CAJ | 학술논문

目的探讨生长抑素(SST)增强阿霉素(DOX)杀伤胆囊癌细胞株(GBC-SD)的作用机制.方法以GBC-SD细胞为实验对象,按处理因素不同,共分为4组:SST组、DOX组、SST-DOX联合用药组和仅添加等量磷酸盐缓冲液(PBS)的对照组.根据我们以前的研究结果,药物作用浓度分别为SST(75 μg/ml),DOX(5μg/ml).药物作用0,6,12,24,36 h后,MTT法观察各组细胞活性;荧光分光光度法检测各组细胞内DOX浓度的变化;分别采用Real-time PCR与Western印迹检测药物作用后各时间点细胞多药耐药基因1(MDR1)mRNA表达及P-糖蛋白表达(P-gp)的变化情况.结果单独应用SST没有明显抑制GBC-SD细胞生长的作用(P＞0.05);药物作用12 h,与空白组比较,DOX组与SST+DOX组细胞杀伤显著增多,但DOX与SST+DOX组间差异无统计学意义;SST联合作用24 h可显著增强DOX对GBC-SD细胞的杀伤作用,与DOX组比较差异有统计学意义(P＜0.05).与DOX比较,SST联合作用可升高细胞内DOX浓度,二者间差异以联合作用24 h后最为显著(P＜0.05);SST作用可显著降低GBC-SD细胞MDR1 mRNA表达(P＜0.05)及其转录翻译产物P-gp蛋白表达(P＜0.05).结论 SST通过降低GBC-SD细胞内MDR1基因和P-gp蛋白的表达水平,使GBC-SD细胞泵出DOX减少,提高了细胞内DOX浓度,增强DOX对GBC-SD细胞的杀伤作用.
목적 탐토생장억소(SST)증강아매소(DOX)살상담낭암세포주(GBC-SD)적작용궤제.방법 이GBC-SD세포위실험대상,안처리인소불동,공분위4조:SST조、DOX조、SST-DOX연합용약조화부첨가등량린산염완충액(PBS)적대조조.근거아문이전적연구결과,약물작용농도분별위SST(75 μg/ml),DOX(5μg/ml).약물작용0,6,12,24,36 h후,MTT법관찰각조세포활성;형광분광광도법검측각조세포내DOX농도적변화;분별채용Real-time PCR여Western인적검측약물작용후각시간점세포다약내약기인1(MDR1)mRNA표체급P-당단백표체(P-gp)적변화정황.결과 단독응용SST몰유명현억제GBC-SD세포생장적작용(P＞0.05);약물작용12 h,여공백조비교,DOX조여SST+DOX조세포살상현저증다,단DOX여SST+DOX조간차이무통계학의의;SST연합작용24 h가현저증강DOX대GBC-SD세포적살상작용,여DOX조비교차이유통계학의의(P＜0.05).여DOX비교,SST연합작용가승고세포내DOX농도,이자간차이이연합작용24 h후최위현저(P＜0.05);SST작용가현저강저GBC-SD세포MDR1 mRNA표체(P＜0.05)급기전록번역산물P-gp단백표체(P＜0.05).결론 SST통과강저GBC-SD세포내MDR1기인화P-gp단백적표체수평,사GBC-SD세포빙출DOX감소,제고료세포내DOX농도,증강DOX대GBC-SD세포적살상작용.
Objective To investigate the possible mechanisms by which Somatostatin (SST)enhances the anti-tumor effect of doxorubicin (DOX) on gallbladder cancer cells. Methods GBC-SD cells were grouped into 4 groups: SST-treated group, DOX-treated group, SST + DOX co-treated group and control group. The concentrations of SST and DOX were 75 μg/ml and 5 μg/ml based on our previous studies. In control group, cells were cultivated with phosphate buffered saline (PBS). In experimental groups, cells were cultivated with medium and the corresponding drugs. After drug treatment, cell viability was examined by MTT assay at 6, 12, 24 and 36 h respectively. Meanwhile, intracellular concentrations of doxorubicin in each group was determined by microspectrofluorimetry; Real-time polymerase chain reaction (RT-PCR) was used to determine the expressions of MDR1 mRNA in the cells at different time points and the expressions of P-gp protein, a product of MDR1 mRNA, were determined by Western blot analysis. Results SST did not exhibit significant inhibitory effect on the proliferation of GBC-SD cells as compared to that of control group (P ＞ 0. 05). SST + DOX co-treatment group and DOX showed significantly inhibitory effect on the growth of GBC-SD cells at Hour 12 post-treatment. However no statistical difference was found between SST + DOX and DOX groups. Interestingly, at Hour 24 post-treatment, SST + DOX group showed more robust inhibitory effect on GBC-SD cells as compared to DOX alone group. Moreover, SST could significantly down-regulate the expressions of MDR1 mRNA and P-gp protein. SST could increase intracellular DOX concentration. And the difference of intracellular DOX concentration between SST + DOX group and DOX group at Hour 24 was statistically significant. Conclusions In our experiment, SST decreases the expression of MDR1 mRNA and P-gp protein so as to reduce the efflux of DOX and elevate DOX concentrations in GBC-SD cells. This eventually leads to enhanced cytotoxic effects of DOX on GBC-SD cells.