AIM： To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination...AIM： To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination with histone deacetylase inhibitor NaB. METHODS： After SGC7901 and BGC823 cells were treated with 5-Aza-CdR and/or NaB, the methylation state of RASSFIA gene was detected by methylationspecific PCR, and the changes in expression of mRNA and protein level of RASSFIA gene were observed by RT-PCR and Western-blotting before and after drug treatment. RESULTS： Hypermethylation was detected in the promoter region of RASSF1A gene in both SGC7901 and BGC823 cells, and there was no expression of this gene at both mRNA and protein level. After treatment with 5-Aza-CdR, demethylation occurred in the promoter region of RASSFIA gene, which subsequently induced re-expression of this gene. The treatment with NaB alone showed no effect on the methylation state and expression of RASSFIA gene. The combined treatment of 5-Aza-CdR and NaB induced complete demethylation of RASSFIA gene, leading to a significantly higher reexpression of the mRNA and protein of RASSFIA than those treated with 5-Aza-CdR alone （P 〈 0.05）. CONCLUSION： Hypermethylation in the promoter region is related to inactivation of RASSFIA gene in human gastric cancer cell lines SGC7901 and BGC823, while demethlylating agent 5-Aza-CdR can reverse the methylation state of RASSF1A gene and induce itsre-expression. Histone deacetylase inhibitor NaB had a synergistic effect with 5-Aza-CdR in both demethylation and gene transcriptional regulation.展开更多
背景与目的肿瘤发生、发展过程中,抑癌基因启动子区域Cp G岛异常甲基化起着重要的作用。已有研究显示RAS相关区域家族1A(Ras association domain family 1A,RASSF1A)基因,作为一个抑癌基因其启动子区域甲基化与非小细胞肺癌(non-small c...背景与目的肿瘤发生、发展过程中,抑癌基因启动子区域Cp G岛异常甲基化起着重要的作用。已有研究显示RAS相关区域家族1A(Ras association domain family 1A,RASSF1A)基因,作为一个抑癌基因其启动子区域甲基化与非小细胞肺癌(non-small cell lung cancer,NSCLC)的发生发展密切相关。在NSCLC患者癌组织中RASSF1A基因启动子往往表现为异常高甲基化。本研究采用meta分析的方法探讨RASSF1A基因启动子甲基化与NSCLC发生之间的关系。方法通过检索Medline、EMBASE、CNKI和万方数据库,按照已拟定的纳入与剔除标准筛选收集公开发表的关于RASSF1A基因启动子甲基化与NSCLC相关性的研究。以比值比(odds ratio,OR)和95%置信区间(confidence interval,CI)为效应指标,分析RASSF1A基因启动子甲基化与NSCLC的关系。结果共有23篇文献纳入本研究,RASSF1A基因启动子甲基化率在NSCLC患者肺部组织和对照组中分别为41.50%(95%CI:34%-49%)和5.58%(95%CI:2%-9%),meta分析显示肿瘤组织中的甲基化率高于对照组(OR=8.72,95%CI:4.88-15.58,P<0.05);亚组分析显示:肿瘤组织中的甲基化频率高于血浆(OR=10.99,95%CI:2.48-48.68)和正常对照组织(OR=8.74,95%CI:4.39-17.41)。结论 NSCLC患者肺癌组织中RASSF1A基因启动子甲基化率高于对照组,组织中RASSF1A基因启动子甲基化率对肺癌的发生更具影响,RASSSF1A甲基化可能与肺癌的发生存在相关并可作为肺癌诊断的潜在标志物。展开更多
[目的]研究RASSF1A基因的杂合性丢失(loss of heterozygosity,LOH)及人乳头瘤病毒(human papillo-mavirus,HPV)感染与宫颈癌临床病理参数之间的关系。[方法]选择3p上2个微卫星位点,对110例宫颈组织进行LOH及HPV感染状态的分析。[结果]...[目的]研究RASSF1A基因的杂合性丢失(loss of heterozygosity,LOH)及人乳头瘤病毒(human papillo-mavirus,HPV)感染与宫颈癌临床病理参数之间的关系。[方法]选择3p上2个微卫星位点,对110例宫颈组织进行LOH及HPV感染状态的分析。[结果]宫颈癌及CIN中RASSF1A基因LOH阳性的比例明显高于正常宫颈(P﹤0.05);宫颈癌Ⅲ期和Ⅳ期LOH的阳性率明显高于Ⅰ期和Ⅱ期(P﹤0.05);低分化宫颈癌的LOH阳性率明显大于高中分化宫颈癌(P﹤0.05);随CIN级别的增加LOH阳性率也呈逐渐递增趋势,高级别CIN(CINⅢ及原位癌)明显高于低级别CIN(CINⅠ/Ⅱ)(P﹤0.05)。宫颈癌中HPV感染阳性率明显高于CIN组及正常宫颈组(P﹤0.05);RASSF1A的LOH阳性率在HPV感染阳性组明显高于阴性组(P﹤0.05)。[结论]RASSF1A基因的改变是宫颈癌发生过程中的较晚期事件,RASSF1A基因的LOH对于宫颈癌的筛查、早期诊断及判断预后可能具有临床实用价值。HPV感染与RASSF1A基因的LOH共同作用在宫颈癌发展过程中更有意义。展开更多
目的探讨子痫前期孕妇血浆中超甲基化的Ras相关区域家族1A（ras association domain family 1A，RASSF1A）基因的水平变化及应用价值。方法选择晚期妊娠子痫前期患者60例为实验组，其中轻度和重度子痫前期各30例；正常晚期孕妇60名为对...目的探讨子痫前期孕妇血浆中超甲基化的Ras相关区域家族1A（ras association domain family 1A，RASSF1A）基因的水平变化及应用价值。方法选择晚期妊娠子痫前期患者60例为实验组，其中轻度和重度子痫前期各30例；正常晚期孕妇60名为对照组。提取血浆游离DNA，经甲基化敏感的限制性内切酶处理，实时定量检测酶切前、后RASSF1A基因的浓度，同时检测β肌动蛋白（β-actin）基因以确保酶的完全消化。结果子痫前期孕妇血浆中超甲基化的RASSF1A基因含量为正常妊娠组的3．31倍。轻、重度子痫前期患者浓度有差异，中位数分别为1659．00copies／mL及2036．50copies／mL（P〈0．05）。结论子痫前期孕妇血浆中的超甲基化RASSF1A基因含量明显升高，且浓度水平与子痫前期的严重程度相关。展开更多
基金The National Natural Science Foundation of China, No. 30572162, No. 30271477The Special Scientific Research Fundation for Doctors, State Education Ministry,No.20050159001
文摘AIM： To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination with histone deacetylase inhibitor NaB. METHODS： After SGC7901 and BGC823 cells were treated with 5-Aza-CdR and/or NaB, the methylation state of RASSFIA gene was detected by methylationspecific PCR, and the changes in expression of mRNA and protein level of RASSFIA gene were observed by RT-PCR and Western-blotting before and after drug treatment. RESULTS： Hypermethylation was detected in the promoter region of RASSF1A gene in both SGC7901 and BGC823 cells, and there was no expression of this gene at both mRNA and protein level. After treatment with 5-Aza-CdR, demethylation occurred in the promoter region of RASSFIA gene, which subsequently induced re-expression of this gene. The treatment with NaB alone showed no effect on the methylation state and expression of RASSFIA gene. The combined treatment of 5-Aza-CdR and NaB induced complete demethylation of RASSFIA gene, leading to a significantly higher reexpression of the mRNA and protein of RASSFIA than those treated with 5-Aza-CdR alone （P 〈 0.05）. CONCLUSION： Hypermethylation in the promoter region is related to inactivation of RASSFIA gene in human gastric cancer cell lines SGC7901 and BGC823, while demethlylating agent 5-Aza-CdR can reverse the methylation state of RASSF1A gene and induce itsre-expression. Histone deacetylase inhibitor NaB had a synergistic effect with 5-Aza-CdR in both demethylation and gene transcriptional regulation.
文摘[目的]研究RASSF1A基因的杂合性丢失(loss of heterozygosity,LOH)及人乳头瘤病毒(human papillo-mavirus,HPV)感染与宫颈癌临床病理参数之间的关系。[方法]选择3p上2个微卫星位点,对110例宫颈组织进行LOH及HPV感染状态的分析。[结果]宫颈癌及CIN中RASSF1A基因LOH阳性的比例明显高于正常宫颈(P﹤0.05);宫颈癌Ⅲ期和Ⅳ期LOH的阳性率明显高于Ⅰ期和Ⅱ期(P﹤0.05);低分化宫颈癌的LOH阳性率明显大于高中分化宫颈癌(P﹤0.05);随CIN级别的增加LOH阳性率也呈逐渐递增趋势,高级别CIN(CINⅢ及原位癌)明显高于低级别CIN(CINⅠ/Ⅱ)(P﹤0.05)。宫颈癌中HPV感染阳性率明显高于CIN组及正常宫颈组(P﹤0.05);RASSF1A的LOH阳性率在HPV感染阳性组明显高于阴性组(P﹤0.05)。[结论]RASSF1A基因的改变是宫颈癌发生过程中的较晚期事件,RASSF1A基因的LOH对于宫颈癌的筛查、早期诊断及判断预后可能具有临床实用价值。HPV感染与RASSF1A基因的LOH共同作用在宫颈癌发展过程中更有意义。
文摘目的探讨子痫前期孕妇血浆中超甲基化的Ras相关区域家族1A（ras association domain family 1A，RASSF1A）基因的水平变化及应用价值。方法选择晚期妊娠子痫前期患者60例为实验组，其中轻度和重度子痫前期各30例；正常晚期孕妇60名为对照组。提取血浆游离DNA，经甲基化敏感的限制性内切酶处理，实时定量检测酶切前、后RASSF1A基因的浓度，同时检测β肌动蛋白（β-actin）基因以确保酶的完全消化。结果子痫前期孕妇血浆中超甲基化的RASSF1A基因含量为正常妊娠组的3．31倍。轻、重度子痫前期患者浓度有差异，中位数分别为1659．00copies／mL及2036．50copies／mL（P〈0．05）。结论子痫前期孕妇血浆中的超甲基化RASSF1A基因含量明显升高，且浓度水平与子痫前期的严重程度相关。
