High level of CFTR expression is associated with tumor aggression and knockdown of CFTR suppresses proliferation of ovarian cancer in vitro and in vivo

The cystic fibrosis transmembrane conductance regulator (CFTR) belongs to the ATP-binding cassette (ABC) transporter family, members of which are involved in various types of cancer. The relationship between CFTR and ovarian cancer remains to be elucidated. The aim of the present study was to investigate the expression of CFTR in human ovarian cancer tissues and its clinical significance in the progression of ovarian cancer. The role of CFTR in the malignant invasion, migration and proliferation of ovarian cancer in vitro and in vivo was also investigated. Immunohistochemical staining analysis was performed to detect the expression of CFTR in 83 cases of human epithelial ovarian cancer specimens. Moreover, SKOV3 and A2780 stable cell lines containing shRNA gene specific for CFTR were established. Cell proliferation and motility were observed and compared with CFTR-RNAi cells. Tumorigenicity of CFTR-RNAi cells was investigated by tumor xenograft experiments conducted subcutaneously in nude mice. The expresssion of CFTR in ovarian cancer was significantly higher than that in benign ovarian tumor and normal ovaries (P<0.05). In ovarian cancer, CFTR expression was significantly associated with advanced FIGO stage, poor histopathological grade and serum Ca-125 (P<0.05). Furthermore, we observed that CFTR staining was stronger in the serous type as compared to the other types (P<0.05). Compared with the negative control, decreased cell invasion, migration, proliferation, adhesion and colony formation were observed in CFTR-RNAi cells in vitro. In vivo, tumorigenic abilities of CFTR-RNAi cells were significantly repressed compared with that of the control groups. CFTR overexpression may play an important role in the development and progression of ovarian cancer. Additionally, the downregulation of CFTR suppresses aggressive malignant biological behaviors of ovarian cancer cells in vitro and in vivo.