ObjectiveTo study the expression of apoptosissuppressing gene (bcl2) and apoptosispromoting gene (bax) in colorectal cancerous tissue and transitional mucosas. MethodsColorectal cancerous tissue, transitional mucosas (3 cm from the cancerous tissue) and normal tissue were taken respectively in thirtyone cases. Immunohistochemical technique SP method was used to detect the expression in those tissues. ResultsThe positive expression rate of bcl2 protein in cancerous tissue and transitional mucosa were 64.5%and 60.0% respectively and significantly higher than that in normal tissue (P＜0.05). The positive expression rate of bcl2 protein in normal tissue was 35.0%. The positive expression rate of bax protein in cancerous tissue and transitional mucosa were 45.2%and 45.0% respectively and significantly lower than that in normal mucosa (P＜0.05). The positive expression rate of bax protein in normal tissue was 60.0%. There was no obvious difference in the positive rate of bax and bcl2 protein between cancerous tissue and transitional mucosa (Pgt;0.05). The expression rate of bax and bcl2 protein in colorectal cancer was irrelative to clinical pathological gradation and clinical stage (Pgt;0.05). ConclusionThere is over expression of bcl2 protein and low expression of bax protein in colorectal cancer and transitional mucosa. bcl2 protein and bax protein can affect the generation of colorectal cancer by participating in the regulation of apoptosis. But it is irrelative to clinical pathological gradation and clinical stage. Transitional mucosas should be viewed as precancerous lesion and resected during operation.
The expression and rearrangement of bcl-2 gene in 64 cases with colorectal carcinoma were studied by immunohistochemical technique and semi-nest PCR respectively. The results showed the abnormal changes of the expression and rearrangement of bcl-2 gene had emerged in the early stage of colorectal carcinoma. The tumors with the expression of bcl-2 were associated with a higher incidence of metastasis to lymphatic node. The rearragement of bcl-2 was significantly higher in late-stage than that in early-stage. These suggest that bcl-2 gene involves in the regulation of the development of colorectal carcinoma. The state of the changes of bcl-2 gene in colorectal carcinoma may predict the therapeutic effect and prognosis of colorectal carcinoma.