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

Abstract

Activity of metalloproteinases 2 and 9 (MMP-2 and 9) during promotion and progression of rat liver carcinogenesis was investigated in a modified resistant hepatocyte model. Development of preneoplastic liver lesions positive for glutathione S-transferase 7-7-(GST-P 7-7-positive PNL) and tumors besides hepatocytes positive for proliferating cell nuclear antigen (PCNA) were quantified and compared to MMP-2 and-9 activity using gelatin zymography. Marked increases in GST-P 7-7-positive PNL development, PCNA labeling indices, MMP-2 (pro, intermediate and active forms) and pro-MMP-9 activity were observed after proliferative stimulus induced by 2-acetylaminofluorene (2-AAF) exposure cycles. After 2-AAF withdrawal, increase in MMP-2 activity was detected only in neoplastic mixed lesions, whereas active MMP-9 was increased in both PLN and neoplastic tissues. Our findings suggest that MMP-2 may be associated with proliferative events induced by 2-AAF rather than with selective growth of PNL and that MMP-9 could be associated with progression of PNL and neoplastic mixed lesions.

Coffee and Caffeine Protect against Liver Injury Induced by Thioacetamide in Male Wistar Rats

“…GST‐P expression is used as a potential marker for hepatic pre‐neoplastic and neoplastic lesions in male Wistar rats . Short‐ and medium‐term TAA treatment can induce the development of few PNL in the liver of non‐initiated male rats .…”

“…PCNA S‐phase or growth fraction (G1 late, S, G2 and M phases) labelling (%) and cleaved caspase‐3 labelling indexes (%) for each animal were estimated by counting the number of immunohistochemically labelled hepatocytes per total number of counted hepatocytes (~2000) . Pre‐neoplastic lesions (PNL) were detected by GST‐P expression in liver sections.…”

“…The number of GST‐P‐positive PNL was assessed using a Nikon photomicroscope (Microphot‐FXA, Tokyo, Japan) connected to a KS‐300 apparatus (Kontron Elektronic, Munich, Germany). Data were expressed as number of PNL per liver area (cm 2 ) .…”

“…The integrated optical density (IOD) spectrophotometry was determined in an Image Master VDS version 3.0 (Pharmacia Biotechnology, Piscataway, NJ, USA). The values of IOD were analysed statistically and plotted in histograms .…”

An integrative analysis of chemically-induced cirrhosis-associated hepatocarcinogenesis: Histological, biochemical and molecular features

“…Frozen liver samples (-80°C) were mechanically homogenized in 50 mM Tris buffer pH 7.5 plus 1% triton-X 100 and CaCl 2 10 mM with a Polytron (30 s at 4°C), centrifuged and proteins extracted on supernatant were quantified by Bradford method. Aliquots (30 μg protein) from liver extracts were subjected to electrophoresis in 8% polyacrylamide gel containing 0.1% gelatin in the presence of SDS under non-reducing conditions (Furtado et al, 2009). The gels (0.75 mm thick) were electrophoresed (2 h at 100 V, 4°C), in a Bio-Rad Mini-Protean II system (Bio-Rad Laboratories, USA).…”