HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wood, G. A. Articles by Archer, M. C. Search for Related Content PubMed PubMed Citation Articles by Wood, G. A. Articles by Archer, M. C.

---

ORIGINAL ARTICLE

Matrix Metalloproteinases-2 and 9 Do Not Play a Role in the Growth of Preneoplastic Liver Lesions in F344 Rats

Geoffrey A. Wood^* and Michael C. Archer^,1

^* Departments of Medical Biophysics and
Nutritional Sciences, University of Toronto, Toronto, Canada M5S 3E2

Matrix metalloproteinases- (MMPs) 2 and 9 (gelatinases A and B) have been implicated in tumor invasion and metastasis, and recent studies have shown increased levels of these enzymes during recovery from partial hepatectomy (PH) in rats. F344 rats are highly susceptible to the growth of glutathione S-transferase 7-7- (GST 7-7) positive preneoplastic liver lesions promoted using the modified resistant hepatocyte (RH) protocol. Since the RH protocol consists of 2-acetylaminofluorene (2-AAF) followed by a PH, we reasoned that MMP-2 and -9 might be critical for the growth of lesions. Using gelatin zymography, we examined the expression of these enzymes in the livers of F344 rats treated with the RH protocol and sacrificed on Days 2, 4, 7, 14, and 21 after 2-AAF/PH. We found increases in both pro- and active MMP-2 and -9 over baseline levels, with the highest levels occurring on Day 7 post-PH. Also, a 54-kDa band, likely to be proMMP-1, was elevated in a pattern similar to MMP-2 and -9. In contrast to F344 rats, identically treated Copenhagen rats that are highly resistant to promotion of liver lesion growth using the RH protocol had significantly lower levels of proMMP-1 and -2. To test the importance of these MMPs to the growth of liver lesions, F344 rats that had been initiated with diethylnitrosamine were treated using the RH protocol. They then received either the MMP inhibitor batimastat (30 mg/kg, intraperitoneally) or vehicle alone daily from Day 3 to 20 post-PH and were sacrificed on Day 21. There were no differences in the percentage of liver volume occupied by GST 7-7-positive lesions (19.1 ± 4.84 vs 19.4 ± 3.31, treated versus vehicle, mean ± SEM) or liver weight as a percentage of body weight (4.11% ± 0.15 vs 4.07% ± 0.18, treated versus vehicle, mean ± SEM) between the treated and control groups. Treatment of rats with batimastat clearly did not affect lesion growth or liver regeneration following the RH protocol. These results suggest that increases in gelatinase expression during the RH protocol are a result of the promotional stimulus rather than a mechanism by which 2-AAF/PH causes lesion growth.

Key Words: matrix metalloproteinases • gelatinases • liver preneoplasia • liver regeneration

This article has been cited by other articles:

				K. K. Nelson, S. Subbaram, K. M. Connor, J. Dasgupta, X.-F. Ha, T.-C. Meng, N. K. Tonks, and J. A. Melendez Redox-dependent Matrix Metalloproteinase-1 Expression Is Regulated by JNK through Ets and AP-1 Promoter Motifs J. Biol. Chem., May 19, 2006; 281(20): 14100 - 14110. [Abstract] [Full Text] [PDF]