Immunohistochemical detection of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in ameloblastomas.
BACKGROUND
To evaluate the roles of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in tumor progression, expression of MMP-1, -2 and -9 and TIMP-1 and -2 was analyzed in ameloblastomas as well as tooth germs.


METHODS
Frozen tissue sections of seven tooth germs and 22 ameloblastomas were immunohistochemically examined using anti-MMP-1, -2 and -9 and anti-TIMP-1 and -2 antibodies.


RESULTS
MMP-1, -2 and -9 and TIMP-1 and -2 were expressed strongly in mesenchymal components of tooth germs, and stromal cells of ameloblastomas. Immunoreactivity for MMP-9 in stromal cells of ameloblastomas was significantly stronger than in mesenchymal cells of dental follicles and dental papillae. Dental laminae showed weak MMP-2 expression in six tooth germs, MMP-9 expression in two tooth germs and TIMP-1 expression in six tooth germs. Some tumor cells showed weak MMP-2 expression in 19 ameloblastomas, MMP-9 expression in four ameloblastomas and TIMP-1 expression in all cases. TIMP-2 reactivity was prominently found in basement membrane zones of dental laminae in tooth germs, and tumor cell islands or nests in ameloblastomas.


CONCLUSIONS
Expression of MMPs and TIMPs was considered to be associated with interactions between epithelial cells and mesenchymal components in normal and neoplastic odontogenic tissues; these molecules might play a role in regulation of tumor progression in ameloblastomas as well as regulation of developmental processes in tooth germs.
Kumamoto
Hiroyuki
H
Department of Oral Medicine and Bioregulation, Tohoku University Graduate School of Dentistry, Sendai, Japan. kumamoto@mail.cc.tohoku.ac.jp
Yamauchi
Kensuke
K
Yoshida
Mitsuhide
M
Ooya
Kiyoshi
K
D000293:Adolescent; D000564:Ameloblastoma / Q000201:enzymology*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007573:Jaw Neoplasms / Q000201:enzymology*; D008297:Male; D020782:Matrix Metalloproteinases / Q000096:biosynthesis*; D018709:Statistics, Nonparametric; D019714:Tissue Inhibitor of Metalloproteinases / Q000096:biosynthesis*; D014083:Tooth Germ / Q000201:enzymology
D019714:Tissue Inhibitor of Metalloproteinases; D020782:Matrix Metalloproteinases