DNA ploidy, c-myc oncoprotein p62 and v-H-ras oncoprotein p21 in colorectal carcinoma.

DNA ploidy and expression of the c-myc oncoprotein p62 and the v-H-ras oncoprotein p21 were examined in 54 colorectal carcinomas. DNA ploidy, determined by DNA flow cytometry, was diploid in 19 samples and aneuploid in 35. Expression of the p62 oncoprotein, determined by immunohistochemical staining, was intensely positive in 18 samples while that of the p21 oncoprotein, also determined by immunohistochemical staining, was positive in 29. There was no correlation between DNA ploidy and expression of the p62 oncoprotein, and DNA ploidy did not correlate with expression of the p21 oncoprotein. There was, however, a close correlation between expression of the p62 oncoprotein and that of the p21 oncoprotein being P < 0.01 according to Peason's chi-square test.