Selective inhibition of stemness through EGFR/FOXA2/SOX9 axis reduces pancreatic cancer metastasis

Oncogene. 2021 Jan;40(4):848-862. doi: 10.1038/s41388-020-01564-w. Epub 2020 Dec 7.

Abstract

Pancreatic cancer (PC) is difficult to defeat due to mechanism (s) driving metastasis and drug resistance. Cancer stemness is a major challenging phenomenon associated with PC metastasis and limiting therapy efficacy. In this study, we evaluated the pre-clinical and clinical significance of eradicating pancreatic cancer stem cells (PCSC) and its components using a pan-EGFR inhibitor afatinib in combination with gemcitabine. Afatinib in combination with gemcitabine significantly reduced KrasG12D/+; Pdx-1 Cre (KC) (P < 0.01) and KrasG12D/+; p53R172H/+; Pdx-1 Cre (KPC) (P < 0.05) derived mouse tumoroids and KPC-derived murine syngeneic cell line growth compared to gemcitabine/afatinib alone treatment. The drug combination also reduced PC xenograft tumor burden (P < 0.05) and the incidence of metastasis by affecting key stemness markers, as confirmed by co-localization studies. Moreover, the drug combination significantly decreases the growth of various PC patient-derived organoids (P < 0.001). We found that SOX9 is significantly overexpressed in high-grade PC tumors (P < 0.05) and in chemotherapy-treated patients compared to chemo-naïve patients (P < 0.05). These results were further validated using publicly available datasets. Moreover, afatinib alone or in combination with gemcitabine decreased stemness and tumorspheres by reducing phosphorylation of EGFR family proteins, ERK, FAK, and CSC markers. Mechanistically, afatinib treatment decreased CSC markers by downregulating SOX9 via FOXA2. Indeed, EGFR and FOXA2 depletion reduced SOX9 expression in PCSCs. Taken together, pan-EGFR inhibition by afatinib impedes PCSCs growth and metastasis via the EGFR/ERK/FOXA2/SOX9 axis. This novel mechanism of pan-EGFR inhibitor and its ability to eradicate CSC may serve as a tailor-made approach to enhance chemotherapeutic benefits in other cancer types.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Afatinib / therapeutic use
  • Animals
  • Cell Line, Tumor
  • Deoxycytidine / analogs & derivatives
  • Deoxycytidine / therapeutic use
  • ErbB Receptors / antagonists & inhibitors
  • ErbB Receptors / physiology
  • Gemcitabine
  • Hepatocyte Nuclear Factor 3-beta / antagonists & inhibitors*
  • Hepatocyte Nuclear Factor 3-beta / physiology
  • Humans
  • Mice
  • Neoplasm Metastasis
  • Neoplastic Stem Cells / drug effects
  • Pancreatic Neoplasms / drug therapy*
  • Pancreatic Neoplasms / pathology
  • SOX9 Transcription Factor / antagonists & inhibitors*
  • SOX9 Transcription Factor / physiology

Substances

  • FOXA2 protein, human
  • SOX9 Transcription Factor
  • SOX9 protein, human
  • Deoxycytidine
  • Hepatocyte Nuclear Factor 3-beta
  • Afatinib
  • EGFR protein, human
  • ErbB Receptors
  • Gemcitabine