HNRNPA2B1 inhibited SFRP2 and activated Wnt-β/catenin via m6A-mediated miR-106b-5p processing to aggravate stemness in lung adenocarcinoma

Cancer stem cells (CSCs) exhibit strong self-renewal capability to contribute to tumorigenesis in lung adenocarcinoma (LUAD). N6-methyladenosine (m6A) methylation is confirmed as a key mechanism for stemness acquisition and tumor growth. Heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1) is a known m6A reader and is reported to participate in LUAD progression, but its relation with stemness of LUAD cells is unknown. Thus, this study aimed to uncover the effect of HNRNPA2B1 in stemness of LUAD cells. The association of HNRNPA2B1 with LUAD prognosis was analyzed via Gene Expression Profiling Interactive Analysis (GEPIA). Sphere formation, cytometry flow analysis and western blot of stemness-related genes were performed to examine the stemness of LUAD cells. m6A modification was investigated by RNA immunoprecipitation. Results depicted that HNRNPA2B1 was upregulated in LUAD CSCs. HNRNPA2B1 knockdown repressed cell stemness, proliferation, migration, and tumor growth of LUAD. As to mechanism, HNRNPA2B1 read the m6A site on primary microRNA-106b (pri-miR-106b) to facilitate the maturing of miR-106b-5p, so that miR-106b-5p targeted secreted frizzled-related protein 2 (SFRP2), activating Wnt/β-catenin signaling. In conclusion, HNRNPA2B1 inhibits SFRP2 and activates Wnt-β/catenin via m6A-mediated maturing of miR-106b-5p to aggravate stemness and LUAD progression, which potentially offered HNRNPA2B1 as a potential marker in CSCs-targeted treatment for LUAD.