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 different rat colon cancer cell lines transfected and non-transfected with Rous sarcoma virus-33 was studied. Concentrations of the p53 protein were detected by commonly used immunochemical methods after its isolation by affinity chromatography columns with the gel fiberglass membranes. The main component of tumor-associated antigens (TAA) eluted from virus-transfected cells was the 53 kDa protein in its cytoplasmic soluble fraction. The non-virogenic colon cancer cells contain a few proteins and concentration of 53 kDa protein was low. Western immunoblotting revealed that the 53 kDa protein isolated from the cell lyzates studied was distinctly recognized by the p53 MAb. ELISA showed that its concentration was markedly higher in the lyzate obtained from the highly virogenic 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 role of this phenomenon in the etiology of cancer is discussed.