丙戊酸盐对胃癌细胞株SGC-7901/VCR耐药性的逆转作用

Reversal effect of valproate on drug resistance in gastric cancer cell line SGC-7901/VCR

目的探讨丙戊酸盐对人胃癌耐药细胞株SGC-7901/VCR耐药的逆转作用。方法 MTT法检测SGC-7901/VCR对VCR的耐药指数;MTT法检测丙戊酸盐对SGC-7901和SGC-7901/VCR细胞增殖的抑制作用和对VCR耐药逆转的效果;用流式细胞术检测丙戊酸盐诱导细胞凋亡的作用,将SGC-7901/VCR细胞用VCR联合丙戊酸盐处理48h后,检测各组凋亡率的差别;用Western blot检测丙戊酸盐处理后蛋白质的表达水平,分别用不同浓度(0、0.5、1.0、2.0mmol/L)的丙戊酸盐作用于48h或同一浓度(1mmol/L)作用12、24、48h后,检测SGC-7901/VCR细胞中乙酰化组蛋白3(AcH3)表达水平对丙戊酸盐所呈现的剂量或时间依赖性变化。结果与亲代细胞SGC-7901相比,耐药细胞SGC-7901/VCR对VCR高度耐药,耐药指数为36.0(P<0.05);亲代细胞SGC-7901和耐药细胞SGC-7901/VCR对丙戊酸盐的敏感性相似,二者的IC50差异无统计学意义(P>0.05),丙戊酸盐与VCR联用能逆转SGC-7901/VCR细胞对VCR的耐药性,并增加细胞的凋亡(P<0.05);丙戊酸盐能增加SGC-7901/VCR细胞AcH3的表达,且具有浓度和时间依赖性。结论丙戊酸盐可通过诱导细胞凋亡和增加组蛋白的表达逆转SGC-7901/VCR细胞的耐药性。

Objective To explore the reversal effect of valproate on drug resistance of gastric cancer cell line SGC-7901/VCR. Methods The reversal effect of valproate on VCR resistance of SGC-7901/VCR was analyzed by MTT assay. Cells were treated with VCR and valproate for 48 hours,followed by measurement of cell survival rates. The apoptosis rates of SGC-7901/VCR cells were detected by FACS,cells were treated with VCR in combination with valproate for 48 hours followed by apoptosis assay with Annexin V staining. To detect the effect of valproate on the expression levels of AcH3,SGC-7901/VCR cells were treated with in creasing concentrations（0,0.5,1.0 and 2.0 mmol/L） of valproate for 48 hours,or with 1 mmol/L valproate for 12,24 or 48 hours, the expression levels of AcH3 were assayed by Western blot. Results Compared with the parental cell line SGC-7901 ,the drug re sistance cell line SGC-7901/VCR was highly resistant to VCR,and the resistance index was 36.0（P^0, 05）. The parental cell line SGC-7901 and the drug resistance cell line SGC-7901/VCR were almost equally sensitive to valproate with similar IC50 values（P~ 0.05）. Importantly,combinational use of VCR and valproate resulted in reversal of VCR resistance and induced apoptosis of SGC 7901/VCR cells（P〈0.05）. Furthermore,treatment with valproate increased expression levels of AcH3 in SGC-7901/VCR cells in a time and dosage dependent manner. Conclusion Valproate can reverse VCR resistance of SGC-7901/VCR through inducing apop tosis and increasing the expression of AcH3.