Up-regulated aldo-keto reductase family 1 member B10 in chronic hepatitis C: association with serum alpha-fetoprotein and hepatocellular carcinoma

Abstract

Background: Elevated serum alpha-fetoprotein (AFP) is not only a diagnostic marker for hepatocellular carcinoma (HCC), but is also a risk factor for HCC in chronic hepatitis C patients who do not have HCC.

Aim: The aim was to analyse the hepatic gene expression signature in chronic hepatitis C patients with elevated AFP, who were at high risk for HCC.

Methods: Liver tissue samples from 48 chronic hepatitis C patients were stratified by their serum AFP levels and analysed for gene expression profiles. The association between aldo-keto reductase family 1 member B10 (AKR1B10) expression and serum AFP was confirmed by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemical analyses. A matched case-control study was performed to evaluate the risk of AKR1B10 expression for HCC development.

Results: Distinct hepatic gene expression patterns were demonstrated in patients with elevated AFP (≥10 ng/mL) and normal AFP (<10 ng/mL). Of the 627 differently expressed genes, the most abundantly expressed gene in patients with elevated AFP was AKR1B10 (fold change, 26.2; P < 0.001), which was originally isolated as an overexpressed gene in human HCC. The qRT-PCR and immunohistochemical studies confirmed a proportional correlation between AKR1B10 expression and serum AFP. A matched case-control study identified that AKR1B10 up-regulation (>6%) was an independent risk factor for HCC development (hazard ratio, 21.4; P = 0.001).

Conclusion: AKR1B10 was up-regulated in association with serum AFP, and was an independent risk factor for HCC in chronic hepatitis C patients, suggesting its possible involvement at a very early stage of hepatocarcinogenesis.

Fig. 1

Analysis of gene expression data. (A) Principal component analysis for the 627 differentially expressed genes between the patients with normal alpha-fetoprotein (AFP) (N = 33, blue dots) and elevated AFP (N = 15, red dots). (B) Hierarchical clustering for the 627 differentially expressed genes between the patients with normal AFP (N = 33, blue squares) and elevated AFP (N = 15, red squares). Red and blue cells indicate the ratio of each expression level above and below the median respectively.

Fig. 2

Quantitative real-time RT-PCR analysis. (A) Comparison of AKR1B10 mRNA expression between the patients with normal alpha-fetoprotein (AFP) and the patients with elevated AFP (Mann–Whitney U-test, P < 0.001). (B) Regression of AKR1B10 mRNA and serum AFP (N = 48, R² = 0.326, P < 0.001).

Fig. 3

AKR1B10 immnohistochemical analysis. (A) Representative immunohistochemical staining of normal control liver tissue. Bile duct epithelium served as the positive control. (B) Representative immunohistochemical staining of liver tissue with chronic hepatitis C (magnification × 100). (C) Quantification of AKR1B10 immunoreactivity (Mann–Whitney U-test). (D) Regression of AKR1B10 immunoreactivity and serum alpha-fetoprotein in patients with chronic hepatitis C (N = 48, R² = 0.613, P < 0.001).

Fig. 4

Cumulative incidence of hepatocellular carcinoma development according to AKR1B10 expression (log-rank test, P = 0.001).