The study by Nanda R. Rodrigues et al. investigates the overexpression of p53 protein in colorectal cancer and its molecular basis. Immunohistochemical staining of primary colorectal carcinomas revealed overexpression of p53 in approximately 50% of malignant tumors, while benign adenomas were negative. To understand this overexpression, the researchers examined p53 protein expression in 10 colorectal cancer cell lines. Six of these cell lines showed high levels of p53 expression, which was confirmed by ELISA, cell-staining, and immunoprecipitation studies. Direct sequencing and chemical-mismatch-cleavage analysis of p53 cDNA using PCR identified mutant p53 proteins in all six cell lines with high p53 expression. In two of the four cell lines with lower p53 expression, point mutations were still detected. The findings suggest that overexpression of p53 is synonymous with mutation, but some mutations may not be detected by immunohistochemical analysis. The study concludes that mutation of the p53 gene is a common genetic change in the development of human colorectal cancer, emphasizing its significance in both prevention and treatment strategies.The study by Nanda R. Rodrigues et al. investigates the overexpression of p53 protein in colorectal cancer and its molecular basis. Immunohistochemical staining of primary colorectal carcinomas revealed overexpression of p53 in approximately 50% of malignant tumors, while benign adenomas were negative. To understand this overexpression, the researchers examined p53 protein expression in 10 colorectal cancer cell lines. Six of these cell lines showed high levels of p53 expression, which was confirmed by ELISA, cell-staining, and immunoprecipitation studies. Direct sequencing and chemical-mismatch-cleavage analysis of p53 cDNA using PCR identified mutant p53 proteins in all six cell lines with high p53 expression. In two of the four cell lines with lower p53 expression, point mutations were still detected. The findings suggest that overexpression of p53 is synonymous with mutation, but some mutations may not be detected by immunohistochemical analysis. The study concludes that mutation of the p53 gene is a common genetic change in the development of human colorectal cancer, emphasizing its significance in both prevention and treatment strategies.