An integrin alpha(v)beta(3)-c-Src oncogenic unit promotes anchorage-independence and tumor progression

Nat Med. 2009 Oct;15(10):1163-9. doi: 10.1038/nm.2009. Epub 2009 Sep 6.

Abstract

Integrins regulate adhesion-dependent growth, survival and invasion of tumor cells. In particular, expression of integrin alpha(v)beta(3) is associated with progression of a variety of human tumors. Here we reveal a previously undescribed adhesion-independent role for integrin alpha(v)beta(3) in pancreatic cancer and other carcinomas. Specifically, alpha(v)beta(3) expressed in carcinoma cells enhanced anchorage-independent tumor growth in vitro and increased lymph node metastases in vivo. These effects required recruitment of c-Src to the beta(3) integrin cytoplasmic tail, leading to c-Src activation, Crk-associated substrate (CAS) phosphorylation and tumor cell survival that, unexpectedly, was independent of cell adhesion or focal adhesion kinase (FAK) activation. Pharmacological blockade of c-Src kinase activity or decreased expression of endogenous alpha(v)beta(3) integrin or c-Src not only inhibited anchorage-independent growth but also suppressed metastasis in vivo, yet these manipulations did not affect tumor cell migration or invasion. These data define an unexpected role for an integrin as a mediator of anchorage independence, suggesting that an alpha(v)beta(3)-c-Src signaling module may account for the aggressive behavior of integrin alpha(v)beta(3)-expressing tumors in humans.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • CSK Tyrosine-Protein Kinase
  • Carcinoma / metabolism
  • Carcinoma / pathology
  • Cell Adhesion / physiology
  • Cell Proliferation
  • Female
  • Fibronectins / metabolism
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism
  • Green Fluorescent Proteins / metabolism
  • Humans
  • In Situ Nick-End Labeling / methods
  • Integrin alphaVbeta3 / metabolism*
  • Ki-67 Antigen / metabolism
  • Lymphatic Metastasis
  • Mice
  • Mice, Nude
  • Neoplasm Invasiveness
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Protein-Tyrosine Kinases / metabolism*
  • RNA, Small Interfering / metabolism
  • Substrate Specificity
  • Time Factors
  • Transfection
  • Transplantation, Heterologous
  • Tumor Cells, Cultured
  • src-Family Kinases

Substances

  • Fibronectins
  • Integrin alphaVbeta3
  • Ki-67 Antigen
  • RNA, Small Interfering
  • Green Fluorescent Proteins
  • Protein-Tyrosine Kinases
  • CSK Tyrosine-Protein Kinase
  • Focal Adhesion Protein-Tyrosine Kinases
  • src-Family Kinases
  • CSK protein, human