Biopolymers and cell. 1997; 13 (4): 308 - 313

Transforming growth factor a production, EOF receptor level and expression of transformed phenotype in HEp-2 human carcinoma cells transfected with HIV-1 tat gene

A. A. Phylchenkov, 1. A. Yakimovich, A. G. Korchinsky, Yu. I. Kudryavels, R. S. Stoika

Several clones of HEp-2 human carcinoma cells transfected with HIV-1 lot regulatory gene were studied for the presence of transforming growth factor a (TGF-a) activity in the serum-free culture medium conditioned by these cells, the level of epidermal growth factor (EGF)lTGF-a receptors and the expression of transformed phenotype. Clone A5st was shown to secrete growth stimulating factors whose activity was inhibited by the monoclonal antibody against TGF-a. The cells of alt studied clones possessed the same level of EGFl TGF-a receptors measured by two different, methods — indirect flow cytometry and radioreceptor analysis. The expression of transformed phenotype (estimated on the basis of intensity of colonyforming by the cells cultured in the medium supplemented with 0.33 % agar) did not change under the effect of EOF in A5st clone producing TGF-a immunoreactivc factors. But this expression was induced in the other studied clones of HEp-2 cells. Thus, the expression of HIV-1 tat regulatory gene can induce cellular production of TGF-a which participates in the cell trans¬formation and in this way increases the risk of development of oncological diseases in AIDS patients.