LC3B upregulation by NANOG promotes immune resistance and stem-like property through hyperactivation of EGFR signaling in immune-refractory tumor cells

Autophagy. 2021 Aug;17(8):1978-1997. doi: 10.1080/15548627.2020.1805214. Epub 2020 Aug 14.

Abstract

Immune selection drives tumor cells to acquire refractory phenotypes. We previously demonstrated that cytotoxic T lymphocyte (CTL)-mediated immune pressure enriches NANOG+ tumor cells with stem-like and immune-refractory properties that make them resistant to CTLs. Here, we report that the emergence of refractory phenotypes is highly associated with an aberrant macroautophagic/autophagic state of the NANOG+ tumor cells and that the autophagic phenotype arises through transcriptional induction of MAP1LC3B/LC3B by NANOG. Furthermore, we found that upregulation of LC3B expression contributes to an increase in EGF secretion. The subsequent hyperactivation of EGFR-AKT signaling rendered NANOG+ tumor cells resistant to CTL killing. The NANOG-LC3B-p-EGFR axis was preserved across various types of human cancer and correlated negatively with the overall survival of cervical cancer patients. Inhibition of LC3B in immune-refractory tumor models rendered tumors susceptible to adoptive T-cell transfer, as well as PDCD1/PD-1 blockade, and led to successful, long-term control of the disease. Thus, our findings demonstrate a novel link among immune-resistance, stem-like phenotypes, and LC3B-mediated autophagic secretion in immune-refractory tumor cells, and implicate the LC3B-p-EGFR axis as a central molecular target for controlling NANOG+ immune-refractory cancer.Abbreviations: ACTB: actin beta; ATG7: autophagy related 7; BafA1: bafilomycin A1; CASP3: caspase 3; CFSE: carboxyfluorescein succinimidyl ester; ChIP: chromatin immunoprecipitation; CI: confidence interval; CIN: cervical intraepithelial neoplasia; CSC: cancer stem cell; CTL: cytotoxic T lymphocyte; EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; FIGO: International Federation of Gynecology and Obstetrics; GFP: green fluorescent protein; GZMB: granzyme B; HG-CIN: high-grade CIN; IHC: immunohistochemistry; LG-CIN: low-grade CIN; LN: lymph node; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCL1: myeloid cell leukemia sequence 1; MLANA/MART-1: melanoma antigen recognized by T cells 1; MUT: mutant; NANOG: Nanog homeobox; PDCD1/PD-1: programmed cell death 1; PMEL/gp100: premelanosome protein; RTK: receptor tyrosine kinase; TMA: tissue microarray; WT: wild type.

Keywords: Cancer immunoediting; EGFR; LC3B; MAP1LC3B; NANOG; immune resistance; immunotherapy.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / genetics
  • Cell Line, Tumor
  • ErbB Receptors / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Microtubule-Associated Proteins / metabolism*
  • Nanog Homeobox Protein / metabolism*
  • Neoplastic Stem Cells / metabolism
  • Signal Transduction / genetics
  • Up-Regulation

Substances

  • MAP1LC3B protein, human
  • Map1lc3b protein, mouse
  • Microtubule-Associated Proteins
  • NANOG protein, human
  • Nanog Homeobox Protein
  • Nanog protein, mouse
  • EGFR protein, human
  • ErbB Receptors

Grants and funding

This work was supported by funding from the National Research Foundation of Korea (NRF-2017R1A2A1A17069818, NRF-2017R1D1A1B03035438, NRF-2019R1A4A1029000, NRF-2019M3A9A8066884 and NRF-2020R1A2C1007157) and the Intramural Research Program of the National Institutes of Health (NIH), National Cancer Institute (NCI), Center for Cancer Research.