论文部分内容阅读
目的探讨5-杂氮-2′-脱氧胞苷(5-Aza-CdR)对乳腺癌MDA-MB-231细胞实验性肺转移的影响及可能的机制。方法将MDA-MB-231细胞分为对照组与5-Aza-CdR处理组,通过半定量RT-PCR(SqRT-PCR)与甲基化特异性PCR(MSP)方法检测两组细胞的乳腺癌转移抑制基因-1(BRMS1),CXC趋化因子受体-4(CXCR4)基因的mRNA表达及启动子区甲基化的状况。分别将两组细胞通过边缘尾静脉注射至BALB/c nu/nu裸鼠体内(每组5只)。5周后,用荧光定量RT-PCR(FqRT-PCR)检测裸鼠肺组织内的目的基因HPRT及内参GAPDH的mRNA丰度。结果对照组和处理组细胞的BRMS1相对灰度值(IDV)分别为0与0.39±0.001,处理组BRMS1 mRNA表达较对照组明显上调(P<0.05),5-Aza-CdR使BRMS1启动子区甲基化的CpG岛B完全去甲基化;CXCR4相对IDV分别为0.58±0.003与0.58±0.01,两组间差异无统计学意义(P>0.05),CXCR4启动子区CpG岛1的非甲基化状态亦无明显改变。对照组与处理组细胞的裸鼠肺脏HPRT和GAPDH的Ct值分别为:24.75±1.55,16.19±0.69与27.61±1.67,17.48±0.96,2-ΔΔCt=0.34,处理组裸鼠肺脏HPRTmRNA丰度明显低于对照组,肺组织内转移癌较少。结论 5-Aza-CdR通过去甲基化机制重新激活肿瘤转移抑制基因BRMS1的表达,从而降低了MDA-MB-231细胞实验性肺转移能力。
Objective To investigate the effects of 5-Aza-2’-deoxycytidine (5-Aza-CdR) on experimental lung metastasis of breast cancer MDA-MB-231 cells and its possible mechanism. Methods MDA-MB-231 cells were divided into control group and 5-Aza-CdR treatment group. The breast cancer cells in both groups were detected by semi-quantitative RT-PCR (SqRT-PCR) and methylation- (BRMS1), CXCR4 (CXCR4) gene mRNA expression and promoter methylation status. Two groups of cells were respectively injected into the BALB / c nu / nu nude mice through the marginal tail vein (5 in each group). After 5 weeks, the mRNA abundance of HPRT and GAPDH in the lung tissue of nude mice was detected by real-time fluorescence quantitative RT-PCR (FqRT-PCR). Results Compared with the control group, BRMS1 relative gray value (IDV) of the control group and the treated group were 0 and 0.39 ± 0.001 respectively (P <0.05). The BRMS1 promoter region Methylation of CpG island B was completely demethylated. The relative IDVs of CXCR4 were 0.58 ± 0.003 and 0.58 ± 0.01, respectively. There was no significant difference between the two groups (P> 0.05) There was no significant change in the state of alkalization. The Ct values of HPRT and GAPDH in nude mice in control group and treated group were 24.75 ± 1.55, 16.19 ± 0.69 and 27.61 ± 1.67, 17.48 ± 0.96, and 2-ΔΔCt = 0.34, respectively. The abundance of HPRT mRNA in lung of nude mice in treatment group was significantly Less than the control group, less metastatic lung cancer. Conclusions 5-Aza-CdR can reactivate BRMS1 expression through demethylation mechanism, thereby reducing the experimental lung metastasis of MDA-MB-231 cells.