MEX3A promotes the malignant progression of ovarian cancer by regulating intron retention in TIMELESS

Comprehensive bioinformatics analysis of MEX3 family genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal malignancy associated with poor prognosis due to late-stage diagnosis and high recurrence rates. The MEX3 family genes has been implicated in various cancers; however, their roles in HCC remain largely unexplored. This study aims to systematically analyze the expression patterns, prognostic significance, and immune-related functions of MEX3A, MEX3B, MEX3C, and MEX3D in HCC using comprehensive bioinformatics approaches. We conducted a multi-level bioinformatics analysis to investigate the expression, prognostic significance, clinicopathological correlations, genetic alterations, immune associations, and functional mechanisms of MEX3 family members in HCC. Transcriptomic data from TCGA and GEO databases, along with experimental validation via qRT-PCR and Western blotting, were used to assess expression profiles. Kaplan-Meier, ROC curve, and Cox regression analyses were employed for prognostic evaluation. Co-expression, enrichment, and immune infiltration analyses further elucidated the functional and immunological relevance of MEX3 family genes. A prognostic model based on co-expressed genes was constructed and validated using LASSO and time-dependent ROC analyses. MEX3A, MEX3B, MEX3C, and MEX3D were significantly upregulated in HCC tissues compared to normal liver tissues (P < 0.05). ROC curve analysis demonstrated high diagnostic accuracy, particularly for MEX3A (AUC = 0.915). Kaplan-Meier survival analysis indicated that elevated MEX3A and MEX3C expression was associated with poorer overall survival (OS) and disease-specific survival (DSS) (P < 0.05). Mutation analysis revealed that MEX3A exhibited the highest alteration frequency (11%), primarily through gene amplifications. Immune infiltration analysis demonstrated significant correlations between MEX3 expression and multiple immune cell populations, including regulatory T cells (Tregs), cytotoxic T cells, and macrophages. Moreover, MEX3B, MEX3C, and MEX3D expression correlated with key immune checkpoint genes, including PDCD1, CD274, and CTLA4. Functional enrichment analysis revealed that MEX3 co-expressed genes were significantly involved in RNA metabolism, immune response regulation, and oncogenic signaling pathways. A 17-gene MEX3 co-expression-based prognostic model stratified patients into high- and low-risk groups with significantly different survival outcomes (AUC = 0.791 at 1 year). This study highlights the oncogenic potential of MEX3 family members in HCC and their associations with immune regulation. The findings suggest that MEX3 family genes could serve as potential biomarkers for HCC prognosis and immunotherapy responsiveness. Further experimental validation is warranted to elucidate the mechanistic roles of MEX3 family genes in HCC progression and immune evasion.

MEX3A promotes cell proliferation by regulating the RORA/β-catenin pathway in hepatocellular carcinoma

BACKGROUND

MEX3A is a member of the human homologous gene MEX-3 family. It has been shown to promote cell proliferation and migration in various cancers, indicating its potential clinical significance. However, the role of MEX3A in hepatocellular carcinoma (HCC) remains largely unexplored, with limited reports available in the literature.

AIM

To investigate expression and clinical significance of MEX3A in HCC and explore its potential role in tumor progression.

METHODS

We analyzed MEX3A mRNA expression in HCC and adjacent tissues using data from The Cancer Genome Atlas (TCGA). The correlation between MEX3A expression and overall survival (OS) was evaluated. Immunohistochemistry was performed on HCC surgical specimens to validate MEX3A expression and its association with clinical parameters, including hepatitis B virus (HBV) positivity, tumor differentiation and tumor size. Additionally, MEX3A knockdown HCC cell lines were constructed to explore the biological functions of MEX3A. Cell proliferation was assessed using cell counting kit-8 and clone formation assays, while cell cycle progression was analyzed by flow cytometry. The effects of MEX3A on the Wnt/β-catenin signaling pathway were examined by western blotting and immunofluorescence. Cell migration was evaluated using scratch and Transwell assays. Finally, the role of the transcription factor RORA in mediating MEX3A effects was explored by silencing RORA and analyzing its impact on cell proliferation and protein expression.

RESULTS

TCGA data analysis revealed that MEX3A mRNA expression was significantly higher in HCC tissues compared to adjacent tissues. Higher MEX3A expression was associated with poorer OS. These findings were validated in HCC surgical specimens. Immunohistochemistry confirmed elevated MEX3A expression in HCC tissues and showed positive correlations with Ki-67 and vimentin levels. MEX3A expression was closely related to HBV positivity, tumor differentiation and tumor size. Mechanistic studies demonstrated that MEX3A knockdown inhibited cell proliferation and cell cycle progression, as shown by reduced expression of β-catenin, c-Myc and cyclin D1. Additionally, MEX3A knockdown inhibited the nuclear entry of β-catenin, thereby suppressing the activation of downstream oncogenic pathways. MEX3A depletion significantly reduced the migratory ability of HCC cells, likely through downregulation of the epithelial-mesenchymal transition pathway. Transcription factor analysis identified RORA as a potential mediator of MEX3A effects. Silencing RORA antagonized the effects of MEX3A on cell proliferation and the expression of β-catenin, c-Myc and cyclin D1.

CONCLUSION

MEX3A promotes cell proliferation in HCC by regulating the RORA/β-catenin pathway. Our findings suggest that MEX3A could serve as a prognostic marker and therapeutic target for HCC.

Mex3a promoter hypomethylation can be utilized to diagnose HBV-associated hepatocellular carcinoma: a randomized controlled trial

BACKGROUND

Hepatocellular carcinoma remains a health challenge for humanity. Therefore, there is an urgent need to develop novel biomarkers with high efficiency yet fast ability to meet the requirements of hepatocellular carcinoma treatment.

METHODS

A total of 229 patients with HBV-associated hepatocellular carcinoma (HCC), 298 patients with chronic hepatitis B (CHB), and 96 healthy controls were retrospectively analyzed. Methylation levels of the Mex3a promoter in peripheral blood mononuclear cells (PBMCs) were measured using MethyLight to obtain clinical and laboratory parameters.

RESULTS

The Mex3a promoter methylation level in HCC patients (median: 0.289% and interquartile range: 0.126%-0.590%) was significantly lower than that in CHB patients (median: 0.999%, interquartile range: 0.417%-1.268%, and p < 0.001) and healthy people (median: 2.172%, interquartile range: 1.225%-3.098%, and p < 0.001). The Mex3a mRNA levels in HCC patients (median: 12.198 and interquartile range: 3.112-18.996) were significantly higher than those in CHB patients (median: 1.623 and interquartile range: 0.066-6.000, and p < 0.001) and healthy controls (median: 0.329, interquartile range: 0.031-1.547, and p < 0.001). MethyLight data were expressed as a percentage of the methylated reference (PMR) value. The Mex3a PMR value was negatively correlated with the mRNA expression level (Spearman's R = -0.829 and p < 0.001). The Mex3a PMR value of HCC patients was significantly correlated with age (Spearman's R = 0.113 and p = 0.044), and the mRNA level was significantly correlated with ALT (Spearman's R = 0.132 and p = 0.046). The Mex3a promoter methylation levels and mRNA levels were also independent factors in the development of liver cancer. The Mex3a promoter methylation and mRNA levels were better at distinguishing HCC from CHB than AFP [area under the receiver operating characteristic curve (AUC) for predicting HCC vs. CHB: 0.915 vs. 0.715: p < 0.001]. The combined use of AFP and Mex3a methylation levels and mRNA levels further improved the area under the receiver operating characteristic curve.

CONCLUSION

The presence of Mex3a promoter hypomethylation in hepatocellular carcinoma can be used as a non-invasive biomarker for the early detection of liver cancer.

Highly Efficient Synergistic Chemotherapy and Magnetic Resonance Imaging for Targeted Ovarian Cancer Therapy Using Hyaluronic Acid-Coated Coordination Polymer Nanoparticles

The diagnosis and treatment of ovarian cancer (OC) are still a grand challenge, more than 70% of patients are diagnosed at an advanced stage with a dismal prognosis. Magnetic resonance imaging (MRI) has shown superior results to other examinations in preoperative assessment, while cisplatin-based chemotherapy is the first-line treatment for OC. However, few previous studies have brought together the two rapidly expanding fields. Here a technique is presented using cisplatin prodrug (Pt-COOH), Fe3+, and natural polyphenols (Gossypol) to construct the nanoparticles (HA@PFG NPs) that have a stable structure, controllable drug release behavior, and high drug loading capacity. The acidic pH values in tumor sites facilitate the release of Fe3+, Pt-COOH, and Gossypol from HA@PFG NPs. Pt-COOH with GSH consumption and cisplatin-based chemotherapy plus Gossypol with pro-apoptotic effects displays a synergistic effect for killing tumor cells. Furthermore, the release of Fe3+ at the tumor sites promotes ferroptosis and enables MRI imaging of OC. In the patient-derived tumor xenograft (PDX) model, HA@PFG NPs alleviate the tumor activity. RNA sequencing analysis reveals that HA@PFG NPs ameliorate OC symptoms mainly through IL-6 signal pathways. This work combines MRI imaging with cisplatin-based chemotherapy, which holds great promise for OC diagnosis and synergistic therapy.

Alternative splicing in ovarian cancer

Ovarian cancer is the second leading cause of gynecologic cancer death worldwide, with only 20% of cases detected early due to its elusive nature, limiting successful treatment. Most deaths occur from the disease progressing to advanced stages. Despite advances in chemo- and immunotherapy, the 5-year survival remains below 50% due to high recurrence and chemoresistance. Therefore, leveraging new research perspectives to understand molecular signatures and identify novel therapeutic targets is crucial for improving the clinical outcomes of ovarian cancer. Alternative splicing, a fundamental mechanism of post-transcriptional gene regulation, significantly contributes to heightened genomic complexity and protein diversity. Increased awareness has emerged about the multifaceted roles of alternative splicing in ovarian cancer, including cell proliferation, metastasis, apoptosis, immune evasion, and chemoresistance. We begin with an overview of altered splicing machinery, highlighting increased expression of spliceosome components and associated splicing factors like BUD31, SF3B4, and CTNNBL1, and their relationships to ovarian cancer. Next, we summarize the impact of specific variants of CD44, ECM1, and KAI1 on tumorigenesis and drug resistance through diverse mechanisms. Recent genomic and bioinformatics advances have enhanced our understanding. By incorporating data from The Cancer Genome Atlas RNA-seq, along with clinical information, a series of prognostic models have been developed, which provided deeper insights into how the splicing influences prognosis, overall survival, the immune microenvironment, and drug sensitivity and resistance in ovarian cancer patients. Notably, novel splicing events, such as PIGV|1299|AP and FLT3LG|50,941|AP, have been identified in multiple prognostic models and are associated with poorer and improved prognosis, respectively. These novel splicing variants warrant further functional characterization to unlock the underlying molecular mechanisms. Additionally, experimental evidence has underscored the potential therapeutic utility of targeting alternative splicing events, exemplified by the observation that knockdown of splicing factor BUD31 or antisense oligonucleotide-induced BCL2L12 exon skipping promotes apoptosis of ovarian cancer cells. In clinical settings, bevacizumab, a humanized monoclonal antibody that specifically targets the VEGF-A isoform, has demonstrated beneficial effects in the treatment of patients with advanced epithelial ovarian cancer. In conclusion, this review constitutes the first comprehensive and detailed exposition of the intricate interplay between alternative splicing and ovarian cancer, underscoring the significance of alternative splicing events as pivotal determinants in cancer biology and as promising avenues for future diagnostic and therapeutic intervention.

HMGB1-mediated transcriptional activation of circadian gene TIMELESS contributes to endometrial cancer progression through Wnt-β-catenin pathway

TIMELESS (TIM) is a circadian gene which is implicated in the regulation of daily rhythm, DNA replication and repair, and cancer initiation and progression. Nevertheless, the role of TIM in endometrial cancer (EC) development is largely unknown. Bioinformatics analysis showed that TIM was aberrantly up-regulated in EC tissues and positively correlated with clinical or histological grade of EC. Functional studies showed that TIM knockdown reduced EC cell viability and restrained EC cell migration in vitro, as well as blocked xenograft tumor growth in vivo. Mechanistically, HMGB1 transcriptionally up-regulated TIM expression in EC cells. In addition, TIM could activate the transcription of the canonical Wnt ligand WNT8B, and TIM depletion could reduce the malignant potential of EC cells largely by targeting and down-regulating WNT8B. As a conclusion, HMGB1/TIM/WNT8B signal cascade was identified in this study for the first time. HMGB1 exerted its oncogenic role by activating the transcription of TIM, leading to the activation of Wnt signaling and EC progression.

Intra-sample reversed pairs based on differentially ranked genes reveal biosignature for ovarian cancer

Ovarian cancer, a major gynecological malignancy, often remains undetected until advanced stages, necessitating more effective early screening methods. Existing biomarker based on differential genes often suffers from variations in clinical practice. To overcome the limitations of absolute gene expression values including batch effects and biological heterogeneity, we introduced a pairwise biosignature leveraging intra-sample differentially ranked genes (DRGs) and machine learning for ovarian cancer detection across diverse cohorts. We analyzed ten cohorts comprising 872 samples with 796 ovarian cancer and 76 normal. Our method, DRGpair, involves three stages: intra-sample ranking differential analysis, reversed gene pair analysis, and iterative LASSO regression. We identified four DRG pairs, demonstrating superior diagnostic performance compared to current state-of-the-art biomarkers and differentially expressed genes in seven independent cohorts. This rank-based approach not only reduced computational complexity but also enhanced the specificity and effectiveness of biomarkers, revealing DRGs as promising candidates for ovarian cancer detection and offering a scalable model adaptable to varying cohort characteristics.

N6-methyladenosine modification of the mRNA for a key gene in purine nucleotide metabolism regulates virus proliferation in an insect vector

The titer of viruses that persist and propagate in their insect vector must be high enough for transmission yet not harm the insect, but the mechanism of this dynamic balance is unclear. Here, expression of inosine monophosphate dehydrogenase (LsIMPDH), a rate-limiting enzyme for guanosine triphosphate (GTP) synthesis, is shown to be downregulated by increased levels of N6-methyladenosine (m6A) on LsIMPDH mRNA in rice stripe virus (RSV)-infected small brown planthoppers (SBPHs; Laodelphax striatellus), the RSV vector, which decreases GTP content, thus limiting viral proliferation. Moreover, planthopper methyltransferase-like protein 3 (LsMETTL3) and m6A reader protein LsYTHDF3 are found to catalyze and recognize the m6A on LsIMPDH mRNA, respectively, and cooperate in destabilizing LsIMPDH transcripts. Co-silencing assays show that negative regulation of viral proliferation by both LsMETTL3 and LsYTHDF3 is partially dependent on LsIMPDH. This distinct mechanism limits virus replication in an insect vector, providing a potential gene target to block viral transmission.

From clinical management to personalized medicine: novel therapeutic approaches for ovarian clear cell cancer

Ovarian clear-cell cancer is a rare subtype of epithelial ovarian cancer with unique clinical and biological features. Despite optimal cytoreductive surgery and platinum-based chemotherapy being the standard of care, most patients experience drug resistance and a poor prognosis. Therefore, novel therapeutic approaches have been developed, including immune checkpoint blockade, angiogenesis-targeted therapy, ARID1A synthetic lethal interactions, targeting hepatocyte nuclear factor 1β, and ferroptosis. Refining predictive biomarkers can lead to more personalized medicine, identifying patients who would benefit from chemotherapy, targeted therapy, or immunotherapy. Collaboration between academic research groups is crucial for developing prognostic outcomes and conducting clinical trials to advance treatment for ovarian clear-cell cancer. Immediate progress is essential, and research efforts should prioritize the development of more effective therapeutic strategies to benefit all patients.

SH3RF2 contributes to cisplatin resistance in ovarian cancer cells by promoting RBPMS degradation

Platinum-based chemotherapy remains one of the major choices for treatment of ovarian cancer (OC). However, primary or acquired drug resistance severely impairs their efficiency, thereby causing chemotherapy failure and poor prognosis. SH3 domain containing ring finger 2 (SH3RF2) has been linked to the development of cancer. Here we find higher levels of SH3RF2 in the tumor tissues from cisplatin-resistant OC patients when compared to those from cisplatin-sensitive patients. Similarly, cisplatin-resistant OC cells also express higher levels of SH3RF2 than normal OC cells. Through in vitro and in vivo loss-of-function experiments, SH3RF2 is identified as a driver of cisplatin resistance, as evidenced by increases in cisplatin-induced cell apoptosis and DNA damage and decreases in cell proliferation induced by SH3RF2 depletion. Mechanistically, SH3RF2 can directly bind to the RNA-binding protein mRNA processing factor (RBPMS). RBPMS has been reported as an inhibitor of cisplatin resistance in OC. As a E3 ligase, SH3RF2 promotes the K48-linked ubiquitination of RBPMS to increase its proteasomal degradation and activator protein 1 (AP-1) transactivation. Impairments in RBPMS function reverse the inhibitory effect of SH3RF2 depletion on cisplatin resistance. Collectively, the SH3RF2-RBPMS-AP-1 axis is an important regulator in cisplatin resistance and inhibition of SH3RF2 may be a potential target in preventing cisplatin resistance.

Comprehensive Analysis of METTLs (METTL1/13/18/21A/23/25/2A/2B/5/6/9) and Associated mRNA Risk Signature in Hepatocellular Carcinoma

Currently, 80%-90% of liver cancers are hepatocellular carcinomas (HCC). HCC patients develop insidiously and have an inferior prognosis. The methyltransferase-like (METTL) family principal members are strongly associated with epigenetic and tumor progression. The present study mainly analyzed the value of METTLs (METTL1/13/18/21A/23/25/2A/2B/5/6/9) and associated mRNA risk signature for HCC. METTLs expression is upregulated in HCC and is a poor prognostic factor in HCC. METTLs were upregulated in patients older than 60 and associated with grade. Except for METTL25, the remaining 10 genes were associated with the HCC stage, invasion depth (T). In addition, METTLs showed an overall alteration rate of 50%. Except for METTL13/2A/25/9, the expression of the other seven genes was significantly associated with overall survival, disease-specific survival, and progression-free survival. Multivariate studies have shown that METTL21A/6 can be an independent prognostic marker in HCC. A total of 664 mRNAs were selected based on Pearson correlation coefficient (R > 0.5), unsupervised consensus clustering, weighted coexpression network analysis, and univariate Cox analysis. These mRNAs were significantly associated with METTLs and were poor prognostic factors in HCC patients. The least absolute shrinkage and selection operator (lasso) was used to construct the best METTLs associated with mRNA risk signature. The mRNA risk signature was significantly associated with age, stage, and t grade. The mRNA high-risk group had higher TP53 and RB1 mutations. This study constructed a nomogram with the mRNA risk profile and clinicopathological features, which could better predict the OS of individuals with HCC. We also analyzed associations between METTLs and mRNA risk signatures in epithelial-mesenchymal transition, immune checkpoints, immune cell infiltration, tumor mutational burden, microsatellite instability, cancer stem cells, tumor pathways, and drug sensitivity. In addition, this study constructed a protein interaction network network including METTLs and mRNA risk signature genes related to tumor microenvironment remodeling based on single-cell sequencing. In conclusion, this study provides a theoretical basis for the mechanism, biomarker screening, and treatment of HCC.

Comprehensively analyzing the genetic alterations, and identifying key genes in ovarian cancer

Though significant improvements have been made in the treatment methods for ovarian cancer (OC), the prognosis for OC patients is still poor. Exploring hub genes associated with the development of OC and utilizing them as appropriate potential biomarkers or therapeutic targets is highly valuable. In this study, the differentially expressed genes (DEGs) were identified from an independent GSE69428 Gene Expression Omnibus (GEO) dataset between OC and control samples. The DEGs were processed to construct the protein-protein interaction (PPI) network using STRING. Later, hub genes were identified through Cytohubba analysis of the Cytoscape. Expression and survival profiling of the hub genes were validated using GEPIA, OncoDB, and GENT2. For exploring promoter methylation levels and genetic alterations in hub genes, MEXPRESS and cBioPortal were utilized, respectively. Moreover, DAVID, HPA, TIMER, CancerSEA, ENCORI, DrugBank, and GSCAlite were used for gene enrichment analysis, subcellular localization analysis, immune cell infiltration analysis, exploring correlations between hub genes and different diverse states, lncRNA-miRNA-mRNA co-regulatory network analysis, predicting hub gene-associated drugs, and conducting drug sensitivity analysis, respectively. In total, 8947 DEGs were found between OC and normal samples in GSE69428. After STRING and Cytohubba analysis, 4 hub genes including TTK (TTK Protein Kinase), (BUB1 mitotic checkpoint serine/threonine kinase B) BUB1B, (Nucleolar and spindle-associated protein 1) NUSAP1, and (ZW10 interacting kinetochore protein) ZWINT were selected as the hub genes. Further, it was validated that these 4 hub genes were significantly up-regulated in OC samples compared to normal controls, but overexpression of these genes was not associated with overall survival (OS). However, genetic alterations in those genes were found to be linked with OS and disease-free (DFS) survival. Moreover, this study also revealed some novel links between TTK, BUB1B, NUSAP1, and ZWINT overexpression and promoter methylation status, immune cell infiltration, miRNAs, gene enrichment terms, and various chemotherapeutic drugs. Four hub genes, including TTK, BUB1B, NUSAP1, and ZWINT, were revealed as tumor-promotive factors in OC, having the potential to be utilized as novel biomarkers and therapeutic targets for OC management.

Nonsense-Mediated mRNA Decay as a Mediator of Tumorigenesis

Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved and well-characterized biological mechanism that ensures the fidelity and regulation of gene expression. Initially, NMD was described as a cellular surveillance or quality control process to promote selective recognition and rapid degradation of erroneous transcripts harboring a premature translation-termination codon (PTC). As estimated, one-third of mutated and disease-causing mRNAs were reported to be targeted and degraded by NMD, suggesting the significance of this intricate mechanism in maintaining cellular integrity. It was later revealed that NMD also elicits down-regulation of many endogenous mRNAs without mutations (~10% of the human transcriptome). Therefore, NMD modulates gene expression to evade the generation of aberrant truncated proteins with detrimental functions, compromised activities, or dominant-negative effects, as well as by controlling the abundance of endogenous mRNAs. By regulating gene expression, NMD promotes diverse biological functions during development and differentiation, and facilitates cellular responses to adaptation, physiological changes, stresses, environmental insults, etc. Mutations or alterations (such as abnormal expression, degradation, post-translational modification, etc.) that impair the function or expression of proteins associated with the NMD pathway can be deleterious to cells and may cause pathological consequences, as implicated in developmental and intellectual disabilities, genetic defects, and cancer. Growing evidence in past decades has highlighted NMD as a critical driver of tumorigenesis. Advances in sequencing technologies provided the opportunity to identify many NMD substrate mRNAs in tumor samples compared to matched normal tissues. Interestingly, many of these changes are tumor-specific and are often fine-tuned in a tumor-specific manner, suggesting the complex regulation of NMD in cancer. Tumor cells differentially exploit NMD for survival benefits. Some tumors promote NMD to degrade a subset of mRNAs, such as those encoding tumor suppressors, stress response proteins, signaling proteins, RNA binding proteins, splicing factors, and immunogenic neoantigens. In contrast, some tumors suppress NMD to facilitate the expression of oncoproteins or other proteins beneficial for tumor growth and progression. In this review, we discuss how NMD is regulated as a critical mediator of oncogenesis to promote the development and progression of tumor cells. Understanding how NMD affects tumorigenesis differentially will pave the way for the development of more effective and less toxic, targeted therapeutic opportunities in the era of personalized medicine.

MEX3A Mediates p53 Degradation to Suppress Ferroptosis and Facilitate Ovarian Cancer Tumorigenesis

Epithelial ovarian cancer is a highly heterogeneous and malignant female cancer with an overall low survival rate. Mutations in p53 are prevalent in the major ovarian cancer histotype, high-grade serous ovarian carcinoma (HGSOC), while p53 mutations are much less frequent in other ovarian cancer subtypes, particularly in ovarian clear cell carcinoma (OCCC). Advanced stage OCCC with wild-type (WT) p53 has a worse prognosis and increased drug resistance, metastasis, and recurrence than HGSOC. The mechanisms responsible for driving the aggressiveness of WT p53-expressing ovarian cancer remain poorly understood. Here, we found that upregulation of MEX3A, a dual-function protein containing a RING finger domain and an RNA-binding domain, was critical for tumorigenesis in WT p53-expressing ovarian cancer. MEX3A overexpression enhanced the growth and clonogenicity of OCCC cell lines. In contrast, depletion of MEX3A in OCCC cells, as well as ovarian teratocarcinoma cells, reduced cell survival and proliferative ability. MEX3A depletion also inhibited tumor growth and prolonged survival in orthotopic xenograft models. MEX3A depletion did not alter p53 mRNA level but did increase p53 protein stability. MEX3A-mediated p53 protein degradation was crucial to suppress ferroptosis and enhance tumorigenesis. Consistently, p53 knockdown reversed the effects of MEX3A depletion. Together, our observations identified MEX3A as an important oncogenic factor promoting tumorigenesis in ovarian cancer cells expressing WT p53.

SIGNIFICANCE

Degradation of p53 mediated by MEX3A drives ovarian cancer growth by circumventing p53 tumor suppressive functions, suggesting targeting MEX3A as a potential strategy for treating of ovarian cancer expressing WT p53.

RNA-Binding Protein MEX3A Interacting with DVL3 Stabilizes Wnt/β-Catenin Signaling in Endometrial Carcinoma

Disease recurrence and metastasis lead to poor prognosis in patients with advanced endometrial carcinoma (EC). RNA-binding proteins (RBPs) are closely associated with tumor initiation and metastasis, but the function and molecular mechanisms of RBPs in EC are unclear. RBPs were screened and identified using the TCGA, GEO, and RBPTD databases. The effect of MEX3A on EC was verified by in vitro and in vivo experiments. Gene set enrichment analysis (GSEA), immunofluorescence (IF), and co-immunoprecipitation (Co-IP) were used to identify potential molecular mechanisms of action. We identified 148 differentially expressed RBPs in EC. MEX3A was upregulated and related to poor prognosis in patients with EC. In vitro and vivo experiments demonstrated that MEX3A promoted the growth, migration, and invasion capacities of EC cells. Mechanistically, DVL3, a positive regulator of the Wnt/β-catenin pathway, also increased the proliferation and metastasis of EC cells. MEX3A enhanced EMT and played a pro-carcinogenic role by interacting with DVL3 to stabilize β-catenin and upregulated the expression of its downstream target genes. MEX3A is upregulated in EC and promotes tumor progression by activating EMT and regulating the Wnt/β-catenin pathway via DVL3. MEX3A may therefore be a novel therapeutic target for EC.