Matrix metalloproteinase-21 expression is associated with keratinocyte differentiation and upregulated by retinoic acid in HaCaT cells.

In the skin, expression of several matrix metalloproteinases (MMPs) occurs in response to tissue injury, tumorigenesis, angiogenesis, apoptosis, and inflammation. The recently cloned MMP-21 has been implicated in skin development and various epithelial cancers. In this study, we found that it is also expressed by differentiated keratinocytes (KCs) in various benign skin disorders, in which it was not associated with KC apoptosis or proliferation, and in organotypic cultures.

MMP-21 is expressed by macrophages and fibroblasts in vivo and in culture.

Matrix metalloproteinase (MMP)-21 and MMP-26 (matrilysin-2) are two recently cloned epithelial metalloproteases. Here we examined their expression in various benign skin disorders, in which macrophages and fibroblasts have been implicated as well as in cultures of these cells. Expression of MMP-21 was detected by immunohistochemistry in a subset of macrophages of granulomatous skin lesions and in fibroblasts in dermatofibromas.

Matrix metalloproteinases 21 and 26 are differentially expressed in esophageal squamous cell cancer.

Matrix metalloproteinase 21 (MMP-21) and MMP-26 (matrilysin-2) are the two newest members of the human MMP gene family that have both been suggested to play an important role in epithelial tumor progression and to be regulated via the Wnt signaling pathway. We studied their expression in 34 esophageal squamous cell carcinomas and non-neoplastic epithelium. MMP-21 protein was detected in cancer cells and inflammatory cells at the invasive front.

MMP-21 is upregulated at early stages of melanoma progression but disappears with more aggressive phenotype.

The expression of matrix metalloproteinases (MMPs) is frequently altered during malignant transformation. We examined the profile of three recently cloned MMPs, MMP-21, MMP-26, and MMP-28, in melanomas in vivo and in culture. Immunohistochemistry for MMPs-21, -26, -28, and -13 in melanoma specimens (27 nonmetastatic, 26 with nodal micrometastases, and 10 in situ melanomas) from 63 patients was performed.

Matrilysin-2 (matrix metalloproteinase-26) is upregulated in keratinocytes during wound repair and early skin carcinogenesis.

Matrilysin-2 (matrix metalloproteinase (MMP)-26) is a small protein of the MMP family expressed in some epithelial carcinomas and normal tissues. We studied its role in benign skin disorders characterized by epithelial proliferation, in wound repair, skin cancer, and regulation in keratinocyte (KC) cultures. MMP-26 is expressed by laminin-5-positive KC in the migrating area during wound repair, in benign skin disorders characterized by inflammation and microdisruptions of basement membrane, but in intact skin only in hair follicles.