[Expression of proliferation and apoptosis related genes in colorectal adenoma with malignant transformation]

The effect of proliferation and apoptosis related genes of colorectal adenoma with malignant transformation and its clinicopathologic significance was studied.

p53, bcl-2, Fas, bax expression were detected immunohistochemically in 61 cases of colorectal adenoma with either mild or severe dysplasia and carcinoma. The rate of proliferation was evaluated with Ki-67 and apoptosis with TUNEL.

The positive rates for p53 and bcl-2 protein in carcinomatous area, adenoma with severe and mild dysplasia were 67.2%, 57.4%, 19.7% and 77.1%, 80.3%, 49.2% respectively. The mean Ki-67 index and PCD index were 38.4%, 36.5%, 16.1% and 2.2%, 1.9%, 0.5% respectively. The difference of the expression of p53 protein, bcl-2 protein and Ki-67 index, PCD index in carcinomatous region and adenoma with severe dysplasia compared with mild dysplasia was statistically significant (P < 0.05).

It is apparent that both apoptosis inhibition and abnormal proliferation play an important role in tumor formation. Adenoma with severe dysplasia is a lesion very close to carcinoma in nature, which possesses active tendency to become fully malignant. Detection of these proteins is important in the early diagnosis of malignant transformation of an adenoma.