反基因及反义寡核苷酸对人前列腺癌裸鼠移植瘤生长的抑制作用

目的 探讨三螺旋形成寡核苷酸(TFO)和反义寡核苷酸(ASO)对人前列腺癌裸鼠移植瘤雄激素受体(AR)表达和肿瘤细胞生长的抑制作用.方法 32只荷LNCaP-CA-2前列腺癌移植瘤裸鼠随机分成4组:TFO治疗组、ASO治疗组、序列对照寡核苷酸(SCO)非特异性对照组和阴性对照组.采用瘤内注射给药,寡核苷酸用量25 mg/kg,隔天给药1次,共14次.观察裸鼠体重和肿瘤体积变化.测量移植瘤重量计算抑瘤率,放射免疫分析法检测裸鼠血清前列腺特异抗原(PSA)水平,RT-PCR方法检测肿瘤组织AR Mrna表达,免疫组化和放射配基结合分析方法检测AR蛋白表达.结果 TFO和ASO均能有效抑制移植瘤生长,抑瘤率分别为67.55%和41.06%,与对照组相比差异有统计学意义(均P<0.01).TFO组的瘤重和肿瘤组织AR表达水平显著低于ASO组(均P<0.05),TFO组动物血清PSA水平[(6.6±1.0)ng/ml]也显著低于ASO组[(19.8±3.7)ng/ml,P<0.05].结论 TFO对前列腺癌裸鼠移植瘤AR表达和肿瘤生长的抑制作用强于ASO,具有较好的抗前列腺癌应用前景.

Effects of anti-gene and antisense therapeutics on human prostate cancer xenograft in nude mice

Objective To investigate the effects of triple-helix forming oligonucleotide (TFO) and antisense oligonucleotide (ASO) on androgen receptor (AR) expression and tumor growth of human prostate cancer xenografts in nude mice.Methods Thirty-two nude mice were inoculated with human prostate cancer cells of the line LNCaP-C4-2 were randomized into 4 equal groups:TFO treatment group,undergoing intra-tumor injection of TFO at the dose of 25 mg · kg-1 · (2d)-1 for 14 times,ASO treatment group, undergoing intra-tumor injection of ASO at the same dose for 14 times,SCO group,undergoing intra-rumor injection of sequence control oligonucleotide (SCO) at the same dose for 14 times,and control group.The body weight and xenograft tumor volume of the nude mice were monitored during the therapy.28 days later venous blood samples were collected to measure the level of prostate specific antigen (PSA) by radioimmunoassay and then the mice were killed with their tumors taken out to measure the weight,and RTPCR,immunohistochemistry,and radioligand binding assay were used to detect the AR gene mRNA and protein expression in the tumor tissues.Results By the end of experiment the volumes and weights of tumor of the ASO and ASO groups were all significantly lower than those of the control group ( all P < 0.01 ) with the inhibition rates of 67.55% and 41.06% respectively,and the volumes and weights of tumor of the TFO group were all significantly lower than those of the ASO group ( all P < 0.05 ).The tumor weight and AR expression levels of TFO group were significantly lower than those of ASO group ( P < 0.05 ).The serum PSA level of TFO group was (6.6 ± 1.0) ng/ml,significantly lower than that of the ASO group [ ( 19.8 ± 3.7) ng/ml,P < 0.05 ].The mRNA and protein expression levels of AR of the TFO group were significantly lower than those of the other groups ( all P < 0.05).There were no significant differences in all the above mentioned markers between the SCO and control groups ( all P > 0.05 ) .Conclusion TFO shows significantly higher inhibitory effect on AR expression and tumor growth of human prostate cancer xenograft than ASO,and is a promising agent for prostate cancer gene therapy.