调节DKK-1影响胰腺癌Wnt活性

Epigenetic modification of DKK-1 affects the Wnt pathway activity in pancreatic cancers

目的:研究胰腺癌细胞中Wnt通路的活性变化,观察Wnt通路拮抗剂DKK-1的表达及其在胰腺癌中可能的发生机制,探讨DKK-1对Wnt通路活性的调节作用.方法:通过luciferase活性检测观察Wnt活性在胰腺癌细胞的变化,通过Real-timePCR技术检测Wnt拮抗剂DKK-1的mRNA的表达.通过MSP分析以及5-氮杂-脱氧胞苷酸处理分析DKK-1在胰腺癌细胞中的甲基化情况.应用基因重组技术调节DKK-1在不同胰腺癌细胞中的表达,观察Wnt活性的变化,分析DKK-1的表达变化能否在胰腺癌中调节Wnt通路.结果:Wnt通路在不同的胰腺癌细胞中表达程度不同,多数胰腺癌表现为Wnt通路的异常激活.DKK-1在胰腺癌细胞中表达较低,MSP分析发现DKK-1在部分胰腺癌细胞中表达为甲基化,5-氮杂-脱氧胞苷酸处理后能够显著提高DKK-1表达.调节DKK-1在不同细胞中的表达影响Wnt通路活性的变化.结论:胰腺癌细胞中存在Wnt通路的异常激活,胰腺癌中Wnt拮抗剂DKK-1的甲基化是引起胰腺癌Wnt活性变化的原因之一.

AIM：To investigate Wnt pathway activity in pancreatic cancer cell lines.To observe the methylation of Wnt antagonist（DKK-1） and its possible function on pancreatic cancer.METHODS：Wnt pathway activity was detected through luciferase activity.The expression of Wnt antagonist（DKK-1） was detected with Realtime-PCR technique.MSP analysis was applied to observe the methylation of DKK-1.Gene recombination technique was applied to modulate the DKK-1 expression on pancreatic cancers.RESULTS：Abnormal Wnt activity was detected in pancreatic cancer cell lines.Compared with normal pancreas cell lines,Wnt activity and its target gene expression were upregulated.As the Wnt antagonist,DKK-1 mRNA level was obviously downregulated.MSP analysis confirmed that methylation of DKK-1 was detected in pancreatic cancer cells.Methylated DKK-1 was found in several pancreatic cancer cells.With 5-aza-2＇-deoxycytidine treatment,the expression of DKK-1 could be repaired.With the upregulation of DKK-1 expression,the Wnt pathway activity was inhibited.On the contrary,with the knockdown of DKK-1 expression,the Wnt pathway activity was increased.CONCLUSION：The Wnt pathway was deregulated in pancreatic cancer cells.Epigenetic Modification of DKK-1,the Wnt antagonist,was considered to contribute to active Wnt pathway in pancreatic cancers.