miR-210敲低联合放疗对裸鼠移植人肝癌的抑瘤效应

Anti-tumor effects of knockdown miR-210 combined with radiotherapy on human hepatoma xenograft in nude mice

为探索miR-210敲低联合放疗对裸鼠体内移植人肝癌细胞SMMC-7721的抑瘤效应,将稳定转染miR-210反义序列和随机序列的人肝癌细胞SMMC-7721接种于裸鼠。待各组裸鼠肿瘤直径达到6 mm–8 mm,检测各组裸鼠miR-210和相关蛋白表达;各组裸鼠肿瘤局部在正常氧或乏氧条件下接受8 Gy X射线照射,检测各组裸鼠放疗后不同时间的肿瘤体积;照射后24 h用免疫组化染色检测肿瘤细胞增殖活性和肿瘤间质微血管密度,用TUNEL法检测肝癌细胞凋亡率。结果表明:miR-210敲低组的miR-210和乏氧诱导因子-1α(Hypoxia induced factor 1α,HIF-1α)表达明显低于对照组;miR-210靶基因蛋白表达明显高于对照组;照射后9 d–30 d,miR-210敲低常氧或乏氧照射组的肿瘤体积分别明显小于随机序列常氧或乏氧照射组;照射后24 h,miR-210敲低常氧或乏氧照射组的肿瘤细胞增殖活跃度和肿瘤间质微血管密度明显低于随机序列常氧或乏氧照射组,细胞凋亡率则明显升高。结果提示,miR-210敲低可提高裸鼠移植人肝癌的放疗效果。

In order to investigate the anti-tumor effects of knockdown of miR-210 combined with radiotherapy on human hepatoma xenograft in nude mice, SMMC-7721, SMMC/Lv-scr and SMMC/Lv-anti-miR-210 cells were subcutaneously implanted into nude mice, when the diameter of tumor reached 6 ram-8 rnm, we assessed expression of miR-210 and relative protein in tumor tissues. After irradiation of 8 Gy X rays under normoxia and hypoxia conditions for 24 h, the cell proliferation and intratumoral microvessel density were detected by Immunohistochemical staining while apoptotic cells in turner tissue were detected by TUNEL method. The results showed that knockdown of miR-210 decreased expression of miR-210 and hypoxia induced factor 1α （HIF-1α）, but increased the expression of proteins which are target genes of miR-210 in hepatoma xenograft. The tumor volums of m210 （Normal＋8 Gy） group and m210 （Hypoxia＋8 Gy） group were significantly lower than those of scr （Normal＋8Gy） group and scr （Hypoxia＋8 Gy） group within 9-30 days after the beginning of therapy, respectively. The cell proliferation and intratumoral microvessel density of m210 （Normal＋8 Gy） group and m210 （Hypoxia＋8 Gy） group were significantly lower than those of scr （Normal＋8 Gy） group and scr （Hypoxia＋8 Gy） group, respectively, while the percentage of apoptotic cells in tumor tissue was higher 1 day after therapy. These results can be suggested that knockdown of miR-210 combined with radiotherapy can effectively enhance the anti-tumor effects either in normoxia or hypoxia condition on human hepatoma xenografl.