吉西他滨联合放射对人胰腺癌CFPAC-1细胞株裸鼠移植瘤EphB4、Caspase3表达的影响

Effect of Gemcitabine Combined with Radiation on EphB4,Caspase3 Expressions in Human Pancreatic Cancer CFPAC-1 Cell Lines of Nude Mouse Transplantation Tumor

目的 探讨吉西他滨联合放射对胰腺癌发病机制的调节。方法 建立裸小鼠皮下移植瘤模型,模型建立后将36只裸小鼠随机分为6组[对照组(A),单体放疗组(B),25 mg/kg吉西他滨组(C),50 mg/kg吉西他滨组(D),25 mg/kg吉西他滨+放射组(E),50 mg/kg吉西他滨+放射组(F)]。RT-PCR测各组组织中EphB4、Caspase3基因表达,免疫组化测定组织EphB4、Caspase3的蛋白表达。MTT(3-(4,5-Dimethyl thiazol-2-yl)-2,5-diphenytetrazolium bromide)法分析CFPAC-1细胞的增殖水平。结果 与A组(抑瘤率为0%)比较,E、F组的抑瘤率明显高于B组(P<0.05)和C、D组(P<0.05)。采用RT-PCR检测新鲜组织,在EphB4和Caspase3基因中A组、B组、C组、D组、E组、F组依次为递减趋势和递增趋势。免疫组化检测显示EphB4、Caspase3抗体六组两两比较具有统计学意义(P<0.05)。MTT实验显示人胰腺癌CFPAC-1细胞株在联合组中增殖率最低。结论 通过本实验的研究,可以得出以下结论:(1)吉西他滨联合放射的作用优于吉西他滨单药以及单纯放射。(2)吉西他滨对人胰腺癌CFPAC-1细胞株裸鼠移植瘤有放射增敏作用,其可能的机制之一是通过下调EphB4和上调Caspase3的表达。(3)MTT法提示吉西他滨联合放射可能具有放射增敏作用。

Objective To explore the effect of gemcitabine combined with radiation on pancreatic cancer.Methods Nude mice subcutaneous transplantation tumor model were build,and 36 nude mice were divided into 6 groups.The control group(group A),radiotherapy group( group B),25 mg/kg gemcitabine group(group C),50 mg/kg gemcitabine group(group D),25 mg/kg gemcitabine and radiotherapy group(group E),and 50 mg/kg gemcitabine and radiotherapy group(group F).RT-PCR was used to detect EphB4,Caspase3 protein expression,and MTT was used to detect the proliferation level of CFPAC-1 cells.Results Compared with group A(tumor inhibition rate was 0%),tumor inhibition rates of group E and group F were significantly higher than group B(P<0.05)and group C and group D(P<0.05).RT-PCR test was used to test fresh tissues,EphB4 and Caspase3 receptor mRNA specimens expressed in the tissues,the expression was respectively decreasing and increasing from group A,B,C,D and E to F.Meanwhile,immunohistochemical detection of EphB4 and Caspase3 receptor expressed in all six groups between each other were statistically significant(P<0.05).The MTT experiments showed the human pancreatic cancer cell CFPAC-1 proliferation ratio in combination group was the lowest.Conclusions(1) Gemcitabine combined with radiation is superior to single-agent gemcitabine and radiotherapy alone.(2) Gemcitabine has radiosensitizing effect is likely one of the mechanisms by down-regulating the expression of EphB4 and raised Caspase3 in human pancreatic cancer cell lines CFPAC-1 xenograft.(3) MTT assay suggesting that gemcitabine combined with radiation may has a radiosensitizing effect.