IGF2BP3 regulates CACNA1A-Mediated Ferroptosis in Ovarian Cancer Through m6A Modification

Background: Ovarian cancer is the most lethal gynecological malignancy due to its heterogeneity in the genome, where epigenetics plays a critical role. N6-methylation of adenosine (m6A) modification is the most widespread epigenetic modification of RNA. However, the m6A modification and its key 'reader' IGF2BP3 in ovarian cancer are largely unexplored.Methods: The expression of IGF2BP3 and its association with clinical prognosis were evaluated by tissue microarray. The biological role of IGF2BP3 was studied further through in vitro and in vivo models. Transcriptomic RNA sequencing (RNA-Seq) and Methylated RNA immunoprecipitation sequencing (MeRIP-seq) were used to assess the downstream targets of IGF2BP3. MeRIP-qPCR, RIP, Dual-Luciferase Reporter assay, RNA stability assays, ChIP and Flow cytometry were further applied to dissect the detailed mechanisms.Findings: IGF2BP3 was elevated in ovarian cancer and correlated with the clinic pathological characteristics and prognosis of ovarian cancer patients. Biologically, IGF2BP3 inhibited ferroptosis and facilitated the proliferation of ovarian cancer cells in vitro and in vivo. Mechanistically, CACNA1A was directly identified as a target of IGF2BP3 and modified by m6A modification. Meanwhile, the knockdown of CACNA1A caused abnormal calcium (Ca2+) uptake and intracellular Ca2+ overload, resulting in excessive ROS accumulation and triggering ferroptosis. In addition, we further identified IGF2BP3-super-enhancer (IGF2BP3-SE), which drives IGF2BP3 expression and oncogenic effects in ovarian cancer.Interpretation: This study reveals the significant roles of IGF2BP3 in modulating ferroptosis in ovarian cancer through m6A modification and advocates for attenuating the IGF2BP3-CACNA1A regulatory axis to combat ovarian cancer progression.Funding: This research was supported by National Natural Science Foundation of China (NO. 82072864), (NO. 81971626), (NO. U22A20346); Natural Science Foundation of Heilongjiang Province (LH2020H023); Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province (LBH-Q20136).Declaration of Interest: The writers have declared no conflict of interest.Ethical Approval: Informed consent was obtained from clinical patients and granted by Ethics Committee of the Second Affiliated Hospital of Harbin Medical University. The procedures followed were all consistent with the standards of ethics of the Committee for Responsible Human Experimentation and the Helsinki Declaration of 1975. The patients included in the study received informed consent. The Animal Care Use Committee of the Second Hospital of Harbin Medical University approved all research protocols.