辐射诱导的G2期阻滞可能导致乳腺癌干细胞的放射抗性。

[Radiation-induced G2 phase arrest may contribute to the radioresistance of breast cancer stem cells].

作者信息

Tian Yun-hong, Xie Guo-zhu, Ren Chen, Sun Quan-quan, Sun Ai-min, Liu Ying, Yuan Ya-wei

机构信息

Department of Radiation Oncology, Southern Medical University, Guangzhou 510515, China.

出版信息

Nan Fang Yi Ke Da Xue Xue Bao. 2011 Jan;31(1):53-6.

PMID:21269956

Abstract

OBJECTIVE

To investigate radiation-induced cell cycle changes of human breast cancer stem cells enriched by suspension culture.

METHODS

The tumorigenicity of human breast cancer stem cell line MCF-7 cultured in serum-free media was confirmed in NOD/SCID mice, and the radiosensitivity of the cells was tested by clone formation assay following radiation exposure. Flow cytometry was performed to evaluate radiation-induced cell cycle changes, and the protein expression of pCDC25C (ser216) was measured by Western blotting.

RESULTS

After the exposure to 2 Gy radiation, the survived fraction of the cells in suspension culture and those in adherent culture was 0.856 ∓ 0.061 and 0.783 ∓ 0.097, respectively, and the cells in suspension culture showed an obviously greater capacity of tumorigenicity in NOD/SCID mice. The radiation exposure resulted in an obvious increase in the proportion of G2 phase cells from (22.03 ∓ 2.12)% to (45.83 ∓ 2.25)% and significantly increased the expression of pCDC25C (ser216).

CONCLUSION

Radiation- induced G2 phase arrest may contribute to the resistance of the breast cancer stem cells to radiotherapy.

摘要

目的

研究悬浮培养富集的人乳腺癌干细胞辐射诱导的细胞周期变化。

方法

在无血清培养基中培养的人乳腺癌干细胞系MCF-7的致瘤性在NOD/SCID小鼠中得到证实，照射后通过克隆形成试验检测细胞的放射敏感性。进行流式细胞术以评估辐射诱导的细胞周期变化，并通过蛋白质印迹法测量pCDC25C（ser216）的蛋白表达。

结果

照射2 Gy后，悬浮培养和贴壁培养的细胞存活分数分别为0.856±0.061和0.783±0.097，悬浮培养的细胞在NOD/SCID小鼠中显示出明显更强的致瘤能力。辐射照射导致G2期细胞比例从（22.03±2.12）%明显增加到（45.83±2.25）%，并显著增加pCDC25C（ser216）的表达。