoma cultures with adenosine or its hydrolysis‐resistant analog 2‐chloro‐adenosine (2‐CL‐AD) inhibited proliferation, induced apoptosis, and reduced proportion of myocytes in S‐ and G2‐M phases of the cell cycle. Decreased proliferation was accompanied by reduced expression of phospho‐Akt, phospho‐Cdk2‐Tyr15, and phospho‐Histone H3. Enforced expression of the A2B adenosine receptor (ADORA2B) and ADORA2B‐selective agonists similarly suppressed proliferation and inhibited Akt phosphorylation. Collectively, these observations broadly implicate CD73 and reduced extracellular concentrations of adenosine as key regulators of leiomyoma growth and potentially identify novel strategies for clinically managing these common tumors.

Remembering Sydney Brenner, in situ

Citric acid of ovarian cancer metabolite induces pyroptosis via the caspase‐4/TXNIP‐NLRP3‐GSDMD pathway in ovarian cancer

Abstract Malignant tumors display profound changes in cellular metabolism, yet how these altered metabolites affect the development and growth of tumors is not fully understood. Here, we used metabolomics to analyze the metabolic profile differences in ovarian cancer and found that citric acid (CA) is the most significantly downregulated metabolite. Recently, CA has been reported to inhibit the growth of a variety of tumor cells, but whether it is involved in pyroptosis of ovarian cancer and its potential molecular mechanisms still remains to be further investigated. Here, we demonstrated that CA inhibits the growth of ovarian cancer cells in a dose‐dependent manner. RNA‐seq analysis revealed that CA significantly promoted the expression of thioredoxin interacting protein (TXNIP) and caspase‐4 (CASP4). Morphologic examination by transmission electron microscopy indicated that CA‐treated ovarian cancer cells exhibited typical pyroptosis characteristics. Further mechanistic analyses showed that CA facilitates pyroptosis via the CASP4/TXNIP‐NLRP3‐Gesdermin‐d (GSDMD) pathway in ovarian cancer. This study elucidated that CA induces ovarian cancer cell death through classical and non‐classical pyroptosis pathways, which may be beneficial as an ovarian cancer therapy.

The role of Tim‐3/Galectin‐9 pathway in T‐cell function and prognosis of patients with human papilloma virus‐associated cervical carcinoma

Abstract The interaction between Tim‐3 on T cell and its ligand, Galectin‐9, negatively regulates cellular immune responses. However, the role of Tim‐3/Galectin‐9 pathway in the immune evasion of cervical cancer remains unknown. This study is to investigate the expression, function, and regulation of Tim‐3/Galectin‐9 signaling pathway in human papilloma virus (HPV) positive cervical cancer. Flow cytometry showed that Tim‐3 expression on T cell and Galectin‐9 expression on monocytes in HPV positive cervical cancer patients were significantly higher compared to cervical intraepithelial neoplasia and benign uterine fibroids Tim‐3 + CD4+ Th1 cells and Tim‐3 + CD8+ T cells in HPV positive cervical cancer patients were significantly reduced after surgery. Serum TGF‐β and IL‐10 levels were positively correlated with Tim‐3 + Treg cells, while IFN‐γ and IL‐2 were negatively correlated with Tim‐3 + Th1 cells. Additionally, Tim‐3 + CD4+ T cells were positively correlated with Galectin‐9 + monocytes. Survival curve analysis showed that Tim‐3 + CD4+ T cells were negatively correlated with patient survival, and closely related to FIGO stage, degree of differentiation, and lymph node metastasis of HPV positive cervical cancer. In vitro experiments showed that by blocking the Tim‐3/Galectin‐9 pathway, the proliferation of T cells and their ability to express IFN‐γ, IL‐2, perforin, and granzyme B was significantly restored. In conclusion, high levels of Tim‐3 and Galectin‐9 in HPV positive cervical cancer patients play roles in the progression of disease by promoting Treg cells to inhibit the cytotoxic function of Th1 and CD8+ T cells. Tim‐3/Galectin‐9 may serve as a new immunotherapy target for patients with HPV positive cervical cancer.

N‐Alpha‐Acetyltransferase 30, Transcriptionally Regulated by NR2C2 , Promotes Ovarian Cancer Progression by Mediating ARPC1B Acetylation

ABSTRACT N‐terminal acetyltransferases are emerging as potential therapeutic targets in cancer. N‐alpha‐acetyltransferase 30 (NAA30), which serves as the catalytic subunit of the NATC complex. However, the role of NAA30 in ovarian cancer remains unknown. In this study, we found that NAA30 expression was abnormally upregulated in ovarian cancer tissues compared to normal tissues. Functionally, NAA30 promoted cell proliferation, migration, and invasion in ovarian cancer cells. Moreover, in vivo experiments revealed that NAA30 enhanced tumor growth and intraperitoneal metastasis in mouse models. We further explored the regulatory mechanisms underlying NAA30 upregulation. Dual‐luciferase assays demonstrated that the transcription factor nuclear receptor subfamily 2 group C member 2 (NR2C2) significantly enhanced the transcriptional activity of the NAA30 promoter. Besides, NR2C2 increased the migratory, invasive, and proliferative capabilities of ovarian cancer cells. Importantly, NAA30 knockdown reversed the pro‐tumorigenic effects of NR2C2 overexpression on the malignant phenotype. To identify the downstream targets of NAA30, we employed IP‐LC/MS and N‐terminal acetylation modification omics. Actin‐Related Protein 2/3 Complex Subunit 1B (ARPC1B) was identified as a direct target of NAA30. It was demonstrated that NAA30 protein binds to ARPC1B protein and that NAA30 knockdown enhanced the polyubiquitination of ARPC1B and promotes its degradation. Crucially, the re‐expression of ARPC1B in NAA30‐silenced cells effectively restored these malignant phenotypes. These findings highlight the critical role of the NR2C2‐NAA30‐ARPC1B axis in ovarian cancer progression and provide more foundation for the development of more effective treatment strategies for patients with ovarian cancer.

SAA1 Induces TGF ‐β1 Secretion by Ovarian Cancer Cells, Leading to M2 Macrophage Polarization and Inhibition of NK Cell Activity

ABSTRACT Natural killer (NK) cells play an important role in immune surveillance of tumors. The molecular mechanism of NK cells killing ovarian cancer cells remains elusive. This study attempts to show a potential mechanism of NK cell killing by polarization of M2 macrophages. Serum amyloid A1 protein (SAA1) expression in ovarian cancer tissue and its correlation with macrophage markers and TGF‐β1 expression were analyzed using bioinformatics. TGF‐β1 levels were determined by western blot and ELISA. Immunohistochemistry, flow cytometry, and immunofluorescence were employed to analyze the expression of M1 and M2 macrophage markers and NK cell markers. NK cytotoxicity was assessed using the lactate dehydrogenase assay and ELISA. TUNEL staining was used to detect tumor cell apoptosis. The xenograft tumor mouse model was utilized to reveal the in vivo function of the SAA1/TGF‐β1 axis. SAA1 was upregulated in ovarian cancer and positively correlated with M2 macrophage marker expression. Overexpression of SAA1 upregulated M2 macrophage markers in mouse tumor tissue. In vitro experiments showed that SAA1 induced polarization of M2 macrophages, and this effect was reversed by anti‐TGF‐β1 treatment. SAA1 inhibited the expression of NK cell activity markers and cytotoxicity by mediating M2 macrophage polarization. Finally, we demonstrated in vivo that partial reversal of the effects of SAA1 overexpression on NK cell activity and M2 macrophage polarization was achieved through anti‐TGF‐β1 therapy. SAA1 repressed NK cell killing in ovarian cancer by facilitating M2 macrophage polarization through TGF‐β1. The findings suggested that SAA1 may be a target for ovarian cancer therapy.

Deubiquitinase OTUD4 Stabilizes SLC5A2 to Promote Pancreatic Cancer Proliferation and Migration Through Enchaining Glycolysis‐Mediated Autophagy

ABSTRACT Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy characterized by its insidious onset, rapid progression, and poor treatment outcomes. Sodium glucose transporter 2 (SLC5A2) is the predominant sodium‐glucose transporter. Our study reveals that SLC5A2 interacted with ovarian tumor family deubiquitinase 4 (OTUD4) to stabilize and increase its expression in PDAC. SLC5A2 overexpression promoted pancreatic cancer cell proliferation in vitro and in vivo, while also promoting cell migration, invasion, and autophagy. Conversely, SLC5A2 knockdown reversed these effects. RNA‐seq and GSEA revealed that glycolysis pathway activation was inhibited following SLC5A2 knockdown. Consistent with this, qRT‐PCR and western blot analyses indicated reduced glycolysis‐related gene expression levels. Metabolomics further revealed that knockdown of SLC5A2 decreased intermediate product levels in glycolysis, as well as glucose intake. Glycolysis inhibitor (2‐DG) amplified the effect of SLC5A2 knockdown in promoting autophagy, resulting in decreased pancreatic cancer proliferation, migration, and invasion. Notably, the antitumor effects of SLC5A2 knockdown were reversed by Bafilomycin A1. Additionally, treatment with the SLC5A2 inhibitor, canagliflozin (CANA), inhibited pancreatic cancer growth by inhibiting glycolysis and enhancing autophagy in vitro/vivo. These findings suggest that SLC5A2 promotes pancreatic cancer progression by regulating the glycolysis‐autophagy axis, suggesting it as a therapeutic target for improving PDAC treatment outcomes.

Spartin Promotes Smurf1‐Mediated Ubiquitination Modification of YWHAZ to Inhibit Cisplatin Resistance in Ovarian Cancer

ABSTRACT Cisplatin (DDP) remains the commonly used chemotherapeutic drug for ovarian cancer (OV); however, DDP resistance poses a great challenge to the outcomes of patients. This work investigated the biological function and mechanism of Spartin in DDP resistance of OV. The growth and apoptosis of DDP‐resistant OV cells were assessed by CCK‐8, colony formation, and flow cytometry, respectively. Autolysosome fusion was observed by immunofluorescent staining of LC3 and LAMP2. The interaction between E3 ligase Smurf1 and YWHAZ or Spartin protein, and the ubiquitination level of YWHAZ were determined by Co‐IP assay. Expression levels of autophagy or apoptosis‐related markers were measured by RT‐qPCR, western blotting, and immunohistochemistry. DDP resistance was assessed by xenograft tumor experiments in vivo. We found that Spartin expression was lower, while YWHAZ expression was higher in DDP‐resistant OV samples and cells. Lower expression of Spartin indicated a poorer survival rate of OV patients. In addition, overexpression of Spartin sensitized OV cells to DDP and repressed autophagy. Moreover, Spartin bound to Smurf1 to promote Smurf1‐mediated ubiquitination and degradation of YWHAZ, restraining autophagy and DDP resistance. Overexpression of YWHAZ counteracted the effects of Spartin against DDP resistance by promoting autophagy. In conclusion, Spartin‐induced Smurf1‐mediated ubiquitination modification of YWHAZ to inactivate autophagy, thereby increasing the sensitivity of OV cells to DDP. Our findings suggest that Spartin‐combined therapy might act as an effective approach to fight against DDP resistance in OV.

SETD5‐Coordinated LC3B Methylation Inhibits Autophagy in Ovarian Cancer

ABSTRACT MAP1LC3/LC3 is an essential autophagy regulator involved in both the formation of autophagosome and the recruitment of autophagy cargo. Although several post‐translational modifications (PTMs) have been identified to regulate the function of LC3, the effect of protein methylation on its function has not been well characterized. Here, we show that SETD5 interacts with and methylates nuclear LC3B (a member of the LC3 subfamily) at lysines 5 and 65, leading to its nuclear retention. In the nucleus of human ovarian cancer (OC) cells, methylated LC3B binds the nuclear transcription factor PRDM10 to the promoter regions of autophagy‐related genes (ATGs), including ATG2a , ATG7 , ATG12 , and ATG16L1 , to suppress their transcription, thereby resulting in reduced formation of autophagosomes. Moreover, the methylation of LC3B facilitates OC cell migration by inhibiting autophagy. Overall, our study defines a novel modification of LC3B and unveils a SETD5‐mediated methylation‐dependent regulatory mechanism controlling nuclear LC3B function in autophagy and migration in OC cells, offering potential therapeutic targets for OC.

Metformin Enhances PD ‐ L1 Inhibitor Efficacy in Ovarian Cancer by Modulating the Immune Microenvironment and RBMS3 Expression

ABSTRACT Ovarian cancer (OC) is associated with poor prognosis and immune evasion through PD‐L1 expression. While anti‐PD‐L1 therapies have shown limited efficacy, combination strategies may enhance therapeutic outcomes. This study explores the potential of metformin to modulate the immune microenvironment and improve the efficacy of PD‐L1 inhibitors in OC. An immunocompetent C57BL/6 mouse model of OC was used to evaluate the effects of metformin and PD‐L1 inhibitors on tumor progression, immune cell infiltration, and cytokine expression. Mice received daily metformin treatment for 2 weeks, with PD‐L1 inhibitors administered twice weekly. Tumor growth was monitored via volume measurements, immune cell infiltration was assessed by flow cytometry, and cytokine levels (Granzyme B, IFN‐γ) were quantified using ELISA. Metformin significantly reduced tumor growth, increased CD8 + T cell infiltration, upregulated RBMS3, and elevated Granzyme B and IFN‐γ expression. Additionally, metformin downregulated PD‐L1 expression, and its combination with PD‐L1 inhibitors further enhanced CD8 + T cell activity. Silencing RBMS3 reversed these effects, underscoring its critical role in immune modulation. These findings suggest that metformin, in combination with PD‐L1 inhibitors, may enhance antitumor immune responses and improve treatment outcomes in OC. Targeting RBMS3 could represent a novel therapeutic approach for overcoming immune evasion in OC.

TIPE2 inhibits the migration and invasion of epithelial ovarian cancer cells by targeting Smad2 to reverse TGF ‐β1‐induced EMT

Abstract Epithelial ovarian cancer is the deadliest gynecologic malignancy, characterized by high metastasis. Transforming growth factor‐β1 (TGF‐β1) drives epithelial‐ mesenchymal transformation (EMT), a key process in tumor metastasis. Tumor necrosis factor‐α‐induced protein 8 (TNFAIP8)‐like 2 (TIPE2) acts as a negative regulator of innate and adaptive immunity and involves in various cancers. However, its relationship with TGF‐β1 in ovarian cancer and its role in reversing TGF‐β1‐induced EMT remain unclear. This study examined TIPE2 mRNA and protein expression using quantitative RT‐PCR (qRT‐PCR), western blot and immunohistochemistry. The effects of TIPE2 overexpression and knockdown on the proliferation, migration and invasion of epithelial ovarian cancer cells were assessed through 5‐ethynyl‐2‐deoxyuridine, colony‐forming, transwell migration and invasion assays. The relationship between TIPE2 and TGF‐β1 was investigated using qRT‐PCR and enzyme‐linked immunosorbent assay, while the interaction between TIPE2 and Smad2 was identified via co‐immunoprecipitation. The results revealed that TIPE2 protein was significantly down‐regulated in epithelial ovarian cancer tissues and correlated with the pathological type of tumor, patients' age, tumor differentiation degree and FIGO stage. TIPE2 and TGF‐β1 appeared to play an opposite role to each other during the progression of human ovarian cancer cells. Furthermore, TIPE2 inhibited the metastasis and EMT of ovarian cancer cells by combining with Smad2 in vitro or in an intraperitoneal metastasis model. Consequently, these findings suggest that TIPE2 plays a crucial inhibitory role in ovarian cancer metastasis by modulating the TGF‐β1/Smad2/EMT signaling pathway and may serve as a potential target for ovarian cancer, providing important direction for future diagnostic and therapeutic strategies.

THUMPD3‐AS1 inhibits ovarian cancer cell apoptosis through the miR‐320d/ARF1 axis

Abstract Ovarian cancer is one of the most common gynecologic malignancies that has a poor prognosis. THUMPD3‐AS1 is an oncogenic long noncoding RNA (lncRNA) in several cancers. Moreover, miR‐320d is downregulated and inhibited proliferation in ovarian cancer cells, whereas ARF1 was upregulated and promoted the malignant progression in epithelial ovarian cancer. Nevertheless, the role of THUMPD3‐AS1 in ovarian cancer and the underlying mechanism has yet to be elucidated. Human normal ovarian epithelial cells (IOSE80) and ovarian cancer cell lines (CAVO3, A2780, SKOV3, OVCAR3, and HEY) were adopted for in vitro experiments. The functional roles of THUMPD3‐AS1 in cell viability and apoptosis were determined using CCK‐8, flow cytometry, and TUNEL assays. Western blot was performed to assess the protein levels of ARF1 , Bax , Bcl‐2 , and caspase 3 , whereas RT‐qPCR was applied to measure ARF1 mRNA, THUMPD3‐AS1 , and miR‐320d levels. The targeting relationship between miR‐320d and THUMPD3‐AS1 or ARF1 was validated with dual luciferase assay. THUMPD3‐AS1 and ARF1 were highly expressed in ovarian cancer cells, whereas miR‐320d level was lowly expressed. THUMPD3‐AS1 knockdown was able to repress cell viability and accelerate apoptosis of OVCAR3 and SKOV3 cells. Also, THUMPD3‐AS1 acted as a sponge of miR‐320d , preventing the degradation of ARF1 . MiR‐320d downregulation reversed the tumor suppressive function induced by THUMPD3‐AS1 depletion. Additionally, miR‐320d overexpression inhibited ovarian cancer cell viability and accelerated apoptosis, which was overturned by overexpression of ARF1 . THUMPD3‐AS1 inhibited ovarian cancer cell apoptosis by modulation of miR‐320d / ARF1 axis. The discoveries might provide a prospective target for ovarian cancer treatment.

Multi‐Omics Data Reveal Estrogen‐Driven Dysregulation and Stromal‐Epithelial Signaling Alterations in Endometrial Polyps

ABSTRACT Endometrial polyps (EPs) are common uterine lesions associated with abnormal uterine bleeding and infertility, yet their pathogenesis remains poorly defined. Here, we performed single‐cell RNA sequencing of normal endometrium, para‐polyp, and polyp tissues, identifying distinct cellular compositions and transcriptional programs. EPs showed enhanced estrogen signaling and increased epithelial proliferation, accompanied by decreased expression of cytokines and reduced T cell cytotoxicity. Notably, we observed epithelial subpopulations with elevated copy number variations and transcription factors associated with hyperplasia. Cell–cell communication analyzes revealed aberrant stromal‐epithelial crosstalk, characterized by upregulated WNT, IGF, and VEGF signaling originating from stromal cells. Spatial transcriptomic analyzes further demonstrated enhanced WNT signaling between stromal and epithelial compartments in endometrial cancer. In vitro glandular organoid models showed that epithelial transcriptional alterations contribute to polyp formation. These findings highlight a critical role of stromal‐epithelial interactions in EP development and suggest potential therapeutic targets.

GSTO1 Promotes Cell Proliferation and Stemness of Cervical Cancer via Activating PI3K / AKT / mTOR Pathway

ABSTRACT Glutathione S‐transferase omega 1 (GSTO1) is overexpressed in a variety of cancers and plays an important role in the promotion of tumor proliferation and metastasis. Nevertheless, the function of GSTO1 in cervical cancer (CC) is unknown. Immunohistochemistry (IHC) was applied to observe GSTO1 protein levels in CC tissues. Cell proliferation, migration, and invasion capabilities were assessed using CCK8, EdU, plate cloning assays, and Transwell experiments in vitro. Flow cytometry was employed to analyze cell cycle progression and reactive oxygen species (ROS) levels. A subcutaneous xenograft model was utilized to observe cell growth in vivo. Cell stemness was assessed via sphere formation assay. Transcriptome sequencing and enrichment analysis were conducted to explore GSTO1‐related signaling pathways. The proteins linked to cell cycle regulation, stemness, epithelial‐mesenchymal transition (EMT), and the PI3K/AKT/mTOR signaling pathway were identified through western blotting and IHC. In this study, GSTO1 was highly expressed in CC tissues and associated with poor prognosis of patients. Knockdown of GSTO1 suppressed CC cell proliferation in vivo and in vitro and inhibited the cell cycle, stemness, migration, and EMT as in C1‐27 treatment. Conversely, down‐regulation of GSTO1 promoted ROS production in CC cells. RNA sequencing indicated that GSTO1 mediated the activation of the PI3K/AKT signaling pathway. In addition, silencing GSTO1 decreased the phosphorylation of PI3K, AKT, and mTOR proteins. Interestingly, 740 Y‐P (PI3K activator) reversed the inhibitory effects of GSTO1‐induced cell proliferation, cycle, stemness, and EMT via the PI3K/AKT/mTOR signaling axis. GSTO1 was important in CC progression through the PI3K/AKT/mTOR pathway and could serve as a promising therapeutic target.

IGF2BP2 promotes ovarian cancer growth and metastasis by upregulating CKAP2L protein expression in an m 6 A ‐dependent manner

Abstract Ovarian cancer (OC) is the second leading cause of gynecological cancer‐related death in women worldwide. N6‐methyladenosine (m 6 A) is the most abundant internal modification in eukaryotic RNA. Human insulin‐like growth factor 2 mRNA‐binding protein 2 (IGF2BP2), an m 6 A reader, can enhance mRNA stability and promote translation by recognizing m 6 A modifications. Its tumor‐promoting effects have been demonstrated in several cancers. However, the roles of m 6 A modification and IGF2BP2 in OC remain unclear. Here, by using methylated RNA immunoprecipitation sequencing, we demonstrated that there is widespread dysregulation of m 6 A modification in OC tissues. The m 6 A modification and the mRNA and protein levels of IGF2BP2 were significantly elevated in OC. Overexpression of IGF2BP2 facilitated OC cell proliferation, migration, and invasion in vitro and accelerated tumor growth and metastasis in vivo. While IGF2BP2‐knockdown showed the opposite effect. Mechanistically, we identified cytoskeleton‐associated protein 2‐like (CKAP2L) as a target of IGF2BP2. IGF2BP2 promoted CKAP2L translation dependent on m 6 A modification, rather than affecting mRNA and protein stability. Overexpression of CKAP2L rescued the tumor‐suppressive effect of IGF2BP2 knockdown in OC cells. In conclusion, this study revealed the potential role of IGF2BP2 in tumor progression, at least partially via promoting the translation of CKAP2L in an m 6 A‐dependent manner.

UTND Effect Mediates Macrophage Ferroptosis and Promotes Immune Microenvironment Remodeling of Ovarian Cancer

ABSTRACT Tumor‐associated macrophages (TAMs) act as a vital player in the immunosuppressive tumor microenvironment (TME) and have received widespread attention in the treatment of cancer in recent times. Nevertheless, simultaneously inducing TAM repolarization and strengthening their phagocytic ability on cancer cells is still a significant challenge. Ferroptosis has received widespread attention due to its lethal effects on tumor cells, but its role in TAMs and its impact on tumor progression have not yet been defined. Here, M2‐type tumor‐associated macrophages (M2‐TAMs) targeted nanobubbles (NBs)‐based (M2‐pep@SF‐NBs) were constructed for ultrasound‐controlled delivery of the ferroptosis agonist sorafenib (SF) to enhance macrophage‐mediated cancer immunotherapy. SF causes ferroptosis of M2 and regulates repolarization to M1 and promotes intratumoral (cytotoxic T lymphocyte) CTL infiltration, leading to activation of the TME that significantly inhibits tumor growth. Additionally, ultrasound (US)‐induced macrophage ferroptosis notably improved the effectiveness of anti‐PD‐1 (aPD‐1) therapy against tumors. M2‐pep@SF‐NBs were constructed to specifically target macrophage ferroptosis and repolarization, and combining this treatment with aPD‐1 exerted significant anti‐tumor efficacy. These findings lay the groundwork for deeper exploration of ferroptosis activation in TAMs and the regulation of their infiltration and function, aiming to enhance tumor prevention and therapeutic outcomes.

EM2, a Novel Elephantopus mollis H.B.K. Monomer, Enhances Radiosensitivity in Cervical Cancer Through Dual Inhibition of AKT and Autophagy

ABSTRACT Radiotherapy activates both the PI3K/AKT pathway and autophagy in cervical cancer, contributing to radioresistance. To address this, EM2, a dual AKT/autophagy inhibitor, was investigated for its potential to enhance radiosensitivity. RNA‐Seq, Western blot, qRT‐PCR, and transmission electron microscopy were employed to analyze PI3K/AKT and autophagy pathways following irradiation, while CCK8, clone formation, and flow cytometry assays evaluated proliferation, apoptosis, and cell cycle effects. KEGG and GSEA analyses confirmed irradiation‐induced activation of the PI3K/AKT pathway. Both PI3K and autophagy inhibitors significantly improved efficacy, whereas EM2 suppressed AKT pathway activation and autophagy, synergistically inducing G2/M phase arrest, and increasing apoptosis. In vivo experiments using a nude mouse xenograft model demonstrated that EM2 combined with irradiation effectively suppressed tumor growth, PI3K/AKT activation, and autophagy without significant toxicity. These results underscore EM2 as a promising therapeutic agent to overcome radioresistance by simultaneously targeting the PI3K/AKT pathway and autophagy.

CDK11 Promotes Paclitaxel Resistance in Cervical Cancer by Regulating LATS1 ‐Mediated Hippo Signaling Pathway Through Phosphorylation of NF2

ABSTRACT Paclitaxel (PTX) is a first‐line chemotherapeutic agent for cervical cancer, but resistance remains a major clinical challenge. This study investigates the role of cyclin‐dependent kinase 11 (CDK11) in mediating PTX resistance and explores its underlying molecular mechanisms. Cell viability, proliferation, and apoptosis were measured using CCK8, EdU staining, colony formation, and flow cytometry, respectively. The transcriptional activity of YAP/TEAD was assessed using a dual luciferase reporter gene assay, and LATS1 ubiquitination level was assessed using an IP assay. The binding relationships between CDK11, CCNL2, and NF2 were examined by co‐IP assay. PTX resistance was further investigated in xenograft mouse models. Our results showed that CDK11 expression was significantly elevated in PTX‐resistant cervical cancer tissues and cells, and its knockdown markedly reduced PTX resistance in cervical cancer cells. Mechanically, CDK11 inactivated the Hippo signaling pathway by promoting CRL4‐mediated LATS1 ubiquitination degradation. Additionally, the CDK11/CCNL2 complex inactivated the Hippo signaling pathway by phosphorylating NF2 at the S518 site and further reducing the binding of NF2 and CRL4 in the nucleus. Finally, in vivo xenograft experiments validated that CDK11 knockdown sensitized cervical cancer cells to PTX by activating the Hippo signaling pathway through inhibiting NF2 phosphorylation at the S518 site. In conclusion, the CDK11/CCNL2 complex promoted PTX resistance in cervical cancer by phosphorylating NF2 at the S518 site, which further reduced the binding of NF2 and CRL4 in the nucleus and inactivated the Hippo signaling pathway by promoting CRL4‐mediated LATS1 ubiquitination degradation.

TCEB3 initiates ovarian cancer apoptosis by mediating ubiquitination and degradation of MCL‐1

Abstract Platinum resistance remains a major contributor to the poor prognosis of ovarian cancer. Anti‐apoptotic protein myeloid cell leukemia‐1 (MCL‐1) has emerged as a promising target for overcoming drug resistance, but different cancer cells utilize distinct protein degradation pathways to alter MCL‐1 level. We systematically investigated E3 ligases to identify novel candidates that mediate platinum resistance in ovarian cancer. Transcription Elongation Factor B (TCEB3) has been identified as a novel E3 ligase recognition subunit that targets MCL‐1 in the cytoplasm during platinum treatment other than its traditional function of targeting the Pol II in the nuclear compartment. TCEB3 expression is downregulated in platinum‐resistant cell lines and this low expression is associated with poor prognosis. The ubiquitination of MCL‐1 induced by TCEB3 leads to cell death in ovarian cancer. Moreover, platinum treatment increased the cytoplasm proportion of TCEB3, and the cytoplasm localization of TCEB3 is important for its targeting of MCL‐1. This study emphasizes the dual function of TCEB3 in homeostasis maintenance and in cell fate determination under different conditions, and provides a new insight into drug resistance in ovarian cancer.

Uterine carcinosarcoma: Unraveling the role of epithelial‐to‐mesenchymal transition in progression and therapeutic potential

Abstract Uterine carcinosarcoma (UCS) is a rare and highly aggressive gynecological malignancy characterized by poor prognosis. Due to its rarity, UCS remains relatively unexplored, and specific treatment guidelines are scarce. Despite standard treatments, including surgery, adjuvant chemotherapy, and radiotherapy, UCS has a high recurrence rate and poor overall prognosis. The aggressive nature of UCS is attributed to the metaplastic transformation of carcinomatous elements into sarcoma. This “biphasic” neoplasm features a mixture of epithelial and mesenchymal/tumor components, which partially share molecular signatures and exhibit a typical epithelial‐to‐mesenchymal transition (EMT) gene expression profile. Recent scientific advancements have highlighted the pivotal role of EMT in UCS progression and mortality. This review covers the epidemiology of UCS, theories regarding its origin, and the current state of clinical trials with more emphasis on the role of EMT drivers in UCS progression and scope of targeting these molecules. By shedding light on the molecular mechanisms supporting UCS, particularly emphasizing the importance of EMT, we aim to provide a more comprehensive understanding of the disease to support the development of more effective therapeutic strategies.

KIF23 promotes cervical cancer progression via inhibiting NLRP3‐mediated pyroptosis

Abstract Background Cervical cancer (CC), closely linked to persistent human papillomavirus infection, represents a major health problem for women worldwide. The objective of this study is to elucidate KIF23's role in the development of CC and its regulatory mechanism. Methods The bioinformatics methods were utilized to extract pyroptosis‐associated differentially expressed genes (DEGs) and pivot genes from the GSE9750 and GSE63678 datasets, followed by immune infiltration analysis and quantification of these genes' expression. The effects of kinesin family member 23 (KIF23) were verified through functional experiments in vitro and a mouse xenograft model. The NLPR3 activator, nigericin, was applied for further analyzing the potential regulatory mechanism of KIF23 in CC. Results A total of 8 pyroptosis‐related DEGs were screened out, among which 4 candidate core genes were identified as candidate hub genes and confirmed upregulation in CC tissues and cells. These genes respectively showed a positive correlation with the infiltration of distinct immune cells or tumor purity. Downregulation of KIF23 could suppress the proliferation, migration, and invasion abilities in CC cells and tumorigenesis through enhancing pyroptosis. Conversely, KIF23 overexpression accelerated the malignant phenotypes of CC cells and inhibited pyroptosis activation, which was blocked by nigericin treatment. Conclusions KIF23 may play an oncogenic role in CC progression via inhibition of the NLRP3‐mediated pyroptosis pathway.

LAMA5 promotes cell proliferation and migration in ovarian cancer by activating Notch signaling pathway

Abstract LAMA5 (laminin α5) is a member of the laminin family. Despite the recent research implicating LAMA5 in cancer, the function of LAMA5 has remained uncertain in the progression of ovarian cancer (OC). Here, we investigated the functional influences of LAMA5 knockdown on OC in vitro and in vivo. In this study, we used immunohistochemistry (IHC) analysis to detect the relative expression of LAMA5 in OC and non‐cancer tissues, and we analyzed its connection with the overall survival (OS) of OC patients. To prove the role of LAMA5 in cell proliferation, migration, and invasion, LAMA5 expression in OC cell lines was inhibited by lentivirus. Compared with normal fallopian tube tissue, epithelial ovarian cancer (EOC) tissue showe d critically higher LAMA5 expression levels; additionally, high LAMA5 levels were a poor predictor of OS. We found that cell progression was restrained in LAMA5‐knockdown OC cell lines in vivo and in vitro. Finally, LAMA5 might be a commanding inducer of the expression of epithelial‐mesenchymal transition (EMT) and Notch signaling pathway‐related markers. Together, our research indicates that LAMA5 is highly connected to OC progression as it may play a role in the EMT process through the Notch signaling pathway.

Upregulation of SOX9 promotes the self‐renewal and tumorigenicity of cervical cancer through activating the Wnt/β‐catenin signaling pathway

Abstract Sry‐box9 (SOX9) maintains stem cell properties and plays crucial roles in many cancers. However, whether SOX9 is correlated with cervical cancer cell stemness and its detailed mechanism remains obscure. We studied the relationship between SOX9 and prognosis of cervical cancer through public database, and SOX9 was related to poor prognosis of cervical cancer. Elevated SOX9 expression enhanced the self‐renewal properties and promotes tumorigenicity in cervical cancer. Overexpression of SOX9 could promote the expression of stem cell‐related factors in cervical cancer cells and xenografts. Meanwhile, overexpression of SOX9 could also enhance the expressions of FZD10, β‐catenin, and c‐Myc in cervical cancer cells and xenografts, while inhibiting the expression of DDK1. The activation of Wnt pathway by chir‐99 021 raised the tumor spheroid ability of SOX9 knockdown HeLa cells. In addition, SOX9 could transcriptional inhibit DKK1 and activate FZD10 and MYC by binding to their promoters to affect the Wnt/β‐catenin pathway. These results demonstrated SOX9 regulated the self‐renewal and tumorigenicity of cervical cancer through Wnt/β‐catenin pathway by directly transcriptional activation of FZD10, MYC and transcriptional inhibition of DKK1.

Targeting of PFKFB3 with miR‐206 but not mir‐26b inhibits ovarian cancer cell proliferation and migration involving FAK downregulation

Abstract Few studies explored the role of microRNAs (miRNAs) in the post‐transcriptional regulation of glycolytic proteins and downstream effectors in ovarian cancer cells. We recently showed that the functional activation of the cytoskeletal regulator FAK in endothelial cells is fostered by the glycolytic enhancer 6‐phosphofructo‐2‐kinase/fructose‐2,6‐biphosphatase 3 (PFKFB3). We tested the hypothesis that miR‐206 and mir‐26b, emerging onco‐suppressors targeting PFKFB3 in estrogen‐dependent tumors, would regulate proliferation and migration of serous epithelial ovarian cancer (EOC) cells via common glycolytic proteins, i.e., GLUT1 and PFKFB3, and downstream FAK. PFKFB3 was overexpressed in SKOV3, and its pharmacological inhibition with 3‐(3‐pyridinyl)‐1‐(4‐pyridinyl)‐2‐propen‐1‐one (3PO) significantly reduced cell proliferation and motility. Both miR‐206 and miR‐26b directly targeted PFKFB3 as evaluated by a luciferase reporter assay. However, endogenous levels of miR‐26b were higher than those of miR‐206, which was barely detectable in SKOV3 as well as OVCAR5 and CAOV3 cells. Accordingly, only the anti‐miR‐26b inhibitor concentration‐dependently increased PFKFB3 levels. While miR‐206 overexpression impaired proliferation and migration by downregulating PFKFB3 levels, the decreased PFKFB3 protein levels related to miR‐26 overexpression had no functional consequences in all EOC cell lines. Finally, consistent with the migration outcome, exogenous miR‐206 and miR‐26b induced opposite effects on the levels of total FAK and of its phosphorylated form at Tyr576/577. 3PO did not prevent miR‐26b‐induced SKOV3 migration. Overall, these results support the inverse relation between endogenous miRNA levels and their tumor‐suppressive effects and suggest that restoring miR‐206 expression represents a potential dual anti‐PFKFB3/FAK strategy to control ovarian cancer progression.

Research Progress of RAD51AP1 in Malignant Tumors of the Female Reproductive System

ABSTRACT Genomic instability may contribute to the occurrence and progression of malignant tumors of the female reproductive system. Homologous recombination repair (HRR) is vital in maintaining cellular genomic stability. RAD51‐associated protein 1 (RAD51AP1) plays a vital role in HRR, mainly participating in the formation of displacement loop (D‐loop), and is an important molecule for maintaining cellular genomic stability. Recent studies showed that RAD51AP1 was significantly overexpressed in a variety of cancer types and correlated with prognosis, suggesting that it may have a significant pro‐carcinogenic effect. However, the mechanism underlying its pro‐carcinogenic effect remains unclear, which may be closely associated with cancer stemness. Meanwhile, RAD51AP1 also plays an important role in resistance to radiotherapy and chemotherapy. Exploring RAD51AP1 and its regulatory molecules may provide new targets for overcoming cancer progression and treatment resistance. Here, we reviewed the latest research on RAD51AP1 in female reproductive system tumors and summarized its differential expression and prognostic implications. In this review, we also outlined the potential mechanisms of its procancer and drug resistance‐promoting effects to provide several potential directions for further research.

Matrix Metalloproteinases as Candidate Antigenic Determinants for Anti‐Tumor Autoantibodies in Human Ovarian Cancer: A Post Hoc Analysis

ABSTRACT Circulating antibodies in patients with cancer can facilitate the identification of accessible epitopes on autoantigens expressed by tumors. To identify previously unrecognized protein targets in ovarian cancer, we computationally assessed a heptapeptide consensus motif (VPELGHE, flanked by two cysteine residues yielding a cyclic nonapeptide under oxidizing conditions) previously discovered via phage display‐based epitope mapping of autoantibodies in patients. Eight proteins associated with ovarian cancer encompass amino acid sequences similar to the consensus motif and were, therefore, considered as candidate native autoantigens. Among these candidate targets, however, matrix metalloproteinase 14 ( MMP14 ) demonstrates gene expression that is both high and negatively correlated with survival in ovarian cancer patient cohorts. MMP14 protein levels are also stable in tumor versus non‐tumor tissues. Moreover, the corresponding heptapeptide mimic in MMP14 occurs within an α‐helical secondary structural element observed in its catalytic domain. These findings demonstrate that a subset of patient‐derived autoantibodies may interact with a previously unknown antigenic epitope found in MMP14 and other MMPs, thereby providing opportunities for the development of new targeted agents.

Targeting thiol isomerase activity with zafirlukast to treat ovarian cancer from the bench to clinic

Abstract Thiol isomerases, including PDI, ERp57, ERp5, and ERp72, play important and distinct roles in cancer progression, cancer cell signaling, and metastasis. We recently discovered that zafirlukast, an FDA‐approved medication for asthma, is a pan‐thiol isomerase inhibitor. Zafirlukast inhibited the growth of multiple cancer cell lines with an IC 50 in the low micromolar range, while also inhibiting cellular thiol isomerase activity, EGFR activation, and downstream phosphorylation of Gab1. Zafirlukast also blocked the procoagulant activity of OVCAR8 cells by inhibiting tissue factor‐dependent Factor Xa generation. In an ovarian cancer xenograft model, statistically significant differences in tumor size between control vs treated groups were observed by Day 18. Zafirlukast also significantly reduced the number and size of metastatic tumors found within the lungs of the mock‐treated controls. When added to a chemotherapeutic regimen, zafirlukast significantly reduced growth, by 38% compared with the mice receiving only the chemotherapeutic treatment, and by 83% over untreated controls. Finally, we conducted a pilot clinical trial in women with tumor marker‐only (CA‐125) relapsed ovarian cancer, where the rate of rise of CA‐125 was significantly reduced following treatment with zafirlukast, while no severe adverse events were reported. Thiol isomerase inhibition with zafirlukast represents a novel, well‐tolerated therapeutic in the treatment of ovarian cancer.

Haploinsufficient tumor suppressor PRP4K is negatively regulated during epithelial‐to‐mesenchymal transition

Abstract The pre‐mRNA processing factor 4 kinase (PRP4K, also known as PRPF4B) is an essential gene. However, reduced PRP4K expression is associated with aggressive breast and ovarian cancer phenotypes including taxane therapy resistance, increased cell migration and invasion in vitro, and cancer metastasis in mice. These results are consistent with PRP4K being a haploinsufficient tumor suppressor. Increased cell migration and invasion is associated with epithelial‐to‐mesenchymal transition (EMT), but how reduced PRP4K levels affect normal epithelial cell migration or EMT has not been studied. Depletion of PRP4K by small hairpin RNA (shRNA) in non‐transformed mammary epithelial cell lines (MCF10A, HMLE) reduced or had no effect on 2D migration in the scratch assay but resulted in greater invasive potential in 3D transwell assays. Depletion of PRP4K in mesenchymal triple‐negative breast cancer cells (MDA‐MB‐231) resulted in both enhanced 2D migration and 3D invasion, with 3D invasion correlated with higher fibronectin levels in both MDA‐MB‐231 and MCF10A cells and without changes in E‐cadherin. Induction of EMT in MCF10A cells, by treatment with WNT‐5a and TGF‐β1, or depletion of eukaryotic translation initiation factor 3e (eIF3e) by shRNA, resulted in significantly reduced PRP4K expression. Mechanistically, induction of EMT by WNT‐5a/TGF‐β1 reduced PRP4K transcript levels, whereas eIF3e depletion led to reduced PRP4K translation. Finally, reduced PRP4K levels after eIF3e depletion correlated with increased YAP activity and nuclear localization, both of which are reversed by overexpression of exogenous PRP4K. Thus, PRP4K is a haploinsufficient tumor suppressor negatively regulated by EMT, that when depleted in normal mammary cells can increase cell invasion without inducing full EMT.

KRCC1: A potential therapeutic target in ovarian cancer

Abstract Using a systems biology approach to prioritize potential points of intervention in ovarian cancer, we identified the lysine rich coiled‐coil 1 (KRCC1), as a potential target. High‐grade serous ovarian cancer patient tumors and cells express significantly higher levels of KRCC1 which correlates with poor overall survival and chemoresistance. We demonstrate that KRCC1 is predominantly present in the chromatin‐bound nuclear fraction, interacts with HDAC1, HDAC2, and with the serine‐threonine phosphatase PP1CC. Silencing KRCC1 inhibits cellular plasticity, invasive properties, and potentiates apoptosis resulting in reduced tumor growth. These phenotypes are associated with increased acetylation of histones and with increased phosphorylation of H2AX and CHK1, suggesting the modulation of transcription and DNA damage that may be mediated by the action of HDAC and PP1CC, respectively. Hence, we address an urgent need to develop new targets in cancer.

HPV16 E6 oncoprotein‐induced upregulation of lncRNA GABPB1‐AS1 facilitates cervical cancer progression by regulating miR‐519e‐5p/Notch2 axis

Abstract Human papillomaviruses 16 (HPV16) is the primary causative agent of cervical cancer (CC). E6 oncoprotein plays a crucial role in cervical carcinogenesis and commonly cause the dysregulation of the long noncoding RNAs (lncRNAs) expression. However, the biological function of lncRNAs in HPV16‐related CC remains largely unexplored. In the present study HPV16 E6‐induced differential expression of lncRNAs, miRNA, and mRNA were identified using microarray‐based analysis and verified in tumor r cell lines and tumor tissues, and the function of lncRNA in CC was investigated in vitro and in vivo. We found that an lncRNA, named GABPB1‐AS1, was significantly upregulated in HPV16‐positive CC tissues and cell lines. GABPB1‐AS1 expression in HPV16‐positive CC tissues was positively associated with tumor size, lymph node metastasis, and FIGO stage. High expression of GABPB1‐AS1 was correlated with a poor prognosis for HPV16‐positive CC patients. Functionally, E6‐induced GABPB1‐AS1 overexpression facilitated CC cells proliferation and invasion in vitro and in vivo. Mechanistically, GABPB1‐AS1 acted as a competing endogenous RNA (ceRNA) by sponging miR‐519e‐5p, resulting in the de‐repression of its target gene Notch2 which is well known as an oncogene. Therefore, GABPB1‐AS1 functioned as a tumor activator in CC pathogenesis by binding to miR‐519e‐5p and destroying its tumor suppressive function. Collectively, current results demonstrate that GABPB1‐AS1 is associated with CC progression, and may be a promising biomarker or target for the clinical management of CC.

Isoquercetin and Zafirlukast Cooperatively Suppress Tumor Growth and Thromboinflammatory Signaling in a Xenograft Model of Ovarian Cancer

ABSTRACT Cancer‐associated thrombosis (CAT), encompassing both venous thromboembolism and arterial thrombosis, contributes to up to 14% of cancer‐related mortality and remains difficult to treat due to the bleeding risks of conventional anticoagulants. Protein disulfide isomerase (PDI) and its family member ERp57 (PDIA3) are thiol isomerases that regulate both arterial and venous thrombosis and are also upregulated in tumors, where they promote growth, metastasis, and immune evasion. Here, we evaluated the therapeutic potential of two thiol isomerase inhibitors—isoquercetin (ISOQ), a selective PDI inhibitor, and zafirlukast (ZAF), a broad‐spectrum inhibitor of thiol isomerases such as PDI and ERp57—individually and in combination, in a xenograft model of ovarian cancer. ISOQ inhibited both platelet aggregation and Factor Xa generation induced by tumor cells and significantly suppressed tumor growth, thromboinflammatory markers, and expression of tissue factor, VEGF, TMEM176B, and PD‐L1. ISOQ also potentiated standard cisplatin/gemcitabine chemotherapy. Notably, the combination of low‐dose ISOQ plus ZAF achieved ≥ 80% inhibition of key tumor‐associated markers at one‐third the monotherapy dose and outperformed either agent alone. These findings support ISOQ and ZAF as promising agents for the treatment of cancer and CAT and establish thiol isomerase inhibition as a strategy to simultaneously target thrombosis, tumor progression, and immune escape.