Genetic analyses for apoptosis susceptibility and identification of genes involved

细胞凋亡易感性的遗传分析和相关基因的鉴定

• 批准号: 10680521
• 负责人: MORI Nobuko
• 金额: $ 1.6万
• 依托单位: Osaka Prefecture University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680521/
• 关键词: apoptosis; apoptosis susceptibility; genetic analysis; mouse; thymus; radiation; radiation lymphomagenesis; 感受性; 遺伝子

This study was aimed at fine mapping and identification of apoptosis susceptibility genes Rapop1, Rapop2 and Rapop3, which had been mapped on mouse chromosomes 16.9 and 3 respectively as well as at analyses of apoptosis susceptibility. The STS allele at any of these loci decreases radiation-induced apoptosis of thymocytes in the BALB/c background. Both Rapop1 and Rapop2 have been suggested to be also involved in radiation-induced apoptosis in colon, but in a different way from that in the thymus. In addition, Rapop1 has been shown to affect steroid- as well as radiation-induced apoptosis in the thymus. p53 deficiency has been shown to enhance steroid-induced apoptosis. Analysis of several mice with recombination in the STS-derived segment of chromosome 16 in the BALB/c background showed that the critical region for Rapop1 was 0.45 cM near D16Mit34. Since DNA-PKcs, the catalytic subunit of DNA-dependent protein kinase (DNA-PK) critical for DNA double-strand break (dsb) repair, has been centered in this region, we tested DNA-PKcs as a potential candidate for Rapop1. On sequencing cDNAs for DNA-PKcs, two different variations producing amino acid substitutions between BALB/c and STS have been identified. Haplotype analysis for DNA-PKcs in number of inbred strains showed that the majority carried the STS allele, indicating that the STS allele was wild type. DNA-PK activity was pronouncedly diminished in the mice with the BALB/c allele at DNA-PKcs, concomitant with decreased DNA-PKcs expression at the similar levels of mRNA.Rapop1 congenic mice that carried the STS allele at DNA-PKcs in the BALB/c background were less sensitive to both radiation-induced apoptosis and lymphomas as compared with BALB/c. This might be explained by different capability in dsb repair between DNA-PKcs haplotypes. The results strongly implicated DNA-PKcs as a candidate for Rapop1.

本研究旨在对分别定位于小鼠16.9号和3号染色体上的凋亡易感基因Rapop 1、Rapop 2和Rapop 3进行精细定位和鉴定，并进行凋亡易感性分析。STS等位基因在任何这些位点减少辐射诱导的胸腺细胞凋亡的BALB/c背景。Rapop 1和Rapop 2都被认为也参与了辐射诱导的结肠细胞凋亡，但方式与胸腺不同。此外，Rapop 1已被证明影响类固醇以及辐射诱导的胸腺细胞凋亡。已经显示p53缺陷增强类固醇诱导的细胞凋亡。在BALB/c背景下，对几只在16号染色体STS衍生片段中具有重组的小鼠的分析表明，Rapop 1的关键区域为D16 Mit 34附近的0.45 cM。由于DNA-PKcs是DNA依赖性蛋白激酶（DNA-PK）的催化亚基，对DNA双链断裂（dsb）修复至关重要，因此已集中在该区域，我们将DNA-PKcs作为Rapop 1的潜在候选者进行了测试。在DNA-PKcs的cDNA测序中，已经鉴定了在BALB/c和STS之间产生氨基酸取代的两种不同变异。DNA-PKcs单倍型分析表明，绝大多数近交系均携带STS等位基因，表明STS等位基因为野生型。在DNA-PKcs位点携带STS等位基因的BALB/c小鼠中，DNA-PK活性显著降低，同时DNA-PKcs表达水平降低;与BALB/c相比，在DNA-PKcs位点携带STS等位基因的BALB/c Rapop 1同源小鼠对辐射诱导的细胞凋亡和淋巴瘤的敏感性降低。这可能是通过DNA-PKcs单倍型之间dsb修复能力的不同来解释的。这些结果强烈暗示DNA-PKcs是Rapop 1的候选者。

项目成果

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Oka, S.、Mori, N.等人：“胸腺细胞内 B220 的存在及其在细胞凋亡过程中在细胞表面的表达。”免疫学。

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Mori, N.et al.: "Variations in Prkdc encoding the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) and susceptibility to radiation-induced apoptosis and lymphomagenesis."Oncogene. (in press).

Mori, N.等人：“编码 DNA 依赖性蛋白激酶 (DNA-PKcs) 催化亚基的 Prkdc 的变异以及对辐射诱导的细胞凋亡和淋巴瘤发生的易感性。”癌基因。