Preliminary mechanism on the methylation modification of Dkk-1 and Dkk-3 in hepatocellular carcinoma

Tumour Biol. 2015 Feb;36(2):1245-50. doi: 10.1007/s13277-014-2750-y. Epub 2014 Oct 26.

Abstract

Wnt/β-catenin signaling pathway, having a crucial role in regulating diverse cellular processes, can be a new therapeutic target in cancer. To investigate the role of Dkk-1 (Dickkopf-1) and Dkk-3 in tumors and cirrhoses of the liver tissue in hepatocellular carcinoma (HCC), tissues from 38 patients with HCC resections including 5 patients who underwent hemangioma surgery of adjacent tumor tissues at the same time were obtained. Tissues were divided into three groups (nonfibrosis, cirrhosis, and carcinoma) through hematoxylin-eosin (HE) staining. Methylation-specific polymerase chain reaction (PCR) (MSP) measured the methylation status, and reverse transcription-PCR tested the messenger RNA (mRNA) levels, and immunohistochemical analysis provided levels of protein expression. The methylation detection rate of Dkk-1 and Dkk-3 was the highest (P < 0.05) and the mRNA levels of Dkk-1 and Dkk-3 were the lowest (P < 0.05) in the carcinoma tissues. The mRNA levels of β-catenin were significantly higher in the carcinoma tissue than the other tissues (P < 0.05). The expression of Dkk-1 and Dkk-3 was significantly higher in the carcinoma tissues than the other tissues (P < 0.05); but the β-catenin expression was the highest (P < 0.05). Compared with the control, the mRNA levels of β-catenin in the Dkk-1 and Dkk-3 silencing cells increased 5.34 (P < 0.05) and 3.5 times (P > 0.05). After the interference of 5-aza-2'-deoxycytidine, the mRNA levels of Dkk-1 and Dkk-3 significantly increased 58.9 and 59.3 times (P < 0.0001), and the mRNA levels of β-catenin decreased 6.02 times (P < 0.05). In the process of HCC, the abnormal activity of Wnt/β-catenin signaling may be associated with the methylation of Dkk-1 and Dkk-3.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Chemokines
  • DNA Methylation / genetics
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Intercellular Signaling Peptides and Proteins / biosynthesis*
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / pathology
  • RNA, Messenger / biosynthesis
  • Wnt Signaling Pathway / genetics
  • beta Catenin / biosynthesis

Substances

  • Adaptor Proteins, Signal Transducing
  • Chemokines
  • DKK1 protein, human
  • DKK3 protein, human
  • Intercellular Signaling Peptides and Proteins
  • RNA, Messenger
  • beta Catenin