TY - JOUR
T1 - Epigenetic instability is rare in fibrolamellar carcinomas but common in viral-associated hepatocellular carcinomas
AU - Vivekanandan, Perumal
AU - Torbenson, Michael
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/6/8
Y1 - 2008/6/8
N2 - Fibrolamellar carcinomas have a unique predilection for younger individuals and arise in livers without recognizable liver disease. In contrast to typical hepatocellular carcinomas, fibrolamellar carcinomas show few chromosomal changes and lack mutation in key genes such as TP53 and CTNNB1. Epigenetic instability, manifesting as methylation of important tumor suppressor gene promoters, has not been investigated in fibrolamellar carcinomas. Thus, the methylation status of 11 tumor suppressor gene promoters was investigated using methylation-specific PCR: RASSF1, CDH1, CDKN2B, HPP1, CDKN2A, GSTP1, P16, RARA, FLJ13081, SOCS1, and TP53. Nine fibrolamellar carcinomas were studied including primary tumors (N=5) and metastatic deposits (N=4) along with control groups of typical hepatocellular carcinoma arising in livers with (N=21) and without cirrhosis (N=10). In fibrolamellar carcinomas, RASSF1A and CDH1 (e-cadherin) were the most commonly methylated genes with 80-100% of tumors methylated. However, overall fibrolamellar carcinomas showed low levels of methylation with no differences between fibrolamellar carcinomas and their paired normal livers. However, fibrolamellar carcinomas showed significantly less methylation than hepatocellular carcinomas that arose in the background of viral cirrhosis. Overall, methylation was most strongly linked to viral cirrhosis. In conclusion, fibrolamellar carcinoma shows low levels of methylation. In contrast, higher levels of promoter methylation are associated with hepatocellular carcinomas that arise in the setting of viral induced cirrhosis.
AB - Fibrolamellar carcinomas have a unique predilection for younger individuals and arise in livers without recognizable liver disease. In contrast to typical hepatocellular carcinomas, fibrolamellar carcinomas show few chromosomal changes and lack mutation in key genes such as TP53 and CTNNB1. Epigenetic instability, manifesting as methylation of important tumor suppressor gene promoters, has not been investigated in fibrolamellar carcinomas. Thus, the methylation status of 11 tumor suppressor gene promoters was investigated using methylation-specific PCR: RASSF1, CDH1, CDKN2B, HPP1, CDKN2A, GSTP1, P16, RARA, FLJ13081, SOCS1, and TP53. Nine fibrolamellar carcinomas were studied including primary tumors (N=5) and metastatic deposits (N=4) along with control groups of typical hepatocellular carcinoma arising in livers with (N=21) and without cirrhosis (N=10). In fibrolamellar carcinomas, RASSF1A and CDH1 (e-cadherin) were the most commonly methylated genes with 80-100% of tumors methylated. However, overall fibrolamellar carcinomas showed low levels of methylation with no differences between fibrolamellar carcinomas and their paired normal livers. However, fibrolamellar carcinomas showed significantly less methylation than hepatocellular carcinomas that arose in the background of viral cirrhosis. Overall, methylation was most strongly linked to viral cirrhosis. In conclusion, fibrolamellar carcinoma shows low levels of methylation. In contrast, higher levels of promoter methylation are associated with hepatocellular carcinomas that arise in the setting of viral induced cirrhosis.
KW - Fibrolamellar carcinoma
KW - HPP1
KW - Hepatocellular carcinoma
KW - Methylation
KW - RASSF1A
KW - Viral hepatitis
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U2 - 10.1038/modpathol.2008.32
DO - 10.1038/modpathol.2008.32
M3 - Article
C2 - 18264082
AN - SCOPUS:44349154093
SN - 0893-3952
VL - 21
SP - 670
EP - 675
JO - Modern Pathology
JF - Modern Pathology
IS - 6
ER -