N6-methyladenosine reader protein IGF2BP1 suppresses CD8 + T cells-mediated tumor cytotoxicity and apoptosis in colon cancer

Apoptosis. 2024 Apr;29(3-4):331-343. doi: 10.1007/s10495-023-01893-7. Epub 2023 Oct 17.

Abstract

Tumor immune escape is an important manner for colon cancer to escape effective killing by immune system. Currently, the immune checkpoint PD-1/PD-L1-targeted immunotherapy has emerged as a promising therapeutic strategy in colon cancer. Here, present work aims to investigate the biological function of N6-methyladenosine (m6A) reader insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) in regulating colon cancer's immune escape and CD8 + T cells-mediated tumor cytotoxicity and apoptosis. Results illustrated that IGF2BP1 was closely correlated to the colon cancer patients' poor clinical outcome. Functionally, upregulation of IGF2BP1 suppressed the CD8+ T-cells mediated antitumor immunity through reducing their tumor cytotoxicity. Mechanistically, MeRIP-Seq revealed that programmed death ligand 1 (PD-L1) mRNA had a remarkable m6A modified site on 3'-UTR genomic. Moreover, PD-L1 acted as the target of IGF2BP1, which enhanced the stability of PD-L1 mRNA. Overall, these results indicated that IGF2BP1 targeted PD-L1 to accelerate the immune escape in colon cancer by reducing CD8 + T cells-mediated tumor cytotoxicity in m6A-dependent manner. The findings demonstrate the potential of m6A-targeted immune checkpoint blockade in colon cancer, providing a novel insight for colon cancer immune escape and antitumor immunity in further precise treatment.

Keywords: IGF2BP1.; Immune escape; N6-methyladenosine; PD-L1; colon cancer.

MeSH terms

  • Apoptosis / genetics
  • B7-H1 Antigen / genetics
  • CD8-Positive T-Lymphocytes* / metabolism
  • Colonic Neoplasms* / drug therapy
  • Colonic Neoplasms* / genetics
  • Colonic Neoplasms* / metabolism
  • Humans
  • RNA, Messenger / metabolism

Substances

  • B7-H1 Antigen
  • RNA, Messenger