Constitutive activation of pp125fak in newly isolated human breast cancer cell lines

摘要: Summary Our laboratory has developed twelve human breast cancer cell lines from primary and metastatic sites. In this report we demonstrate that eight of examined exhibit constitutively tyrosine phosphorylated enzymatically active endogenous pp125 fak when grown in monolayer. The activation status cells monolayer is significantly elevated over exhibited by normal mammary epithelial cultured under the same conditions. Constitutive only characteristic so far studied all these have common. contrast to HBC cells, phosphorylation HME was low or absent culture but induced high levels culturing Matrigel. Thus a regulated process constitutive cells. Finally, analysis ability grow anchorage-independent conditions indicated rapidly uniformly lost viability not substrate-attached, whereas survived for 3-week period. Furthermore, subset grew form large colonies Interestingly, decreased dramatically two weeks suspension, suggesting kinase necessary long-term growth These results suggest preferential survival sole mediator colony formation.