大黄素提高胰腺癌细胞化疗敏感性的机制研究

Mechanism of emodin enhancing chemosensitivity of pancreatic cancer cells

目的 探讨大黄素能否提高胰腺癌细胞化疗敏感性及其作用机制.方法 设立对照组（正常人皮肤成纤维细胞/胰腺癌BXPC-3细胞）,顺铂组（5 mg/L）,吉西他滨组（0.5 μmol/L）,大黄素与顺铂联合组（50 μmol/L、5 mg/L）,大黄素与吉西他滨联合组（50 μmol/L、0.5 μmol/L）.应用MTT法检测细胞存活率,流式细胞仪检测细胞凋亡率,RT-PCR法检测不同细胞株中多药耐药相关蛋白1（MRP1）、多药耐药相关蛋白2（MRP2）、乳腺癌耐药蛋白（BCRP）和P-糖蛋白（P-gp）mRNA的表达.采用t检验比较两组差异.结果 顺铂组胰腺癌BXPC-3细胞的存活率和凋亡率分别为62.44%±3.42%和27.10%±4.24%,大黄素与顺铂联合组胰腺癌BXPC-3细胞的存活率和凋亡率分别为30.53%±0.05%和66.33%±9.37%,两组比较,差异有统计学意义（t=13.20,5.35,P〈0.05）.吉西他滨组胰腺癌BXPC-3细胞的存活率和凋亡率分别为79.82%±2.83%和13.48%±1.65%,大黄素与吉西他滨联合组胰腺癌BXPC-3细胞的存活率和凋亡率分别为45.65%±2.46%和62.74%±10.18%,两组比较,差异有统计学意义（t=12.89,8.28,P〈0.05）.顺铂组和大黄素与顺铂联合组正常人皮肤成纤维细胞存活率比较,差异无统计学意义（t=2.08,P〉0.05）.吉西他滨组和大黄素与吉西他滨联合组正常人皮肤成纤维细胞存活率比较,差异无统计学意义（t=0.64,P〉0.05）.在胰腺癌BXPC-3细胞中,只能检测到MRP1 mRNA的表达,未能检测到MRP2、BCRP、P-gp mRNA的表达.顺铂组胰腺癌BXPC-3细胞的MRP1 mRNA表达水平显著降低,而大黄素与顺铂联合组胰腺癌BXPC-3细胞的MRP1 mRNA表达水平则进一步下调.结论 大黄素能够提高胰腺癌细胞对顺铂的敏感性,其机制与下调的MRP1 mRNA表达有关.

Objective To investigate whether emodin enhances chemosensitivity of pancreatic cancer cells and the mechanism. Methods Normal human skin fibroblasts and pancreatic BXPC-3 cells were divided into control group, cisplatin （5 mg/L） treatment group, gemcitabine （0.5 μmol/L） treatment group, emodin （50 μmol/L）＋ cisplatin （5 mg/L） co-treatment group and emodin （50 μmol/L） ＋ gemcitabine （0.5 μmol/L） co-treatmentgroup. The cell viability was detected by MTT assay, the cell apoptosis rate by flow cytometry, the expression of the multidrug resistance-associated protein 1 （ MRP1 ）, MRP2, breast cancer resistance protein （BCRP） and P-glycoprotein （P-gp） mRNA in different cell lines was determined by reverse transcription polymerase chain reaction.All data were analyzed using the t test. Results The cell viability and apoptosis rate of pancreatic BXPC-3 cells after treatment were 62.44% ± 3.42% and 27. 10% ± 4.24% in the cisplatin treatment group, and they were 30.53% ±0.05% and 66.33% ±9.37% in the emodin ＋ cisplatin co-treatment group. There were significant differences in cell viability and apoptosis rate between the two groups （t = 13.20, 5. 35, P 〈 0.05 ）. The cell viability and apoptosis rate of pancreatic BXPC-3 cells after treatment were 79.82% ±2.83% and 13.48% ± 1.65%in the gemcitabine treatment group, and they were 45.65% ± 2.46% and 62.74% ± 10. 18% in the emodin ＋gemcitabine co-treatment group. There were significant differences in cell viability and apoptosis rate between the two groups （t = 12.89, 8.28, P 〈 0. 05 ）. There was no significant difference in the viability of normal human skin fibroblasts between the cisplatin treatment group and the emodin ＋ cisplatin co-treatment group, and also between the gemcitabine treatment group and the emodin ＋ gemcitabine co-treatment group （t = 2. 08, 0. 64, P 〉0.05 ）. Expression of MRP1 mRNA was detected in pancreatic BXPC-3 cells, whereas the expression of MRP2,BCRP and P-gp mRNA was undetectable. The expression of MRP1 mRNA in pancreatic BXPC-3 cells was significantly down-regulated in the cisplatin treatment group, and cisplatin ＋ emodin co-treatment had an additive effect on down-regulating the expression of MRP1 mRNA. Conclusion Emodin may enhance chemosensitivity of pancreatic cancer cells to cisplatin by down-regulating the expression of MRP1 mRNA.