Elevated expression of flotillin-1 is associated with lymph node metastasis and poor prognosis in early-stage cervical cancer

Accumulating evidence has revealed that the expression of the lipid raft protein flotillin-1 is elevated in various human cancers, but the role flotillin-1 plays in the carcinogenesis of cervical cancer remains unclear. The expression profile of flotillin-1 was assayed using real-time PCR, western blotting, and immunohistochemical (IHC) staining in cervical cancer cell lines and cancer tissues with paired adjacent noncancerous cervical tissues. The expression of flotillin-1 protein was detected by IHC staining in a large cohort of 308 paraffin-embedded cervical cancer tissues. Ectopic expression and the short hairpin RNA interference approach were employed to determine the role of flotillin-1 in cervical cancer cell metastasis and the possible mechanism involved. Flotillin-1 expression protein and mRNA were significantly upregulated in cervical cancer cell lines and cancer tissues; elevated expression of flotillin-1 protein in early-stage cervical cancer was significantly associated with pelvic lymph node metastasis (P < 0.001), and was an independent predictive factor of poor overall survival. Moreover, flotillin-1 up-and downregulation remarkably affected cervical cancer cell motility and invasion, respectively, through epithelial-mesenchymal transition (EMT) regulated by the Wnt/beta-catenin and nuclear factor-kappa B (NF-kappa B) pathways. Our results suggest that flotillin-1 facilitates cervical cancer cell metastasis through Wnt/beta-catenin and NF-kappa B pathway-regulated EMT and that the flotillin-1 expression profile serves not only as novel predictor of pelvic lymph node metastasis, but also as neoteric risk factor for patients with early-stage cervical cancer.