CAJ | 학술논문

目的探讨印记基因PHLDA2过表达对骨肉瘤放射敏感性的影响及相关分子机制.方法通过基因转染技术,将真核表达质粒pEGFP-C3-PHLDA2导入骨肉瘤U2OS细胞,经G418持续筛选获得稳定高表达PHLDA2蛋白的亚克隆细胞.实验分为3组:不转染的空白对照组,U2OS;稳定转染pEGFP-C3质粒的阴性对照组,U2OS-neo;pEGFP-C3-PHLDA2质粒的稳定转染组,U2OS-PHLDA2.采用CKK8比色法测定4和8 GyX射线照射后细胞的增殖活性;克隆形成实验观察0～8 Gy照射后细胞的存活能力;Annexin V/PI染色法检测8 Gy照射后的细胞凋亡;Western blot测定蛋白的表达变化.建立人骨肉瘤裸鼠移植瘤模型,观察10 Gy照射后PHLDA2基因的体内增敏效应.结果经筛选获得的骨肉瘤亚克隆U2OS-PHLDA2细胞中PHLDA2蛋白表达上调(t=13.73,16.28,P＜0.05).与U2OS和U2OS-neo组相比,PHLDA2高表达组在4和8 Gy的增殖能力明显降低(t=5.00 ～ 8.23,P＜0.05),2～8 Gy的克隆形成能力明显降低(t=-2.52～-1.26,P＜0.05);同时照后裸鼠移植瘤的生长抑制作用显著提高(=3.27、2.91,P＜0.05).8 Gy照后,PHLDA2高表达组的凋亡率为(17.97±1.69)％,高于U2OS组的(6.47±1.01)％和U2OS-neo组的(7.15±0.96)％(t=10.11、9.61,P＜0.05);同时Caspase-3活性明显提高(t=11.26、10.72,P＜0.05).结论外源性PHDLA2基因在U2OS细胞中稳定过表达能够提高骨肉瘤对X射线的敏感性,其机制可能是通过增强Caspase-3的活性、促进射线诱导的细胞凋亡作用实现的.
목적 탐토인기기인PHLDA2과표체대골육류방사민감성적영향급상관분자궤제.방법 통과기인전염기술,장진핵표체질립pEGFP-C3-PHLDA2도입골육류U2OS세포,경G418지속사선획득은정고표체PHLDA2단백적아극륭세포.실험분위3조:불전염적공백대조조,U2OS;은정전염pEGFP-C3질립적음성대조조,U2OS-neo;pEGFP-C3-PHLDA2질립적은정전염조,U2OS-PHLDA2.채용CKK8비색법측정4화8 GyX사선조사후세포적증식활성;극륭형성실험관찰0～8 Gy조사후세포적존활능력;Annexin V/PI염색법검측8 Gy조사후적세포조망;Western blot측정단백적표체변화.건립인골육류라서이식류모형,관찰10 Gy조사후PHLDA2기인적체내증민효응.결과 경사선획득적골육류아극륭U2OS-PHLDA2세포중PHLDA2단백표체상조(t=13.73,16.28,P＜0.05).여U2OS화U2OS-neo조상비,PHLDA2고표체조재4화8 Gy적증식능력명현강저(t=5.00 ～ 8.23,P＜0.05),2～8 Gy적극륭형성능력명현강저(t=-2.52～-1.26,P＜0.05);동시조후라서이식류적생장억제작용현저제고(=3.27、2.91,P＜0.05).8 Gy조후,PHLDA2고표체조적조망솔위(17.97±1.69)％,고우U2OS조적(6.47±1.01)％화U2OS-neo조적(7.15±0.96)％(t=10.11、9.61,P＜0.05);동시Caspase-3활성명현제고(t=11.26、10.72,P＜0.05).결론 외원성PHDLA2기인재U2OS세포중은정과표체능구제고골육류대X사선적민감성,기궤제가능시통과증강Caspase-3적활성、촉진사선유도적세포조망작용실현적.
Objective To study the effects of PHLDA2 overexpression on radiosensitivity and the underlying mechanisms in human osteosarcoma U2OS cell line.Methods To obtain the subclone,cells were exposed to G418 persistently after transfection of pEGFP-C3-PHLDA2 vector into U2OS cells.Three groups of blank control (U2OS),negative control (U2OS-neo) and transfected group (U2OS-PHLDA2) were used.The expression of PHLDA2 in the subclone cells was determined by Western blot.After exposure to X-ray irradiation,cellular growth activity and survival were detected by CKK-8 assay and colony formation assay,respectively.The cell apoptosis was measured by the Annexin V/PI staining,and the apoptotic protein was analyzed by Western blot.The in-vivo effects of PHLDA2 on irradiation were evaluated by xenografts.Results Compared with U2OS group and U2OS-neogroup,the sabclone cells were successfully obtained by G418 selection,in which the expression of PHLDA2 was upregulated(t =13.73,16.28,P ＜ 0.05).In vitro,PHLDA2 overexpression significantly enhanced the response to radiation in U2OS cells with a reduction of colony survival and proliferation with the increase of doses (t =5.00-8.23,P ＜0.05;t =-2.52--1.26,P ＜ 0.05).In vivo,PHLDA2-upregulated xenografts had more radiosensitivity than control groups with a significant inhibition of tumor growth (t =3.27,2.91,P ＜ 0.05).After 8 Gy irradiation,the apoptosis was significantly increased (t =10.11,9.61,P ＜ 0.05),accompanied with the activation of Caspased-3 in U2OS-PHLDA2 cells,which was presented by upregulation of cleaved Caspase-3 (t =11.26,10.72,P ＜ 0.05).Conclusions Exogenetic expression of PHLDA2 could significantly enhance the radiosensitivity of human osteosarcoma cells,which may be attributed to the activation of Caspase-3 that increases irradiation-induced apoptosis.