一氧化氮在亚细胞结构精确照射诱导旁效应中的作用

研究了肿瘤细胞的亚结构在荷能离子照射下所诱导的旁效应及其信号分子。以氦离子微束装置所产生的精确数量离子定位照射神经胶质瘤细胞T98G细胞核或细胞质,检测细胞染色体损伤和胞内一氧化氮(Nitric Oxide,NO)自由基的产额,探索NO清除剂对它们的影响,并以(Diethylamine nitric oxide,DEANO)研究NO的细胞效应。结果表明,无论是细胞核照射还是细胞质照射,只要1个细胞受到1个离子的照射,就可通过损伤的级联放大形成辐射旁效应,引起周围数十个细胞的损伤。对比核、质照射的生物效应,细胞核照射比细胞质照射具有更加显著的直接作用,但这两种照射所诱导的旁效应程度却相当。而NO自由基清除剂c-PTIO(2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide)可抑制旁效应的产生。NO分子探针DAF-FM(4-amino-5-methylamino-2',7'-difluorofluorescein diacetate)原位检测表明,即使只有1%的细胞核或细胞质受到单离子照射,具有NO阴性表达的细胞百分数增加了30%,使NO引起的细胞荧光密度增加15%。DEANO实验表明,NO可引起细胞微核的产生。因此,NO是亚细胞结构照射引起旁效应的一个重要信号因子。

Sublethal Irradiation Promotes Migration and Invasiveness of Prostate Cancer PC-3 Cells:Implications for Radiotherapy of Human Prostate Cancer

OBJECTIVE To study the changes in the matrix metalloproteinases-2 and 9 （MMP2, MMP9） induced by ^60Co γ-ray external irradiation of human prostate cancer PC-3 cells. METHODS Human prostate cancer PC-3 cells were irradiated with different doses of ^60Co γ-rays. Cell migration and invasiveness were evaluated and the expression of MMP2, and MMP9 was investigated by RT-PCR, Western blotting and flow cytometry（FCM）. RESULTS Irradiation enchances invasive protential at the doses of 1,3 and 5 Gy,whereas it significantly inhibits cell migration. CONCLUSION The different doses of ^60Co γ-ray external irradiation for prostate cancer may have different effects through the changes of MMP2, and MMP9 expression.