DKK3基因甲基化在输卵管癌诊断中的价值及临床意义

The Value and Clinical Significance of DKK3 Gene Methylation in the Diagnosis of Primary Fallopian Tube Cancer

目的研究Wnt抑制因子(dickkopf-related protein 3,DKK3)在原发性输卵管癌中的表达,并探讨DKK3启动子甲基化的临床意义。方法选取46例输卵管癌患者的输卵管癌组织标本和相应的癌旁组织标本。通过免疫组织化学法检测DKK3蛋白表达情况,通过荧光定量PCR检测DKK3 mRNA的表达水平,通过甲基化特异性PCR(MSP)检测DKK3基因启动子甲基化水平,并分析其与患者临床病理的关系。结果免疫组化检测结果显示,输卵管癌组织中DKK3蛋白高表达率为28.3%(13/46),明显低于癌旁对照组65.2%(30/46),差异具有统计学意义(P<0.01)。荧光定量PCR结果显示,输卵管癌组织中DKK3 mRNA水平明显低于癌旁对照组,差异具有统计学意义(P<0.01)。MSP检测结果显示,输卵管癌组织DKK3基因发生甲基化概率为73.9%(34/46),明显高于癌旁对照组的39.1%(18/46),差异具有统计学意义(P<0.01)。DKK3启动子甲基化水平与输卵管癌患者年龄(χ^2=0.031,P>0.05)、输卵管癌病理分级(χ^2=3.184,P>0.05)和病理类型(χ^2=0.654,P>0.05)均无显著相关性。DKK3甲基化水平与FIGO分期存在显著相关性(χ^2=5.007,P<0.05)。结论DKK3基因启动子甲基化水平与输卵管癌的发生发展密切相关,可作为输卵管癌诊断和治疗的签字靶点。

Objective To investigate the expression of Wnt inhibitory factor(dickkopf-related protein 3,DKK3)in primary fallopian tube cancer(PFTC)and to explore the clinical significance of DKK3 promoter methylation.Methods The specimens of PFTC and adjacent normal tissues from 46 cases of PFTC patients were collected for the study.The expression of DKK3 protein was detected by immunohistochemistry,and the expression level of DKK3 mRNA was detected by real-time PCR.The methylation level of DKK3 gene promoter was detected by methylation-specific PCR(MSP)and its association with clinical pathology was further analyzed.Results The results of immunohistochemistry showed that the high expression rate of DKK3 protein in PFTC tissues was 28.3%(13/46),which was significantly lower than that in the adjacent normal tissues which was 65.2%(30/46)(P<0.01).The results of real-time PCR showed that the level of DKK3 mRNA in oviduct cancer tissues was significantly lower than that in the control group(P<0.01).The MSP test showed that the probability of methylation of DKK3 gene promoter in PFTC tissues was 73.9%(34/46),which was significantly higher than that in the adjacent normal tissues at 39.1%(18/46)(P<0.01).The correlation analysis showed that the methylation rate of DKK3 gene promoter was not correlated with age(χ^2=0.031,P>0.05),pathological grade(χ^2=3.184,P>0.05)and pathological type(χ^2=0.654,P>0.05).There was a significant correlation between the methylation level of DKK3 gene promoter and FIGO stage(χ^2=5.007,P<0.05).Conclusion The methylation level of DKK3 gene promoter is closely related to the occurrence and development of PFTC,and it can be used as a signature target for the diagnosis and treatment of PFTC.