BTG1蛋白及其上下游信号通路对X射线和碳离子辐射的应激响应

BTG1 and Its Related Pathways in Cellular Response to X-ray and Carbon Ion Radiation

BTG1是重要的抗细胞增殖蛋白,在细胞对外界胁迫如电离辐射等的应激响应过程中发挥重要功能。到目前为止,电离辐射诱导BTG1蛋白表达水平的长期变化情况、其对细胞基因组稳定性的影响及上下游相关的信号通路仍未完全阐明。通过荧光定量PCR技术发现BTG1对X射线和碳离子的应激呈现出先迅速升高再缓慢下降的过程。此外,微核实验表明,通过转染基因的质粒过表达载体或si RNA的方法外源性增加或抑制786-O细胞内BTG1的表达水平均能够显著影响碳离子辐照诱导的基因组不稳定性。深入研究发现电离辐射诱导的NF-κB的表达和活化可能通过引起SKA2基因的表达而间接地调控BTG1的表达,而BTG1则可能激活PRMT1的活性而引起基因组表观遗传学的改变,进而影响细胞的基因组稳定性、细胞周期调控以及凋亡等进程。

BT G1, an important anti-proliferative gene, plays critical roles in cellular response to stresses,including ionizing radiation（IR）. However, the long term expression of BTG1 induced by IR and its upstream/downstream signal pathways have not been elucidated clearly until now. The q RT-PCR results showed that the expression level of BT G1 in 786-O cells was rapidly elevated by IR in a short time, and then decreased slowly. In addition, upregulation or downregulation by transfection of BTG1 overexpression vector or si RNA could significantly affect the carbon ion radiation-induced genomic instability. Further study indicated that IRinduced BTG1 expression may be regulated by NF-κB-mediated activation of SKA2 indirectly; On the other hand, expression of BTG1 may cause epigenetic changes by activating PRMT1, and subsequently influence the genomic stability, cell cycle regulation and apoptosis.