胃癌侧群细胞耐药性研究及干细胞相关基因检测

目的研究胃癌侧群（Side Population，sP）细胞对化疗药物5-Fu（氟尿嘧啶）的耐药性及可能机制，并检测干细胞相关基因Nanog、Musashi-1及cD44的表达情况。方法选择人胃癌细胞株sGc-7901，以荧光染料H0echst 33342染色，维拉帕米桔抗对照，应用流式细胞仪分选sP细胞和nonsP细胞。细胞耐药实验比较sP细胞与nonsP细胞对化疗药物5．Fu的耐药性差异；westem_h10t检测ABcG2和bcl-2蛋白表达情况；流式细胞仪分析细胞周期；荧光定量PcR检测两组细胞中干细胞相关基因Nanog、Musashi-1及cD44mRNA的表达差异。结果胃癌细胞株sGc．790l中sP细胞的比例为2．8％，sP细胞对5-Fu的耐药存活率明显高于non-sP细胞（P〈0．05），与nonsP细胞相比，sP细胞高表达耐药蛋白ABcG2和抗凋亡蛋白bcl-2，有更多的细胞处于c0／G1期（P〈0．05），并高表达干细胞相关基因Musashi-1和cD44。结论胃癌sGC_7901细胞株中sP细胞对化疗药物5．Fu的耐药性明显高于nonsP细胞，其耐药机制可能与sP细胞高表达耐药蛋白ABcG2和抗凋亡蛋白bcl-2，有更多细胞处于G0／Gl期有关；Musashi-1和cD44可能是相对特异性的胃癌干细胞标志物。

Chemoresistance Study and Detection of Stem Cell Related Genes of SP Cells from SGC-7901 Cell Strain

Objective to research chemoresistanee of SP cells to 5-FU and examine stem ceil related genes of SP cells from gastric cancer SGC- 7901 cell strain. Methods SGC-7901 cells were sorted as SP cells and nonSP cells using flow eytometry after SGC-7901 cells were stained with Hoechst33342 ;chemoresistance experiment was used to observe two group cells＇ resistance to 5-FU ;western-blot was performed to examine the expression of ABCG2 and Bel-2;flow cytometry was applied to analyze eeil cycle;the mRNA expression of Nanog, Musashi-1 and CD44 was detected by real-time PCR. Results SP cells have a stronger resistance to 5-FU and have a higher expression of ABCG2 and Bcl- 2 than nnnSP ceils,and the proportion of cells in GO/G1 phase is also larger than nonSP cells;SP cells show a higher expression of Musashi-l and CD44 than nonSP cells. Conclusion SP cells have a higher resistance to 5-FU than nonSP cells, the possible mechanisms are related to higher expression of ABCG2 and Bel2 and more cells in G0/G1 phase. ; Musashi-l and CD44 may be the markers of gastric cancer stem cells.