Oncogenes and tumor suppressor gene expressed in human bladder tumor

Kim, wun Jae; Song, Hyung Geun; Kim, Young Kyoon

Abstract

Bladder tumor, like many other types of solid tumors, is expected to arise through a series of genertic changes that lead to tumor progression. These changes have been directly identified as alterations of various genes usually involved in cell growth and proliferation. Two basic types of these cellular genes have been identified as oncogenes and tumor suppressor genes.25 transitional cell carcinoma and 1 squamous cell carcinoma specimens of the human bladder were analyzed immunohistochemically to detect the expression of ras family(H-, K-, N- ras), c-myc, c-jun/AP-1, and p53 proteins.The expression of these proteins was not detected in 1 case of squamous cell carcinoma. In 25 transitional cell carcinomas, the positive staining of H-ras and p53 proteins was observed in 8 cases (32%) and 6 cases (24%), respectively. H-ras was expressed in 1 Ta (1/6), 6 T1 (6/11), 1 T3b (1/2), and in 3 grade I (3/10), 4 grade II (4/11), 1 grade III (1/4), but the positive staining was not significantly correlated with tumor stage and grade. The expression of p53 was found in 2 T1 (2/11), 1 T2 (1/3), 1 T3a (1/3), 2 T3b (2/2), and 1 grade I (1/10), 1 grade II (1/11), 4 grade III (4/4). The tumor grade was significantly correlated with the positivity of p53(p<0.005). Although the expression of p53 in higher state tumor tended to be higher than lower stage tumor, there was no correlation between stage and p53 expression. Probably due to the expression of p53 correlated with histological grade and individual positive tumor cell showing a malignant feature, p53 expression might be related to tumor progression.In 4 cases of high stage and grade transitional cell carcinoma, both H-ras and p53 proteins were expressed. These data suggested that H-ras and p53 might act on tumorigenesis and malignant potential in bladder transitional cell carcinoma collaboratively. But, K-ras, N-ras, c-jun/AP-1, and c-myc oncoproteins were not detected at all.