Ogino Hideki, Nakayama Robert, Sakamoto Hiromi, Yoshida Teruhiko, Sugimura Takashi, Masutani Mitsuko
Biochemistry Division, National Cancer Center Research Institute, 1-1 Tsukiji 5-chome, Chuo-ku, Tokyo, Japan.
Cancer Genet Cytogenet. 2010 Feb;197(1):8-15. doi: 10.1016/j.cancergencyto.2009.10.012.
The poly(ADP-ribose) polymerase-1 protein (PARP-1) functions in DNA repair, maintenance of genomic stability, induction of cell death, and transcriptional regulation. We previously analyzed alterations of the PARP1 gene in 16 specimens of human germ cell tumors, and found a heterozygous sequence alteration that causes the amino acid substitution Met129Thr (M129T) in both tumor and normal tissues in a single patient. In this study, aberration of the PARP1 gene and protein was further analyzed in human germ cell tumor cell lines. We found a nonheterozygous sequence alteration that causes the amino acid substitution Glu251Lys (E251K) located at a conserved peptide stretch of PARP-1 in cell line NEC8. Sequencing of 95 samples from Japanese healthy volunteers revealed that all the samples were homozygous for the wild-type alleles at M129T and E251K. The M129T allele is thus suggested to be a rare single-nucleotide polymorphism (SNP). We observed a decrease in auto-poly(ADP-ribosyl)ation activity of PARP-1 proteins harboring M129T or E251K amino acid substitution, but the difference was not statistically significant. The levels of PARP-1 and poly(ADP-ribosyl)ation were heterogeneous among germ cell tumor cell lines. The SNPs of the PARP1 gene, as well as differences in the levels of PARP-1 and poly(ADP-ribosyl)ation of proteins, may influence germ cell tumor development and responses to chemotherapy and radiotherapy.
聚（ADP - 核糖）聚合酶 -1蛋白（PARP -1）在DNA修复、基因组稳定性维持、细胞死亡诱导及转录调控中发挥作用。我们之前分析了16例人类生殖细胞肿瘤标本中PARP1基因的改变，在一名患者的肿瘤组织和正常组织中均发现了导致氨基酸替换Met129Thr（M129T）的杂合序列改变。在本研究中，我们进一步分析了人类生殖细胞肿瘤细胞系中PARP1基因和蛋白的异常情况。我们在细胞系NEC8中发现了一种非杂合序列改变，该改变导致位于PARP -1保守肽段的氨基酸替换Glu251Lys（E251K）。对95名日本健康志愿者的样本进行测序发现，所有样本在M129T和E251K位点均为野生型等位基因纯合子。因此，M129T等位基因被认为是一种罕见的单核苷酸多态性（SNP）。我们观察到携带M129T或E251K氨基酸替换的PARP -1蛋白的自身聚（ADP - 核糖）基化活性降低，但差异无统计学意义。生殖细胞肿瘤细胞系中PARP -1和聚（ADP - 核糖）基化水平存在异质性。PARP1基因的SNP以及PARP -1水平和蛋白聚（ADP - 核糖）基化的差异可能会影响生殖细胞肿瘤的发生发展以及对化疗和放疗的反应。
