Hypermethylation of multiple genes as clonal markers in multicentric hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is highly malignant and prone to multicentric occurrence. Differentiation between a true relapse of HCC and a second primary tumour appearing is of clinical importance. At this point, no convenient method is available to determine the origin of these HCCs. Tissue samples were obtained from 19 patients and analysed for the promoter hypermethylation status of multiple tumour suppressor genes (p16, DAP-Kinase, MGMT, GSTP1, APC, RIZ1, SFRP1, SFRP2, SFRP5, RUNX3, and SOCS1) using methylation-specific PCR (MSP). Methylation status was used to determine tumour clonality. In each of the 19 cases, at least one tumour was recognised as having an aberrantly methylated gene. The frequency of the methylation in tumour tissue was 57.1% in p16, 2.4% in DAP-kinase, 23.8% in GSTP1, 90.5% in APC, 45.2% in RIZ1, 64.3% in SFRP1, 59.5% in SFRP2, 28.6% in SFRP5, 47.6% in RUNX3, and 54.8% in SOCS1, while in MGMT, no aberrant methylation was detected. The methylation status of these genes was assessed using MSP as being either positive or negative, and was used to determine the tumour clonality. The clonality of every tumour could be decided even with lesions that could not be judged by clinical diagnosis or by another molecular method (mt DNA mutation). Determining the methylation status of multiple genes in multicentric HCC was useful as a clonal marker and provided useful information for characterising the tumour. From our findings, multicentric HCCs tend to occur more independently than metastatically from the original tumour. Expanded study should be pursued further for a better understanding of the molecular mechanism of hepatocarcinogenesis.

Clinicopathologic Characteristics and Prognoses for Multicentric Occurrence and Intrahepatic Metastasis in Synchronous Multinodular Hepatocellular Carcinoma Patients

“…Most mutations in cancers occur in the D-loop region of mtDNA. Mutations in the mtDNA D-Loop region are a useful marker for determining the cell clonal origin for multiple HCC (Nomoto et al, 2002).…”

“…However, in clinical practice, it is important to identify the original type of multinodular HCC preoperatively to determine the appropriate therapeutic strategy, but this is a considerable challenge. Detection of the mutations in the mtDNA D-Loop in the plasma may be useful (Nomoto et al, 2002), but further study is needed.…”

“…Patients with MO have better outcomes than those with IM (Yasui et al, 1997;Huang et al, 2012). Many studies (Oda et al, 1992; Liver Cancer Study Group of Japan, 1997;Yamamoto et al, 1999;Chen et al, 2000;Nomoto et al, 2002;Okamoto et al, 2006;Nomoto et al, 2007;Li et al, 2008) have examined the differentiation of the origins of recurrent HCC, also known as metachronous multiple HCC, because the original type is important for the preoperative assessment, determining the treatment modality and predicting patient prognosis. The same problem also appears in synchronous multinodular HCC patients, but few studies have examined this population.…”

Identifying Molecular Markers for the Early Detection of Pancreatic Neoplasia

“…Mitochondrial mutations are commonly found in multiple cancers types 133-137 . One advantage of mitochondrial DNA as a marker for cancer is that each cell has many more copies of the mitochondrial genome than of nuclear DNA, and the amount of mitochondrial DNA in cancer cells is several times more abundant than it is in normal tissues 133,134,136,138 . A "MitoChip" has been developed to interrogate the mitochondrial genome, 135 , and initial studies suggest that this chip can be used to detect mitochondrial mutations in pancreatic juice samples obtained from patients with pancreatic cancer 135 .…”

Role of P14 and MGMT Gene Methylation in Hepatocellular Carcinomas: a Meta-analysis

“…The range of P14 and MGMT methylation in HCC tissues was 0-80% and 0-64.3% (Tannapfel et al, 2001;Yu et al, 2002;Yang et al, 2003;Yu et al, 2003;Anzola et al, 2004;Qian et al, 2005;Liu et al, 2006;Nomoto et al, 2007;Ruan et al, 2007;Lou et al, 2008;Herath et al, 2009;Li et al, 2010;Li et al, 2013), respectively, and some studies reported that the levels of methylation were higher in control than in cancer tissues (Su et al, 2007;Zhang et al, 2007;Formeister et al, 2010). Based on these inconsistent results, we performed a meta-analysis using the accumulated data to accurately assess the association between P14 and MGMT methylation and the risk of HCC.…”