Abstract: Abstract: Objective To investigate the effect of long non-coding RNA UCA1 on proliferation, invasion, apoptosis and cell cycle of human pharyngeal squamous cell carcinoma FaDu cells. Methods UCA1-siRNA was transfected into FaDu cells to silence UCA1, the untransfected cells were served as blank control, and transfected negative control siRNA cells were served as negative control. The interfering effect of UCA1-siRNA was determined by Real-time PCR. The effects of UCA1-siRNA on proliferation, invasion and cell cycle of FaDu cells were detected by CCK-8 assay, Transwell invasion assay and flow cytometry. Western blot assay was performed to evaluate the effect of UCA1-siRNA on the expressions of Bax, Bcl-2, cleaved-Caspase 9, cyclin D1 and PCNA proteins related to the proliferation, apoptosis and cell cycle of FaDu cells. Results Si-UCA1 effectively downregulated the expression of UCA1 in FaDu cells. After siRNA interference, the proliferation and invasion abilities of FaDu cells were significantly decreased, the proportion of cells in G1 phase was significantly increased and the proportions of cells in S phase and G2 phase were significantly decreased. The down-regulation of UCA1 by siRNA suppressed the expressions of Bcl-2, cyclin D1 and PCNA, meanwhile promoted the expressions of Bax and cleaved-Caspase 9 in FaDu cells (P＜0.05). Conclusion The downregulation of UCA1 inhibits the invasion and proliferation, blocks cell cycle, and promotes apoptosis of FaDu cells.

Key words: nasopharyngeal neoplasms, carcinoma, squamous cell, cell line, tumor, RNA, small interfering, cell proliferation, apoptosis, urothelial carcinoma associated 1