Epigenetic silencing of WIF-1 in hepatocellular carcinomas.
OBJECTIVE
To examine the expression profile and promoter methylation status of WIF-1 in hepatocellular carcinoma (HCC) and identify the possible relationship between the WIF-1 expression pattern and promoter methylation status.


METHODS
Quantitative real-time PCR was performed to detect mRNA level of WIF-1 in 4 HCC cell lines, 15 paired HCC clinical samples and 3 normal liver tissues. Methylation-specific PCR and bisulfite DNA sequencing were used in methylation analysis. In vitro assays for HCC cells, colony formation and cell proliferation assay were carried out to observe the effect of WIF-1 on cell growth; TOP-flash luciferase analysis was employed to determine its role in the Wnt pathway.


RESULTS
Quantitative real-time PCR analysis showed the extensive low expression of WIF-1 mRNA in HCC, and this down-regulation was generally dependent on the degree of methylation at its promoter region. In vitro assays indicated WIF-1 can inhibit cell growth by blocking Wnt signaling in HCC cells.


CONCLUSIONS
WIF-1 silencing as a result of its promoter hypermethylation may be a frequent event in HCC.
Deng
Yun
Y
State Key Laboratory for Oncogenes and Related Genes, Shanghai Cancer Institute, Shanghai Jiao Tong University School of Medicine, 200032, Shanghai, China.
Yu
Bin
B
Cheng
Qin
Q
Jin
Jie
J
You
Haiyan
H
Ke
Ronghu
R
Tang
Ning
N
Shen
Qiujin
Q
Shu
Huiqun
H
Yao
Genfu
G
Zhang
Zhigang
Z
Qin
Wenxin
W
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D002455:Cell Division; D019175:DNA Methylation / Q000235:genetics; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D020868:Gene Silencing; D017930:Genes, Reporter; D056945:Hep G2 Cells; D006801:Humans; D008099:Liver / Q000502:physiology; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000379:methods*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012016:Reference Values; D012097:Repressor Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D048868:Adaptor Proteins, Signal Transducing; D017931:DNA Primers; D004273:DNA, Neoplasm; D012097:Repressor Proteins; C485569:WIF1 protein, human