Insulin-like growth factor 2 gene methylation in peripheral blood mononuclear cells of patients with hepatitis C related cirrhosis or hepatocellular carcinoma.
Igf2 gene specific hypomethylation has been demonstrated in hepatocellular carcinoma (HCC) cells and in non-tumoral liver samples from patients with HCV-related cirrhosis who further developed HCC. In patients with colorectal cancers, Igf2 hypomethylation is found in peripheral blood mononuclear cells (PBMC) even prior to the occurrence of cancer.


OBJECTIVE
To compare Igf2 methylation in PBMC from healthy donors and patients with HCV-related cirrhosis without or with history of HCC.


METHODS
After DNA extraction from frozen PBMC samples of 52 healthy blood donors and 121 patients with HCV-related cirrhosis either without (n=59) or with past or present HCC (n=62), and sodium bisulfite treatment, unbiased PCR amplification and Denaturing High Performance Liquid Chromatography (DHPLC) analysis were used for methylation analysis at the differentially methylated region 2 of Igf2. Methylation profiles were classified in three groups (unmethylated, U; methylated, M; and intermediate, UM) according to the proportions of M and U alleles, blindly to clinical data. In addition, 677C-T mutation of Methylenetetrahydrofolate Reductase (MTHFR) was investigated by fluorescent probes.


RESULTS
Prevalences of U, UM and M Igf2 profiles were: 8%, 65% and 27% in blood donors, 0%, 81% and 19% in patients with HCV-related cirrhosis without HCC, 71%, 29% and 0% in patients with HCC (P<0.0001). Igf2 methylation profile was independent from gender, age, body mass index, and presence of 677C-T mutation of MTHFR.


CONCLUSIONS
These observations suggest a decrease of Igf2 methylation from cirrhosis to HCC in patients with HCV infection, which may be an additional risk factor for HCC.
Inserm U939, Dyslipidemia, Inflammation and Atherosclerosis in metabolic diseases, 75013 Paris, France.
Philippe
P
Couvert
Alain
A
Carrié
Sophie
S
Tezenas du Montcel
Jenny
J
Vaysse
Angela
A
Sutton
Nathalie
N
Barget
Jean-Claude
JC
Trinchet
Michel
M
Beaugrand
Nathalie
N
Ganne
Philippe
P
Giral
Jamel
J
Chelly
D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D006526:Hepatitis C / Q000150:complications / Q000235:genetics*; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D007963:Leukocytes, Mononuclear; D008103:Liver Cirrhosis / Q000150:complications / Q000235:genetics*; D008113:Liver Neoplasms / Q000150:complications / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
D007335:Insulin-Like Growth Factor II