Radiosensitivity enhancement of human hepatocellular carcinoma cell line SMMC-7721 by sorafenib through the MEK/ERK signal pathway
Radiosensitivity enhancement of human hepatocellular carcinoma cell line SMMC-7721 by sorafenib through the MEK/ERK signal pathway
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DOI：
10.3109/09553002.2013.791405
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发表时间：
2013-09-01
影响因子：
2.6
通讯作者：
Wu, Gang
中科院分区：
文献类型：
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作者：
Dai, Xiao-Fang;Ding, Jie;Wu, Gang
目的：索拉非尼是一种口服多激酶抑制剂，是第一种在晚期肝细胞癌中显示出改善总体生存获益的药物，为一线治疗制定了新标准。然而，放射敏感性和索拉非尼之间的关联仍不清楚。本研究旨在探讨索拉非尼对人肝癌细胞株SMMC-7721的放射增敏作用及其机制。实验设计：采用MTT法检测人肝癌细胞株SMMC-7721的放射增敏作用。采用克隆形成实验、免疫荧光DNA双链断裂检测和蛋白质印迹法检测索拉非尼对SMMC-7721细胞的放射增敏作用。放射治疗前1小时给予索拉非尼导致放射增敏，如克隆形成试验所示，增敏比（SER）为1.65。此外，索拉非尼B预处理导致SMMC-7721细胞中细胞外信号调节激酶（ERK）和蛋白激酶B（AKT）磷酸化水平降低。有趣的是，在肝癌细胞中，丝裂原活化蛋白激酶激酶/细胞外信号调节激酶（MEK/ERK）信号传导抑制剂U 0126预处理与索拉非尼B预处理具有相似的效果，而在相同细胞中，磷酸肌醇3-激酶/蛋白激酶B（PI 3 K/AKT）信号传导抑制剂LY 294002预处理对放射增敏没有影响。索拉非尼和放射治疗组是更敏感的辐射单独证明的DNA双链断裂detecting.Conclusions的结果：索拉非尼和辐射的组合影响细胞活力比单独辐射更有效。索拉非尼显著增强SMMC-7721细胞对辐射的敏感性，显示DNA双链断裂的修复显著减少。MEK/ERK信号通路可能是索拉非尼增强放射敏感性的途径。我们的数据为索拉非尼联合放射治疗肝细胞癌和其他癌症的可能性提供了实验支持。
Purpose: Sorafenib, an oral multikinase inhibitor, is the first agent that has demonstrated an improved overall survival benefit in advanced hepatocellular carcinoma, setting a new standard for first-line treatment. However, the association between radiosensitivity and sorafenib remains unclear. The purpose of this study was to investigate whether sorafenib could enhance radiosensitivity and the possible mechanisms of sorafenib-mediated radiosensitization in human hepatocellular carcinoma cell line SMMC-7721.Experimental design: The cell viability of human hepatocellular carcinoma cell line SMMC-7721 was determined by the 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The radiosensitization of sorafenib in SMMC-7721 cells was evaluated by clonogenic assays, and immunofluorescence for DNA double-strand break detection, and Western blotting for protein detection.Results: The MTT results clearly showed that sorafenib affected cell viability in human hepatocellular cell line SMMC-7721. Sorafenib administered 1 h before the radiation treatment resulted in radiosensitization with a sensitivity enhancement ratio (SER) of 1.65 as shown by clonogenic assays. Furthermore, sorafenib pretreatment led to decreased phosphorylation levels of extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) in SMMC-7721 cells. Interestingly, pretreatment of mitogen-activated protein kinase kinases/extracellular signal-regulated kinase (MEK/ERK) signaling inhibitor U0126 had a similar effect as that of sorafenib pretreatment in hepatocellular carcinoma cells, whereas pretreatment of phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling inhibitor LY294002 in the same cells had no effect on radiosensitization. The group treated with sorafenib and radiation was more sensitive to irradiation alone as demonstrated by the results of the DNA double-strand break detection.Conclusions: The combination of sorafenib and radiation affected cell viability more effectively than radiation alone. Sorafenib significantly enhanced the sensitivity of SMMC-7721 cells to radiation showing significantly reduced repair of DNA double-strand breaks. The MEK/ERK signaling pathway may be a pathway responsible for the radiosensitivity enhancement of sorafenib. Our data provided experimental support for the possible combination of sorafenib with radiation for the treatment of hepatocellular carcinoma and other cancers.