辐射诱导人细胞系CEM、外周血单个核细胞DNA修复基因hHR21^(sp)的表达研究

Studies on hHR21^(sp) expression induced by irradiation in the peripheral blood cells and human cell line (CEM)

目的 研究辐射对人T淋巴细胞白血病细胞系 (CEM)、外周血单个核细胞的hHR2 1sp基因转录表达水平的影响及意义。方法 分别对人T淋巴细胞白血病细胞系CEM和正常人外周血单核细胞在UV或γ辐射后不同时间提取细胞总RNA ,通过RT PCR与hHR2 1sp 基因特异引物杂交 ,以 β actin为内参照放射影像密度扫描检测人T淋巴细胞白血病细胞系CEM、单核细胞DNA修复基因表达。结果 在UV 辐射、γ 辐射后早期 (3～ 6h) ,人T淋巴细胞白血病细胞系CEM和淋巴细胞hHR2 1sp基因的表达水平明显增加 ,照射后 6hhHR2 1sp基因的表达水平增加最多且UV辐射更明显 ,在晚期 (9h)降低。比较人细胞系CEM和淋巴细胞两者hHR2 1sp基因的表达水平 ,γ辐射 (3Gy)后淋巴细胞对hHR2 1sp基因表达高于人细胞系CEM ,且表达增加时间较长 ,达 9h ;而人细胞系CEM受到γ辐射后早期表达增加 ,在 6～ 9h后表达降低。结论 人T淋巴细胞白血病细胞系 (CEM)和人淋巴细胞的DNA修复基因hHR2 1sp基因在一定剂量辐射 (UV、γ辐射 )范围内其表达水平随辐射剂量增加而诱导表达水平增高 ,且对UV辐射更敏感 ;提示hHR2 1sp基因在人细胞系CEM细胞和人单核细胞在照射损伤后表达增加 ,可能是促进单核细胞损伤修复的原因之一。

Objective\ To study the effects of UV and gamma\|ray irradiation on hHR21\+\{sp\} transcription in a human T lymphocytic leukemia cell line,CEM. Methods\ Total RNA was extracted from normal human peripheral blood mononuclear cells (PB\|MNC) and CEM cells after exposure to UV and gamma\|ray irradiation.The level of hHR 21 transcripts was deteced using RT\|PCR with southern blot hybridization and phosphorlmage autoradiogram analysis. Results\ hHR21 sp mRNA increased significantly at 3 h to 9 h after UV irradiation in PB\|MNC and CEM cells,and the induction doses were 40 to 80 J/M and 80\|120 J/M for PB\|MNC and CEM cells,respectively.In PB\|MNC,hHR21\+\{sp\} mRNA increased at 6 to 9 h after 1 to 5 Gy of gamma\|ray irradiation.In contrast,hHR21\+\{sp\} mRNA was induced only at 3 h after irradiation in CEM cells,and its peak appeared at 9 h after irradiation with 3 Gy. Conclusion\ The results revealed that hHR21\+\{sp\} gene transcription could be induced by UV as well as gamma\|ray irradiation.The levles of hHR21\+\{sp\} mRNA induced by gamma\|ray irradiation was obviously different between PB\|MNC and CEM cells.\;