Zhou Ju-ying, Zhou Chong, Wang Li-li, Xu Xiao-ting, Qin Song-bing
Department of Radiation Oncology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China.
Zhonghua Zhong Liu Za Zhi. 2011 Oct;33(10):747-51.
To explore the influence of knock-down of miR-21 expression on the radiosensitivity of radioresistant glioma SHG-44 cells and its mechanism.
Radioresistant cell line SHG-44(R) cells were established from radiosensitive parental SHG-44 glioma cells. Then the expression levels of miR-21 in SHG-44(R) and SHG-44 were determined by quantitative real-time PCR. The effect of miR-21 on the radiosensitivity was assessed in SHG-44(R) with miR-21 inhibitor to decrease the miR-21 expression.
miR-21 was up-regulated 1.49-fold in SHG-44(R) cells relative to the SHG-44 cells. But after transfection with As-miR-21, the miR-21 expression in SHG-44(R) cells was knocked down significantly. As-miR-21 combined with radiation could synergistically enhanced mitotic death and apoptosis of SHG-44(R) cells, with SER of D(0) and D(q) being equal to 1.48 and 1.54, respectively. Expression levels of caspase-3 in the radiation group, AS-miR-21 transfection group and combination group were 2.24 ± 0.14, 2.05 ± 0.19 and 5.72 ± 0.45, respectively, and its expression in the combination group was higher than that in the other two groups.
miR-21 may be involved in the formation of radioresistance of glioma cells and as a potential target for enhancing the response of radioresistant-glioma cells to radiotheapy.
探讨敲低miR-21表达对放射抗拒性胶质瘤SHG-44细胞放射敏感性的影响及其机制。
从放射敏感的亲代SHG-44胶质瘤细胞建立放射抗拒细胞系SHG-44(R)细胞。然后通过定量实时PCR测定SHG-44(R)和SHG-44中miR-21的表达水平。用miR-21抑制剂降低SHG-44(R)细胞中miR-21的表达，评估miR-21对放射敏感性的影响。
与SHG-44细胞相比，SHG-44(R)细胞中miR-21上调了1.49倍。但转染As-miR-21后，SHG-44(R)细胞中miR-21的表达明显降低。As-miR-21与辐射联合可协同增强SHG-44(R)细胞的有丝分裂死亡和凋亡，D(0)和D(q)的增敏比分别为1.48和1.54。辐射组、AS-miR-21转染组和联合组中caspase-3的表达水平分别为2.24±0.14、2.05±0.19和5.72±0.45，联合组中其表达高于其他两组。
miR-21可能参与胶质瘤细胞放射抗拒的形成，并可作为增强放射抗拒性胶质瘤细胞对放疗反应性的潜在靶点。
