中文摘要：

目的：探索体外肿瘤微环境中正常成体干细胞是否可以发生恶性转化而具有相关肿瘤学特性。方法：利用共培养池建立黑素瘤A-375细胞诱导表皮干细胞转化的模型，应用相差显微镜观察诱导前后表皮干细胞形态变化，免疫荧光法检测诱导后表皮干细胞E-钙黏着蛋白、肿瘤相关抗原P53突变蛋白的表达变化和双层软琼脂实验鉴定诱导后表皮干细胞克隆形成能力情况。结果：7d后与黑素瘤细胞A-375直接接触共培养的表皮干细胞开始克隆样生长，细胞E-钙黏着蛋白表达下降，部分细胞表达P53突变蛋白，软琼脂培养克隆形成率为0．55％。结论：表皮干细胞经黑素瘤细胞直接诱导后，可以具有肿瘤细胞的相关生物学特性。结果表明，肿瘤微环境可以造成干细胞自我更新能力的失控。

英文摘要：

Objective.. To study whether normal adult stem cells can have malignant transformation （have tumor characteristics） when exposed to tumor microenvironment. Methods.. We established an in vitro model of melanoma cell-induced malignant transformation of epidermal stem cells in a cell co-culture system. The morphological changes of epidermal stem cells were observed before and after induction by phase-contrast microscope; the expression of E-cadherin and P53 mutant protein were examined by immunofluorescence method. Soft agar test was used to examine the colony forming ability of epidermal stem cells after co-culture. Results： Seven days after co-culture with A-375 cells, epidermal stem cells began to form visible colonies. The expression of E-cadherin protein was decreased and P53 mutant protein was observed in some cells. Soft agar test showed that 0.55 % epidermal stem cells formed colony in the soft agar. Conclusion： This study shows that epidermal stem cells can obtain the characteristics of tumor cells when exposed to inducement of A-375 cells, suggesting that tumor microenvironment can cause disturbance in self-renewing and differentiation of stem cells.