Kindlin-2 Expression in Arsenite- and Cadmium-transformed Bladder Cancer Cell Lines and in Archival Specimens of Human Bladder Cancer

Abstract

To confirm a microarray study that suggested that Kindlin-2 might play a role in the development and progression of bladder cancer. There has been no previous examination of Kindlin-2 expression in human bladder cancer. A combination of real-time polymerase chain reaction, Western analysis, and immunohistochemistry was used to characterize Kindlin-2 expression in arsenite (As(+3))- and cadmium (Cd(+2))-transformed human cell lines, their tumor transplants in immunocompromised mice, and in archival specimens of human bladder and bladder cancer. The results show that the Kindlin-2 expression patterns in the cell lines were not duplicated in the tumor tissues. However, it was shown that Kindlin-2 was expressed in the stromal element of all the transplanted tumors and archival specimens of human bladder cancer. It was also shown that a small number of high-grade invasive urothelial cancers have focal expression of Kindlin-2 in the tumor cells. Kindlin-2 is expressed in the stromal component of most, if not all, human bladder cancers. Kindlin-2 is not expressed in normal urothelium. Kindlin-2 is expressed in a small subset of high-grade invasive bladder cancers and may have potential as a prognostic marker for tumor progression.