5-氮杂-2’-脱氧胞苷对人前列腺癌裸鼠移植瘤生长及雄激素受体表达影响的研究

目的探讨5-氮杂-2’-脱氧胞苷(5-Aza-2’deoxycytidine,5-Aza-CdR)对LNCaP荷瘤裸鼠的肿瘤生长及雄激素受体(androgen receptor,AR)表达的影响。方法裸鼠皮下接种LNCaP细胞,建立人前列腺癌裸鼠移植瘤模型,待肿瘤长至300 mm3大小时,荷瘤裸鼠腹腔内注射5-Aza-CdR,0.25 mg/kg,隔天1次。对照组给予生理盐水注射。每3天测量肿瘤体积1次,共观察24天。实验结束时处死裸鼠,取出肿块称重后,肿瘤组织抽提RNA和蛋白质,分别应用实时定量PCR和western blot方法,检测AR在mRNA和蛋白质水平上的表达。结果 LNCaP荷瘤裸鼠经5-Aza-CdR治疗后,与对照组相比,肿瘤生长缓慢。第24天观察结束时,5-Aza-CdR处理组肿瘤体积[(982±83)mm3]显著低于对照组[(1 867±195)mm3](P<0.01)。移植瘤重量与对照组相比明显下降[(796±178)mg vs(1 267±252)mg],抑瘤率为37.2%,差异有统计学意义(P<0.01)。5-Aza-CdR组游离PSA(FPSA)浓度相对对照组显著下降,分别为(40.25±13.3)ng/mL和(79.7±13.2)ng/mL,差异有统计学意义(P<0.01)。荷瘤裸鼠经5-Aza-CdR处理后,AR在mRNA水平上的表达下降为对照组的0.5倍,在蛋白质水平上的表达也显著降低(P<0.01)。结论 5-Aza-CdR能够有效抑制LN-CaP荷瘤裸鼠移植瘤的生长,并显著降低AR基因表达,为前列腺癌的去甲基化治疗提供了理论依据。

The Effect of 5-Aza-CdR on the Growth of Tumors and Androgen Receptor Expression in LNCaP Xenografted

Objective To investigate the effect of 5-Aza-2＇deoxycytidine（5-Aza-CdR） on the growth of tumors and expression of androgen receptor（AR） in LNCaP xenografted in nude mice.Methods LNCaP cells were inoculated subcutaneously in nude mice to establish xenograft models of human prostate cancer.When the tumor volume grew to 300 mm3,5-Aza-CdR was injected intraperitoneally in nude mice,0.25 mg/kg every two days.The tumor volumes were monitored every 3 days until 24 days.At the end of the experiment,all mice were killed,tumor weight were measured.Real-time PCR and western blot were used to determine the expression of AR mRNA and protein.Results 5-Aza-CdR treatments could significantly suppressed tumor growth,compared to the control group.Tumor volume[（982±83）mm3]in 5-Aza-CdR group was significantly smaller than that of control group [（1 867±195）mm3]at 24 th days when experiments were finished.Tumor weight in 5-Aza-CdR group [（796±178）mg] significantly decreased compared to the control group [（1 267±252） mg]and the tumor growth suppression rate was 37.2%.5-Aza-CdR group of free PSA（FPSA） levels [（40.25±13.3）ng/mL]decreased significantly relative to the control group [（79.7±13.2）ng/mL]（P0.01）.MRNA and protein expression of AR in 5-Aza-CdR treatment decreased significantly compared to controls（P0.01）.Conclusion Our data demonstrated that 5-Aza-CdR can suppress the growth of LNCaP xenograft and reduce AR expression in nude mice,which provides a theoretical basis and guidelines for treatment of prostate cancer with demethylating agents.