天花粉蛋白对胃癌多药耐药细胞的细胞毒和诱导凋亡作用

Effect of trichosanthin on cytotoxicity and induction of apoptosis of multiple drugs resistence cells in gastric cancer

目的 研究天花粉蛋白(TCS)对胃癌多药耐药细胞细胞毒和诱导凋亡作用,探讨其治疗胃癌多药耐药的可能性。 方法 采用生长曲线、MTT、电镜、TUNEL染色和流式细胞仪等技术,研究TCS对胃癌多药耐药细胞SGC-7901/VCR和MKN-45/VCR的增殖抑制和诱导凋亡作用。 结果 TCS明显抑制胃癌多药耐药细胞SGC-7901/VCR和MKN-45/VCR的生长,其作用与对其本细胞的抑制作用相近。TCS对SGC-7901/VCR和MKN-45/VCR细胞有较强的细胞毒作用,TCS对SGC-7901和SGC-7901/VCR的IC50分别为28.6μg/mL和35.3μg/mL;对MKN-45和MKN-45/VCR的IC50分别为和10.67μg/mL和14.61μg/mL。TCS作用于MKN-45细胞后,光镜和电镜下能见到典型的细胞凋亡形态学特征:细胞核染色质致密浓缩,染色质断裂、凋亡小体形成等。TUNEL检测显示耐药细胞凋亡指数为2.8％～11.5％,流式细胞仪DNA直方图上出现典型的亚二倍体“凋亡峰”,耐药细胞凋亡率在4.73％～21.5％,细胞凋亡与TCS作用时间和浓度相关。 结论 TCS对胃癌多药耐药细胞有较强的细胞毒和诱导凋亡作用,具有治疗胃癌多药耐药的潜在价值。

AIM To explore the effect of trichosanthin (TCS) on cytotoxicity and induction of apoptosis of multiple drugs resistence (MDR) cells in gastric cancer. METHODS Cell proliferation of gastric cancer MDR cell SGC-7901/ VCR and MKN-45/ VCR treated by TCS was studied by growth curve. The cytotoxicities of TCS on gastric cancer MDR cells were determined by MTT assay. Apoptosis of gastric MDR cells induced by TCS was investigated by TUNEL method and flow cytometry. RESULTS The results showed TCS could significantly inhibit the growth of SGC-7901/ VCR and MKN-45/ VCR. The inhibition rate of gastric cancer MDR cells was similar to its parent cells. TCS had remarkable cytotoxic effects on SGC-7901/ VCR and MKN-45/ VCR. The IC50 of SGC-7901, SGC-7901/VCR, MKN-45 and MKN-45/VCR were 28.6μg/mL, 35.3μg/mL, 10.67 μg/mL and 14.61μg/mL respectively, after 72 hours expoeure to TCS. After 12 hours of exposure to TCS, MKN-45 exhibited morphologic features of apoptosis, including cell shrinkage, nuclear condensation, DNA fragmentation and formation of apoptotic bodies. The apoptotic index was 2.8%-11.5% by TUNEL. A typical subdiploid peak before G0/G1 phase was detected by flow cytometry. The apoptosis rate was 5.32%-21.5% by FACS assay. The effect of TCS on the cytotoxicity and induction of apoptosis of gastric cancer MDR cells was dependent on the concentration and time of TCS exposure.CONCLUSION TCS has strong effects on cytotoxicity and induction of apoptosis of gastric cancer MDR cells. TCS might have a promising prespect in the treatment of gastric cancer MDR and is worthy to be further studied.