IGF2BP3 knockout alters mRNA m7G methylation in lymph node T cells of hepatocellular carcinoma
IGF2BP3 is an m7G methylated RNA reader protein, but its role in lymph node T cells during liver cancer progression is still unclear. We specifically knocked out IGF2BP3 in T cells within the lymph nodes of hepatocellular carcinoma mice. We then performed m7G sequencing to profile mRNA m7G methylation in these T cells. We found that IGF2BP3 knockout broadly reduces m7G modifications on T cell mRNAs. Transcripts controlling T cell migration and immune function are most affected. Genes such as S1PR1 show markedly lower m7G levels and reduced mRNA stability. These results show that IGF2BP3 maintains the m7G methylation program of T cells in tumor-draining lymph nodes. Loss of IGF2BP3 disrupts T cell gene expression through m7G-dependent mRNA regulation.