Tyrosine phosphorylation of 100-130 kDa proteins in lung cancer correlates with poor prognosis

Abstract

Summary To search for the signalling pathways in lung cancer relevant to its aggressive behaviour, we studied tyrosine phosphorylated proteins in lung cancer cell lines and surgical specimens. We found that the profiles of protein phosphorylation were closely matched among these cell lines and cancer tissues of different histological origins, and 100 -130 kDa proteins were the major components of phosphorylated proteins. In surgical specimens, approximately half of the cases showed tyrosine phosphorylation of these proteins in a tumourspecific manner, and phosphorylation of these proteins showed good correlation with the survival length of patients after operation. By immunoprecipitation with specific antibodies, we found that pl25FAK, p120 and ,Bcatenin were the major components of tyrosine-phosphorylated proteins in the surgical specimens. These results suggest that tyrosine phosphorylation of these proteins may play a role in tumour relapse and is available as a clinical marker.

Pulmonary perspective: immunology in diagnosis and treatment of lung cancer

“…Interestingly, recent studies in lung cancer also support the role of tyrosine phosphorylation in tumorigenesis. Thus, one report demonstrated that tyrosine phosphorylation used in vitro is a mitogenic signal in SCLC, while another study found a good correlation between the presence of tyrosine phosphorylated proteins in resected lung tumours and tumour relapses after surgery [170,171].…”

Overexpression of RhoA, Rac1, and Cdc42 GTPases Is Associated with Progression in Testicular Cancer

“…Recent studies have shown that overexpression of p120 catenin leads to morphological change and increased cell migration by modulating Rho GTPases, e.g., Rac1/Cdc42 activation and RhoA inactivation (31)(32)(33), suggesting that p120 catenin is a key regulator of Rho-family GTPases in both cell-cell adhesion and migration. Furthermore, tyrosine phosphorylation of p120 catenin is associated with tumor relapse, and p120 catenin is available as a clinical marker in human lung cancer (34). It should be possible to elucidate the specific roles of each member of the Rho family GTPases, the cross-talk between members, and the regulators of their function to understand the molecular mechanisms of carcinogenesis and spread of testicular GCT.…”

Phosphorylated tyrosine-containing proteins in primary lung cancer correlates with proliferation and prognosis

“…Yet, there are a few reports concerning the relationship between the expression of pTyr-proteins and human cancer (Hunter and Sefton, 1980;Shibamoto et al, 1994). According to a previous investigation using immunoprecipitation, the overexpression of tyrosine-phosphorylated 100 -130 kDa proteins correlated with poor prognosis in lung cancer cases (Nishimura et al, 1996;Imaizumi et al, 1997). We also detected these 100 -130 kDa pTyr-proteins by Western blot analysis of surgically resected materials of both normal and cancerous tissues of the lung (Figure 2).…”

“…Furthermore, increase of pTyr-proteins might correlate with the morphological transformation of tumour cells (Hamaguchi et al, 1988). Clinically, it was reported that overexpression of pTyrproteins 100 -130 kDa in molecular weight might predict shortened survival of lung cancer patients (Nishimura et al, 1996). Thus, a close relationship between tyrosine phosphorylation and biological characteristics of the malignant tumours has been speculated upon.…”