黑色素瘤细胞经太空环境诱变后致瘤性和基因表达变化

目的 筛选经太空环境诱变后B16细胞致瘤性改变的细胞株,观察其基因表达的改变,寻找与黑色素瘤发生及转移密切相关的基因.方法 将小鼠黑色素瘤B16细胞搭载于第20颗返回式卫星,返地后克隆化,随机选择5株克隆细胞株（1^#、5^#、6^#、7^#和8^#）,接种C57BL/6J小鼠,分别观察细胞致瘤性、荷瘤小鼠生存期及瘤体病理变化,用基因表达谱分析其中2株初筛致瘤性改变细胞株（1^#和8^#）的基因表达情况。结果 与对照组比较,1#细胞株接种小鼠后,肿瘤潜伏期延长（P＜0.05）,1^#和8^#细胞株移植瘤瘤体重量减小（P＜0.01）,且荷瘤小鼠生存期延长（P＜0.01）;病理诊断结果显示：1^#和8^#细胞移植瘤内血管不及对照组丰富,坏死区较少,瘤体内浸润淋巴细胞较对照组有不同程度的增多,瘤旁组织内有较多淋巴细胞;基因芯片分析结果表明：与对照B16细胞相比,2株诱变细胞（1^#和8^#）分别有145和125个基因表达水平发生改变（P＜0.05）,其中9个基因为共同变化基因,前列腺素D2合成酶基因在2株细胞中的表达均明显增高,与对照相比,差别在5倍以上。结论 1^#和8^#细胞株致瘤性减弱,且2株细胞的移植瘤肿瘤新生血管及癌旁浸润减少,癌旁组织中有较多淋巴细胞,推测可能与前列腺素D2合成酶等多种肿瘤相关基因表达的改变有关。

Changes of tumorigenicity and gene expressions of melanoma cells mutated in outer space

ObjectiveTo screen the cell lines with decreased tumorigenicity, and identify those genes related to the development and metastasis of melanoma. Methods The murine melanoma B16 cells were carried into the outer space by No.20 retrievable satellite, and the survival cells were cloned after returned to earth. Five monoclonal cell lines(1~#,5~#,6~#,7~#,8~#)were utilized for further study. The cells were injected into C57BL/6J mice subcutaneously and abdominally respectively, then tumor-free time and survival time were recorded, tumor lumps were examined by routine pathological method. Gene chips were used to detect the gene expressions in 2 cell lines(1~#,8~#)with decreased tumorigenicity. Results Compared with the control group, the tumor-free time was longer for 1~# cell lines (P<0.05). The survival time was significantly increased (P<0.01)and the weights of tumors were significantly decreased (P<0.01)for both 1~# and 8~# cell lines. The lymphocytes were infiltrated into tumors and adjacent tissues in those mice injected with 1~# and 8~# cell lines. Changes in 145 gene expressions were identified in 1~# cell lines, and 124 genes in 8~# cell lines (P<0.05), 9 genes of them were common to both cell lines. Furthermore, prostaglandin D2 synthase gene was markedly upregulated. Conclusion The study implied that the decrease of tumorigenicity was related to the changes of carcinoma-associated gene expressions.