重组人肿瘤坏死因子相关凋亡诱导配体对人肺腺癌A549细胞裸鼠移植瘤内survivin基因表达的影响

Effect of rhTRAIL on survivin expression of human lung adeno-carcinoma A549 xenografted tumor in nude mice

目的 观察重组人肿瘤坏死因子相关凋亡诱导配体（rhTRAIL）对人肺腺癌A549细胞裸鼠移植瘤内sruvivin基因表达的影响,并探讨rhTRAIL抑制肺癌生长的可能作用机制.方法 用人肺腺癌细胞A549接种于24只裸鼠皮下,建立人肺腺癌裸鼠移植瘤模型.将荷瘤裸鼠随机分为0.9％氯化钠注射液（NS）和顺铂（DDP）对照组、rhTRAIL单用组及rhTRAIL＋ DDP联合组四组,每组各6只.将rhTRAIL单用或联合顺铂腹腔内注射,隔天1次,共8次.实验结束后处死荷瘤裸鼠,完整剥离肿瘤,RT-PCR法和免疫组织化学法分别检测肿瘤组织中survivin mRNA及其蛋白表达水平.应用ELISA法检测荷瘤裸鼠血清survivin蛋白表达水平.结果 各组肿瘤细胞的survivin mRNA表达情况为：rhTRAIL组（48.7±2.5）％、rhTRAIL＋ DDP组（53.1±4.6）％,DDP组为（99.1±5.3）％,NS组为（95.6±3.7）％.各组裸鼠移植瘤组织内survivin蛋白表达情况为：rhTRAIL组（0.319±0.025）、rhTRAIL＋ DDP组（0.483±0.058）,DDP组为（0.635±0.041）,NS组为（0.619±0.017）.各组裸鼠血清survivin蛋白表达情况为：rhTRAIL组（71.9±7.05）,rhTRAIL＋ DDP组（80.26±10.80）,DDP组为（112.75±15.41）,NS组为（105.03±20.37）.含rhTRAIL组survivin mRNA和蛋白的表达水平均明显低于NS和DDP对照组（P＜0.05）;与rhTRAIL＋ DDP组相比较,rhTRAIL组更低,但差异无统计学意义（P＞0.05）;与NS对照组比较,DDP组则表达略有增高,但差异无统计学意义（P＞0.05）.结论 rhTRAIL可下调人肺腺癌A549细胞裸鼠移植瘤内sruvivin基因的表达.通过下调survivin基因的表达,促进肿瘤细胞凋亡可能是rhTRAIL抑制肿瘤生长的分子机制之一.

Objective To observe the effect of rhTRAIL on survivin gene expression of human lung adeno-carcinoma A549 xenografted tumor in nude mice,and investigate the possible inhibitory mechanism of rhTRAIL on the implanted-tumor growth.Methods The solid tumor model was formed in nude mice with human lung adeno-carcinoma cell line.A549.24 mice were randomly divided into the four groups,rhTRAIL single treated group （1 μg/mL）,rhTRAIL combined with cisplatin （DDP） treated group,cisplatin treated （1.5mg/kg） and 0.9% sodium chloride injection（NS） control group.The rhTRAIL and DDP were injected once every other day by intraperitoneal injection to mice in the treated groups,lasting eight times,the same volume of saline solution was injected to the control group.After these,mice were killed and dissected completely.The expression level of survivin mRNA and protein in the tumor tissues was detected by real-time polymerase chain reaction （RT-PCR） and immunohistochemistry,respectively.And the expression of survivin gene in serum of each group was tested by ELISA.Results The expression levels of survivin mRNA in implanted-tumor tissues in rhTRAIL,rhTRAIL combined with DDP,DDP and NS group were （48.7 ± 2.5） %,（53.1 ± 4.6） %,（99.1 ± 5.3） % and （95.6 ± 3.7） %,respectively.While the protein expressions of survivin gene in those groups were （0.319 ± 0.025）,（0.483 ± 0.058）,（0.635 ± 0.041） and （0.619 ± 0.017）,respectively.Moreover,the serum levels of survivin were （71.9 ± 7.05）,（80.26 ± 10.80）,（112.75 ± 15.41） and （105.03 ± 20.37）,respectively.The data showed that the expression levels of rhTRAIL and rhTRAIL combined with DDP group were lower than that of DDP-treated group or the NS control group （P 〈 0.0 5）.Compared with the rhTRAIL combined with DDP group,the survivin gene expression level of rhTRAIL-single treated group decreased a little lower,but the difference was not significant （P 〉 0.05）.Conversely,the survivin gene level was increased to some degree compared with the NS control group,and uniformly there was no significant difference （P 〉 0.05）.Conclusion rhTRAIL can downregulate the expression level of survivin gene of human lung adeno-carcinoma A549 xenografted tumor in nude mice.It may be one of the possible inhibitory mechanisms of rhTRAIL on the implanted-tumor growth that rhTRAIL can downregulate survivin gene expression and promote tumor cell apoptosis.