Heavy ion irradiation increases apoptosis and STAT-3 expression, led to the cells arrested at G2/M phase in human hepatoma SMMC-7721 cells
Heavy ion irradiation increases apoptosis and STAT-3 expression, led to the cells arrested at G2/M phase in human hepatoma SMMC-7721 cells
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DOI：
10.1007/s11010-009-0069-6
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发表时间：
2009-08-01
影响因子：
4.3
通讯作者：
Wang, Xiaopeng
中科院分区：
文献类型：
--
作者：
Ma, Jianxun;Ye, Lanping;Wang, Xiaopeng
研究STAT-3表达对X射线和碳离子照射诱导人肝癌细胞SMMC-7721凋亡的影响。方法采用碳离子束和X射线联合照射人肝癌SMMC-7721细胞。通过标准集落形成测定确定细胞存活。通过Western免疫印迹分析STAT-3蛋白表达。流式细胞仪检测细胞周期和凋亡。结果随着碳离子束剂量的增加，SMMC-7721细胞的存活率逐渐降低，高LET碳离子束使细胞阻滞于G（2）/M期。Western Blot分析显示STAT-3表达随辐射剂量的增加而增加。与X射线照射相比，碳离子照射可诱导细胞凋亡，并显著促进STAT-3基因的表达。不同剂量的X射线和重离子束照射后，人肝癌SMMC-7721细胞凋亡率与STAT-3的表达相关。结论与低LET X射线照射相比，重离子照射可增加STAT-3基因表达，使SMMC-7721细胞阻滞于G（2）/M期，增加细胞凋亡。STAT-3的表达可以被认为是当癌细胞受到强刺激如高LET照射时的保护性反应。STAT-3在人肝癌中的表达与其他细胞因子的相互作用以及STAT-3与辐射诱导细胞凋亡的关系有待进一步研究。
Background The impact of STAT-3 expression on the apoptosis of human hepatomas cell SMMC-7721 line induced by X-ray and carbon ion irradiations was investigated. Methods Human hepatoma SMMC-7721 cells were irradiated with a carbon ion beam and X-ray. Cell survival was determined by a standard colony-forming assay. STAT-3 protein expression was analysed by Western Immunoblots. Cell cycle and apoptosis were performed by flow cytometry. Results The viability of SMMC-7721 cells decreased with increasing dose of the carbon ion beam, and the high-LET carbon ion beam led to the cells getting arrested at G(2)/M phase. Western Blot analyses show that STAT-3 expression increased with increasing radiation dose. The carbon ion irradiation induced cell apoptosis and significantly promoted the expression of STAT-3 gene compared with the X-ray irradiation. The apoptosis rate is correlated with the expression of STAT-3 in human hepatoma SMMC-7721 cells after exposure to different doses of X-ray and heavy ion beam. Conclusions Heavy ion irradiation increases the expression of STAT-3 gene, makes SMMC-7721 cells arrested at G(2)/M phase and increases cell apoptosis in comparison with that induced by low-LET X-ray. The STAT-3 expression may be regarded as a protected reaction when the cancerous cells suffer a strong stimulus such as high-LET irradiation. The interaction of STAT-3 expression and other cytokines in human hepatoma and the relationship between STAT-3 and radiation-induced apoptosis remain to be clarified in the future.