A study for a transcription factor gene regulating radiation sensitivity

我们克隆了电离辐射诱导的新型kruppel型锌指基因ZK1。Biophys。《平民法典》，第249期：595-600,1998年。)ZK1促进电离辐射后造血细胞凋亡死亡。为了阐明ZK1基因产物对细胞凋亡的作用，我们在表达载体pBK-CMV中构建了稳定转染ZK1cDNA的HeLa、MCAS（腺瘤细胞型）、SCC-TF（鳞状细胞型）和U937（白血病细胞型）。这些基因对电离辐射、抗肿瘤药物、热休克（42℃）和H_2O_2均有较高的敏感性。这些数据提示ZK1在各种应激引起的凋亡细胞死亡信号通路的共同部位有一定的功能。我们进一步利用PCR和EMSA技术分析了ZK1基因产物基因组DNA的结合序列。本研究发现ZK1基因产物可以结合CACCC基序。这一结果强烈提示ZK1基因产物可以作为转录调控因子发挥作用。需要进一步分析阐明ZK1基因产物转录调控凋亡细胞死亡信号通路中的靶基因。

We cloned a novel Kruppel-type zinc finger gene, ZK1, induced following exposure to ionizing radiation (Biochem. Biophys. Res. Commun. 249 : 595-600, 1998.) ZK1 enhances apoptotic death on hematopoietic cells after exposure to ionizing radiation.We investigated function of the ZK1 gene product on apoptotic death caused by various stresses such as anti-tumor drugs, VP-16 or cisplatin, heat shock, or H_2O_2 on other cell types such as squamous or adenomatous carcinoma cellsTo elucidate this function of the ZK1 gene product, we constructed HeLa, MCAS (adenomatous cell type), SCC-TF (squamous cell type), and U937 (leukemia cell type) stably transfected with ZK1cDNA in expression vector, pBK-CMV.These transfectants had higher sensitivity to exposure not only to ionizing radiation but also to anti-tumor drugs, heat shock (42℃) or H_2O_2. These data suggest that ZK1 has some functions on common parts lying signalling pathway of apoptotic cell death caused by various stresses.We further analyzed binding sequence on genomic DNA of the ZK1 gene product by PCR and EMSA techniques. As the result of this research, we found that the ZK1 gene product could bind CACCC motif.This result strongly suggest that the ZK1 gene product can function as a transcriptional regulator. Further analysis will be needed to elucidate target genes lying signalling pathway of apoptotic cell death transcriptionally regulated by the ZK1 gene product.