Abstract:

Objective To investigate the effect of long non-coding RNA GAS5 （lncRNA GAS5） on proliferation and apoptosis of laryngeal carcinoma Hep2 cells and its possible mechanism. Methods  Real-time fluorescence quantitative PCR （QPCR） was used to detect the expression of GAS5 in laryngeal carcinoma and adjacent normal tissues. The relationship between the expression of GAS5 and the clinicopathological features of laryngeal carcinoma was analyzed. Hep2 cells were transfected with pcDNA3.1-GAS5 or siGAS5， and pcDNA3.1-NC or siNC respectively as control. MTT assay was used to detect the proliferation activity of Hep2 cells after transfection， and Hep2 cell cycle and apoptosis were detected by flow cytometry. QPCR and Western blotting were used to detect the expression of E2F1 and BTF3 mRNA and protein. Results The expression levels of GAS5 in laryngeal carcinoma and adjacent normal tissues were 0.56±0.10 and 0.98±0.11 respectively， and the difference was statistically significant（P＜0.05）. The expression of GAS5 was related to the degree of differentiation and TNM stage. The survival rate of Hep2 cells in pcDNA3.1-GAS5 group at 24， 48， 72 and 96 hours was significantly lower than that in pcDNA3.1-NC group （P＜0.05）， and that in siGAS5 group was significantly higher than that in siNC group （P＜0.05）. The proportion of G1 phase cells transfected with pcDNA3.1-GAS5 was（68.14±4.33）％ higher than that of pcDNA3.1-NC group（P＜0.05）. The apoptotic rate in group pcDNA3.1-GAS5 was higher than that in group pcDNA3.1-NC， and the difference was statistically significant （P＜0.05）. The mRNA and protein levels of E2F1 and BTF3 in pcDNA3.1-GAS5 transfection group were significantly lower than those in pcDNA3.1-NC group （P＜0.05）； the mRNA and protein levels of E2F1 and BTF3 in siGAS5 transfection group were significantly higher than those in siNC group （P＜0.05）. Conclusion GAS5 can negatively regulate the expression of E2F1 and BTF3， and thus participate in the regulation of laryngeal cancer cell proliferation and apoptosis.

Key words: Laryngeal carcinoma, GAS5, Transcription factor E2F1, Basic transcription factor 3, Proliferation, Prognosis