[Analysis of DNA methylation pattern of c-myc oncogene in hepatocellular carcinoma].
OBJECTIVE
To assess whether hypomethylation of c-myc gene occours in HCC and to determine its clinical significance.


METHODS
The methylation pattern at 3' end of c-myc gene was analyzed by Southern blot using methylation sensitive restrcition endonuclease enzymes Hpa I and Msp I in six normal liver tissues and 18 HCCs.


RESULTS
At least 5 CCGG sites were methylated at 3' end of c-myc gene in 6 normal liver tissues. However, the normal hypermethylation pattern was absent in 11 hepatocellular carcinoms (HCC) which showed different degree of hypomethylation even if among subclonal cells of same tumour tissues. The hypomethylation was observed more often in markedly advanced HCC with metastasis and poorly differentiated histological grade.


CONCLUSIONS
Scattered CpG at 3' end of c-myc gene was methylated in normal liver tissues. Methyl groups were deleted in different extent in HCC, which can lead to abnormal expression of c-myc gene. The hypomethylation of c-myc can reflect the malignlant extent of HCC and may serve as a useful prognostic indicator in clinical practice.
Xiao
W
W
Laboratory of Gastroenterology, Southwest Hospital, Third Military Medical University, Chongqing.
Liu
W
W
Lu
Y
Y
D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D019175:DNA Methylation; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics*