关键词: 组蛋白H3K27, CNE-1, 增殖, 细胞周期, 去甲基化酶抑制剂GSK-J4

Abstract: Objective To investigate the effects of inhibiting histone H3K27me3/2 demethylase on proliferation of well-differentiated human nasopharyngeal carcinoma cell in vitro and explore the underlying mechanisms. Methods Human nasopharyngeal carcinoma cell line CNE-1 was cultured in vitro, and histone H3K27me3/2 demethylation was specifically blocked by histone H3K27me3/2 demethylase inhibitor GSK-J4. The cells were incubated with 0.25,0.5,1.0,2.0,4.0 mmol/L GSK-J4 as the experimental groups, while DMSO was applied as control group. Immunofluorescence assay and flow cytometry were used to analyze the expression of intracellular histone H3K27me3. Real-time quantitative PCR was applied to detect the expression of cyclinD1 and Ki-67 mRNA in cells. Cell counting kit-8 (CCK-8) was used to evaluate cell proliferation. The cloning of CNE-1 cells was observed by colony formation assay. Flow cytometry was also used to detect cell cycle distribution. Results The expression level of histone H3K27me3 in the experimental group was significantly higher than that in the control group (P＜0.05); cyclinD1 and Ki-67 mRNA expression levels in the experimental groups were down-regulated compared with the control group (P＜0.05); The cell viability of CNE-1 cells decreased gradually with the increase of GSK-J4 concentration. The cell proliferation and colony formation in the experimental group were significantly decreased than those in the control group (P＜0.05); cell cycle was blocked in G₀/G₁ phase, the percentage of cells in G₀/G₁ phase was increased and the S phase decreased in the experimental group(P＜0.05). Conclusions Up-regulation of methylation of histone H3K27 in CNE-1 cells induces cell cycle arrest and inhibits cell proliferation. The mechanism may be related to down-regulation of cyclinD1 and Ki-67 mRNA levels.

Key words: histone H3K27, CNE-1, cell proliferation, cell cycle, demethylase inhibitor GSK-J4