Processing of three different types of DNA damage in cell lines of a cutaneous squamous cell carcinoma progression model
Processing of three different types of DNA damage in cell lines of a cutaneous squamous cell carcinoma progression model
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DOI：
10.1093/carcin/18.4.657
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发表时间：
1997-04-01
期刊：
影响因子：
4.7
通讯作者：
Runger, TM
中科院分区：
文献类型：
--
作者：
Diem, C;Runger, TM
为了研究DNA损伤处理在皮肤鳞状细胞癌（SCC）发展中的作用，我们评估了来自多阶段肿瘤进展模型的六种角质形成细胞系修复三种类型DNA损伤的能力：嘧啶二聚体、氧化性DNA损伤和DNA双链断裂（DSB）。该模型包括自发永生化的非致瘤性人角质形成细胞系HaCaT，四种不同的HaCaT c-Ha-rns转染子用UVB处理的质粒载体pRSVcat进行的宿主细胞再活化测定显示，与非致瘤细胞系相比，在致瘤细胞系中UVB诱导的嘧啶二聚体的修复没有显著改变，使用单线态氧处理的质粒pRSVcat，Ha-ras-HaCaT-克隆和SCC-细胞表现出与HaCaT细胞无显著差异的DNA修复效率，以评估细胞连接游离DNA末端的能力我们用线性化质粒pZ 189进行质粒穿梭载体测定，发现非致瘤性、良性和恶性HaCaT-克隆II-4中DNA末端连接能力显著增加，而恶性HaCaT-克隆II-3表现出显著较低的线性化质粒再连接率，该细胞系还显示出高度和显著升高的微核率，这反映了明显的染色体不稳定性。SCC细胞比HaCaT细胞表现出更有效的DNA DSB修复。我们得出结论，在所检查的模型中，人角质形成细胞从非致瘤性表型发展到高度致瘤性表型，并不伴随着细胞修复UVB和单线态氧诱导的DNA损伤的能力降低，然而，修复DNA双链断裂的获得性缺陷可能是促进恶性进展的一种机制，可能通过损害染色体稳定性。
In order to study the role of DNA damage processing in the development of cutaneous squamous cell carcinoma (SCC), we assessed the ability of six keratinocyte cell lines from a multistage-tumor progression model to repair three types of DNA damage: pyrimidine dimers, oxidative DNA lesions and DNA double strand breaks (DSB), The model comprised the spontaneously immortalized, non-tumorigenic human keratinocyte cell line HaCaT, four different c-Ha-rns transfectants of HaCaT (non-, benign- and two malignant-tumorigenic) and a SCC-derived cell line, Host cell reactivation assays with UVB-treated plasmid vectors pRSVcat showed no significantly altered repair of UVB-induced pyrimidine dimers in the tumorigenic cell lines, compared with the non-tumorigenic lines, Using the singlet oxygen-treated plasmids pRSVcat the Ha-ras-HaCaT-clones and the SCC-cells, exerted a DNA repair efficiency that was not significantly different from HaCaT cells, In order to assess the ability of the cells to ligate free DNA ends (repair of DSB), we used a plasmid shuttle vector assay with linearized plasmid pZ189, We found a significant increase of DNA end joining ability in the non-tumorigenic, the benign and in one of the malignant HaCaT-clones II-4, The malignant HaCaT-clone II-3, however, exerted a significantly lower rate of rejoining the linearized plasmid, This cell line also showed a highly and significantly elevated rate of micronuclei, which reflects a pronounced chromosomal instability, The SCC-cells exhibited a more efficient repair of DNA DSB than the HaCaT cells, We conclude that in the examined model, progression of human keratinocytes from the non-tumorigenic to the highly tumorigenic phenotype, is not accompanied by a decrease in the cell's capacity to repair UVB- and singlet oxygen-induced DNA lesions, However, an acquired deficiency in repairing DNA double strand breaks can be one mechanism promoting progression towards malignancy, possibly through impairing chromosomal stability.