title: Genomic instability induced by ionizing radiation in human hepatocytes.
abstract: The aim of this study was to characterize genomic instability induced by ionizing radiation (IR) in human hepatocytes as reflected by alterations in cloning efficiency, micronucleus (MN) frequency, and apoptosis. The human normal liver 7702 cell line (HL7702) was subjected to initial irradiation of (60)Co-γ ray at doses of 0 (control group), 2, 4, 6, 8, or 10 Gy in each group. Progeny of surviving cells from a second irradiation at dose of 2 Gy were cultured for 15 passages until they were transferred. The cloning efficiency, MN frequency, and apoptotic rate were measured after the initial irradiation, and repeated at passage 15 before and after the second irradiation. The initial irradiation resulted in a dose-dependent decline in cloning efficiency and an increase in MN frequency and apoptotic rate. At passage 15 in progeny of initially irradiated cells, cloning efficiency, MN frequency returned to control levels while apoptotic rate rose. After the second irradiation, cloning efficiency fell while a rise in MN frequency and apoptosis occurred. Our results show that the second irradiation may further enhance cell progeny injury induced by initial irradiation, such that genomic instability that may be difficult to detect after one irradiation is more apparent with subsequent irradiation.
authors: Division of Radiology and Environmental Medicine, China Institute for Radiation Protection, Taiyuan, China.
authors: Ya-Hui
authors: YH
authors: Zuo
authors: Xu-Hong
authors: XH
authors: Dang
authors: Hui-Fang
authors: HF
authors: Zhang
authors: Jian-Gong
authors: JG
authors: Liu
authors: Zhi-Kai
authors: ZK
authors: Duan
authors: Zhong-Wen
authors: ZW
authors: Wang
authors: Jian
authors: J
authors: Tong
mesh_terms: D017209:Apoptosis / Q000528:radiation effects; D002460:Cell Line; D003001:Cloning, Molecular / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects*; D042822:Genomic Instability / Q000528:radiation effects*; D022781:Hepatocytes / Q000528:radiation effects*; D006801:Humans; D048629:Micronuclei, Chromosome-Defective / Q000528:radiation effects; D015162:Micronucleus Tests