Analysis of the NF-κB and Apoptosis Inducing Genes in Bladder Tumor

Abstract

Purpose: A multi-subunit transcription factor NF-κB mediates the antiapoptotic signals in several cancer cell lines and it is activated in a broad range of human tumors. In this study, we investigated whether the expression levels of the NF-κB and the apoptosis inducing genes were related to the pathogenesis and clinical properties of human bladder tumor. Materials and Methods: The expressions of NF-κB, BCL2-associated X protein (BAX), BCL2-associated death protein (BAD) and BH3-interacting domain death agonist protein (BID) were investigated by performing immunohistochemical staining on 133 archival bladder tissue paraffin blocks; these blocks included 122 transitional cell carcinomas of the urinary bladder and 11 normal bladder mucosae. Results: The expression levels of NF-κB were significantly higher in the bladder tumors than those of the normal bladder mucosae (p=0.001). The expression levels of BAX in the superficial and low-grade (grade 1 and 2) bladder tumors were significantly enhanced more than those of the high-grade and invasive cases (p=0.042 and p=0.045, respectively), while the expression levels of BAD in the tumor tissues and low-grade tumors were significantly elevated compared with those of the normal mucosae and high grade tumor (p=0.007 and p=0.048, respectively). But the expressions of BID were not correlated with any pathologic and clinical properties. Conclusions: The expressions of the NF-κB and apoptosis inducing genes such as BAX and BAD are strongly associated with the pathogenesis and clinical properties of bladder tumor. (Korean J Urol 2007;48:483-488)