HBV 感染时肝细胞癌中 PADI4mRNA 与整体低甲基化的关联减少。

Decreased PADI4 mRNA association with global hypomethylation in hepatocellular carcinoma during HBV exposure.

机构信息

Tumor Immunology and Gene Therapy Center, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China.

出版信息

Cell Biochem Biophys. 2013 Mar;65(2):187-95. doi: 10.1007/s12013-012-9417-3.

DOI:10.1007/s12013-012-9417-3

PMID:22907585

Abstract

To gain insight into the role of peptidylarginine deiminase type 4 (PADI4), we determined the relationship between PADI4 mRNA and global hypomethylation during HBV exposure in hepatocarcinogenesis. We analyzed Line-1 methylation by MSP, and CD133 mRNA by real-time PCR in 74 HCC. The HCC cancer lines (7721, Huh7, and Hep-G2) were treated with 5-Aza-CdR and TSA. PADI4 mRNA were lower in HCC tissues (Mean(-∆Ct) = 1.41) than that in Non-Hcc tissues (Mean(-∆Ct) = 3.10). Expression of PADI4 was elevated in only 20 (27 %) of the 74 HCC patients but decreased in 54 (73 %) of the patients. The declined PADI4 mRNA was significantly associated with Line-1 demethylation in HCC patients. PADI4 mRNA were lower in HCC patients with Line-1 ∆MI <-0.15 (Mean(-∆∆Ct) = -2.66) than those with Line-1 ∆MI >= -0.15 (Mean(-∆∆Ct) = -1.02). The results suggested that HCC showing hypomethylation of Line-1 is considered to be silencing PADI4 mRNA. And the lower PADI4 mRNA was also found in HCC patients with HBV >= 10(5) (copy/ml) than those with HBV < 10(5) (copy/ml). After treated by 5-Aza-CdR and TSA, we found that PADI4 mRNA induced significantly by TSA in Huh7 and Hep-G2 cells, but not in 7721 cells. Meanwhile, PADI4 mRNA induced by the combination of 5-Aza-CdR and TSA in HCC cells, and it could no effect for exposure to 5-Aza-CdR alone. The results suggested that decreased PADI4 mRNA is associated with global hypomethylation in HCC during HBV exposure.

摘要

为了深入了解肽基精氨酸脱亚氨酶 4（PADI4）的作用，我们在乙肝病毒（HBV）暴露导致肝癌发生的过程中，确定了 PADI4mRNA 与总体低甲基化之间的关系。我们通过 MSP 分析了 LINE-1 甲基化，并用实时 PCR 分析了 74 例 HCC 中的 CD133mRNA。用 5-Aza-CdR 和 TSA 处理 HCC 细胞系（7721、Huh7 和 Hep-G2）。与 Non-Hcc 组织（Mean(-∆Ct)=3.10）相比，HCC 组织中的 PADI4mRNA 水平较低（Mean(-∆Ct)=1.41）。仅在 74 例 HCC 患者中的 20 例（27%）中升高，而在 54 例（73%）患者中降低。在 HCC 患者中，下调的 PADI4mRNA 与 LINE-1 去甲基化显著相关。LINE-1 ∆MI <-0.15（Mean(-∆∆Ct)=-2.66）的 HCC 患者的 PADI4mRNA 水平低于 LINE-1 ∆MI >= -0.15（Mean(-∆∆Ct)=-1.02）的患者。结果表明，LINE-1 低甲基化的 HCC 被认为是沉默 PADI4mRNA。此外，HBV>=10(5)（拷贝/ml）的 HCC 患者的 PADI4mRNA 水平也低于 HBV<10(5)（拷贝/ml）的患者。用 5-Aza-CdR 和 TSA 处理后，我们发现 TSA 可显著诱导 Huh7 和 Hep-G2 细胞中的 PADI4mRNA，但不能诱导 7721 细胞。同时，5-Aza-CdR 和 TSA 的联合作用可诱导 HCC 细胞中的 PADI4mRNA，而单独暴露于 5-Aza-CdR 则没有效果。结果表明，HBV 暴露期间 HCC 中的 PADI4mRNA 下调与总体低甲基化有关。