G. Yu. Shuvayeva 1, Yaroslav P. Bobak 1, O. M. Mayevska 1, N. I. Igumentseva 1, M. L. Barska 1, R. Z. Sheremeta 2, Andriy Zuravthak 2, Alexander Shulyak 2, V. L. Buchman 3, Ludmila B. Drobot 1
- 1 Institute of Cell Biology, NAS of Ukraine, Lviv, Ukraine
2 Lviv National Medical University, Department of the Urology, Ukraine
3 Cardiff School of Biosciences, Cardiff University, United Kingdom
- Introduction and objectives. For today the renal tumors are the important object of cytogenetic and molecular genetic studies of searching target strategies against genes and encoded proteins involved in cancer progression. Ruk/CIN85 is a ubiquitously expressed SH3-containing adapter/scaffold protein that plays important roles in endocytosis-mediated down-regulation of receptor tyrosine kinase signalling and control of apoptosis. All the available functional data suggest that Ruk/CIN85 plays important roles in the regulation of homeostasis in normal cells and also can be involved in carcinogenesis. In the present study we investigate the expression of Ruk/CIN85 in human renal cell carcinoma.
- Materials and methods. Expression of Ruk/CIN85 adapter protein in human clear renal cell carcinomas (20 samples with its controls - morphologically nontransformed tissue isolated from the same operated organ after radical nephrectomy) was studied both at the level of mRNA and protein by using Northern-blotting and Western-blotting correspondingly as well as by immunohistochemistry. The insert of the RUK gene original 3E7clone was used as a probe for Northern hybridization. For protein analysis, N-termanal anti-SH3A monoclonal and C-terminal anti-Ruks polyclonal antibodies were used.
- Results. As the result of Northern-blotting 3,5 kb transcript encoded the full-length form of Ruk/CIN85 was detected in tumor and control samples. According to Western-blotting data, the main immunoreactive bands in analyzed specimens are presented by proteins with apparent molecular weights of 85, 70, 56, 34 kDa. It was shown that the expression of p85 full-length form decreased in 12 samples among 20 studied in comparison with its controls. The obtained data correlated with Northern-blotting results and were also confirmed by immunohistochemical studies.
- Conclusions. The data of our investigation suggest that decrease in the expression level of full-length form of Ruk/CIN85 adapter protein in renal cell carcinoma may lead to the loss of coordinated control of apoptosis and proliferation in the transformed epithelial cells.