METTL3 Promotes Pancreatic Tumor Progression Through Regulating the miR-196a/CPEB3 Axis

Background: Methyltransferase-like 3(METTL3)-mediated N6-methyladenosine (m6A) modification has been reported to regulate microRNAs maturation. Here, the study was designed to investigate the regulatory effect of m6A-dependent miRNA maturation on pancreatic cancer progression which is still limited before.Results: We found that METTL3 significantly upregulated in the pancreatic tumor tissues. Overexpression of METTL3 promoted cancer cell proliferation and migration in vitro and tumor progression in vivo. METTL3-mediated m6A modification facilitated miR-196a maturation in pancreatic cancer cells, and miR-196a increased the proliferation and migration of cancer cells in vitro. Luciferase reporter assay verified that cytoplasmic polyadenylation element binding protein 3 (CPEB3) was a direct target gene of miR-196a. In vivo studies proved that overexpression of miR-196a inhibited the anti-tumor effect of knockdown of METTL3, and overexpression of CPEB3 inhibited the miR-196a-enhanced tumor progression. Conclusions: We identified that METTL3 was upregulated in pancreatic cancer, leading to the upregulation of miR-196a, resulting in the downregulation of CPEB3, which promoted the pancreatic tumor progression. We first demonstrated that CPEB3 was a tumor suppressor gene in pancreatic cancer, and the METTL3 regulated miR-196a/CPEB3 axis may be a therapeutic target for pancreatic cancer therapy.