文章基本信息

标题：Inverse Dose-rate-effects on the Expressions of Extra-cellular Matrix-related Genes in Low-dose-rate γ-ray Irradiated Murine Cells
其他标题：Inverse Dose-rate-effects on the Expressions of Extra-cellular Matrix-related Genes in Low-dose-rate γ-ray Irradiated Murine Cells
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作者：Takashi SUGIHARA ; Hayato MURANO ; Kimio TANAKA 等
期刊名称：Journal of Radiation Research
印刷版ISSN：0449-3060
电子版ISSN：1349-9157
出版年度：2008
卷号：49
期号：3
页码：231-240
DOI：10.1269/jrr.07074
摘要：Based on the results of previous microarray analyses of murine NIH3T3/PG13Luc cells irradiated with continuous low-dose-rate (LDR) γ-ray or end-high-dose-rate-irradiations (end-HDR) at the end of the LDR-irradiation period, the inverse dose-rate-effects on gene expression levels were observed. To compare differences of the effects between LDR-irradiation and HDR-irradiation, HDR-irradiations at 2 different times, one (ini-HDR) at the same time at the start of LDR-irradiation and the other (end-HDR), were performed. The up-regulated genes were classified into two types, in which one was up-regulated in LDR-, ini-HDR-, and end-HDR irradiation such as Cdkn1a and Ccng1 , which were reported as p53-dependent genes, and the other was up-regulated in LDR- and ini-HDR irradiations such as pro-collagen TypeIa2/Col1a2 , TenascinC/Tnc , and Fibulin5/Fbln5 , which were reported as extra-cellular matrix-related (ECM) genes. The time dependent gene expression patterns in LDR-irradiation were also classified into two types, in which one was an early response such as in Cdkn1a and Ccng1 and the other was a delayed response such as the ECM genes which have no linearity to total dose. The protein expression pattern of Cdkn1a increased dose dependently in LDR- and end-HDR-irradiations, but those of p53Ser15/18 and MDM2 in LDR-irradiations were different from end-HDR-irradiations. Furthermore, the gene expression levels of the ECM genes in embryonic fibroblasts from p53 -deficient mice were not increased by LDR- and end-HDR-irradiation, so the delayed expressions of the ECM genes seem to be regulated by p53. Consequently, the inverse dose-rate-effects on the expression levels of the ECM genes in LDR- and end-HDR-irradiations may be explained from different time responses by p53 status.
关键词：Low-dose-rate radiation; p53; Extra-cellular matrix; Gene expression