大鼠肝癌干细胞生物学行为研究

The biological behavior of hepatocarcinoma stem cells in rats

目的研究大鼠肝癌干细胞生物学行为。方法二乙基亚硝胺为诱癌剂制造大鼠肝癌模型,分离培养肿瘤细胞,按照卵圆细胞表面标记物[CD34、c-Kit、Thy-1、甲胎蛋白(AFP)、细胞角蛋白(CK)7、CK8、CK14、CK18、 CK19和γ-谷氨酰转肽酶]分选肿瘤细胞,比较各个表面标记物阳性肿瘤细胞亚群与阴性肿瘤细胞亚群移植裸鼠后成瘤能力的差异;找出成瘤能力差异大的亚群细胞组,比较成瘤能力强的细胞与一般细胞的生长特征,并对其细胞周期分布进行研究。结果 Thy-1阳性细胞、CK7阴性细胞与AFP阳性细胞成瘤能力明显大于对应细胞亚群(P<0．01),具备初步的肝癌干细胞特征;这三种细胞比对应亚群细胞具有较低的增殖能力、更长的倍增时间与更小的最大增生倍数;细胞周期检测发现,无论是S期比例,还是(S+G2／M)期比例,这三种细胞也较对应亚群细胞为低,说明其体外增殖能力较弱。结论 CK7阴性、Thy-1阳性和AFP阳性细胞具备大鼠肝癌干细胞的初步特征;大鼠肝癌干细胞可能具备增殖能力较低的生物学行为特征。

Objective To study the biological behavior of hepatocarcinoma stem cells in rats. Method Primary liver carcinomas were induced in rats using diethylnitrosamine. Tumor cells from 8 rats were separated according to rats oval cell （OVC） markers CD34, c-Kit Thy-1, AFP, CKT, CKS, CK14, CK18, CK19 and GGT and then they were separately injected into the livers of nude mice. The tumors grown from the different subpopulation of OVC markers in the nude mice livers （10 OVC markers negative or positive cells） were weighted 1 month after the inoculations. The hepatocarcinoma cell subpopulations with higher ability in causing tumor growths were further studif, d in vitro. The cell cycles and DNA content of those subpopulation cells were investigated using flow cytometry. Results （1） Subpopulation cells with CKT（-）, Thy-l（＋） and AFP（＋） markers had a higher ability in causing tumors in nude mice; （2） SubpopulatiOn cells, exhibiting characters of TSC, had a low growth rate in vitro. Condusions （1） Different subpopulations of hepatocarcinoma cells had different abilities in causing tumors in rats. Some subpopulation cells, such as CKT（-）, Thy- 1（＋） and AFP（＋） cells, have characteristics of tumor stem cells. （2） The bepatocarcinoma stem ceils may have a low growth rate in vitro.