Chronic ethanol intake promotes double gluthatione S‐transferase/transforming growth factor‐α‐positive hepatocellular lesions in male Wistar rats

Abstract

The chronic ethanol intake influence on the gluthatione S-transferase (GST-P) and transforming growth factor α α α α (TGF-α α α α) expression in remodeling/persistent preneoplastic lesions (PNLs) was evaluated in the resistant hepatocyte model. Male Wistar rats were allocated into five groups: G1, non-treated, fed water and chow ad libitum; G2, non-treated and pair-fed chow (restricted to match that of G3 group) and a maltodextrin (MD) solution in tap water (matched ethanol-derived calories); G3, fed 5% ethanol in drinking water and chow ad libitum; G4, diethylnitrosamine (DEN, 200 mg/kg, body weight) plus 200 parts per million of 2-acetylaminofluorene (2-AAF) for 3 weeks and pair-fed chow (restricted to match that of G5 group) and an MD solution in tap water (matched ethanol-derived calories); G5, DEN/2-AAF treatment, fed ethanol 5% and chow ad libitum. All animals were subjected to 70% partial hepatectomy at week 3 and sacrificed at weeks 12 or 22, respectively. Liver samples were collected for histological analysis or immunohistochemical expression of GST-P, TGF-α α α α and proliferating cell nuclear antigen or zymography for matrix metalloproteinases-2 and -9. At the end of ethanol treatment, there was a significant increase in the percentage of liver area occupied by persistent GST-P-positive PNLs, the number of TGF-α α α α-positive PNLs and the development of liver tumors in ethanol-fed and DEN/2-AAF-treated groups (G5 versus G4, P < < < < 0.001). In addition, ethanol feeding led to a significant increase in cell proliferation mainly in remodeling and persistent PNLs with immunoreactivity for TGF-α α α α at week 22 (P < E thanol consumption is a widespread habit, especially in the western world, with imperative familial and socioeconomic effects. Various studies have shown that chronic ethanol abuse increases the risk of developing cancer of the breast, liver, pancreas, colon and the upper aerial-digestive tract.<(1-4) Alcohol is a known risk factor for the development of hepatocellular carcinoma (HCC), mainly in patients infected with the hepatitis C virus (HCV) who drink heavily.(1,3) However, a direct correlation between alcohol consumption and the development of HCC in humans remains inconclusive.The hepatocyte represents the major site of ethanol metabolism using three main pathways, including alcohol dehydrogenase (ADH), inducible CYP2E1 and catalase enzymes, leading to the generation of acetaldehyde and reactive oxygen and nitrogen species.(5,6) These free radicals can bind rapidly to cell constituents, including DNA, lipids and proteins, raising mainly oxidative DNA damage, lipid peroxidation, protein impairment and depletion of many antioxidant systems, including reductions in glutathione, vitamin E and phosphatidylcholine. (6,7) In addition, acetaldehyde is highly toxic, mutagenic and carcinogenic (8,9) and the induction of CYP2E1 has been demonstrated to enhance the activation of many xenobiotics, among them diethylnitrosamine (DEN), a known carcinogen, genotoxic to the liver, present in many al...

Proteomic Analysis of Differentially Expressed Proteins in Peripheral Cholangiocarcinoma

“…Other proteins that have also been shown to be elevated in hepatocellular carcinoma include fibrinogen gamma chain precursor [30], glutathione S transferase [31], glycerol-3-phosphate dehydrogenase [32], histone-binding protein RBBP4 [33] and nucleophosmin [34]. Lamin-A/C was elevated in sera of patients with a hepatocellular carcinoma [35].…”

Metalloproteinases 2 and -9 activity during promotion and progression stages of rat liver carcinogenesis

“…DEN,diethylnitrosamine (200 mg/kg,b.w.,i.p. ) and 2-AAF, 2-acethylaminofluorene (0.02% in diet) J Mol Hist (2009) 40:1-11 7 hepatocarcinogenesis may be due to the global expansion of hepatic cell compartment induced by 2-AAF-treatment rather than the selective growth of PNL, as previously described (Wood and Archer 2001;Pires et al 2008). At the end of experiment, the activity of pro, intermediate and active forms of MMP-2 and pro-MMP-9 in samples from non-neoplastic liver parenchyma was similar among the different groups treated or non-treated with carcinogens.…”

“…Aliquots (30 lg protein) from liver extracts (non-altered, containing PNL or neoplastic lesions) were subjected to electrophoresis in gelatin containing polyacrylamide (8% acrylamide) gels in the presence of SDS under non-reducing conditions (Pires et al 2008). The gelatin substrate was present at 0.1% final concentration in the gel.…”

“…As the immunohistochemical detection of GST-P 7-7-positive PNL was performed in various fragments of all liver lobes reminiscent after partial hepatectomy, our results were presented as number per cm 2 , mean size (mm 2 ) and percentage of liver area occupied by these lesions (% liver area). (Pinheiro et al 2003;Pires et al 2008).…”

“…PCNA labeling indices (PCNA LI %) for each animal were estimated by counting the number of immunohistochemically labeled hepatocytes nuclei (S-Phase) per total number of counted hepatocytes (*2,000) in normal or bearing PNL parenchyma (Pinheiro et al 2003;Pires et al 2008). PCNA LI% was also measured in neoplastic lesions diagnosed at week 35.…”