CLINICOPATHOLOGIC SIGNIFICANCE OF APOPTOSIS REIATED GENE PRODUCTS, bcl-2 AND p53, AND PCNA LABELING INDEX IN COLORECTAL CANCER

In this study, expressions of apoptosis related gene products, p53 protein and bcl-2 protein, and proliferating cell nuclear antigen (PCNA) in cancer tissues were explored by means of immunohistochemical staining, and their correlations with clinicopathological findings and prognosis were comparatively studied. The subjects were 50 patients operated on for colorectal cancer at the hospital. The positive rate to p53 protein was 60.0%, and had no significant correlations with clinicopathological factors. The positive rate to bcl-2 was 52.0%. The bcl-2 positive rates were significantly low in patients groups of depht of tumor invasion of si, ai, or more; venous invasion; lymph nodes metastasis; and hepatic metastasis (p<0.01). A mean of PCNA-LI was 52.8%; it became high in patients groups of lymph nodes metastasis; hepatic metastasis; peritoneal dissemination; and with increase in the depth of invasion. A clearly better prognoses were observed in bcl-2(+) group and low PCNA group than bcl-2(-) group and high PCNA group, respectively. The expression of bcl-2 protein was inversely related to PCNA-LI. It is suggested that the apoptosis related gene product bcl-2 protein deeply participates in the growth and proliferation of colorectal cancer, and can be an important prognostic factor.