Effect of heavy ion beam irradiation on radioresistance and differentiation of cancer stem cells in neuronal tumors

目的是研究重离子（CI）束对人肿瘤细胞，特别是肿瘤干细胞的放射抵抗和分化的放射生物学效应。将携带野生型p53的人室管膜母细胞瘤和携带突变型p53的胶质母细胞瘤移植到裸鼠体内，分别用CI束或150-kV x射线照射。在2-24 Gy照射后6- 48小时或6周切除肿瘤进行cDNA芯片分析。免疫组织化学检测CD133、CD44、Nestin、p53、PTEN、Ki67和GFAP的表达。在室管膜母细胞瘤中，p53信号通路和凋亡相关通路被认为与辐照有关。高剂量照射后肿瘤生长分数明显降低，cd133阳性率略有升高。这些结果表明cd133阳性和ki -67阴性细胞可能对x射线和CI光束都具有抗性。

The purpose is to investigate the radiobiological effect of heavy ion (CI) beams on radioresistance and differentiation of human tumor cells, especially cancer stem cells. Human ependymoblastoma with wild-type p53 and glioblastoma with mutant-type p53 were transplanted into nude mice and irradiated with CI beams or 150-kV X-rays. Tumors were excised for cDNA microarray analysis 6- 48 hours or 6 weeks after 2-24 Gy irradiation. CD133, CD44, Nestin, p53, PTEN, Ki67, and GFAP expressions were evaluated immunohistochemically. In ependymoblastoma, p53 signaling and apoptosis-related pathways were suggested to be involved following irradiation. The tumors showed a significant decrease in growth fraction and a slight increase of the CD133-positive rate after high-dose irradiation. These results suggest that CD133-positive and Ki-67-negative cells may be resistant to both X-rays and CI beams.