CAJ | 학술논문

目的研究单次、分次和125Ⅰ粒子持续低剂量率照射对结直肠癌CL187细胞生物学效应的影响.方法实验分高剂量率单次照射组(400 cGy/min,单次组)、分次照射组(2 Gy/次/d,400 cGy/min,分次组)和125Ⅰ粒子持续低剂量率照射组(2.77 cGy/h,125Ⅰ组).3组细胞照射0、2、4和8 Gy后,24和48 h进行细胞计数和锥虫蓝染色,比较细胞总数和细胞存活率的差异.利用克隆形成实验比较3组细胞增殖能力的差异.通过流式细胞仪检测细胞凋亡.蛋白免疫印迹法分析PHLPP2、PTEN和Bax蛋白表达的变化.结果与单次组和分次组相比,125Ⅰ组细胞总数减少(t=34.28和29.48,P＜0.05)、存活细胞比例减少(t=-12.38和-14.61,P＜0.05),细胞克隆形成能力下降,相对生物学效应是1.41.照射后48 h细胞凋亡检测发现125Ⅰ组细胞凋亡比例增加(t=-15.08和-11.99,P＜0.05).蛋白免疫印迹法检测发现125Ⅰ组Bax表达量升高,PHLPP2和PTEN的表达量3组间差异无统计学意义.结论单次、分次和持续低剂量率照射后细胞PHLPP2蛋白表达水平均升高,但剂量率的高低并不影响其表达水平.不同方式照射后,凋亡相关蛋白Bax的表达水平上升,125Ⅰ组升高更加明显,125Ⅰ持续低剂量粒子照射可能通过影响凋亡相关蛋白Bax的表达水平实现对结直肠癌CL187细胞的杀伤作用.
목적 연구단차、분차화125Ⅰ입자지속저제량솔조사대결직장암CL187세포생물학효응적영향.방법 실험분고제량솔단차조사조(400 cGy/min,단차조)、분차조사조(2 Gy/차/d,400 cGy/min,분차조)화125Ⅰ입자지속저제량솔조사조(2.77 cGy/h,125Ⅰ조).3조세포조사0、2、4화8 Gy후,24화48 h진행세포계수화추충람염색,비교세포총수화세포존활솔적차이.이용극륭형성실험비교3조세포증식능력적차이.통과류식세포의검측세포조망.단백면역인적법분석PHLPP2、PTEN화Bax단백표체적변화.결과 여단차조화분차조상비,125Ⅰ조세포총수감소(t=34.28화29.48,P＜0.05)、존활세포비례감소(t=-12.38화-14.61,P＜0.05),세포극륭형성능력하강,상대생물학효응시1.41.조사후48 h세포조망검측발현125Ⅰ조세포조망비례증가(t=-15.08화-11.99,P＜0.05).단백면역인적법검측발현125Ⅰ조Bax표체량승고,PHLPP2화PTEN적표체량3조간차이무통계학의의.결론 단차、분차화지속저제량솔조사후세포PHLPP2단백표체수평균승고,단제량솔적고저병불영향기표체수평.불동방식조사후,조망상관단백Bax적표체수평상승,125Ⅰ조승고경가명현,125Ⅰ지속저제량입자조사가능통과영향조망상관단백Bax적표체수평실현대결직장암CL187세포적살상작용.
Objective To investigate the effect and underlying mechanism of single,fractioned and continuous low dose rate radiation on CL187 colorectal cancer cell line.Methods CL187 cells were exposed to 6 MV X-rays at a high dose rate of 4 Gy/min and 125Ⅰ seed at a low dose rate of 2.77 cGy/h with three groups:single dose radiation group (SDR),fractioned dose radiation group (FDR) by 2 Gy/f,and continuous low dose rate radiation group (CLDR).The radiation doses were 0,2,4 and 8 Gy.Total cell number and cell viability were determined by trypan blue.Clone forming assay was used to evaluate the cell proliferation ability.The percentage of apoptosis cells was analyzed by flow cytometry.Western blot was used to detect the protein expression levels of PHLPP2,PTEN and Bax.Results Compared with SDR and FDR groups,the total cell number and survival fraction of CLDR group decreased.The relative biological effect (RBE) for 125Ⅰ seeds compared with 6 MV X-rays was 1.41.The percentage of apoptosis cells of CLDR group was significantly increased (t =-15.08,-11.99,P ＜ 0.05).The expression level of Bax increased in CLDR group,while no obvious changes were observed on PHLPP2 and PTEN among three groups.Conclusions The expression level of PHLPP2 increaseS in SDR,FDR and CLDR group,while it seems that it was not influenced by dose rate.The expression level of Bax increased in three groups,while more colorectal CL187 cells in CLDR group may be killed due to the increase of Bax expression.