Genome-wide CRISPR screens define determinants of epithelial-mesenchymal transition mediated immune evasion by pancreatic cancer cells

Sci Adv. 2023 Jul 14;9(28):eadf9915. doi: 10.1126/sciadv.adf9915. Epub 2023 Jul 14.

Abstract

The genetic circuits that allow cancer cells to evade immune killing via epithelial mesenchymal plasticity remain poorly understood. Here, we showed that mesenchymal-like (Mes) KPC3 pancreatic cancer cells were more resistant to cytotoxic T lymphocyte (CTL)-mediated killing than the parental epithelial-like (Epi) cells and used parallel genome-wide CRISPR screens to assess the molecular underpinnings of this difference. Core CTL-evasion genes (such as IFN-γ pathway components) were clearly evident in both types. Moreover, we identified and validated multiple Mes-specific regulators of cytotoxicity, such as Egfr and Mfge8. Both genes were significantly higher expressed in Mes cancer cells, and their depletion sensitized Mes cancer cells to CTL-mediated killing. Notably, Mes cancer cells secreted more Mfge8 to inhibit proliferation of CD8+ T cells and production of IFN-γ and TNFα. Clinically, increased Egfr and Mfge8 expression was correlated with a worse prognosis. Thus, Mes cancer cells use Egfr-mediated intrinsic and Mfge8-mediated extrinsic mechanisms to facilitate immune escape from CD8+ T cells.

MeSH terms

  • CD8-Positive T-Lymphocytes*
  • Cell Line, Tumor
  • Clustered Regularly Interspaced Short Palindromic Repeats
  • Epithelial-Mesenchymal Transition / genetics
  • ErbB Receptors / genetics
  • Humans
  • Immune Evasion / genetics
  • Pancreatic Neoplasms* / genetics

Substances

  • ErbB Receptors