应用微阵列分析技术研究宫颈癌 252Cf 中子和 X 射线辐射抗拒细胞中 DNA 损伤修复基因表达谱

Microarray analysis of DNA damage repair gene expression profiles in cervical cancer cells radioresistant to 252Cf neutron and X-rays.

机构信息

Cancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing, PR China.

出版信息

BMC Cancer. 2010 Feb 25;10:71. doi: 10.1186/1471-2407-10-71.

BACKGROUND

The aim of the study was to obtain stable radioresistant sub-lines from the human cervical cancer cell line HeLa by prolonged exposure to 252Cf neutron and X-rays. Radioresistance mechanisms were investigated in the resulting cells using microarray analysis of DNA damage repair genes.

METHODS

HeLa cells were treated with fractionated 252Cf neutron and X-rays, with a cumulative dose of 75 Gy each, over 8 months, yielding the sub-lines HeLaNR and HeLaXR. Radioresistant characteristics were detected by clone formation assay, ultrastructural observations, cell doubling time, cell cycle distribution, and apoptosis assay. Gene expression patterns of the radioresistant sub-lines were studied through microarray analysis and verified by Western blotting and real-time PCR.

RESULTS

The radioresistant sub-lines HeLaNR and HeLaXR were more radioresisitant to 252Cf neutron and X-rays than parental HeLa cells by detecting their radioresistant characteristics, respectively. Compared to HeLa cells, the expression of 24 genes was significantly altered by at least 2-fold in HeLaNR cells. Of these, 19 genes were up-regulated and 5 down-regulated. In HeLaXR cells, 41 genes were significantly altered by at least 2-fold; 38 genes were up-regulated and 3 down-regulated.

CONCLUSIONS

Chronic exposure of cells to ionizing radiation induces adaptive responses that enhance tolerance of ionizing radiation and allow investigations of cellular radioresistance mechanisms. The insights gained into the molecular mechanisms activated by these "radioresistance" genes will lead to new therapeutic targets for cervical cancer.

背景

本研究的目的是通过长时间暴露于 252Cf 中子和 X 射线，从人宫颈癌 HeLa 细胞系中获得稳定的耐辐射亚系。通过 DNA 损伤修复基因的微阵列分析，研究了由此产生的细胞中的耐辐射机制。

方法

用分割的 252Cf 中子和 X 射线处理 HeLa 细胞，每个细胞的累积剂量为 75Gy，持续 8 个月，得到 HeLaNR 和 HeLaXR 亚系。通过集落形成试验、超微结构观察、细胞倍增时间、细胞周期分布和细胞凋亡试验检测耐辐射特性。通过微阵列分析研究耐辐射亚系的基因表达模式，并通过 Western blot 和实时 PCR 进行验证。

结果

通过检测耐辐射特性，耐辐射亚系 HeLaNR 和 HeLaXR 比亲本 HeLa 细胞对 252Cf 中子和 X 射线更具耐辐射性。与 HeLa 细胞相比，HeLaNR 细胞中 24 个基因的表达至少被改变了 2 倍。其中 19 个基因上调，5 个基因下调。在 HeLaXR 细胞中，有 41 个基因的表达至少被改变了 2 倍；其中 38 个基因上调，3 个基因下调。