Leila Jeskanen

Expression of matrix metalloproteinase (MMP)‐7 and MMP‐13 and loss of MMP‐19 and p16 are associated with malignant progression in chronic wounds

Background  The risk of squamous cell carcinoma (SCC) is significantly increased in chronic leg ulcers. Very little is known about the molecular pathogenesis of these tumours, which are often undiagnosed for a long time. As matrix metalloproteinases (MMPs) are implicated at all stages of tumorigenesis, we investigated whether the pattern of epithelial MMP expression can predict development of SCC from pseudoepitheliomatous hyperplasia of chronic wounds.

Differential patterns of stromelysin-2 (MMP-10) and MT1-MMP (MMP-14) expression in epithelial skin cancers

Co-expression of several members of the matrix metalloproteinase (MMP) family is characteristic of human malignant tumours. To investigate the role of stromelysin-2 (MMP-10) in growth and invasion of skin tumours, we studied cutaneous carcinomas with high metastatic capacity (squamous cell carcinomas, SCCs), only locally destructive tumours (basal cell carcinomas, BCCs) and pre-malignant lesions (Bowen’s disease and actinic keratosis) using in situ hybridization. Expression of MMP-10 was compared with that of stromelysin-1 (MMP-3) and of MT1-MMP, the expression of which has been shown to correlate with tumour invasiveness. MMP-10 was expressed in 13/21 SSCs and 11/19 BCCs only in epithelial laminin-5 positive cancer cells, while premalignant lesions were entirely negative. MT1-MMP mRNA was detected in 19/21 SCCs both in epithelial cancer cells and stromal fibroblasts and in 14/18 BCCs only in fibroblasts. The level of MMP-10 was upregulated in a cutaneous SCC cell line (UT-SCC-7) by transforming growth factor-α and keratinocyte growth factor, and by interferon-γ in combination with transforming growth factor-β1 and tumour necrosis factor-α both in UT-SCC-7 and HaCaT cells. Our results show that MMP-10 expression does not correlate with the invasive behaviour of tumours as assessed by their histology and MT1-MMP expression, but may be induced by the wound healing and inflammatory matrix remodelling events associated with skin tumours.

Extended follow‐up of the Finnish cartilage‐hair hypoplasia cohort confirms high incidence of non‐Hodgkin lymphoma and basal cell carcinoma

Cartilage‐hair hypoplasia (CHH) is an autosomal recessive chondrodysplasia with short stature, sparse hair and defective cell‐mediated immunity. It is caused by mutations in the RMRP (ribonuclease mitochondrial RNA processing) gene, encoding the RNA component of the ribonuclease complex RNase MRP. The aim of this study was to further elucidate the risk and spectrum of cancer in CHH. A cohort of 123 Finnish patients with CHH (51 males) was followed for malignancy through the Finnish Cancer Registry. The number of identified cancers was compared with expected numbers of cancer using population‐based data to obtain standardized incidence ratios (SIR). Hospital records were reviewed for clinical data related to the malignancies. During the follow‐up (2,365 person‐years; mean 19.2 years), 14 cases of cancer were diagnosed in the CHH cohort (expected number 2.0; SIR 7.0, CI 3.8–12). Non‐Hodgkin lymphoma was the most frequent cancer type (n = 9; SIR 90.2, CI 39.0–180) followed by squamous cell carcinoma (3), leukemia (1) and Hodgkin lymphoma (1). One tumor was not histologically classified. Nine of the 14 cancers were diagnosed in patients less than 45 years of age. In addition, ten patients had basal cell carcinoma of the skin (expected number 0.3; SIR 33.2, CI 16–61). Patients with CHH have significantly increased risk for developing non‐Hodgkin lymphoma or basal cell carcinoma at early age; the overall prognosis is poor. The underlying pathogenetic mechanisms remain to be elucidated in future studies. Careful follow‐up, extending beyond pediatric age, is warranted for early diagnosis of malignancies.

Matrix metalloproteinase-19 is expressed by proliferating epithelium but disappears with neoplastic dedifferentiation.

MMP‐19 (also designated RASI) is a recently discovered member of a large family of zinc‐dependent proteolytic enzymes, most of which have been implicated in cancer growth and metastasis. It differs from the others by its chromosomal location and structure and is expressed by endothelial and vascular smooth muscle cells in vivo. Our aim was to study the putative role of MMP‐19 in skin cancer. We also examined its regulation in keratinocyte cultures using quantitative TaqMan RT‐PCR. Our results show that MMP‐19 can also be detected in stimulated keratinocytes by Northern and Western analyses. In wounds, it was found in keratinocytes outside the migrating area, while in BCC and SCC, it was present in the hyperproliferative (p63‐positive), E‐cadherin‐negative epidermis at the tumor surface but downregulated in invasive cancer islands. Expression was also evident in endothelial cells of neoangiogenic regions and in occasional stromal fibroblasts. Of the 12 tested cytokines/growth factors, only TNF‐α and PMA were able to stimulate the expression of MMP‐19 mRNA in primary keratinocytes. No MMP‐19 mRNA was detected by Northern analysis in cultured HaCaT or A5 cells or in an SCC cell line established from head‐and‐neck cancer. Our data suggest that, unlike most MMPs, MMP‐19 expression in the epidermis is downregulated during transformation and histologic dedifferentiation.

Transforming growht factor β1 and its latent form binding protein‐1 associate with elastic fibres in human dermis: accumulation in actinic damage and absence in anetoderma

Latent transforming growth factor‐β1 (TGF‐β1) and its binding protein‐1 (LTBP‐1) are components of the extracellular matrix microfibrils of cultured human fibroblasts. Using immunohistochemistry we have studied the localization of TGF‐β1 and LTBP‐1 and compred their distribution iwth that of elastic fibres in the interstitial connective tissue matrix of the human dermis. Prominent LTBP‐1 specific fibrillar staining co‐localized with the elastic fibres in normal human skin. Co‐distribution was also observed in a number of pathological states of the elastic fibres such as solar elastosis, solar keratosis and pseudoxanthoma elasticum. TGF‐β1 had a staining pattern similar to that of LTBP‐1 in solar elastosis and solar kertosis. No staining for LTBP‐1 or TGF‐β1 was found in dermis devoid of elastic fibres, as in anetoderma. LTBP‐1 is released from the extracellular matrix of cultured human fibroblasts, epithelial and endothelial cells by proteases. Analyogously, the immunoreactivity for LTBP‐1 and TGF‐β1 were also lost form the skin sections by elastase, and by trypsin, a protease pretreatment commonly used in immunohistochemistry. These results indicate that LTBP‐1 is a component of the elastin‐associated microfibrils of the interstitial connective tissue matrix of human skin. Furthermore, the small latent form of TGF‐β1 is likely to associate with the extracellular matrix of human dermis via LTBP‐1. The release of latent TGF‐β1 from the matrix, as a consequence of proteolytic cleavage of LTBP‐1, is a plausible extracellular mechanism for the regulation of TGF‐β1 activation.

Tyrosine kinase 2 and interferon regulatory factor 5 polymorphisms are associated with discoid and subacute cutaneous lupus erythematosus

Please cite this paper as: Tyrosine kinase 2 and interferon regulatory factor 5 polymorphisms are associated with discoid and subacute cutaneous lupus erythematosus. Experimental Dermatology 2010; 19: 123–131.

Clinicopathological Characterization and Genomic Aberrations in Subcutaneous Panniculitis-Like T-Cell Lymphoma

Subcutaneous panniculitis-like T-cell lymphomas (SPTLs) represent a rare, difficult-to-diagnose, and poorly characterized subtype of cutaneous T-cell lymphomas (CTCLs) affecting younger people more than the other CTCL forms. We performed a thorough clinical, immunohistological, and molecular analysis of nine Finnish SPTL patients. Specifically, we performed single-cell comparative genomic hybridization (CGH) from laser microdissected, morphologically malignant SPTL cells, as well as loss of heterozygosity (LOH) and fluorescence in situ hybridization (FISH) analysis for the NAV3 (neuron navigator 3) gene. CGH revealed large numbers of DNA copy number changes, the most common of which were losses of chromosomes 1pter, 2pter, 10qter, 11qter, 12qter, 16, 19, 20, and 22 and gains of chromosomes 2q and 4q. Some of the DNA copy number aberrations in SPTL, such as loss of 10q, 17p, and chromosome 19, overlap with those characteristic of common forms of CTCL (mycosis fungoides (MF) and Sezary syndrome (SS)), whereas 5q and 13q gains characterize SPTL. Allelic NAV3 aberrations (LOH or deletion by FISH), previously found in MF and SS, were identified in 44% of the SPTL samples. This study demonstrates that SPTL is also moleculocytogenetically a uniform entity of CTCL and supports the current World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification defining SPTL as a subgroup of its own.

Expression of MMP-9, MMP-10 and TNF-α and lack of epithelial MMP-1 and MMP-26 characterize pyoderma gangrenosum

Background:  Pyoderma gangrenosum (PG) is a non‐infectious, autoimmune, chronic ulcer of the skin, often co‐existing with inflammatory bowel disease (IBD). Matrix metalloproteinases (MMPs) have been implicated as mediators of tissue destruction in chronic cutaneous and intestinal wounds.

Transformation-specific matrix metalloproteinases, MMP-7 and MMP-13, are present in epithelial cells of keratoacanthomas

Keratoacanthomas are rapidly growing hyperproliferative skin tumors that may clinically or histologically be difficult to distinguish from well-differentiated squamous cell cancers (SCCs). UV light, trauma, and immune suppression represent their etiological factors. As matrix metalloproteinases (MMPs) are implicated at all stages of tumorigenesis, we investigated the expression profile of several cancer-related MMPs to find markers that would differentiate keratoacanthomas from SCCs and shed light to the pathobiology of keratoacanthoma. Samples from 31 keratoacanthomas and 15 grade I SCCs were studied using immunohistochemistry for MMP-2, -7, -8, -9, -10, -13, and -19 and p16 and laminin-5γ2 chain. In situ hybridization for MMP-7, -10, and -13 was performed in a subset of tumors. Keratinocytes with atypia, presence of neovascularization, and composition of the inflammatory infiltrate were graded from hematoxylin–eosin stainings. MMP-7 was present in the epithelium of 4/31 keratoacanthomas and 9/15 SCCs, MMP-8 in 3/30 keratoacanthomas and 0/15 SCCs, but MMP-13 in 16/31 keratoacanthomas and 10/15 SCCs, and MMP-10 in 28/31 keratoacanthomas and all cancers. MMP-9 was detected in the epithelium in 5/31 keratoacanthomas and 8/15 SCCs, whereas MMP-2 was only present in fibroblasts in both tumors. MMP-19 was upregulated in proliferating epithelium of keratoacanthomas as was p16. Cytoplasmic laminin-5γ2 was particularly abundant in keratinocytes at the pushing border of MMP-13-positive keratoacanthomas. We conclude that although some MMPs (MMP-10 and -13) are abundantly expressed in keratoacanthomas, the presence of MMP-7 and -9 in their epithelial pushing border is rare and should raise suspicion of SCC. Further, the loss of MMP-19 and p16 could aid in making the differential diagnosis between well-differentiated SCC and keratoacanthoma. Frequent expression of the transformation-specific MMP-13 in keratoacanthomas suggests that they are not benign tumors but incomplete SCCs.

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

Abstract:  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. MMP‐21 mRNA was found in THP‐1, U937, HEL 299 and Hs68 cells. Furthermore, MMP‐21 protein was detected by immunohistochemistry in cultures of the same cell lines. In culture MMP‐21 was upregulated by phorbol myristate acetate in THP‐1 cells and by retinoic acid (RA) in U937 cells, and downregulated by transforming growth factor beta 1 (TGF‐β1) in HEL 299 as assessed by Taqman quantitative polymerase chain reaction (PCR). Expression of MMP‐26 was detected by immunohistochemistry in granulomatous skin diseases and actinic elastosis. MMP‐26 at both mRNA and protein levels was only found in HEL 299 cells. In culture it was downregulated by TGF‐β1, RA and IL‐1β as assessed by Taqman quantitative PCR. Our results suggest these two novel MMPs are not only associated with cancer but may be important in connective tissue remodelling and pathobiology of various benign skin disorders.