Paraffin-embedded cervical tissue samples (n = 192) were collected for immunohistochemistry (IHC), while fresh cervical tissue samples (n = 165) and human cervical cell lines were collected for protein and mRNA detection by quantitative real-time PCR and western blot, respectively. Correlations between CFTR expression levels to cancer clinicopathologic features and prognosis were statistically analyzed.
Both CFTR mRNA and protein expression gradually increased from normal to precancerous (LSIL, HSIL) and cervical cancer tissues (p < 0.05). Furthermore, CFTR expression level was well-correlated to tumor stage (p < 0.001), histological grades (p < 0.001), lymphatic metastasis (p < 0.001), vascular invasion (p < 0.05), interstitial invasive depth (p < 0.05), tumor size (p < 0.05) and HPV infection (p < 0.05). In vitro, CFTR mRNA and protein were expressed strongly both in SiHa and HeLa, but little was seen in Caski and H8 (p < 0.05). More importantly, overexpression of CFTR conferred significantly poorer survival in cervical carcinoma (Log rank p = 0.028), although it was not an independent predictor for prognosis according to multivariate analysis (p > 0.05).
These results suggest that higher CFTR expression is closely associated with cervical cancer progression, aggressive behaviors and poorer prognosis, indicating that CFTR may function as a novel tumor marker, a prospective prognostic indicator and a potential therapeutic target for cervical cancer.