Promoter hypermethylation of fibulin 1 gene is associated with tumor progression in hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is one of the most common cancers world-wide but the molecular mechanisms that underlie hepatocarcinogenesis are not fully determined. On the same surgical sample with HCC, we performed microarray-based gene expression profiling and karyotype analysis using a single nucleotide polymorphism (SNP) array. In addition, quantitative real-time reverse transcription polymerase chain reaction (PCR), methylation specific PCR (MSP) and immunohistochemical staining were conducted using specimens from 48 patients with HCC. Gene expression profiling showed the expression of fibulin 1 (FBLN1), located on 22q13, to be decreased in tumor tissue. Karyotype analysis revealed no loss of heterozygosity (LOH) since deletions were not detected in 22q, and one of the SNPs on 22q13 showed AB genotype in both cancerous tissue and in corresponding noncancerous tissue, indicating retention of heterozygosity. Quantitative real-time PCR showed FBLN1 mRNA levels in cancerous tissues to be significantly decreased compared with that in corresponding noncancerous tissues. The immunohistochemical staining results were consistent with both gene expression profiling and quantitative PCR data. Twenty-four out of 48 HCCs gave a positive result in MSP. Moreover, promoter hypermethylation of FBLN1 was significantly associated with advanced stage HCC, multiple tumors and increased tumor size. Our results indicated that FBLN1 is a novel candidate of tumor suppressor gene and that promoter hypermethylation of FBLN1 is associated with tumor progression in HCC. © 2011 Wiley-Liss, Inc.

Molecular alterations in the carcinogenesis and progression of hepatocellular carcinoma: Tumor factors and background liver factors

“…Okabe et al (72) and Shirota et al (73) extracted mRNA from the cancerous and noncancerous tissues of a number of patients with HCC, in order to evaluate the variations in gene expression levels, and detected certain genes that characterize HCC. Nomoto et al (74) performed a double-combination array analysis consisting of an expression array and single nucleotide polymorphism (SNP) array, which facilitated the identification of novel genes associated with hepatocarcinogenesis using expression profiling and chromosomal copy number analysis (74,(76)(77)(78)(79)(80). Microarray analysis was also used to reveal cancer-associated miRNAs (52,81).…”

FBLN1 (fibulin 1)

“…Very recently, also in hepatocellular carcinoma (HCC) model, a downmodulation of fibulin-1 expression caused by its promoter hypermethylation has been proposed as a marker of HCC progression (Kanda et al, 2011).…”

Overexpression of fibulin-4 is associated with tumor progression and poor prognosis in patients with cervical carcinoma

“…Research findings on the role of fibulin-1 and fibulin-3 in different tumor tissues have been controversial. Few researchers have reported oncogenic activities (13)(14)(15)(16)(17)(18)(19), whereas others have reported tumor-suppressive activities (20)(21)(22)(23)(24)(25)(26)(27). This discrepancy may be attributable to the influence of the tumor microenvironment on tumor-associated genes in promoting angiogenesis and metastasis (28).…”