广西医学

目的探讨芒柄花黄素对鼻咽癌5-8F细胞增殖和周期的影响及其可能的作用机制。方法将5-8F细胞分为溶剂对照组（加入完全培养液）、不同浓度芒柄花黄素组（加入终浓度为10 μmol/L、20 μmol/L、40 μmol/L、80 μmol/L、160 μmol/L的芒柄花黄素）、5-氟尿嘧啶（5-Fu）组（加入5-Fu）。分别干预24 h、48 h后，采用MTT法检测各组5-8F细胞增殖率。干预24 h后采用PI染色检测溶剂对照组、20 μmol/L芒柄花黄素组、40 μmol/L芒柄花黄素组、80 μmol/L芒柄花黄素组、5-Fu组的5-8F细胞周期。干预24 h后采用Western blot检测溶剂对照组、20 μmol/L芒柄花黄素组、40 μmol/L芒柄花黄素组、5-Fu组的5-8F细胞增殖细胞核抗原(PCNA)和细胞周期蛋白依赖性激酶1（CDK1）的蛋白表达水平。结果（1）干预24 h和48 h后，20 μmol/L、40 μmol/L、80 μmol/L、160 μmol/L芒柄花黄素组及5-Fu组5-8F细胞增殖率低于溶剂对照组（P＜0.05）。干预24 h后，10 μmol/L、20 μmol/L、40 μmol/L芒柄花黄素组5-8F细胞增殖率高于5-Fu组；干预48 h后，各浓度芒柄花黄素组5-8F细胞增殖率高于5-Fu组（P＜0.05）。（2）与溶剂对照组相比，20 μmol/L、40 μmol/L、80 μmol/L芒柄花黄素组和5-Fu组的G0/G1期细胞比例降低、G2/M期细胞比例增加（P＜0.05）；20 μmol/L、40 μmol/L、80 μmol/L芒柄花黄素组的G0/G1期细胞比例高于5-Fu组，G2/M期细胞比例低于5-Fu组（P＜0.05）。（3）与溶剂对照组相比，20 μmol/L、40 μmol/L芒柄花黄素组和5-Fu组的CDK1和PCNA蛋白表达水平下降（P＜0.05）；5-Fu 组的CDK1和PCNA蛋白表达水平高于40 μmol/L芒柄花黄素组，PCNA蛋白表达水平低于20 μmol/L芒柄花黄素组（P＜0.05）。结论芒柄花黄素能够抑制鼻咽癌5-8F细胞增殖，并阻滞细胞周期于G2/M期，其作用机制可能与下调PCNA和CDK1的表达水平有关。但药物的抗肿瘤作用机制复杂，芒柄花黄素的抗鼻咽癌效果仍有待优化，其具体作用机制亦仍有待深入探究。

ObjectiveTo investigate the effect of formononetin on proliferation and cycle of nasopharyngeal carcinoma 5-8F cells and its possible mechanism. MethodsCells of 5-8F were assigned to solution control group (adding complete culture solution), formononetin in different concentrations groups (adding formononetin with final concentration of 10 μmol/L, 20 μmol/L, 40 μmol/L, 80 μmol/L, and 160 μmol/L), or 5-fluorouracil (5-Fu) group (adding 5-Fu). After 24 and 48 hours of respective intervention, the MTT method was used to detect the proliferation rate of 5-8F cells in various groups. After 24 hours of intervention, the PI staining was employed to detect 5-8F cells cycle in the solution control group, 20 μmol/L formononetin group, 40 μmol/L formononetin group, 80 μmol/L formononetin group, and 5-Fu group. After 24 hours of intervention, the Western blot was used to detect protein expressions of 5-8F cells proliferating cell nuclear antigen (PCNA) and cyclin dependent kinase 1 (CDK1) in the solution control group, 20 μmol/L formononetin group, 40 μmol/L formononetin group, and 5-Fu group.Results(1) After 24 and 48 hours of intervention, the 20 μmol/L, 40 μmol/L, 80 μmol/L, and 160 μmol/L formononetin groups and 5-Fu group exhibited lower proliferation rates of 5-8F cells as compared with the solution control group (P＜0.05). After 24 hours of intervention, the proliferation rates of 5-8F cells in the 10 μmol/L, 20 μmol/L, 40 μmol/L formononetin groups were higher than those in the 5-Fu group. After 48 hours of intervention, the proliferation rates of 5-8F cells in the formononetin with various concentrations groups were higher than those in the 5-Fu group (P＜0.05). (2) Compared with the solution control group, the proportion of cells in G0/G1 phase was decreased, while proportion of cells in G2/M phase was increased in the 20 μmol/L, 40 μmol/L, and 80 μmol/L formononetin groups and the 5-Fu group (P＜0.05). The proportion of cells in G0/G1 phase in the 20 μmol/L, 40 μmol/L, and 80 μmol/L formononetin groups was higher than that in the 5-Fu group, whereas the proportion of cells in G2/M phase was lower than that in the 5-Fu group (P＜0.05). (3) Compared with the solution control group, the protein expressions of CDK1 and PCNA were decreased in the 20 μmol/L and 40 μmol/L formononetin groups and the 5-Fu group (P＜0.05); moreover, the 5-Fu group exhibited higher protein expressions of CDK1 and PCNA as compared with the 40 μmol/L formononetin group, and a lower PCNA protein expression as compared with the 20 μmol/L formononetin group (P＜0.05).ConclusionFormononetin is able to inhibit proliferation of nasopharyngeal carcinoma 5-8F cells, and the cell cycle is blocked in G2/M phase. Its possible mechanism may be related to the down-regulated expressions of PCNA and CDK1; however, the anti-tumor mechanism of drug is complex, the anti-nasopharyngeal carcinoma effect of formononetin remains to be optimized, and its specific mechanism remains to be further explored.