Oncogenic K-Ras upregulates ITGA6 expression via FOSL1 to induce anoikis resistance and synergizes with αV-Class integrins to promote EMT

Oncogene. 2017 Oct 12;36(41):5681-5694. doi: 10.1038/onc.2017.177. Epub 2017 Jun 12.

Abstract

In many cancer types, integrin-mediated signaling regulates proliferation, survival and invasion of tumorigenic cells. However, it is still unclear how integrins crosstalk with oncogenes to regulate tumorigenesis and metastasis. Here we show that oncogenic K-RasV12 upregulates α6-integrin expression in Madin-Darby canine kidney (MDCK) cells via activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)/Fos-related antigen 1-signaling cascade. Activated α6-integrins promoted metastatic capacity and anoikis resistance, and led to perturbed growth of MDCK cysts. Transcriptomic analysis of K-RasV12-transformed MDCK cells also revealed robust downregulation of αV-class integrins. Re-expression of αV-integrin in K-RasV12-transformed MDCK cells synergistically upregulated the expression of Zinc finger E-box-binding homeobox 1 and Twist-related protein 1 and triggered epithelial-mesenchymal transition leading to induced cell motility and invasion. These results delineate the signaling cascades connecting oncogenic K-RasV12 with α6- and αV-integrin functions to modulate cancer cell survival and tumorigenesis, and reveal new possible strategies to target highly oncogenic K-RasV12 mutants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anoikis / genetics
  • Cell Proliferation / genetics
  • Dogs
  • Epithelial-Mesenchymal Transition / genetics*
  • Humans
  • Integrin alpha6 / genetics
  • Integrin alphaV / genetics*
  • Madin Darby Canine Kidney Cells
  • Neoplasms / genetics*
  • Neoplasms / pathology
  • Proto-Oncogene Proteins c-fos / genetics*
  • Proto-Oncogene Proteins p21(ras) / genetics

Substances

  • ITGA6 protein, human
  • Integrin alpha6
  • Integrin alphaV
  • KRAS protein, human
  • Proto-Oncogene Proteins c-fos
  • fos-related antigen 1
  • Proto-Oncogene Proteins p21(ras)