M6A methyltransferase METTL3 promotes the progression of prostate cancer via m6A-modified LEF1.

Abstract

This study aims to uncover the regulatory effects of METTL3 on promoting the progression of prostate cancer (PCa) through N6-Methyladenosine (m6A) methylation on LEF1 mRNA. The relative levels of METTL3 and LEF1 in 48 paired PCa tissues and adjacent ones were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Their correlation in PCa tissues was analyzed by Spearman correlation test. The survival of PCa patients affected by METTL3 was assessed by introducing Kaplan-Meier method. Wound closure assay was performed to evaluate the potential influence of METTL3 on migratory ability in PC-3 cells. Protein level of LEF1 in PC-3 cells with METTL3 or IGF2BP2 knockdown was examined. The activity of the Wnt pathway was tested through TOP/FOP-Flash. Furthermore, the interaction between LEF1 with METTL3 or IGF2BP2 was verified through RIP (RNA-Binding Protein Immunoprecipitation) assay. At last, the regulatory effects of METTL3/LEF1 axis on the activity of the Wnt pathway and migratory ability in PC-3 cells were determined. METTL3 and LEF1 were upregulated in PCa tissues, and they presented a positive correlation in PCa. A high level of METTL3 predicted poor prognosis in PCa patients. The knockdown of METTL3 suppressed the migratory ability in PC-3 cells. Meanwhile, the knockdown of METTL3 downregulated protein level of LEF1 and decreased the activity of the Wnt pathway. The results of RIP assay indicated that METTL3 methylation sites were present on LEF1 mRNA. Moreover, the silence of METTL3 decreased the enrichment abundance of LEF1 in anti-IGF2BP2. Rescue experiments demonstrated that the overexpression of LEF1 partially reversed the regulatory effects of METTL3 on the Wnt activity and migratory ability in PCa cells. METTL3 is upregulated in PCa tissues. METTL3 influences the activity of the Wnt pathway through m6A methylation on LEF1 mRNA, thereafter, promoting the progression of PCa.