LAUSR

The aim of this study was to elucidate the mechanism of action of the insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) on the phenotype of the liver cancer stem cells (LCSCs). To gain insight into the mechanism of action of the IGF2BP1 on LCSCs, the IGF2BP1 shRNA sequences were transfected into HCC cells. The LCSC phenotypes were measured by stemness gene expressions, spheroid formations, percentages of the CD133+ cells, colony formations, and tumorigeneses in vivo. Next, we screened for possible molecular mechanisms from the TCGA database, and a methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) was used to adjust the binding of the IGF2BP1 to the target gene, alpha-1,6-mannosylglycoprotein 6-beta-N-acetylglucosaminyltransferase (MGAT5). The MeRIP-qPCR was used to detect the binding of the IGF2BP1 and MGAT5 via the m6A modification. Furthermore, we adjusted the attenuation of the mRNA of the MGAT5 using quantitative real-time PCR (qRT-PCR). The IGF2BP1 was upregulated in the LCSCs. Furthermore, the IGF2BP1 promoted self-renewal and chemoresistance in human LCSCs and tumorigenesis in mice and it enhanced the expression of stemness genes in the LCSCs compared with the HCC cells. Further exploration indicated that the IGF2BP1 binds directly to the MGAT5 and inhibits its mRNA attenuation, suggesting that the IGF2BP1 impacts MGAT5 mRNA stability via the m6A modification. Thus, it can be concluded that the IGF2BP1 facilitated the LCSC phenotypes by promoting the MGAT5 mRNA stability through the upregulation of the m6A modification of the MGAT5 mRNA.