青果多糖提取物对人胃癌5-FU耐药细胞的逆转作用

Reversal effect of polysaccharide extracts from Canarii Fructus on human gastric cancer 5-FU-resistant cells

目的:建立胃癌5-氟尿嘧啶(5-fluorouracil, 5-FU)耐药细胞BGC823/5-FU,探讨青果多糖提取物对BGC823/5-FU的逆转作用及机制。方法:采用逐步递增5-FU浓度、体外间歇诱导法诱导胃癌BGC823细胞,建立胃癌5-FU耐药细胞BGC823/5-FU;CCK-8试剂盒(Cell Counting Kit-8)检测青果多糖提取物对BGC823/5-FU细胞增殖的抑制作用;不同药物处理BGC823/5-FU细胞后,qRT-PCR分析对谷胱甘肽S-转移酶π(GST-π)和多药耐药基因MDR1 mRNA的表达,Western blot检测GST-π和P糖蛋白(P-gp,由MDR1基因所表达)的表达。结果:历时5个月建立BGC823/5-FU,对5-FU耐药性稳定,耐药指数为6.28,对顺铂、长春新碱和阿霉素也有不同程度的交叉耐药性;青果多糖提取物对BGC823/5-FU的5-FU耐药性有逆转作用,逆转倍数达到3.11倍;与BGC823/5-FU细胞对照组比较,5-FU处理组对GST-π和MDR1的mRNA表达及GST-π和P-gp的蛋白表达无明显影响,但青果多糖提取物组及青果多糖提取物+5-FU组GST-π和MDR1 mRNA及GST-π和P-gp的表达明显降低(P<0.05或P<0.01)。结论:青果多糖提取物对BGC823/5-FU有逆转作用,其机制可能与降低耐药基因GST-π和MDR1 mRNA及GST-π和P-gp的表达有关。

OBJECTIVE To establish a 5-fluorouracil(5-FU)-resistant gastric cancer cell line BGC823/5-FU and observe the reversal effect and mechanism of polysaccharide extracts from Canarii Fructus(PECF) on BGC823/5-FU cell.METHODS BGC823 cells were induced by an incremental concentration of 5-FU and intermittent induction in vitro for establishing BGC823/5-FU cells;CCK-8 kit was utilized for detecting the inhibitory effect of PECF on the proliferation of BGC823/5-FU cells;After treatments of BGC823/5-FU cells with different drugs, the expressions of GST-π and MDR1 mRNA were detected by quantitative reverse transcription-polymerase chain(qRT-PCR). Western blot was utilized for detecting the expressions of GST-π and P-gp.RESULTS The drug resistance of BGC823/5-FU became stable, drug resistance index was 6.28 and it had varying degrees of cross resistance to cisplatin, vincristine and doxorubicin;PECF could reverse the cisplatin resistance of BGC823/5-FU and reversal multiple was 3.11;as compared with control group of BGC823/5-FU cells, the expressions of GST-π and MDR1 mRNA and the protein expressions of GST-π and P-gp were not significantly affected. However, the expressions of GST-π and MDR1 mRNA and the protein expressions of GST-π and P-gp decreased markedly in PECF and PECF+5-FU groups(P<0.05 or P<0.01).CONCLUSION PECF can reverse BGC823/5-FU and its mechanism may be mediated by a down-regulation of gene(GST-π & MDR1 mRNA) and protein(GST-π & P-gp).