Human collagenase-3 is expressed in malignant squamous epithelium of the skin

Inhibition of TGF-β signaling, invasion, and growth of cutaneous squamous cell carcinoma by PLX8394

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer. The prognosis of patients with metastatic cSCC is poor emphasizing the need for new therapies. We have previously reported that the activation of Ras/MEK/ERK1/2 and transforming growth factor β (TGF-β)/Smad2 signaling in transformed keratinocytes and cSCC cells leads to increased accumulation of laminin-332 and accelerated invasion. Here, we show that the next-generation B-Raf inhibitor PLX8394 blocks TGF-β signaling in ras-transformed metastatic epidermal keratinocytes (RT3 cells) harboring wild-type B-Raf and hyperactive Ras. PLX8394 decreased phosphorylation of TGF-β receptor II and Smad2, as well as p38 activity, MMP-1 and MMP-13 synthesis, and laminin-332 accumulation. PLX8394 significantly inhibited the growth of human cSCC tumors and in vivo collagen degradation in xenograft model. In conclusion, our data indicate that PLX8394 inhibits several serine-threonine kinases in malignantly transformed human keratinocytes and cSCC cells and inhibits cSCC invasion and tumor growth in vitro and in vivo. We identify PLX8394 as a potential therapeutic compound for advanced human cSCC.

Super Enhancer-Regulated LINC00094 (SERLOC) Upregulates the Expression of MMP-1 and MMP-13 and Promotes Invasion of Cutaneous Squamous Cell Carcinoma

Long non-coding RNAs (lncRNAs) have emerged as important regulators of cancer progression. Super enhancers (SE) play a role in tumorigenesis and regulate the expression of specific lncRNAs. We examined the role of BRD3OS, also named LINC00094, in cutaneous squamous cell carcinoma (cSCC). Elevated BRD3OS (LINC00094) expression was detected in cSCC cells, and expression was downregulated by SE inhibitors THZ1 and JQ1 and via the MEK1/ERK1/2 pathway. Increased expression of BRD3OS (LINC00094) was noted in tumor cells in cSCCs and their metastases compared to normal skin, actinic keratoses, and cSCCs in situ. Higher BRD3OS (LINC00094) expression was noted in metastatic cSCCs than in non-metastatic cSCCs. RNA-seq analysis after BRD3OS (LINC00094) knockdown revealed significantly regulated GO terms Cell-matrix adhesion, Basement membrane, Metalloendopeptidase activity, and KEGG pathway Extracellular matrix–receptor interaction. Among the top-regulated genes were MMP1, MMP10, and MMP13. Knockdown of BRD3OS (LINC00094) resulted in decreased production of MMP-1 and MMP-13 by cSCC cells, suppressed invasion of cSCC cells through collagen I, and growth of human cSCC xenografts in vivo. Based on these observations, BRD3OS (LINC00094) was named SERLOC (super enhancer and ERK1/2-Regulated Long Intergenic non-protein coding transcript Overexpressed in Carcinomas). These results reveal the role of SERLOC in cSCC invasion and identify it as a potential therapeutic target in advanced cSCC.

Matrix Effectors in the Pathogenesis of Keratinocyte-Derived Carcinomas

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), referred to as keratinocyte carcinomas, are skin cancer with the highest incidence. BCCs, rarely metastasize; whereas, though generally not characterized by high lethality, approximately 2–4% of primary cSCCs metastasize with patients exhibiting poor prognosis. The extracellular matrix (ECM) serves as a scaffold that provides structural and biological support to cells in all human tissues. The main components of the ECM, including fibrillar proteins, proteoglycans (PGs), glycosaminoglycans (GAGs), and adhesion proteins such as fibronectin, are secreted by the cells in a tissue-specific manner, critical for the proper function of each organ. The skin compartmentalization to the epidermis and dermis compartments is based on a basement membrane (BM), a highly specialized network of ECM proteins that separate and unify the two compartments. The stiffness and assembly of BM and tensile forces affect tumor progenitors' invasion at the stratified epithelium's stromal border. Likewise, the mechanical properties of the stroma, e.g., stiffness, are directly correlated to the pathogenesis of the keratinocyte carcinomas. Since the ECM is a pool for various growth factors, cytokines, and chemokines, its' intense remodeling in the aberrant cancer tissue milieu affects biological functions, such as angiogenesis, adhesion, proliferation, or cell motility by regulating specific signaling pathways. This review discusses the structural and functional modulations of the keratinocyte carcinoma microenvironment. Furthermore, we debate how ECM remodeling affects the pathogenesis of these skin cancers.

C1r Upregulates Production of Matrix Metalloproteinase-13 and Promotes Invasion of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer with increasing incidence worldwide. Previous studies have demonstrated the role of complement system in cSCC progression. In this study we have investigated the mechanistic role of serine protease C1r, a component of the classical pathway of complement system, in cSCC. Knockout of C1r in cSCC cells using CRISPR/Cas9 resulted in significant decrease in their proliferation, migration, and invasion through collagen type I compared to wild type cSCC cells. Knockout of C1r suppressed growth and vascularization of cSCC xenograft tumors, and promoted apoptosis of tumor cells in vivo. mRNA-seq analysis after C1r knockdown revealed significantly regulated GO terms Cell-matrix adhesion, Extracellular matrix component, Basement membrane, Metalloendopeptidase activity and KEGG pathway Extracellular matrix-receptor interaction. Among the significantly regulated genes were invasion-associated matrix metalloproteinases MMP1, MMP13, MMP10, and MMP12. Knockout of C1r resulted in decreased production of MMP-1, MMP-13, MMP-10, and MMP-12 by cSCC cells in culture. Knockout of C1r inhibited expression of MMP-13 by tumor cells, suppressed invasion, and reduced the amount of degraded collagen in vivo in xenografts. These results provide evidence for the role of C1r in promoting the invasion of cSCC cells by increasing MMP production.

Design and Synthesis of Water-Soluble and Potent MMP-13 Inhibitors with Activity in Human Osteosarcoma Cells

Osteoarthritis is a degenerative disease, often resulting in chronic joint pain and commonly affecting elderly people. Current treatments with anti-inflammatory drugs are palliative, making the discovery of new treatments necessary. The inhibition of matrix metalloproteinase MMP-13 is a validated strategy to prevent the progression of this common joint disorder. We recently described polybrominated benzotriazole derivatives with nanomolar inhibitory activity and a promising selectivity profile against this collagenase. In this work, we have extended the study in order to explore the influence of bromine atoms and the nature of the S1′ heterocyclic interacting moiety on the solubility/selectivity balance of this type of compound. Drug target interactions have been assessed through a combination of molecular modeling studies and NMR experiments. Compound 9a has been identified as a water-soluble and highly potent inhibitor with activity in MG-63 human osteosarcoma cells.

Complement factor I upregulates expression of matrix metalloproteinase-13 and -2 and promotes invasion of cutaneous squamous carcinoma cells

The incidence of cutaneous squamous cell carcinoma (cSCC) is increasing globally. Here, we have studied the functional role of complement factor I (CFI) in the progression of cSCC. CFI was knocked down in cSCC cells, and RNA-seq analysis was performed. Significant downregulation of genes in IPA biofunction categories Proliferation of cells and Growth of malignant tumor, in Gene Ontology (GO) terms Metallopeptidase activity and Extracellular matrix component, as well as Reactome Degradation of extracellular matrix was detected after CFI knockdown. Further analysis of the latter three networks, revealed downregulation of several genes coding for invasion-associated matrix metalloproteinases (MMPs) after CFI knockdown. The downregulation of MMP-13 and MMP-2 was confirmed at mRNA, protein and tissue levels by qRT-qPCR, Western blot and immunohistochemistry, respectively. Knockdown of CFI decreased the invasion of cSCC cells through type I collagen. Overexpression of CFI in cSCC cells resulted in enhanced production of MMP-13 and MMP-2 and increased invasion through type I collagen and Matrigel, and in increased ERK1/2 activation and cell proliferation. Altogether, these findings identify a novel mechanism of action of CFI in upregulation of MMP-13 and MMP-2 expression and cSCC invasion. These results identify CFI as a prospective molecular marker for invasion and metastasis of cSCC.

Loss of retinoic acid receptor-related receptor alpha (Rorα) promotes the progression of UV-induced cSCC

Cutaneous squamous cell carcinoma (cSCC) is prevalent in the world, accounting for a huge part of non-melanoma skin cancer. Most cSCCs are associated with a distinct pre-cancerous lesion, the actinic keratosis (AK). However, the progression trajectory from normal skin to AK and cSCC has not been fully demonstrated yet. To identify genes involved in this progression trajectory and possible therapeutic targets for cSCC, here we constructed a UV-induced cSCC mouse model covering the progression from normal skin to AK to cSCC, which mimicked the solar UV radiation perfectly using the solar-like ratio of UVA and UVB, firstly. Then, transcriptome analysis and a series of bioinformatics analyses and cell experiments proved that Rorα is a key transcript factor during cSCC progression. Rorα could downregulate the expressions of S100a9 and Sprr2f in cSCC cells, which can inhibit the proliferation and migration in cSCC cells, but not the normal keratinocyte. Finally, further animal experiments confirmed the inhibitory effect of cSCC growth by Rorα in vivo. Our findings showed that Rorα would serve as a potential novel target for cSCC, which will facilitate the treatment of cSCC in the future.

Matrix metalloproteinases in keratinocyte carcinomas

The incidence of cutaneous keratinocyte-derived cancers is increasing globally. Basal cell carcinoma (BCC) is the most common malignancy worldwide, and cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer. BCC can be classified into subtypes based on the histology, and these subtypes are classified further into low- and high-risk tumors. There is an increasing need to identify new therapeutic strategies for the treatment of unresectable and metastatic cSCC, and for aggressive BCC variants such as infiltrating, basosquamous or morpheaform BCCs. The most important risk factor for BCC and cSCC is solar UV radiation, which causes genetic and epigenetic alterations in keratinocytes. Similar gene mutations are noted already in sun-exposed normal skin emphasizing the role of the alterations in the tumor microenvironment in the progression of cSCC. Early events in cSCC progression are alterations in the composition of basement membrane and dermal extracellular matrix induced by influx of microbes, inflammatory cells and activated stromal fibroblasts. Activated fibroblasts promote inflammation and produce growth factors and proteolytic enzymes, including matrix metalloproteinases (MMPs). Transforming growth factor-β produced by tumor cells and fibroblasts induces the expression of MMPs by cSCC cells and promotes their invasion. Fibroblast-derived keratinocyte growth factor suppresses the malignant phenotype of cSCC cells by inhibiting the expression of several MMPs. These findings emphasize the importance of interplay of tumor and stromal cells in the progression of cSCC and BCC and suggest tumor microenvironment as a therapeutic target in cSCC and aggressive subtypes of BCC.

Silencing matrix metalloproteinase-13 (Mmp-13) reduces inflammatory bone resorption associated with LPS-induced periodontal disease in vivo

OBJECTIVES

The aim of this study was to evaluate the effect of specific inhibition of MMP-13 on inflammation and inflammatory bone resorption in a murine model of lipopolysaccharide (LPS)-induced periodontitis.

MATERIALS AND METHODS

Periodontitis was induced in mice by micro-injections of LPS into the gingival tissues adjacent to the palatal surfaces of maxillary molars twice a week for 15 days. Matrix metalloproteinase-13 (Mmp-13) shRNA or a specific biochemical inhibitor were also injected into the same sites in alternating days with the LPS injections. Efficacy of shRNA-mediated silencing of Mmp-13 was verified by quantitative real-time polymerase chain reaction (qPCR) and immunoblot. Bone resorption was assessed by microcomputed tomography (uCT). Histological sections stained with hematoxylin/eosin (H/E) were used in the stereometric analysis of the inflammatory infiltrate. Gingival tissues were used to evaluate expression of Mmp-13, Il-6, Tnf-α, Ptgs2, and Rankl (qPCR). Protein levels of TGF-β and IL-10 in the tissues were determined by enzyme-linked immunosorbent assays (ELISA) or by MMP-13 and p38 immunoblot.

RESULTS

Silencing Mmp-13 expression reduced bone resorption significantly. Expression of Mmp-13, Il-6, and Tnf-α, as well as the protein levels of IL-6 and TNF-α, was reduced in the animals treated with adenovirus-delivered shRNA; however, these effects were not associated with modulation of p38 MAPK signaling. Interestingly, inhibition Mmp-13 did not affect the severity of inflammatory infiltrate.

CONCLUSIONS

Site-specific inhibition of MMP-13 reduced bone resorption and production of inflammatory mediators associated with periodontal disease.

CLINICAL RELEVANCE

The results suggest that site-specific inhibition of MMP-13 may be an interesting strategy to modulate inflammation and reduce bone resorption in osteolytic inflammatory diseases.

p53-Regulated Long Noncoding RNA PRECSIT Promotes Progression of Cutaneous Squamous Cell Carcinoma via STAT3 Signaling

Long noncoding RNAs (lncRNAs) have emerged as putative biomarkers and therapeutic targets in cancer. The role of lncRNA LINC00346 in cutaneous squamous carcinoma (cSCC) was examined. The expression of LINC00346 was up-regulated in cSCC cells compared with normal human epidermal keratinocytes. Elevated expression of LINC00346 was noted in tumor cells in cSCC tissue sections in vivo, as compared with cSCC in situ, and actinic keratosis by RNA in situ hybridization; and the expression in seborrheic keratosis and normal skin was very low. Immunohistochemical analysis of cSCC tissue sections and functional assays of cSCC cells in culture showed that LINC00346 expression is down-regulated by p53. Knockdown of LINC00346 inhibited invasion of cSCC cells in culture and suppressed growth of human cSCC xenografts in vivo. Knockdown of LINC00346 inhibited expression of activated STAT3 and resulted in down-regulation of the expression of matrix metalloproteinase (MMP)-1, MMP-3, MMP-10, and MMP-13. Based on these observations LINC00346 was named p53 regulated carcinoma-associated STAT3-activating long intergenic non-protein coding transcript (PRECSIT). These results identify PRECSIT as a new p53-regulated lncRNA, which promotes progression of cSCC via STAT3 signaling.

New perspectives on role of tumor microenvironment in progression of cutaneous squamous cell carcinoma

Epidermal keratinocyte-derived cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer, and its incidence is increasing worldwide. Solar UV radiation is an important risk factor for cSCC and leads to genetic and epigenetic changes both in epidermal keratinocytes and dermal cells. Tumor cells in cutaneous cSCCs typically harbor several driver gene mutations, but epidermal keratinocytes in sun-exposed normal skin also contain mutations in these same genes. Therefore, alterations in the microenvironment of premalignant lesions are evidently required for their progression to invasive and metastatic cSCC. For example, alterations in the composition of basement membrane and dermal extracellular matrix are early events in cSCC progression. The presence of microbial structures and the influx of inflammatory cells promote the secretion of proteases, which in turn regulate the availability of growth factors, cytokines, and chemokines and thus influence the growth and invasion of cSCC. Together, these observations emphasize the role of the tumor microenvironment in the progression of cSCC and identify it as a novel therapeutic target in cSCC and other malignant tumors. Graphical abstract Tumor-stroma interactions in the progression of cutaneous squamous cell carcinoma (cSCC). Epidermal layer is separated by a well-organized basement membrane (BM) from the dermal layer. UV radiation, other environmental insults, and aging target both epidermal keratinocytes and dermal fibroblasts and lead to genetic and epigenetic changes in these cells. In addition, epidermal keratinocytes in normal sun-exposed skin harbor several mutations in the cSCC driver genes. During transition to premalignant actinic keratosis (AK), the differentiation of keratinocytes is disturbed resulting in a neoplastic epithelium with hyperplastic cells. Expression of proteinases, such as matrix metalloproteinases (MMP) by neoplastic cells and activated stromal fibroblasts and macrophages is induced in AK, and collagen XV and XVIII are lost from the dermal BM. Furthermore, inflammatory cells accumulate at the site of the hyperplastic epithelium. During a later stage of cSCC progression, the number of inflammatory cells increases, and the expression of complement components and inhibitors by tumor cells is induced (CFI complement factor I, CFH complement factor H, FHL-1 Factor H-like protein 1). In addition to MMPs, activated fibroblasts also produce growth factors and promote inflammation, growth, and invasion of tumor cells.

Cutaneous Squamous Cell Carcinoma with Invasion through Ear Cartilage

Cutaneous squamous cell carcinoma of the ear represents a high-risk tumor location with an increased risk of metastasis and local tissue invasion. However, it is uncommon for these cancers to invade through nearby cartilage. Cartilage invasion is facilitated by matrix metalloproteases, specifically collagenase 3. We present the unusual case of a 76-year-old man with an auricular squamous cell carcinoma that exhibited full-thickness perforation of the scapha cartilage. Permanent sections through the eroded cartilage confirmed tumor invasion extending to the posterior ear skin.

MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma

Introduction

Several matrix metalloproteinases (MMPs) are overexpressed in lung cancer and may serve as potential targets for the development of bioactivable probes for molecular imaging.

Objective

To characterize and monitor the activity of MMPs during the progression of lung adenocarcinoma.

Methods

K-ras^LSL-G12D mice were imaged serially during the development of adenocarcinomas using fluorescence molecular tomography (FMT) and a probe specific for MMP-2, -3, -9 and -13. Lung tumors were identified using FMT and MRI co-registration, and the probe concentration in each tumor was assessed at each time-point. The expression of Mmp2, -3, -9, -13 was quantified by qRT-PCR using RNA isolated from microdissected tumor cells. Immunohistochemical staining of overexpressed MMPs in animals was assessed on human lung tumors.

Results

In mice, 7 adenomas and 5 adenocarcinomas showed an increase in fluorescent signal on successive FMT scans, starting between weeks 4 and 8. qRT-PCR assays revealed significant overexpression of only Mmp-13 in mice lung tumors. In human tumors, a high MMP-13 immunostaining index was found in tumor cells from invasive lesions (24/27), but in none of the non-invasive (0/4) (p=0.001).

Conclusion

MMP-13 is detected in early pulmonary invasive adenocarcinomas and may be a potential target for molecular imaging of lung cancer.

EphB2 Promotes Progression of Cutaneous Squamous Cell Carcinoma

Keratinocyte-derived skin cancer, cutaneous squamous cell carcinoma (cSCC), is the most common metastatic skin cancer. We have examined the role of Eph/ephrin signaling in the progression of cSCC. Analysis of the expression of EPH and EFN families in cSCC cells and normal epidermal keratinocytes revealed overexpression of EPHB2 mRNA in cSCC cells and cSCC tumors in vivo. Tumor cell-specific overexpression of EphB2 was detected in human cSCCs and in chemically induced mouse cSCCs with immunohistochemistry, whereas the expression of EphB2 was low in premalignant lesions and normal skin. Knockdown of EphB2 expression in cSCC cells suppressed growth and vascularization of cSCC xenografts in vivo and inhibited proliferation, migration, and invasion of cSCC cells in culture. EphB2 knockdown downregulated expression of genes associated with biofunctions cell viability, migration of tumor cells, and invasion of tumor cells. Among the genes most downregulated by EphB2 knockdown were MMP1 and MMP13. Moreover, activation of EphB2 signaling by ephrin-B2-Fc enhanced production of invasion proteinases matrix metalloproteinase-13 (MMP13) and MMP1, and invasion of cSCC cells. These findings provide mechanistic evidence for the role of EphB2 in the early progression of cSCC to the invasive stage and identify EphB2 as a putative therapeutic target in this invasive skin cancer.

Effects of selective MMP-13 inhibition in squamous cell carcinoma depend on estrogen

Matrix metalloproteinases like MMP-13 cleave and remodel the extracellular matrix and thereby play a crucial role in tumor progression in vivo. Using a highly selective inhibitor to block MMP-13 protein activity, we demonstrate a striking inhibitory effect on invasive tumor growth and vascularization in murine skin squamous cell carcinoma (SCC). Therapy outcome critically depends on animal age in C57Bl/6 mice and was successful in old female but not in young female mice. Treatment success was recovered by ovariectomy in young and abolished by 17ß-estradiol supplementation in old mice, suggesting a hormone dependent inhibitor effect. Responsiveness of the tumorigenic keratinocytes BDVII and fibroblasts to 17ß-estradiol was confirmed in vitro, where MMP-13 inhibitor treatment led to a reduction of cell invasion and vascular endothelial growth factor (VEGF) release. This correlated well with a less invasive and vascularized tumor in treated mice in vivo. 17ß-estradiol supplementation also reduced invasion and VEGF release in vitro with no additional reduction on MMP-13 inhibitor treatment. This suggests that low 17ß-estradiol levels in old mice in vivo lead to enhanced MMP-13 levels and VEGF release, allowing a more effective inhibitor treatment compared to young mice. In our study, we present a strong link between lower estrogen levels in old female mice, an elevated MMP-13 level, which results in a more effective MMP-13 inhibitor treatment in fibroblasts and SCC cells in vitro and in vivo.

Histopathology of Keratoacanthoma Revisited

Background/Aims. Given the defining histopathologic architecture of keratoacanthoma (KA), the aim of this study was to measure the crateriform orifice (“orificial size”) in histopathologically crateriform lesions to ascertain its utility as an objective diagnostic histopathologic adjunct. Methods. This cross-sectional, retrospective study included 97 cases with a histopathologic diagnosis of KA. We measured the “orificial size” using the ocular micrometer in a BH-2 Olympus microscope at 4× magnification, in a blinded manner with respect to information. Frequency of histopathologic features observed was also recorded. Results. The average orificial size for different groups was as follows: 2.3 ± 0.2 mm for cases with a clinical presentation of KA/keratotic papule (KP) (n = 30) versus 2.9 ± 0.3 mm for other (n = 67), P = .18. Histopathologic findings in the 2 groups were as follows: crateriform architecture/epithelial lip and sharp demarcation of tumor from stroma (100% in both groups), fibrosis (29/30 vs 64/67), apoptotic keratinocytes (27/30 vs 56/67), dermal islands of “glassy” keratinocytes (26/30 vs 54/67), entrapped elastic fibers (26/30 vs 49/67), and neutrophilic abscesses (11/30 vs 21/670 [ P = not significant for all]. Conclusion. Our findings indicate that, in the appropriate clinical setting, a smaller orificial size, although predictive of a KA, in itself is not sufficient for a definitive diagnosis. Given that a major limitation is that this is a function of age of the lesion as orificial size depends on the evolution stage of the neoplasm with the largest diameter often evident in lesions at early stages of regression, for now correlation with histopathologic features such as presence of an epithelial lip, sharp demarcation of tumor from stroma, and fibrosis (present in >95% of cases of KAs) is required.

Expression of matrix metalloproteinase-13 and Ki-67 in nonmelanoma skin cancer in xeroderma pigmentosum and non-xeroderma pigmentosum

Xeroderma pigmentosum (XP) is a heterogenous group of genetic diseases in which basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer (NMSC) followed by squamous cell carcinoma (SCC). The aim of this study was to investigate the expression of matrix metalloproteinase (MMP)-13 and Ki-67 in SCC and BCC from patients with and without XP to elucidate their roles in the pathogenesis of these highly aggressive tumors in patients with XP. Immunolabeling using MMP-13 and Ki-67 antibodies was performed on tissue sections derived from skin biopsies of SCC and BCC of 15 patients with XP and 40 non-XP patients. There was no significant difference between XP and non-XP patients as regards MMP-13 expression by epithelial and stromal cells of SCC or BCC. Ki-67 expression in SCC and BCC of patients with XP was significantly higher than in non-XP patients. We concluded that the higher expression of Ki-67 in NMSC of patients with XP than of non-XP patients may reflect the growth and invasive capacity of these tumors in patients with XP. MMP-13 is expressed by tumor epithelial cells, stromal and inflammatory cells of NMSC of both XP and non-XP patients.

Bone marrow-derived myofibroblasts are the providers of pro-invasive matrix metalloproteinase 13 in primary tumor

Carcinoma-associated fibroblasts are key contributors of the tumor microenvironment that regulates carcinoma progression. They consist of a heterogeneous cell population with diverse origins, phenotypes, and functions. In the present report, we have explored the contribution of bone marrow (BM)-derived cells to generate different fibroblast subsets that putatively produce the matrix metalloproteinase 13 (MMP13) and affect cancer cell invasion. A murine model of skin carcinoma was applied to mice, irradiated, and engrafted with BM isolated from green fluorescent protein (GFP) transgenic mice. We provide evidence that one third of BM-derived GFP(+) cells infiltrating the tumor expressed the chondroitin sulfate proteoglycan NG2 (pericytic marker) or α-smooth muscle actin (α-SMA, myofibroblast marker), whereas almost 90% of Thy1(+) fibroblasts were originating from resident GFP-negative cells. MMP13producing cells were exclusively α-SMA(+) cells and derived from GFP(+) BM cells. To investigate their impact on tumor invasion, we isolated mesenchymal stem cells (MSCs) from the BM of wild-type and MMP13-deficient mice. Wild-type MSC promoted cancer cell invasion in a spheroid assay, whereas MSCs obtained from MMP13-deficient mice failed to. Our data support the concept of fibroblast subset specialization with BM-derived α-SMA(+) cells being the main source of MMP13, a stromal mediator of cancer cell invasion.

Suppressive effect of calcipotriol on the induction of matrix metalloproteinase (MMP)-9 and MMP-13 in a human squamous cell carcinoma cell line

BACKGROUND

Vitamin D3 is a potent regulator of cell growth, differentiation and death, tumour invasion, and angiogenesis. Production of matrix metalloproteinase (MMP)-9 and MMP-13 by tumour cells may promote tumour growth, invasion and metastasis.

AIM

To investigate whether calcipotriol could suppress the expression of MMP-9 and MMP-13 in a human squamous cell carcinoma (SCC) cell line (DJM cells), and to examine the mechanism of modulation of MMP-9 and MMP-13 by calcipotriol in DJM cells treated with tumour necrosis factor (TNF)-α.

METHODS

Protein and mRNA levels of MMP-9 and MMP-13 were examined by ELISA and real-time PCR, respectively. Activation of signalling cascades was assessed using several inhibitors of signalling molecules and western blot analysis.

RESULTS

Production of MMP-9 and MMP-13 markedly increased when the cells were treated with TNF-α. Calcipotriol suppressed the production of MMP-9 and MMP-13 mRNA and proteins significantly, in a dose-dependent manner. Induction of MMP-9 by TNF-α was suppressed by an extracellular signal-regulated kinase (ERK) inhibitor but not by a p38 inhibitor, whereas induction of MMP-13 was inhibited by a p38 inhibitor but not by an ERK inhibitor. Calcipotriol inhibited the phosphorylation of both ERK and p38, as shown by western blotting.

CONCLUSION

Calcipotriol reduces MMP-9 and MMP-13 production through inhibiting the phosphorylation of ERK and p38, respectively.

MicroRNA-125b down-regulates matrix metallopeptidase 13 and inhibits cutaneous squamous cell carcinoma cell proliferation, migration, and invasion

Cutaneous squamous cell carcinoma (cSCC) is the second most common human cancer. Although dysregulation of microRNAs (miRNAs) is known to be involved in a variety of cancers, the role of miRNAs in cSCC is unclear. In this study, we aimed to identify tumor suppressive and oncogenic miRNAs involved in the pathogenesis of cSCC. MiRNA expression profiles in healthy skins (n = 4) and cSCCs (n = 4) were analyzed using MicroRNA Low Density Array. MiR-125b expression was analyzed by quantitative real-time PCR and in situ hybridization in skin biopsies from 40 healthy donors, 13 actinic keratosis, and 74 cSCC patients. The effect of miR-125b was analyzed in wound closure, colony formation, migration, and invasion assays in two cSCC cell lines, UT-SCC-7 and A431. The genes regulated by miR-125b in cSCC were identified by microarray analysis and its direct target was validated by luciferase reporter assay. Comparing cSCC with healthy skin, we identified four up-regulated miRNAs (miR-31, miR-135b, miR-21, and miR-223) and 54 down-regulated miRNAs, including miR-125b, whose function was further examined. We found that miR-125b suppressed proliferation, colony formation, migratory, and invasive capacity of cSCC cells. Matrix metallopeptidase 13 (MMP13) was identified as a direct target suppressed by miR-125b, and there was an inverse relationship between the expression of miR-125b and MMP13 in cSCC. Knockdown of MMP13 expression phenocopied the effects of miR-125b overexpression. These findings provide a novel molecular mechanism by which MMP13 is up-regulated in cSCCs and indicate that miR-125b plays a tumor suppressive role in cSCC.

Differential expression patterns of MMPs and their role in the invasion of epithelial premalignant tumors and invasive cutaneous squamous cell carcinoma

Co-expression of several members of the matrix metalloproteinase (MMP) family is characteristic of human malignant tumors. MMP-2, MMP-9, TIMP-2, and MT1-MMP are thought to be involved in the process of destruction of basement membranes and stromal invasion by neoplastic epithelial cells. In this study, we investigated the expression and role of MMPs in cutaneous oncogenesis. Tissue microarray consisting of 62 squamous cell carcinomas (SCC), 32 Bowen's disease (BD) samples, 25 normal epidermis samples were obtained for the study. MMP-2,-9, MT1-MMP and TIMP-2 proteins were examined by immunohistochemical staining and mRNA level was detected by quantitative RT-PCR in fresh tissues consisting of 5 cutaneous SCCs and paired normal epidermis samples. Gelatinase activity of MMP-2 and MMP-9 was investigated by gelatin zymography and protein levels of MT1-MMP and TIMP-2 were measured by western blot in 2 human SCC cell lines. The invasive property was evaluated with invasion assays using Transwell filters. SCC exhibited significantly increased MMP-2, MT1-MMP and decreased TIMP-2 mRNA and protein expression compared to that of the normal epithelium. Immunohistochemical staining revealed that MT1-MMP was strongly expressed on the invasive front of SCCs, whereas BD exhibited higher expression around the dyskeratotic cells in the epithelium. In comparison with the expression observed in BD, SCC exhibited significantly increased MMP-2 expression. In addition, high MMP-2 and MT1-MMP expression and low TIMP-2 expression had a significant positive correlation with the invasiveness of SCC cell lines in vitro. Our results revealed significantly increased MT1-MMP and MMP-2 expression and decreased TIMP-2 expression in cutaneous SCC, and the expression correlated with the invasiveness of SCC cell lines. Therefore, the expression of these factors in cutaneous tumors may serve as an indicator of tumor aggressiveness and invasion.

Dissection of Wnt5a-Ror2 signaling leading to matrix metalloproteinase (MMP-13) expression

It has been shown that constitutively active Wnt5a-Ror2 signaling in osteosarcoma cell lines plays crucial roles in induced expression of matrix metalloproteinase-13 (MMP-13), required for their invasiveness; however, it remains largely unclear about the molecular basis of MMP-13 gene induction by Wnt5a-Ror2 signaling. Here we show by reporter assay that the activator protein 1 (AP1) (binding site in the promoter region of MMP-13 gene is primarily responsible for its transcriptional activation by Wnt5a-Ror2 signaling in osteosarcoma cell lines SaOS-2 and U2OS. Chromatin immunoprecipitation assays revealed that c-Jun and ATF2 are crucial transcription factors recruited to the AP1-binding site in the MMP-13 gene promoter during Wnt5a-Ror2 signaling in SaOS-2 cells. Using siRNA-mediated suppression or specific inhibitors, we also show that Dishevelled2 (Dvl2) and c-Jun N-terminal kinase are required for MMP-13 gene induction presumably via phosphorylation of c-Jun and ATF2 during Wnt5a-Ror2 signaling in SaOS-2 cells. Interestingly, Dvl2 and Rac1, but not Dvl3, are required for MMP-13 expression in SaOS-2 cells, whereas Dvl3, but not Dvl2 and Rac1, is required for its expression in U2OS cells, indicating the presence of distinct intracellular signaling machineries leading to expression of the same gene, in this case MMP-13 gene in different osteosarcoma cell lines. Moreover, we provide evidence suggesting that Wnt5a-Ror2 signaling might also be required for expression of MMP-13 gene during the development of the cartilaginous tissue.

Human matrix metalloproteinases: an ubiquitarian class of enzymes involved in several pathological processes

Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes.

Host-derived MMP-13 exhibits a protective role in lung metastasis of melanoma cells by local endostatin production

Background:

Although matrix metalloproteinases (MMPs) are implicated in tumourigenesis and cancer progression, the role of MMP-13 in melanoma cell metastases is poorly understood.

Methods:

Lung metastases of mouse melanoma B16BL6 cells were analysed in MMP-13 knockout (KO) and wild-type (WT) mice after intravenous injection. The mRNA and protein expression of MMP-13 in lung tissues was analysed by RT–PCR, real-time PCR, immunoblotting and immunohistochemistry. The expression of SDF-1α, CXCR4 and endostatin, and effects of endostatin to cultured melanoma cells and lung metastases were also studied.

Results:

Lung metastases of B16BL6 cells were significantly higher by 2.5–5.7-fold in MMP-13 KO mice than in WT mice. The expression of MMP-13 in WT mouse lung tissue was stimulated on day 1 after intravenous injection of the melanoma cells and MMP-13 was immunolocalised to vascular endothelial cells in the lungs. Endostatin formation, but not degradation of SDF-1α, in the lung tissue was associated with reduced lung metastasis in WT mice. Endostatin significantly inhibited migration of B16BL6 cells in monolayer wounding assay and remarkably suppressed Matrigel invasion and transendothelial invasion of the cells. In addition, lung metastases of melanoma cells in MMP-13 KO mice were reduced by intraperitoneal administration of endostatin.

Conclusion:

Our results suggest that MMP-13 is overproduced by endothelial cells in the lungs with melanoma cells and has a protective role in lung metastasis by local generation of endostatin.

Serpin peptidase inhibitor clade A member 1 (SerpinA1) is a novel biomarker for progression of cutaneous squamous cell carcinoma

The incidence of keratinocyte-derived nonmelanoma skin cancers is increasing worldwide because of cumulative recreational exposure to sunlight. At present, no specific molecular markers are available for assessing the progression of premalignant actinic keratoses to invasive cutaneous squamous cell carcinoma (SCC). We examined the role of the Serpin family in skin SCCs. Expression profiling of cutaneous SCC cell lines (n = 8) revealed up-regulation of SerpinA1 compared with normal epidermal keratinocytes (n = 5). Analysis with quantitative RT-PCR showed that the mean level of SerpinA1 mRNA was markedly up-regulated in cutaneous SCC cell lines (n = 8) compared with in normal keratinocytes. SerpinA1 production by SCC cells was dependent on p38 mitogen-activated protein kinase activity and was up-regulated by epidermal growth factor, tumor necrosis factor-α, interferon-γ, and IL-1β. Immunostaining of tissue arrays with 148 human tissue samples revealed tumor cell-associated expression of SerpinA1 in 19 of 36 actinic keratoses, 22 of 29 Bowen's disease samples, 67 of 71 sporadic SCCs, and all 12 recessive dystrophic epidermolysis bullosa-associated SCCs examined. Moreover, tumor cell-associated SerpinA1 staining was detected in all chemically induced mouse skin SCCs studied (n = 17). Overexpression of SerpinA1 mRNA was also detected by quantitative RT-PCR in chemically induced mouse skin SCCs (n = 14) compared with control tissues (n = 14). These data identify SerpinA1 as a novel tumor cell-associated biomarker for progression of cutaneous SCCs.

Phenotypic overlap between MMP-13 and the plasminogen activation system during wound healing in mice

BACKGROUND

Proteolytic degradation of extracellular matrix is a crucial step in the healing of incisional skin wounds. Thus, healing of skin wounds is delayed by either plasminogen-deficiency or by treatment with the broad-spectrum metalloproteinase (MP) inhibitor Galardin alone, while the two perturbations combined completely prevent wound healing. Both urokinase-type plasminogen activator and several matrix metallo proteinases (MMPs), such as MMP-3, -9 and -13, are expressed in the leading-edge keratinocytes of skin wounds, which may account for this phenotypic overlap between these classes of proteases.

METHODOLOGY

To further test that hypothesis we generated Mmp13;Plau and Mmp13;Plg double-deficient mice in a cross between Mmp13- and Plau-deficient mice as well as Mmp13- and Plg-deficient mice. These mice were examined for normal physiology in a large cohort study and in a well-characterized skin wound healing model, in which we made incisional 20 mm-long full-thickness skin wounds.

PRINCIPAL FINDINGS

While mice that are deficient in Mmp13 have a mean healing time indistinguishable to wild-type mice, wound healing in both Plau- and Plg-deficient mice is significantly delayed. Histological analysis of healed wounds revealed a significant increase in keratin 10/14 immunoreactive layers of kerationcytes in the skin surface in Mmp13;Plau double-deficient mice. Furthermore, we observe, by immunohistological analysis, an aberrant angiogenic pattern during wound healing induced by Plau-deficiency, which has not previously been described.

CONCLUSIONS

We demonstrate a phenotypic overlap, defined as an additional delay in wound healing in the double-deficient mice compared to the individual single-deficient mice, between MMP-13 and the plasminogen activation system in the process of wound healing, but not during gestation and in postnatal development. Thus, a dual targeting of uPA and MMP-13 might be a possible future strategy in designing therapies aimed at tissue repair or other pathological processes, such as cancer invasion, where proteolytic degradation is a hallmark.

Matrix metalloproteinase-7 activates heparin-binding epidermal growth factor-like growth factor in cutaneous squamous cell carcinoma

BACKGROUND

Tumour-specific expression of matrix metalloproteinase (MMP)-7 has been noted in cutaneous squamous cell carcinomas (SCCs) in patients with recessive dystrophic epidermolysis bullosa (RDEB).

OBJECTIVES

To examine the potential role of MMP-7 in shedding of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in RDEB-associated and sporadic SCCs.

METHODS

Tissue microarrays of RDEB-associated SCC (n = 20), non-EB SCC (n = 60) and Bowen disease (n = 28) were immunostained for MMP-7, CD44 variant 3 (CD44v3) and HB-EGF. Shedding of HB-EGF was studied in vitro using two cutaneous SCC cell lines.

RESULTS

Immunohistochemical analysis showed that HB-EGF was absent in tumour cells when MMP-7 and CD44v3 colocalized, and that the absence of HB-EGF was more pronounced in RDEB-associated SCCs than in non-EB SCCs. The loss of HB-EGF in MMP-7-CD44v3 double-positive areas was interpreted to indicate shedding and activation of HB-EGF; this was also detected in Bowen disease indicating its importance in the early phase of SCC development. Specific knockdown of MMP-7 expression in human cutaneous SCC cells by small interfering RNA inhibited shedding of HB-EGF and resulted in diminished activation of the EGF receptor (EGFR) and ERK1/2, and in reduced proliferation of SCC cells.

CONCLUSIONS

These findings provide evidence for the role of MMP-7 in promoting the growth of cutaneous SCCs by shedding HB-EGF, and identify EGFR signalling as a potential therapeutic target in RDEB-associated SCC and unresectable sporadic cutaneous SCC.

Selective MMP13 inhibitors

Pharmacology of MMP13 and MMP13 selective inhibitors is reviewed.

Isolation and characterization of human monoclonal antibodies specific to MMP-1A, MMP-2 and MMP-3

Matrix metalloproteinases (MMPs), a group of more than 20 zinc-containing endopeptidases, are up-regulated in many diseases, but the use of MMP inhibitors for therapeutic purposes has often been disappointing, possibly for the limited specificity of the drugs used in clinical trials. In principle, individual MMPs could be specifically drugged by monoclonal antibodies, either by inhibition of their catalytic activity or by antibody-based pharmacodelivery strategies. In this article we describe the isolation and affinity maturation of recombinant antibodies (SP1, SP2, SP3) specific to the murine catalytic domains of MMP-1A, MMP-2 and MMP-3. These novel reagents allowed a systematic comparative immunofluorescence analysis of the expression patterns of their cognate antigens in a variety of healthy, cancerous and arthritic murine tissues. While all three MMPs were strongly expressed in tumor and arthritis specimens, MMP-1A was completely undetectable in the normal tissues tested, while MMP-2 and MMP-3 exhibited a weak expression in certain normal tissues (e.g., liver). The new antibodies may serve as building blocks for the development of antibody-based therapy strategies in mouse models of pathology.

Stromal collagenase in melanoma: a vascular connection

In this issue, Zigrino et al. report on the role of host-derived mouse collagenase-3 (matrix metalloproteinase (MMP)-13) in melanoma growth and metastasis using a mouse model that lacks MMP-13. The authors demonstrate that vascularization of cutaneous melanomas in these mice is impaired compared with that of controls. This study emphasizes the importance of stromal murine MMP-13, a functional homologue of human MMP-1, in tumor progression.

MMP13 as a stromal mediator in controlling persistent angiogenesis in skin carcinoma

Matrix metalloproteinases (MMPs) such as MMP13 promote tumour growth and progression by mediating extracellular matrix (ECM) reorganization and regulating the biological activity of cytokines. Using Mmp13-/- mice, we demonstrate an essential role of this single collagenase for highly malignant and invasive growth in skin squamous cell carcinoma (SCC). Lack of host MMP13 strongly impaired tumour growth of malignant SCC cells, leading to small, mostly avascular cysts. While initial stromal activation in tumour transplants of Mmp13+/+ and Mmp13-/- animals was similar, MMP13 was essential for maintenance of angiogenesis and for invasion. MMP13 was induced in fibroblasts of the wild-type animals at the onset of invasion and correlated with a strong increase in vascular endothelial growth factor (VEGF) protein and its association with vascular endothelial growth factor receptor-2 on endothelial cells in invasive areas. In contrast, VEGF protein in the stroma was barely detectable and tumour invasion was downregulated in Mmp13-/- animals, despite ongoing VEGF messenger RNA expression. Taken together with in vitro data showing the release of VEGF from the ECM by MMP13 expressing fibroblasts, these data strongly suggest a crucial role of MMP13 in promoting angiogenesis via releasing VEGF from the ECM and thus allowing the invasive growth of the SCC cells.

ING2 is upregulated in colon cancer and increases invasion by enhanced MMP13 expression

Inhibitor of growth 2 (ING2) is associated with chromatin remodeling and regulation of gene expression by binding to a methylated histone H3K4 residue and recruiting HDAC complexes to the region. The aim of our study is to investigate the regulation of ING2 expression and the clinical significance of upregulated ING2 in colon cancer. Here, we show that the ING2 mRNA level in colon cancer tissue increased to more than twice than that in normal mucosa in the 45% of colorectal cancer cases that we examined. A putative NF-kappaB binding site was found in the ING2 promoter region. We confirmed that NF-kappaB could bind to the ING2 promoter by EMSA and luciferase assays. Subsequent microarray analyses revealed that ING2 upregulates expression of matrix metalloproteinase 13 (MMP13), which enhances cancer invasion and metastasis. ING2 regulation of MMP13 expression was confirmed in both ING2 overexpression and knock down experiments. MMP13 expression was further induced by coexpression of ING2 with HDAC1 or with mSin3A, suggesting that the ING2-HDAC1-mSin3A complex members regulates expression of MMP13. In vitro invasion assay was performed to determine functional significance of ING2 upregulation. ING2 overexpressed cells exhibited greater invasive potential. Taken together, upregulation of ING2 was associated with colon cancer and MMP13-dependent cellular invasion, indicating that ING2 expression might be involved with cancer invasion and metastasis.

Stromal expression of MMP-13 is required for melanoma invasion and metastasis

Tumor invasion and metastasis of malignant melanoma have been shown to require proteolytic degradation of the extracellular environment achieved primarily by enzymes of the matrix metalloproteinases (MMP) family. We have earlier shown that increased enzyme activity is localized at the border of tumor cells and the adjacent peritumoral connective tissue, emphasizing the importance of tumor-stroma interactions in the regulation of MMP activity. To confirm the role of stroma-derived MMP-13 in the invasion process, we investigated the invasiveness of melanoma cells upon intradermal injection in mice with complete inactivation of MMP-13. Tumor growth was significantly impaired in mmp-13(-/-) mice and most significant at early time points as compared with wild-type littermates. Moreover, metastasis to various organs was reduced to 17.6 vs 30% in lungs, 2.9 vs 30% in the liver. Strikingly, ablation of MMP-13 completely abrogated formation of metastasis in the heart (0 vs 40%). Notably, decreased tumor growth in mmp-13(-/-) mice was associated with reduced blood vessel density. In addition, decreased blood vessel permeability in the tumors was measured by magnetic resonance imaging of tumor-bearing animals. These data suggest an important role of MMP-13 in tumor growth and an unexpected role in organ-specific metastasis of melanoma cells.

Keratinocyte expression of MMP3 enhances differentiation and prevents tumor establishment

Matrix metalloproteinase (MMP)-3 is induced by multiple cell types in the skin during processes involved in both normal and pathological tissue remodeling. We previously demonstrated that MMP3-null animals have an increased sensitivity to the development of squamous cell carcinoma, suggesting that overall, MMP3 has a protective role in squamous cell carcinoma. However, not all cellular responses affected by a loss of MMP3 are tumor-protective, and tumor expression of MMP3 is co-incident with an invasive tumor phenotype. Transgenic mice were generated with MMP3 targeted to keratinocytes to examine the biological role of tumor-produced MMP3. Overexpression of MMP3 reduced tumor multiplicity in response to chemically induced squamous cell carcinoma. Vascular density was increased with MMP3 overexpression; however, other cellular processes, including tumor growth and leukocyte infiltration, were unaffected. In accordance with the change in tumor multiplicity, SP-1 murine papilloma cell lines that were generated to stably express MMP3 lost the capacity to establish palpable tumors following orthotopic injection into immunocompromised mice. Analysis of epidermal biopsies taken at 1 to 2 weeks postinjection revealed that these MMP3-expressing Sp-1 lines had reduced levels of proliferation and pronounced differentiation. These same cells demonstrated an increased ability to differentiate in vitro, an effect that was inhibited by broad-spectrum MMP and selective MMP3 inhibition. These studies suggest that keratinocyte expression of MMP3 promotes cellular differentiation, impeding tumor establishment during tumorigenesis.

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. Furthermore, MMP-21 was induced in keratinocytes in association with increased calcium and presence of the differentiation marker filaggrin. In stably transfected A431 and HEK293 cell lines, MMP-21 increased invasion of cells but did not associate with increased apoptosis, proliferation, or epithelial-to-mesenchymal transition. Of various agents tested in HaCaT cell cultures, only retinoic acid (10(-6) M) and staurosporine (2.5 x 10(-8) M) upregulated MMP-21 mRNA and protein expression, whereas tumor promoters, hormones, or dexamethasone were without effect. Our results suggest that MMP-21 may be an important protease in the terminal differentiation of keratinocytes.

Is collagenase-3 (MMP-13) expression in chondrosarcoma of the jaws a true marker for tumor aggressiveness?

BACKGROUND

Matrix metalloproteinases (MMPs) play an important role in the modeling and remodeling of the extracellular matrix in both physiologic and pathologic states and thus plays an important role in tumor progression. Human collagenase-3 (MMP-13) is a member of matrix metalloproteinase family of enzymes that was originally identified in breast carcinomas and subsequently detected during fetal ossification and in arthritic processes.

AIM

The present study was designed to investigate the expression MMP-13 and to correlate its expression with clinicopathological parameters in chondrosarcoma of the jaws.

METHODS

Archival tumor tissues from 11 patients with chondrosarcoma of the jaws were analyzed by immunohistochemistry for the expression of MMP-13. Clinical information was obtained through the computerized retrospective database from the tumor registry between 1998 to 2006.

RESULTS

Eight of 11 cases (72.8 %) of chondrosarcomas showed a positive reaction for MMP-13, whereas two cases of normal cartilage were negative for this collagenase. As regard the clinicopathological parameters, there was no correlation between MMP-13 expression and sex, age and tumor site. While, there were significant associations between MMP-13 expression and both of mitotic counts and necrosis. On the other hand, there was a significant difference between low and high grade tumors (P < 0.05) regarding MMP-13 expression. Also, there was no significant correlation between MMP-13 expression in primary lesions and their local recurrence.

CONCLUSION

MMP-13 is expressed in the majority of chondrosarcoma of the jaws. It is also noteworthy that the expression of MMP-13 may be related to tumor biological aggressiveness and used to aid in predicting patient's poor prognosis.

L-NAME inhibits tumor cell progression and pulmonary metastasis of r/m HM-SFME-1 cells by decreasing NO from tumor cells and TNF-alpha from macrophages

Highly metastatic ras/myc-transformed serum-free mouse embryo (r/m HM-SFME-1) cells were injected subcutaneously to mice and the effects of Nomega-nitro-L-arginine methyl ester (L-NAME) on the tumor progression and pulmonary metastasis were investigated. In addition, production of nitric oxide (NO), matrix metalloproteinases (MMPs) and tumor necrosis factor-alpha (TNF-alpha) in the tumor cells and in a mouse macrophage-like cell line, J774.1 cells, was analyzed. The increase in footpad thickness was significantly smaller in the mice which were fed the L-NAME containing water (4.24+/-0.39 mg/day/mouse). The number of the tumor cells metastasized to the lungs was smaller in the L-NAME treated mice, although statistical significance was not found. Co-treatment of r/m HM-SFME-1 cells with interferon-gamma (IFN-gamma; 100 U/ml) and lipopolysaccharide (LPS; 0.5 microg/ml) significantly enhanced NO production, and the presence of L-NAME at 1 mM significantly decreased this response. In r/m HM-SFME-1 cells, MMP-2 was undetectable and MMP-9 was also very little in the basal level, and both MMPs were unaffected by the IFN-gamma and/or LPS treatments, not to mention by the L-NAME treatment. In J774.1 cells, any treatment including LPS appeared to enhance MMP-9 production, however, this upregulation was not inhibited by the additional presence of L-NAME. Production of TNF-alpha by J774.1 cells was markedly enhanced with LPS treatment, and this enhancement was significantly reduced in the presence of L-NAME. These results indicate that the inhibitory effects of L-NAME on the tumor cell progression and pulmonary metastasis could be due to suppression of NO from tumor cells and TNF-alpha from macrophages (Mol Cell Biochem, 2007).

Transformation-specific matrix metalloproteinases (MMP)-7 and MMP-13 are expressed by tumour cells in epidermolysis bullosa-associated squamous cell carcinomas

BACKGROUND

Patients with recessive dystrophic epidermolysis bullosa (RDEB) have an increased risk of developing rapidly progressive and metastatic cutaneous squamous cell carcinomas (SCC). It is unclear why these SCC behave more aggressively than sporadic SCC. Matrix metalloproteinases (MMP) are a family of endopeptidases that contribute to growth, invasion and metastasis of SCC. The role of MMP in RDEB-associated SCC is not known.

OBJECTIVES

To investigate the expression of MMP-7, MMP-13 and MMP-9 in RDEB-associated SCC in comparison with sporadic SCC and Bowen's disease.

METHODS

Immunohistochemical analysis of 25 RDEB-associated SCC, 61 sporadic SCC and 28 sporadic lesions of Bowen's disease was carried out using monoclonal antibodies for MMP-7, MMP-9, MMP-13 and E-cadherin and syndecan-1.

RESULTS

MMP-7 was detected in all RDEB-associated SCC, in tumour cells within the invasive edge, where E-cadherin and syndecan-1 were markedly diminished or absent. MMP-7 expression was also observed in 98% of sporadic SCC and in 68% of Bowen's diseases. MMP-7 staining was significantly stronger in RDEB-associated SCC than in sporadic SCC, and was most abundant in poorly differentiated tumours. MMP-13 was detected in tumour cells in 96% of RDEB-associated SCC and in all sporadic cutaneous SCC. MMP-9 was detected in the inflammatory cells in all SCC examined.

CONCLUSIONS

These results identify MMP-7 and MMP-13 as tumour cell-specific markers for SCC progression and as potential therapeutic targets in RDEB-associated SCC. The pattern of immunolabelling suggests that MMP-7 may shed E-cadherin and syndecan-1 from the SCC cell surface.

Differential expression of stromal MMP-1, MMP-9 and TIMP-1 in basal cell carcinomas of immunosuppressed patients and controls

Matrix metalloproteinases (MMPs) have an important role in the initiation, growth, and invasion of malignant tumors. Basal cell cancer (BCC) is the most common human malignancy. The risk of BCC is 10-16 times higher among organ transplant recipients compared with the nontransplanted population. The aim of this study was to compare the expression of several MMPs and their tissue inhibitors (TIMPs) in BCCs from kidney transplant recipients and controls. Expression of MMPs-1, -7, -8, -9, -10, -13, -26, and TIMPs-1 and -3 was evaluated by immunohistochemistry in 25 samples of BCC of kidney transplant recipients and 25 matched controls representing superficial and nodular subtypes. No significant differences were detected in MMP expression of BCC tumor cells between immunocompetent and immunodeficient patients. However, MMPs-1 and -9 and TIMP-1 were expressed more frequently in stromal macrophages in the BCCs of immunocompetent patients. When tumor subtypes were compared irrespective of the patient group, more MMP-1-positive fibroblasts and MMP-9-positive neutrophils were detected in the superficial subtype, while stromal MMP-10 expression was more abundant in nodular tumors. Our results suggest that abundant peritumoral expression of TIMP-1 in non-immunocompromised patients limits ECM degradation permissive for cancer cell migration.

Silver-stained nucleolar organizer regions and immunoglobulins in cutaneous squamocellular tumors

This study was conducted to elucidate the biological activity of epidermal cells in cutaneous squamocellular tumors by counting the number of silver-stained nucleolar organizer regions (AgNORs), to estimate the quantity of Ig-producing cells and the inflammatory cellular infiltrate (ICI), and to achieve a comparative evaluation. Twenty cases of actinic keratosis (AK), 20 in situ squamous cell carcinomas (ISC), and 20 invasive squamous cell carcinomas (SCCs) were assessed using a silver colloid technique. Ig-producing or binding cells and ICI were also investigated immunohistochemically. In all samples, AgNORs, Ig-producing cells, and ICI increased in proportion to the degree of malignancy. With regard to AgNORs values, a statistically significant difference was confirmed between AK and ISC (p<0.01), AK and SCC (p<0.001), and ISC and SCC (p<0.05). IgG-producing cells predominated in each case. Furthermore, a linear correlation was detected between ICI and AgNORs in AK and ISC. The significant difference in the number of AgNORs among the 3 stages of involution of SCC reinforces the value of AgNORs as a marker for malignant potential. Despite the absence of a correlation between AgNORs and the proportion of Ig-producing cells, the association between ICI and AgNORs in AK and ISC was obvious.

MMP-13 and p53 in the progression of malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNST) are sarcomas with poor prognosis and limited treatment options. Factors contributing to tumor progression are largely unknown. We therefore examined MPNST from 22 neurofibromatosis type 1 (NF1) patients, 14 non-NF1 patients, and 14 neurofibroma patients for matrix metalloproteinase 13 (MMP-13) expression. Because wild-type and mutant p53 were shown to differentially regulate MMP-13 expression, TP53 status and protein levels were also determined. MMP-13 expression was detected in 58% of MPNST and was significantly associated with recurrent MPNST (P = .019). p53 was observed in 78% of MPNST and was found to be strongly associated with MMP-13 expression (P = .005). In contrast, 14 neurofibromas lacked MMP-13 and p53 expressions. TP53 mutations were found in only 11% of MPNST and were associated with high tumor grades (P = .029). No significant association between mutant TP53 and MMP-13 was observed, indicating that other factors drive MMP-13 expression in MPNST. The presence of metastasis was linked to p53Pro(72) polymorphism (P = .041) and shorter survival. In summary, our data suggest that MMP-13 expression in nerve sheath tumors is coupled with malignant progression. Therefore, MMP-13 may serve as a marker for progression and as a therapeutic target.

Matrix metalloproteinases as mediators of tissue injury in different forms of cutaneous lupus erythematosus

BACKGROUND

Matrix metalloproteinases (MMPs) contribute to tissue destruction, regeneration, inflammation and apoptosis and several of them are upregulated by ultraviolet (UV) radiation in skin. Although some MMPs associate with organ manifestations of systemic lupus erythematosus (SLE), their role in cutaneous lupus erythematosus (LE) is elusive.

OBJECTIVES

Our aim was to evaluate the expression of MMPs in SLE, subacute cutaneous LE (SCLE) and discoid LE (DLE) skin lesions and their relation to apoptosis and epidermal changes.

METHODS

Lesional skin biopsies from 20 patients with SLE, 20 with DLE and 17 with SCLE, and from UVA/UVB-photoprovoked skin of healthy volunteers were immunostained using antibodies to multiple MMPs and tissue inhibitors of metalloproteinases (TIMPs). The TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling) method was used for detection of apoptosis.

RESULTS

MMP-3, -10, -19 and -26 were abundantly expressed by keratinocytes in SLE, DLE and SCLE skin samples. MMP-7 was detected in keratinocytes in regions of oedema and vacuolization especially in SLE and SCLE, while MMP-14 was only occasionally observed in keratinocytes. Photoprovocation did not induce MMP-10 or -26 expression in skin of healthy volunteers. Epithelial TIMP-1 expression was low while occasional positive fibroblasts were seen in the dermis. TIMP-3 was abundantly expressed in the epidermis, endothelial cells and macrophages.

CONCLUSIONS

Different subtypes of cutaneous LE are fairly similar in their MMP expression profile. MMP-3 and -10 mediate both epidermal changes and dermal tissue remodelling but are not present in lymphocytes. Low expression of TIMP-1 suggests that lupus skin is characterized by proteolytic events, and targeted action using selective MMP inhibitors may reduce lupus-induced damage in inflamed tissues.

Ras/myc-transformed serum-free mouse embryo cells under simulated inflammatory and infectious conditions increase levels of nitric oxide and matrix metalloproteinase-9 without a direct association between them

Inflammatory and infectious conditions were simulated in cultures of ras/myc-transformed serum-free mouse embryo (ras/myc SFME) cells, using interferon-gamma (IFN-gamma, 100 units/ml) and lipopolysaccharide (LPS, 0.5 microg/ml) co-treatment for 24 h, to investigate their effects on the expression of inducible nitric oxide synthase (iNOS) mRNA and the production of NO. Aminoguanidine (AG, 1 mM; an NOS inhibitor) along with IFN-gamma and LPS, S-nitroso-N-acetyl-DL-penicillamine (SNAP, 100 microM; an NO donor) and/or (+/-)-N-[(E)-4-Ethyl-2-[(Z)-hydroxyimino]-5-nitro-3-hexene-1-yl]-3-pyridine carboxamide (NOR4, 100 microM; an NO donor), were also added to analyze the possible association of NO with matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Co-treatment of cells with IFN-gamma and LPS increased iNOS mRNA expression, NO production, MMP-9 mRNA expression, and 105 kDa MMP-9 production. Additional treatment with the NOS inhibitor AG inhibited NO production, but did not down-regulate the expression of MMP-9 mRNA or 105 kDa MMP-9. The NO donors SNAP and NOR4 did not affect the expression of MMP-9 mRNA, 105 kDa MMP-9 or TIMP-1 mRNA. These results suggest that ras/myc SFME cells respond to infectious and inflammatory conditions and can enhance malignancy as cancer cells due to their increased levels of NO and MMP-9 production, but that NO is not directly associated with MMP-9 in these cells.

Significance of collagenase 3 (matrix metalloproteinase 13) in invasive bladder cancer: correlation with pathological parameters

PURPOSE

To determine if collagenase 3 expression is associated with stage progression and prognosis of bladder cancer.

PATIENTS AND METHODS

Immunohistochemical staining for collagenase 3 was carried out on serial sections from specimens of 42 patients (32 males and 10 females) who underwent radical cystectomy for bladder cancer (median follow-up, 67.2 +/- 5.99 months).

RESULTS

Immunohistochemical expression of collagenase 3 was detected in 13 (31%) patients. Pathological stage was pT2 in 12 (28.57%) patients, pT3a in 7 (16.6%), pT3b in 21 (50%) and pT4 in 2 (4.76%). Four tumours (9.52%) were grade II and 38 (90.47%) were grade III. Stage and tumours >3 cm in size were associated with bladder cancer progression-free survival and overall survival. We did not find any statistical differences with collagenase 3 expression related with stage and size.

CONCLUSIONS

Immunohistochemical expression of matrix metalloproteinase 13 in invasive bladder cancer is not useful as marker for transformation and invasion. These findings should be evaluated in large multicentre prospective trials.

Involvement of matrix metalloproteinase-13 in stromal-cell-derived factor 1 alpha-directed invasion of human basal cell carcinoma cells

Basal cell carcinoma (BCC) is one of the most common skin neoplasms in humans and is usually characterized by local aggressiveness with little metastatic potential, although deep invasion, recurrence, and regional and distant metastases may occur. Here, we studied the mechanism of BCC invasion. We found that human BCC tissues and a BCC cell line had significant expression of CXCR4, which was higher in invasive than non-invasive BCC types. Further, of 19 recurrent tumors among 390 BCCs diagnosed during the past 12 years, 17/19 (89.5%) had high CXCR4 expression. We found that the CXCR4 ligand, stromal-cell-derived factor 1alpha (SDF-1alpha), directed BCC invasion and that this was mediated by time-dependent upregulation of mRNA expression and gelatinase activity of matrix metalloproteinase-13 (MMP-13). The transcriptional regulation of MMP-13 by SDF-1alpha was mediated by phosphorylation of extracellular signal-related kinase 1/2 and activation of the AP-1 component c-Jun. Finally, CXCR4-transfected BCC cells injected into nude mice induced aggressive BCCs that co-expressed CXCR4 and MMP-13. The identification of SDF-1alpha/CXCR4 as an important factor in BCC invasiveness may contribute insight into mechanisms involved in the aggressive potential of human BCC and may improve therapy for invasive BCCs.