Decipher the effects and molecular mechanisms of BCL2A1 in regulating ovarian cancer cell growth

Abstract

Epithelial ovarian cancer (EOC) remains a lethal malignancy due to its propensity for metastatic dissemination and therapeutic resistance. Tumorigenesis involves dynamic adaptation to microenvironmental stresses, including hypoxia, nutrient deprivation and anoikis, enabling cancer cells to evade apoptosis. Central to apoptotic evasion are BCL-2 family proteins, which regulate intrinsic apoptotic signalling. A better understanding of the molecular mechanisms underlying tumour metastasis and chemoresistance could reveal novel pathways of high clinical relevance. This study elucidates the pleiotropic role of the antiapoptotic protein BCL2A1 in promoting metastatic progression and stress adaptation in EOC, while delineating its mechanistic interplay with autophagy-mediated drug resistance. Integrated in silico analyses of pan-cancer datasets and tissue microarrays revealed significant upregulation of BCL2A1 in omental metastases compared to primary ovarian tumours, with elevated expression correlating with advanced-stage disease and poor patient prognosis. These results suggest a potential involvement of BCL2A1 in metastatic adaptation of advanced ovarian carcinomas. Functional studies demonstrated that BCL2A1 overexpression augmented the migration and invasion of ovarian cancer cells, whereas genetic silencing attenuated these phenotypes. Mechanistically, microenvironmental stress triggered nuclear factor-κΒ (NF-κB) activation, which transcriptionally upregulated BCL2A1 expression under conditions mimicking metastatic niche including hypoxia, glucose deprivation and anoikis. Hypoxia-induced HIF-1α stabilization potentiated NF-κB signalling, establishing the HIF-1α - NF-κB - BCL2A1 axis critical for metastatic adaptation. Clinical validation confirmed concomitantly upregulation of BCL2A1 and phosphorylated IκBα (p-IκBα, an NF-κB activation marker) in advanced-stage ovarian cancer, highlighting their synergistic role in metastatic progression. This finding delineates the mechanistic framework wherein hypoxic and metabolic stresses converge on the NF-κB - BCL2A1 axis to drive ovarian cancer metastasis. To identify novel therapeutic strategies targeting BCL2A1, high-throughput in silico drug screening identified MEK inhibitors (MEKi) as prominent candidates whose potency inversely correlated with BCL2A1 expression in ovarian cancer cells. RNA-sequencing analysis revealed significant enrichment of autophagosome - associated pathway following BCL2A1 suppression and MEKi treatment. Genetic inhibition of BCL2A1 enhanced autophagic flux, yet conferred resistance to MEKi (trametinib and selumetinib), which aligns with prior evidence linking autophagic survival mechanism to MEKi resistance. These findings suggest that BCL2A1 knockdown desensitizes cells to MEK inhibition by potentiating autophagy as a compensatory cytoprotective mechanism. Proximity ligation assays demonstrated co-localization between BCL2A1 and Beclin-1, a key autophagy initiator. This coordinated response highlights dual regulatory role for BCL2A1 in antagonizing apoptosis while constraining autophagic activation under microenvironmental stress. Further investigation into the mechanistic crosstalk between BCL2A1, MAPK signalling, and autophagy is warranted to optimize therapeutic paradigms. Collectively, this research establishes BCL2A1 as a multifunctional regulator of ovarian cancer progression, mediating MEKi resistance through autophagy suppression and promoting metastatic adaptation via HIF-1α - NF-κB driven survival signalling. The identification of BCL2A1 as a driver of metastasis and autophagy-mediated chemoresistance provides a framework for dual-targeted therapies in ovarian cancer. Importantly, this study underscores the necessity of addressing both apoptotic and autophagic pathways to circumvent adaptive survival mechanisms, offering a strategic roadmap for clinical translation.