Fig 1.
Genetics and bio-informatics analysis of rs3957357C>T in GSTA1.
A, Linkage disequilibrium analysis between GSTA1 single nucleotide polymorphisms in the CEPH-HapMap population visualized with the Haploview software. Linkage disequilibrium data for GSTA1 gene shows 7 SNPs, among them rs3957357 (highlighted in red). All the single nucleotide polymorphisms are in high linkage disequilibrium. Red squares indicate complete linkage disequilibrium between two single nucleotide polymorphisms. SNPs: single nucleotide polymorphisms. B, Representative image of a PCR-RFLP experiment. The presence of the T allele in rs3957357C>T of GSTA1 gene leads to the production of 380 bp and 100 bp fragments, while the amplicons carrying the C allele remain undigested.
Fig 2.
Prevalence of healthy individuals and patients with hepatocellular carcinoma according to the rs3957357C>T genotype in the GSTA1 gene.
Stratification according to the rs3957357C>T genotype in GSTA1 shows a 5-fold increase in the prevalence of individuals with HCC carrying the TT genotype (27%), compared with healthy individuals and carrying the same genotype (5%).
Fig 3.
GSTA1 expression in hepatocellular carcinomas and matching non-tumor livers.
Real-time PCR analysis of normalized GSTA1 mRNA expression in 36 frozen liver samples including (HCCs), and matching non-tumor livers (C). RNA expression values were calculated by the ΔΔCt method. Statistical significance of the differences between means was assessed by the Mann-Whitney “U” test (p = 0.007).
Fig 4.
GSTA1 mRNA levels are negatively correlated with tumor size in HCCs.
A, Real-time PCR analysis of normalized GSTA1 mRNA expression in 18 HCCs. HCC 0 (large HCC), HCC1 (Small HCC, <3 cm) (p = 0.002). B, Real-time PCR analysis of GSTA1 mRNA expression in 18 HCCs and tumor size are negatively correlated (Spearman’s R = -0.67; p = 0.007).
Fig 5.
Correlation analysis of GSTA1, albumin (ALB) and procollagen type XVIII (COL18A1) mRNA expression in hepatocellular carcinomas.
A, Real-time PCR analysis of albumin mRNA expression levels in 18 HCCs (Spearman’s R = 0.67; p = 0.001). B, Real-time PCR analysis of procollagen type XVIII mRNA expression levels in 18 HCCs (Spearman’s R = 0.50; p = 0.03).
Fig 6.
GSTA1 co-expression network in 247 human HCCs.
GSTA1 is highlighted as a yellow node. Weighted correlation network analyses of mRNA expression data was visualized with Cytoscape with correlation coefficient thresholds > 0.40 (positive correlations) or <– 0.40 (negative correlations). Closeness between nodes is proportional to the number of connections. Thickness of links is proportional to the correlation coefficients between genes. Green nodes, positively correlated genes; blue nodes, negatively correlated genes; red links, positive correlation; blue links, negative correlation.
Fig 7.
Loss of GSTA1 mRNA expression is associated with bad outcome after curative HCC resection.
GSTA1 mRNA expression was significantly related to disease-free and overall survival by Log-Rank and Cox regression analysis on an annotated microarray dataset from 247 HCC-resected patients (Gene Expression Omnibus, GSE14520. Data were normalized and filtered as described).