Expression of matrix metalloproteinases in benign and malignant follicular thyroid lesions.
OBJECTIVE
To examine expression of matrix metalloproteinases (MMPs) and related proteins in follicular thyroid lesions (FTLs) and to determine their usefulness for differential diagnosis of FTLs, particularly between minimally invasive carcinoma and adenoma.


RESULTS
Six widely invasive follicular carcinomas (WIFCs), 15 minimally invasive follicular carcinomas (MIFCs), 19 follicular adenomas (FAs) and 10 adenomatous goitres (AGs) were analysed immunohistochemically for MMP-1, MMP-2, MMP-7, MMP-9, membrane-type 1-MMP (MT1-MMP) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). MMP-1 was positive in all FTLs. MMP-2 and MMP-7 were positive in more than 80% of WIFC and MIFC cases, whereas they were negative in all FA and AG cases except one MMP-2+ FA (P < 0.001). MMP-9 stained positive significantly more in MIFC than FA or AG cases (P < 0.05, respectively). The positivity of MT1-MMP and TIMP-2 was different among some of the FTLs, but with no significant difference between MIFC and FA cases. In-situ hybridization of MMP-2 and MMP-7 mRNA in selected cases demonstrated the expression of these enzymes in the tumour cells as well as in some stromal cells.


CONCLUSIONS
Our results confirm MMP expression mainly in malignant FTLs and suggest that MMP-2 and MMP-7 may be useful markers to distinguish MIFC from FA.
Cho Mar
K
K
Department of Pathology, Nagoya City University Medical School, Nagoya, Japan.
Eimoto
T
T
Tateyama
H
H
Arai
Y
Y
Fujiyoshi
Y
Y
Hamaguchi
M
M
D018263:Adenocarcinoma, Follicular / Q000737:chemistry* / Q000175:diagnosis / Q000235:genetics; D000236:Adenoma / Q000737:chemistry* / Q000175:diagnosis / Q000235:genetics; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis / Q000235:genetics; D020783:Matrix Metalloproteinase 7 / Q000032:analysis / Q000235:genetics; D020782:Matrix Metalloproteinases / Q000032:analysis* / Q000235:genetics; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012333:RNA, Messenger / Q000032:analysis; D013961:Thyroid Gland / Q000737:chemistry / Q000473:pathology; D013964:Thyroid Neoplasms / Q000737:chemistry* / Q000175:diagnosis / Q000235:genetics
D012333:RNA, Messenger; D020782:Matrix Metalloproteinases; D020783:Matrix Metalloproteinase 7; D020778:Matrix Metalloproteinase 2