Matrix metalloproteinases, MMPs
Matrix metalloproteinases are zinc-dependent endopeptidases that degrade extracellular matrix. 23 different MMPs have ben identified. They are activated by proteases. They are inhibited by tissue inhibitors of MMPs (TIMPs). A subset of MMPs remain membrane-bound (MT-MMPs). MMPs are likely to play a role in tumour invasiveness.
Immunohistochemical expression
In follicular thyroid neoplasms:
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Synonym
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Adenomatous goitre
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Follicular adenoma
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Minimally invasive follicular carcinoma
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Widely invasive follicular carcinoma
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MMP-1
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collagenase 1
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10/10
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9/9
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15/15
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6/6
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MMP-2
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gelatinase A
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0/10
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1/19
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12/15
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5/6
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MMP-7
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matrilysin
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0/10
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0/19
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12/15
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5/6
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MMP-9
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gelatinase B
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3/10
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11/19
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13/15
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4/6
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MT1-MMP
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6/10
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15/19
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14/15
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4/6
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TIMP-2
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1/10
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5/19
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8/15
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5/6
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MMP-2 may be a useful indicator of malignancy in adrenocortical tumours
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Adrenocortical adenoma
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1/50(the one case that showed focal staining was of borderline malignancy)2
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Adrenocortical carcinoma
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37/50(staining of the cytoplasm of tumour cells was moderate to strong. 26 cases showed staining in less than 20% of tumour cells; 11 cases showed staining of more than 20% of tumour cells)2
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Adrenal endothelial and stromal cells also stain for MMP-2. Strong staining of adrenocortical carcinomas correlated with a poor prognosis2.
Diagnostic utility
Positivity for MMP-2 and MMP-7 may help to distinguish benign follicular adenomas from invasive carcinomas of the thyroid (including minimally invasive carcinomas).
Diagnosis of malignancy in adrenocortical tumours.
References
1 Cho Mar K, Eimoto T, Tateyama H, et al. Expression of matrix metalloproteinases in benign and malignant follicular thyroid lesions. Histopathology 2006; 48:286-94
2 Volante M, Sperone P, Bollito E, et al. Matrix metalloproteinase type 2 expression in malignant adrenocortical tumors: Diagnostic and prognostic significance in a series of 50 adrenocortical carcinomas. Mod Pathol 2006; 19:1563-9
This page last revised 6.1.2007.
©SMUHT/PW Bishop