Overexpressed miR-375-Loaded Restrains Development of Cervical Cancer Through Down-Regulation of Frizzled Class Receptor 4 (FZD4) with Liposome Nanoparticle as a Carrier

Dysregulation expression of miR-375 is noted to correlate with progression of cervical cancer. This study attempted to investigate the impact of overexpressed miR-375-loaded liposome nanoparticles on proliferation of cervical cancer (CC), to provide an insight on pathogenesis of CC disorder. CC cells were co-cultured with pure liposome nanoparticles (empty vector group), miR-375 agonist-loaded liposome nanoparticles, or transfected with miR-375 antagonist. Besides, some cells were exposed to TGF-beta/Smads signaling pathway inhibitor or activator whilst cell proliferation was assessed by MTT assay, and expressions of FZD4 and miR-375 were determined. Western blot analysis was carried out to detect the expression of TGF-beta pathway factors (TGF-beta, Smad2, Smad7, p-Smad2) and its downstream Smads pathway. The interaction between miR-375 and FZD4 was evaluated by dual-luciferase reporter gene assay. Overexpression of miR375 induced arrest at the G0/G1 phase of cell cycle and elevation of Smad2 protein expression (P < 0.05), with lower expressions of TGF-beta, Smad7, p-Smad2, and FZD4, while transfection with miR-375 inhibitor exhibited opposite activity. Presence of miR-375 agonist-loaded liposome nanoparticles induced decreased cell proliferation. There was a targeting relationship between miR-375 and FZD4, and administration with TGF-beta/Smads agonist resulted in increased miR-375 and Smad2 expressions, as well as decreased TGF-beta, Smad7, p-Smad2, FZD4 protein expression, and the number of S phase and G2/M phase cells (P < 0.05). The signaling inhibitor oppositely suppressed cell proliferation decreasing miR-375 expression. miR-375-loaded liposome nanoparticles activated TGF-beta/Smads signaling pathway to restrain cell cycle and suppress cell division, and proliferation through targeting FZD4 in CC. Its molecular mechanism is related to activation of TGF-beta/Smads signaling pathway.