侧群细胞在胃癌细胞株中的分布及其致瘤特性

目的 研究侧群细胞的致瘤特性及其在胃癌细胞株和胃癌组织中的分布.方法 用荧光激活细胞分选法分析SGC-7901、MKN28和BGC-823三种胃癌细胞株中的侧群细胞.取36只裸鼠,分为6组,将SOC-7901分离出的侧群细胞和非侧群细胞分别以每只500、5000、50 000的数量接种到裸鼠皮下,8周后观察成瘤情况.实时定量PCR检测胃癌组织和胃癌细胞株中三磷酸腺苷结合转运蛋白超家族成员G2(ABCG2)mRNA的表达,免疫组化法检测胃癌组织中ABCG2蛋白的表达.结果 SGC-7901细胞株中侧群细胞比例为1.0%,BGC-823为1.3%,MKN28则为阴性.从SGC-7901中分离的侧群细胞最少可成瘤细胞数是500/只,非侧群细胞为50000/只.胃癌细胞株SGC-7901和BGC-823的ABCG2 mRNA相对量高于MKN28(分别为0.162、0.096和0.005).ABCG2 mRNA和蛋白在胃癌和胃炎组织中有不同程度的表达.结论 胃癌细胞株侧群细胞的致瘤能力明显强于非侧群细胞.在胃癌组织和部分胃炎组织中检测到ABCG2的表达,在胃癌细胞株中侧群细胞比例高的细胞株ABCG2表达高.

Proportion and tumorigenetic characteristics of side population cells in gastric cancer cell lines

Objective To study the tumorigenetic characteristics of side population (SP) cells and their exsistence in gastric cancer cell lines and tissues.Methods Flow cytometry and the DNA-binding dye Hoechst 33342 staining were used to analyze sorted SP cells in 3 gastric cancer cell lines(SGC-7901,BCIC-823 and MKN28).SP cells and non-SP cells(main population cells)isolated from SGC-7901 cell line weresubcutaneously injected into 36 nude mice with 500,5000 or 50 000 cells per mouse,respectively.Thetumorigenity was observed 8 weeks after injection.The expression of ATP-binding cassette sub-family Gmember 2(ABcG2)mRNA in three gastric cell lines and its level in gastric cancer tissues were detected by real-time PCR and immunostaining.respectively.Results The proportion of SP cells was accounted for 1.0%in SGC-7901 cells and 1.3%in BGc-823 cells.No SP cell was found in MKN28 cells.As low as 500 SP cells or 50 000 non-SP cells could initiate tumors in mice.The expression of ABcG2 mRNA was higher in SGC-7901(O.162)and BGC-823(O.096)cell lines than that in MKN28 cell line(0.005).The value of AtCG2 mRNA/beta-aetin mRNA and protein in gastric cancer tissues was different from those in gastritis tissues.Condasimm SP cells have strong ability of tumorigenesis compared with non-SP cells.The expression of ABCG2 is found in gastric cancer tissues and part gastritis tissues.The more the SP cells in gastric cell lines,the higher the expression of ABCG2.