照射时间延长对鼻咽癌放射生物学效应的实验研究

发布时间：2018-05-12 07:00

本文选题：放射治疗 + 鼻咽癌CNE-2Z细胞　；参考：《天津医科大学》2013年博士论文

【摘要】：第一部分照射时间延长对小鼠鼻咽癌CNE-2Z细胞杀灭作用的影响目的模拟精确放疗照射模式,观察照射时间延长对小鼠鼻咽癌CNE-2Z细胞杀灭作用的影响及相关基因蛋白Bcl-2, Bax表达的变化。方法荷鼻咽癌CNE-2Z细胞雄性小鼠随机分成4个组,每组10只：假照组,常规照射组,IMRT模拟组,IGRT模拟组。小鼠用10%水合氯醛(350mg/kg,腹腔注射)麻醉后固定于平板上,利用瓦里安23-EX加速器进行一次性肿瘤靶区照射,6MV-X线,照射野给于1cm厚组织补偿,总剂量18Gy,剂量率6Gy/min。(1)常规照射组分3次照射,每次1min,总时间6min。(2)模拟IMRT组照射总时间15min。(3)模拟IGRT组照射总时间30min。各模拟照射组所受照射剂量同于常规照射组,放疗物理师按照实际放疗的模式进行计划设计,分别对各个照射剂量点进行照射,每个剂量点分7次照射,照射完成总时间分别为15min和30min。24小时后全部小鼠脱颈处死,切取肿瘤迅速用10%中性缓冲福尔马林液固定,常规脱水、透明、包埋,石蜡切片,用TUNEL法测细胞凋亡指数,并免疫组化法测凋亡相关基因蛋白bax和bcl-2。结果1.各组凋亡指数差异明显,有统计学意义(P0.01)。其中假照组的凋亡指数最低,常规照射组的凋亡指数最高。IMRT模拟组,IGRT模拟组与常规照射组比较,凋亡指数降低,差别均有统计学意义(P0.01)；IMRT模拟组与IGRT模拟组之间差别无统计学意义(P=0.05)；各照射组与假照组比较,凋亡指数均增高,差别有统计学意义(P0.01)。2.Bcl-2蛋白的半定量测定结果各组间均有差别。其中假照组的Bcl-2蛋白含量最高,常规照射组最低；常规照射组,IMRT模拟组,IGRT模拟组与假照组比较,Bcl-2蛋白含量均降低差别有统计学意义(P0.01); IMRT模拟组,IGRT模拟组与常规照射组之间比较,Bcl-2蛋白含量高,但差别无统计学意义(P=0.22)。3.各组Bax蛋白的半定量测定结果均有差别。其中假照组的Bax蛋白含量最低,其余各照射组与Bax蛋白含量均增高；IMRT模拟组,IGRT模拟组与常规照射组之间比较,Bax蛋白含量降低；IGRT模拟组较IMRT模拟组Bax蛋白含量低；差别有统计学意义(P0.01)。结论高能X线照射时间延长会导致对小鼠鼻咽癌CNE-2Z细胞杀伤作用降低,具体表现在细胞凋亡指数下降,Bax升高程度与Bcl-2降低程度减小。提示在实际放射治疗过程中应该适当增加总照射剂量来弥补放射生物效应的损失。第二部分照射时间延长对小鼠鼻咽癌CNE-2Z细胞MMP-9及E-cadherin表达的影响目的模拟精确放疗照射模式,观察照射时间延长对小鼠鼻咽癌CNE-2Z细胞基质金属蛋白酶-9(MMP-9)及E-钙黏附素(E-cadherin)表达的影响。方法荷鼻咽癌CNE-2Z细胞雄性小鼠随机分成4个组,每组10只：假照组,常规照射组,IMRT模拟组,IGRT模拟组。小鼠用10%水合氯醛(350mg/kg,腹腔注射)麻醉后固定于平板上,利用瓦里安23-EX加速器进行一次性肿瘤靶区照射,6MV-X线,照射野给于1cm厚组织补偿,总剂量18Gy,剂量率6Gy/min。(1)常规照射组分3次照射,每次1min,总时间6min。(2)模拟IMRT组照射总时间15mmin。(3)模拟IGRT组照射总时间30min。各模拟照射组所受照射剂量同于常规照射组,放疗物理师按照实际放疗的模式进行计划设计,分别对各个照射剂量点进行照射,每个剂量点分7次照射,照射完成总时间分别为15min和30min。24小时后全部小鼠脱颈处死,取出肿瘤迅速用10%中性缓冲福尔马林液固定,常规脱水、透明、包埋,石蜡切片,HE染色,光学显微镜下观察。用免疫组化测细胞转移相关基因MMP-9及E-cadherin。结果各照射组与假照组比较,MMP-9均降低,E-cadherin均增高,差别有统计学意义(P0.01); IMRT模拟组,IGRT模拟组MMP-9表达较常规照射组有所升高,其差别有统计学意义(P0.01)；IMRT模拟组,IGRT模拟组E-cadherin表达较常规照射组有所下降,其差别有统计学意义(P0.01)。IMRT模拟组与IGRT模拟组MMP-9表达与E-cadherin表达无明显差异。结论高能X线在一定的范围内,相同剂量下延长照射时间可导致MMP-9表达升高,E-cadherin表达降低,进而导致放射治疗抑制鼻咽癌CNE-2Z细胞的侵袭转移的能力下降,影响其疗效。
[Abstract]:Effect of irradiation time of first part on killing effect of CNE - 2Z cells in nasopharyngeal carcinoma

Objective To study the effect of irradiation time on the killing effect of CNE - 2Z cells and the expression of Bcl - 2 and Bax in nasopharyngeal carcinoma CNE - 2Z .

Methods Thirty male mice with nasopharyngeal carcinoma CNE - 2Z were randomly divided into four groups : sham group , routine irradiation group , IMRT simulation group and IGRT simulation group . All the mice were irradiated with 10 % chloral hydrate ( 350 mg / kg , intraperitoneal injection ) . The total dose was 18 Gy . The total time was 6 min . ( 2 ) The total time was 15 min and 30 min .

Results 1 . There was a significant difference in the apoptotic index of each group ( P0.01 ) . The apoptosis index of the sham group was the lowest , the apoptosis index of the conventional irradiation group was the highest , and the apoptosis index was decreased in the IMRT simulation group and the IGRT group compared with the conventional irradiation group ( P0.01 ) .
There was no significant difference between the IMRT simulation group and the IGRT simulation group ( P = 0.05 ) .
Compared with the sham group , the apoptosis index increased and the difference was statistically significant ( P0.01 ) . There was a difference in the semi - quantitative measurement of Bcl - 2 protein . The Bcl - 2 protein content in the sham group was the highest , and the routine irradiation group was the lowest .
There was no significant difference in Bcl - 2 protein content between IGRT group and normal irradiation group ( P = 0.22 ) , but there was no significant difference between the two groups ( P = 0.22 ) .
In the IMRT simulation group , the Bax protein content was decreased compared with the conventional irradiation group .
The expression of Bax was lower in IGRT group than in IMRT group .
The difference was statistically significant ( P0.01 ) .

Conclusion The prolonged irradiation time of high - energy X - ray can decrease the killing effect of CNE - 2Z cells in nasopharyngeal carcinoma . It is shown that the decrease of apoptosis index , the increase of Bax and the decrease of Bcl - 2 decrease . It is suggested that the total irradiation dose should be increased properly during the course of radiotherapy to compensate for the loss of radiation biological effect .

Effect of second part irradiation time on the expression of MMP - 9 and E - cadherin in nasopharyngeal carcinoma CNE - 2Z cells

Objective To study the effect of irradiation time on matrix metalloproteinase - 9 ( MMP - 9 ) and E - cadherin expression in nasopharyngeal carcinoma CNE - 2Z cells .

Methods Thirty male mice with nasopharyngeal carcinoma CNE - 2Z were randomly divided into four groups : sham group , routine irradiation group , IMRT simulation group and IGRT simulation group . All the mice were irradiated with 10 % chloral hydrate ( 350 mg / kg , intraperitoneal injection ) . The total dose was 18 Gy . The total time was 6 min . ( 2 ) The total time was 15 min and 30 min .

Results The expression of MMP - 9 and E - cadherin increased and the difference was statistically significant ( P0.01 ) , and the expression of MMP - 9 in IGRT group was higher than that in conventional irradiation group ( P0.01 ) .
In IMRT group , the expression of E - cadherin in IGRT group decreased significantly ( P0.01 ) . There was no significant difference between the expression of MMP - 9 and E - cadherin in the IMRT simulation group and IGRT simulation group .

Conclusion The increase of MMP - 9 expression and decrease of E - cadherin expression in nasopharyngeal carcinoma CNE - 2Z cells caused by high - energy X - ray irradiation could increase the expression of MMP - 9 and decrease the expression of E - cadherin in nasopharyngeal carcinoma CNE - 2Z cells .

【学位授予单位】：天津医科大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R739.63

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