EXPRESSION OF P53 PROTEIN IN RAT COLON-CANCER CELL-LINES TRANSFECTED WITH ROUS-SARCOMA VIRUS-33

Expression of the cytoplasmic soluble form of p53 protein in the diffe rent rat colon cancer cell lines transfected and nontransfected with R ous sarcoma virus-33 was studied. Concentrations of the p53 protein we re detected by commonly used immunochemical methods after its isolatio n by affinity chromatography columns with the gel fiberglass membranes , The main component of tumor-associated antigens (TAA) eluted from vi rus-transfected cells was the 53 kDa protein in its cytoplasmic solubl e fraction. The non-virogenic colon cancer cells contain a few protein s and concentration of 53 kDa protein was low. Western immunoblotting revealed that the 53 kDa protein isolated from the cell lyzates studie d was distinctly recognized by the p53 MAb. ELISA showed that its conc entration was markedly higher in the lyzate obtained from the highly v irogenic and tumorigenic R9 cell line compared with the non-virogenic cell line RT1. We concluded that the expression of the p53 protein is related to the viral transfection of cancerous cells. The possible rol e of this phenomenon in the etiology of cancer is discussed. (C) 1997 Elsevier Science Ireland Ltd.