THE DECREASE OF EPIDERMAL GROWTH-FACTOR R ECEPTOR EXPRESSION IN THE CELLS OF SUBLINE A-431 1522-4 WITH THE FUSED GENE OF TRANSFORMING GROWTH-FACTOR ALPHA-TYPE/

The decrease of EGF-R expression in the A-431/1522-4 cells subline car rying recombinant TGF-alpha gene was observed (the decrease- of R-EGF expression is accompanied by the increase of TGF-alpha expression). Th e R-EGF quantity on the surface of cell membrane decreases essentially and accounts for 40-60 % of the R-EGF steady level of A-431 line. In certain cells the intensity of staining by anti-R-EGF antibodies is ve ry low, this shows the heterogeneity of A-431/1522-4 cell line in the number of receptors. Besides, an increased rate of internalization of I-125-EGF in A-431/1522-4 cell line was observed. Therefore, the proce sses of ligand-receptor interactions in A-431/1522-4 cell line are cha nged because of the increased expression of TGF-alpha.