Decreased cell survival and DNA repair capacity after UVC irradiation in association with down-regulation of GRP78/BiP in human RSa cells
Decreased cell survival and DNA repair capacity after UVC irradiation in association with down-regulation of GRP78/BiP in human RSa cells
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DOI：
10.1016/j.yexcr.2005.01.002
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发表时间：
2005-05-01
影响因子：
3.7
通讯作者：
Suzuki, N
中科院分区：
文献类型：
--
作者：
Zhai, L;Kita, K;Suzuki, N
相对于热休克蛋白等分子伴侣的广泛研究，内质网应激诱导的GRP 78/BiP在哺乳动物细胞DNA损伤应激反应中的作用的报道较少。为了研究GR-P78/BiP是否参与对DNA损伤剂UVC（主要波长为254 nm）的抗性，我们通过用GRP 78/BiP的反义cDNA转染人RSa细胞来建立具有GPP 78/BiP下调的人细胞。我们发现，转染的细胞表现出更高的敏感性，紫外线诱导的细胞死亡比对照细胞单独转染的载体。在反义cDNA转染的细胞中，两种主要类型的紫外线损伤的DNA（胸腺嘧啶二聚体和（6-4）光产物）在体内的清除能力和DNA合成活性的全细胞提取物修复紫外线照射的质粒在体外显着降低与对照细胞相比。此外，反义cDNA转染的细胞也表现出比对照细胞稍高的敏感性顺铂诱导的细胞死亡。顺铂诱导的DNA损伤主要通过核苷酸切除修复来修复，类似于UV C诱导的DNA损伤。目前的结果表明，GRP 78/BiP对紫外线诱导的细胞死亡可能通过核苷酸切除修复起保护作用，至少在测试的人RSa细胞中。(c)2005年爱思唯尔公司All rights reserved.
In contrast to extensive studies on the roles of molecular chaperones, such as heat shock proteins, there are only a few reports about the roles of GRP78/BiP, an endoplasmic reticulum (ER) stress-induced molecular chaperone, in mammalian cell responses to DNA-damaging stresses. To investigate whether GR-P78/BiP is involved in resistance to a DNA-damaging agent, UVC (principally 254 nm in wavelength), we established human cells with down-regulation of GPP78/BiP by transfection of human RSa cells with antisense cDNA for GRP78/BiP. We found that the transfected cells showed higher sensitivity to UVC-induced cell death than control cells transfected with the vector alone. In the antisense-cDNA transfected cells, the removal capacities of the two major types of UVC-damaged DNA (thymine dimers and (6-4) photoproducts) in vivo and DNA synthesis activity of whole cell extracts to repair UVC-irradiated plasmids in vitro were remarkably decreased compared with those in the control cells. Furthermore, the antisense-cDNA transfected cells also showed slightly higher sensitivity to cisplatin-induced cell death than the control cells. Cisplatin-induced DNA damage is primarily repaired by nucleotide excision repair, like UVC-induced DNA damage. The present results suggest that GRP78/BiP plays a protective role against UVC-induced cell death possibly via nucleotide excision repair, at least in the human RSa cells tested. (c) 2005 Elsevier Inc. All rights reserved.