Methylation of serum insulin-like growth factor-binding protein 7 promoter in hepatitis B virus-associated hepatocellular carcinoma

Abstract

Methylation of gene promoter CpG islands is an important early event in hepatocellular carcinoma (HCC), and detection of cell-free tumor-specific DNA methylation is becoming a useful noninvasive method for HCC. This study was aimed at determining the diagnostic value of serum insulin-like growth factor-binding protein 7 (IGFBP7) promoter methylation in hepatitis B virus-associated HCC. A total of 217 subjects, including 136 HCC patients, 46 patients with chronic hepatitis B (CHB), and 35 healthy controls (HCs), were included. The methylation status of the serum IGFBP7 gene promoter was determined using methylation-specific PCR. The frequency of serum IGFBP7 promoter methylation in HCC patients (89/136, 65%) was significantly higher than that in CHB patients (8/46, 17%; X(2) = 31.883, P < 0.001) and HCs (5/35, 14%; X(2) = 29.429, P < 0.001). Moreover, elevated IGFBP7 methylation frequency was also observed in HCC patients with vascular invasion compared with those without vascular invasion (84 versus 60%, X(2) = 6.633, P = 0.010). The sensitivities of serum IGFBP7 methylation and alpha-fetoprotein (AFP) in detecting HCC were 65 and 57%, respectively. Of note, the combination of IGFBP7 methylation and AFP showed 85% for sensitivity. These results suggest that methylation of the serum IGFBP7 gene promoter may serve as a useful noninvasive biomarker for HCC diagnosis.