CAJ | 학술논문

采用高传能线密度(LET)的12C6+离子束和低LET的X射线辐照人正常肝细胞系HL-7702细胞，利用微卫星不稳定性(MSI)检测来分析直接受照射细胞和通过转移培养基方式旁细胞传代八代子细胞以MSI表征的远后效应。实验结果表明，12C6+离子束诱导的远后效应较X射线的低；旁细胞的远后效应较直接受照射细胞的高；辐射引起的MSI与杂合性丢失(LOH)的发生率具有位点特异性。结果提示，重离子放射治疗较X射线放射治疗对正常组织引发的辐射风险要小，可通过对MSI高发位点的筛选来评估放疗后患者长期生存状况和二次癌症发生风险。
채용고전능선밀도(LET)적12C6+리자속화저LET적X사선복조인정상간세포계HL-7702세포，이용미위성불은정성(MSI)검측래분석직접수조사세포화통과전이배양기방식방세포전대팔대자세포이MSI표정적원후효응。실험결과표명，12C6+리자속유도적원후효응교X사선적저；방세포적원후효응교직접수조사세포적고；복사인기적MSI여잡합성주실(LOH)적발생솔구유위점특이성。결과제시，중리자방사치료교X사선방사치료대정상조직인발적복사풍험요소，가통과대MSI고발위점적사선래평고방료후환자장기생존상황화이차암증발생풍험。
Human normal liver cell line HL-7702 cells were irradiated with high linear energy transfer (LET) 12C6+ions and low-LET X-rays, respectively. Delayed effect in terms of microsatellite instability (MSI) in progenies of the directly irradiated cells and bystander cells, obtained in the way of medium transfer at the 8th passage postirradiation, were examined. The delayed effect induced by the high-LET 12C6+ions was different from that induced by the low-LET X-rays, and a higher incidence of MSI was observed in the progenies of the cells after exposure to the X-rays than to the 12C6+ions. We also found that the delayed effect in the progenies of the bystander cells was much more severe than those of directly irradiated cells. Furthermore, the events of MSI and loss of heterozygosity (LOH) induced by the ionizing radiations were not randomly distributed throughout the genome and specific loci existed indeed. These results imply that the radiation risk to normal tissues is lower in heavy ion therapy than in conventional X-ray radiotherapy, and the analysis of microsatellite loci with MSI high frequency occurrence can be applied to access long-term survival condition and second cancer risk for the patients after radiotherapy.