Growth arrest-specific gene 6 expression in human breast cancer

Br J Cancer. 2008 Mar 25;98(6):1141-6. doi: 10.1038/sj.bjc.6604260. Epub 2008 Feb 19.


Growth arrest-specific gene 6 (Gas6), identified in 1995, acts as the ligand to the Axl/Tyro3 family of tyrosine kinase receptors and exerts mitogenic activity when bound to these receptors. Overexpression of the Axl/Tyro3 receptor family has been found in breast, ovarian and lung tumours. Gas6 is upregulated 23-fold by progesterone acting through the progesterone receptor B (PRB). Recently, Gas6 has been shown to be a target for overexpression and amplification in breast cancer. Quantitative real-time PCR analysis was used to determine the levels of Gas6 mRNA expression in 49 primary breast carcinomas. Expression of PRB protein was evaluated immunohistochemically with a commercially available PRB antibody. The results showed a positive association between PRB protein and Gas6 mRNA levels (P=0.04). Gas6 correlated positively with a number of favourable prognostic variables including lymph node negativity (P=0.0002), younger age at diagnosis (P=0.04), smaller size of tumours (P=0.02), low Nottingham prognostic index scores (P=0.03) and low nuclear morphology (P=0.03). This study verifies for the first time the association between PRB and Gas6 in breast cancer tissue.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / genetics*
  • Disease-Free Survival
  • Female
  • Gene Expression
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics*
  • Middle Aged
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis
  • Receptors, Progesterone / metabolism
  • Risk Factors
  • Survival Analysis


  • Intercellular Signaling Peptides and Proteins
  • RNA, Messenger
  • Receptors, Progesterone
  • growth arrest-specific protein 6
  • progesterone receptor B