ALYREF facilitates the proliferation of hepatocellular carcinoma via MAZ-mediated p53-dependent cell cycle promotion

Abstract

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, with poor prognosis and high mortality. Increasing evidence suggests that m5C binding protein ALYREF plays an important role in HCC progression. However, further research is required to understand its mechanism.The mechanism of ALYREF in HCC was investigated through combined RNA-seq, m5C-seq, and iCLIP-seq to identify potential target genes. Moreover, RT-qPCR, m5C dot blot assay, RNA immunoprecipitation, methylated RNA immuno-precipitation, dual-luciferase reporter assay, and RNA decay assay were used to confirm the mechanism.We identified 8 candidate genes which are modified by ALYREF-mediated RNA m5C modification. Moreover, we found that the content of MAZ modified by m5C was regulated by the methyltransferase NSUN2, and ALYREF could bind to the m5C site of MAZ mRNA and increase its stability. Additionally, we found that knockdown MAZ could inhibit HCC proliferation and reduce the promoting effect of ALYREF overexpression on HCC cell growth in vitro and in vivo. ALYREF and MAZ have a positive correlation; the higher the expression of ALYREF and MAZ, the lower the overall survival rate. Moreover, MAZ could bind to the p53 promoter and suppress the expression of p53, then mediate cell cycle promotion. Therefore, ALYREF promotes tumor growth by binding to the m5C site of MAZ mRNA, increasing its stability, and suppressing p53 via MAZ to regulate the cycle, which facilitates the proliferation of HCC. Overall, our study revealed that ALYREF contributes to HCC proliferation through the MAZ-mediated p53-dependent cell cycle, and the co-expression of ALYREF and MAZ in clinical samples may serve as an effective prognostic indicator for HCC.