Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is expressed in the epithelial cells of a wide range of organs/tissues from which most cancers are derived. Although accumulating reports have indicated the association of cancer incidence with genetic variations in CFTR gene, the exact role of CFTR in cancer development and the possible underlying mechanism have not been elucidated. Here, we report that CFTR expression is significantly decreased in both prostate cancer cell lines and human prostate cancer tissue samples. Overexpression of CFTR in prostate cancer cell lines suppresses tumor progression (cell growth, adhesion and migration), whereas knockdown of CFTR leads to enhanced malignancies both in vitro and in vivo. In addition, we demonstrate that CFTR knockdown-enhanced cell proliferation, cell invasion and migration are significantly reversed by antibodies against either urokinase plasminogen activator (uPA) or uPA receptor (uPAR), which are known to be involved in various malignant traits of cancer development. More interestingly, overexpression of CFTR suppresses uPA by upregulating the recently described tumor suppressor microRNA-193b (miR-193b), and overexpression of pre-miR-193b significantly reverses CFTR knockdown-enhanced malignant phenotype and abrogates elevated uPA activity in prostate cancer cell line. Finally, we show that CFTR gene transfer results in significant tumor repression in prostate cancer xenografts in vivo. Taken together, the present study has demonstrated a previously undefined tumor-suppressing role of CFTR and its involvement in regulation of miR-193b in prostate cancer development.

Since the publication of the above article the authors have identified a number of errors in Supplemental Table S1: Chemical properties of inS3-54 and its analogues. The corrections made are listed below:The formula for A3 has been amended to C 28 H 18 Cl 2 N 2 O 4 from C 28 H 18 ClN 2 O 4 . The structure of A30 R1 has been amended.The structure of A55 R2 has been amended. The formula for A58 has been amended to C 24 H 17 Cl 2 NO 2 from C 24 H 17 ClN 2 O 2 . The structure of A63 R1 has been amended.The amended table is available online.The authors wish to apologise for any inconvenience caused.