Short hairpin RNA targeting FOXQ1 inhibits invasion and metastasis via the reversal of epithelial-mesenchymal transition in bladder cancer.

The epithelial-mesenchymal transition (EMT) promotes cancer invasion and metastasis, however, the integrative mechanisms that coordinate the process are incompletely understood. In this study, we defined a pivotal functional role for the Forkhead transcription factor FOXQ1 in regulating EMT in bladder cancer. We initially investigated the expression of FOXQ1, TGF-ß1 and EMT biomarkers E-cadherin, Vimentin in 65 cases of bladder transitional cell carcinoma (BTCC) specimens by reverse transcription-polymerase chain reaction (RT-PCR), western blot analysis and immunohistochemistry. Search results indicated that FOXQ1 expression was inversely correlated to E-cadherin, but positively to TGF-ß1 and Vimentin in patients with BTCC (P<0.05). Furthermore, we aimed to construct short hairpin RNA (shRNA) expression plasmids against the FOXQ1 gene and transfect shRNAs into high metastatic potential human bladder cancer T24 cells with Lipofectamine 2000. RNAi-mediated suppression of FOXQ1 expression reversed the EMT process accompanied by upregulation of E-cadherin, as well as a loss expression of Vimentin in highly invasive T24 cells (P<0.05). The inhibition of FOXQ1 expression with shRNA vector also led T24 cells to acquire an epithelial cobblestone phenotype, significantly reduced motility and subsequent invasiveness of bladder cancer cells (P<0.05). In conclusion that FOXQ1 may be a novel EMT-inducing transcription factor through controlling the expression of E-cadherin and aggressiveness of cancer cells and targeting the transcription factor FOXQ1 could hence serve as a novel therapeutic strategy for cancer patients.