表皮干细胞K19、Bcl-2及PKB蛋白的表达

Expression of K19,Bcl-2 and PKB protein in epithelia stem cells

目的探讨角蛋白19(K19)、Bcl-2及蛋白激酶B(PKB)在人表皮干细胞中的表达及其意义。方法应用表皮组织干细胞培养技术及SP免疫组化技术对120张从正常健康人的包皮及皮肤组织提取培养的干细胞涂片进行K19、Bcl-2及PKB蛋白表达检测。结果 K19、PKB及Bcl-2在表皮干细胞中阳性表达率分别为75%、55%和30%;K19与PKB阳性表达率差异无统计学意义,而Bcl-2阳性表达率与K19及PKB的阳性表达率差异具有统计学意义。结论 K19为表皮干细胞特异性表达蛋白,PKB的阳性表达提示PKB在表皮干细胞的生长、代谢、增殖、凋亡中扮演重要角色,而Bcl-2的低表达,提示表皮干细胞虽然有较强的增殖能力,但抗凋亡能力不如肿瘤细胞。

[ Objective ] To investigate the expression of cytokeratin 19（K19）, Bcl-2 and protein kinase B（PKB） in epithelia stem cells. [Methods] Skin stem cells were obtained by explant culture and the expression of K19, Bcl-2 as well as PKB protein were determined by SP immunohistochemistry. [Results] The positive rates of K19, PKB and Bcl-2 were 75%, 55% and 30% respectively in epithelia stem cells. There was significant difference between the expression of K19 and Bcl-2, as well as PKB and Bcl-2, but no statistical difference between the expression of K19 and PKB. [Conclusions] These findings suggested that K19 protein is a biochemical marker of epithelia stem cell phenotype character; PKB protein may be involved in the cell proliferation, regulation of cellular metabolism and apoptosis. The low expression of Bcl-2 implied that adult stem cells are not as well as carcinoma cells in anti- apoptasis.