It is important to understand the molecular mechanisms of
bladder cancer progression not only to prevent
cancer progression but also to detect new therapeutic targets against advanced
bladder cancer. The
integrin-linked kinase (ILK) is a major signaling integrator in mammalian cells and plays an important role in epithelial-mesenchymal transition (EMT) of human
cancers, but its mechanisms are not completely understood. In this study, we investigated the importance and mechanisms of ILK in
bladder cancer progression. When the expression of ILK in
bladder cancer cell lines and N-butyl-N-(4-hydroxybutyl)
nitrosamine (BBN)-induced murine
bladder cancer was evaluated, ILK has a tendency to be overexpressed in invasive cell lines and invasive BBN-induced murine
bladder cancer. Overexpression of ILK in 253J
bladder cancer cells suppressed
E-cadherin expression, resulting in the promotion of cell invasion. Conversely, ILK knockdown by
siRNA suppresses cell invasion in invasive
bladder cancer cells through the regulation of
E-cadherin or matrix
metalloprotease 9 (MMP-9). To regulate
E-cadherin expression, our results showed that the
glycogen synthase kinase 3β (GSK3β)-Zeb1 pathway may play an important role downstream of ILK. Finally, the results of a human bladder tissue microarray (TMA) showed that ILK expression correlates with the invasiveness of human
bladder cancer. Our study suggests that ILK is overexpressed in invasive
bladder cancer and plays an important role in the EMT of
bladder cancer via the control of
E-cadherin and MMP-9 expression. ILK may be a new molecular target to suppress
tumor progression in advanced and high-risk
bladder cancer patients.