Identification of miR-30c-5p as a tumor suppressor by targeting the m6 A reader HNRNPA2B1 in ovarian cancer

Background: MicroRNAs (miRNAs) and N6-methyladenosine (m⁶ A) play important roles in ovarian Cancer (OvCa). However, the mechanisms by which miRNAs regulate m⁶ A in OvCa have not been elucidated so far.

Methods: To screen m⁶ A-related miRNAs, Pearson's correlation analysis of miRNAs and m⁶ A regulators was implemented using The Cancer Genome Atlas database (TCGA). To determine the level of m⁶ A, RNA m⁶ A quantitative assays were used. Then, colony formation assays, EdU assays, wound healing assays, and Transwell assays were performed. The dual-luciferase reporter assay was used to confirm the miRNA target genes. Protein-protein interaction (PPI) analysis of the target genes was performed, and hub genes were discovered using the cytoHubba/Cytoscape software. The underlying molecular mechanisms were explored by bioinformatics and RNA stability assays.

Results: A total of 126 miRNAs were identified as m⁶ A-related miRNAs by Pearson's correlation analysis. Among them, the high level of miR-30c-5p was associated with good prognosis in OvCa patients. In vitro, the miR-30c-5p agomir lowered the m⁶ A level and inhibited OvCa cell proliferation, migration, and invasion. The hub target genes of miR-30c-5p were identified as (i) XPO1, (ii) AGO1, (iii) HNRNPA2B1, of which m⁶ A reader HNRNPA2B1 was highly expressed in OvCa tissues and related with poor prognosis. In vitro, knockdown of HNRNPA2B1 significantly reduced m⁶ A level and hampered the proliferation and migration of OvCa cells. The inhibition of m⁶ A reader HNRNPA2B1 attenuated the suppression of proliferation and migration and the low m⁶ A level induced by the miR-30c-5p downregulation. Mechanistically, m⁶ A reader HNRNPA2B1 might regulate CDK19 mRNA stability to alter m⁶ A level.

Conclusions: miR-30c-5p inhibits OvCa progression and reduces the m⁶ A level by inhibiting m⁶ A reader HNRNPA2B1, thus providing new insights into the m⁶ A regulatory mechanism in OvCa.

Biological function; HNRNPA2B1; m6A level; miR-30c-5p; ovarian cancer.