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

Overexpression of MMP21 and MMP28 is associated with gastric cancer progression and poor prognosis

Matrix metalloproteinase (MMP)-21 and MMP-28, or epilysin, are overexpressed during the invasion and metastasis of solid tumors. The present study investigated MMP-21 and MMP-28 expression levels in human gastric cancer using tissue microarray (TMA) analysis, and determined their association with clinicopathological characteristics and patient prognosis. TMA blocks, including 436 cases of gastric cancer and 92 non-cancerous adjacent gastric tissues, were investigated using immunohistochemistry. Staining results were analyzed statistically in association with various clinicopathological characteristics and overall survival. The MMP-21 and MMP-28 positive detection rate was 31.9% (139/436) and 34.4% (150/436), respectively, in the gastric carcinoma tissue specimens. MMP-21 and MMP-28 expression levels were negative in the 92 normal gastric tissue samples. In patients with gastric cancer, positive expression of MMP-21 and MMP-28 was correlated with tumor diameter, depth of invasion, vessel invasion, lymph node and distant metastases and tumor-node-metastasis stage. The overall survival rate was significantly lower in MMP-21 and MMP-28-positive compared with negative patients. Cox multivariate analysis revealed that MMP-21 and MMP-28 levels were independent predictors of survival in patients with gastric cancer. These findings emphasize the importance of MMP-21 and MMP-28, which may serve as novel and independent prognostic markers for the invasion and metastasis of human gastric cancer.

Regulation and involvement of matrix metalloproteinases in vascular diseases

Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases whose main function is to degrade and deposit structural proteins within the extracellular matrix (ECM). A dysregulation of MMPs is linked to vascular diseases. MMPs are classified into collagenases, gelatinases, membrane-type, metalloelastase, stromelysins, matrilysins, enamelysins, and unclassified subgroups. The production of MMPs is stimulated by factors such as oxidative stress, growth factors and inflammation which lead to its up- or down-regulation with subsequent ECM remodeling. Normally, excess activation of MMPs is controlled by their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs). An imbalance of MMPs and TIMPs has been implicated in hypertension, atherosclerotic plaque formation and instability, aortic aneurysms and varicose vein wall remodeling. Also, recent evidence suggests epigenetic regulation of some MMPs in angiogenesis and atherosclerosis. Over the years, pharmacological inhibitors of MMPs have been used to modify or prevent the development of the disease with some success. In this review, we discuss recent advances in MMP biology, and their involvement in the manifestation of vascular disease.

On the role of skin in the regulation of local and systemic steroidogenic activities

The mammalian skin is a heterogeneous organ/tissue covering our body, showing regional variations and endowed with neuroendocrine activities. The latter is represented by its ability to produce and respond to neurotransmitters, neuropeptides, hormones and neurohormones, of which expression and phenotypic activities can be modified by ultraviolet radiation, chemical and physical factors, as well as by cytokines. The neuroendocrine contribution to the responses of skin to stress is served, in part, by local synthesis of all elements of the hypothalamo-pituitary-adrenal axis. Skin with subcutis can also be classified as a steroidogenic tissue because it expresses the enzyme, CYP11A1, which initiates steroid synthesis by converting cholesterol to pregnenolone, as in other steroidogenic tissues. Pregnenolone, or steroidal precursors from the circulation, are further transformed in the skin to corticosteroids or sex hormones. Furthermore, in the skin CYP11A1 acts on 7-dehydrocholesterol with production of 7-dehydropregnolone, which can be further metabolized to other Δ7steroids, which after exposure to UVB undergo photochemical transformation to vitamin D like compounds with a short side chain. Vitamin D and lumisterol, produced in the skin after exposure to UVB, are also metabolized by CYP11A1 to several hydroxyderivatives. Vitamin D hydroxyderivatives generated by action of CYP11A1 are biologically active and are subject to further hydroxylations by CYP27B1, CYP27A1 and CP24A. Establishment of which intermediates are produced in the epidermis in vivo and whether they circulate on the systemic level represent a future research challenge. In summary, skin is a neuroendocrine organ endowed with steroid/secosteroidogenic activities.

Step-wise and punctuated genome evolution drive phenotype changes of tumor cells

The pattern of genome evolution can be divided into two phases: the step-wise continuous phase (step-wise clonal evolution, stable dominant clonal chromosome aberrations (CCAs), and low frequency of non-CCAs, NCCAs) and punctuated phase (marked by elevated NCCAs and transitional CCAs). Depending on the phase, system stresses (the diverse CIN promoting factors) may lead to the very different phenotype responses. To address the contribution of chromosome instability (CIN) to phenotype changes of tumor cells, we characterized CCAs/NCCAs of HeLa and HEK293 cells, and their derivatives after genotoxic stresses (a stable plasmid transfection, ectopic expression of cancer-associated CHI3L1 gene or treatment with temozolomide) by conventional cytogenetics, copy number alterations (CNAs) by array comparative genome hybridization, and phenotype changes by cell viability and soft agar assays. Transfection of either the empty vector pcDNA3.1 or pcDNA3.1_CHI3L1 into 293 cells initiated the punctuated genome changes. In contrast, HeLa_CHI3L1 cells demonstrated the step-wise genome changes. Increased CIN correlated with lower viability of 293_pcDNA3.1 cells but higher colony formation efficiency (CFE). Artificial CHI3L1 production in 293_CHI3L1 cells increased viability and further contributed to CFE. The opposite growth characteristics of 293_CHI3L1 and HeLa_CHI3L1 cells were revealed. The effect and function of a (trans)gene can be opposite and versatile in cells with different genetic network, which is defined by genome context. Temozolomide treatment of 293_pcDNA3.1 cells intensified the stochastic punctuated genome changes and CNAs, and significantly reduced viability and CFE. In contrast, temozolomide treatment of HeLa_CHI3L1 cells promoted the step-wise genome changes, CNAs, and increased viability and CFE, which did not correlate with the ectopic CHI3L1 production. Thus, consistent coevolution of karyotypes and phenotypes was observed. CIN as a driving force of genome evolution significantly influences growth characteristics of tumor cells and should be always taken into consideration during the different experimental manipulations.

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.

MMP-10 (Stromelysin-2) and MMP-21 in human and murine squamous cell cancer

The squamous cell cancers (SCC) of renal transplant recipients are more aggressive and metastasize earlier than those of the non-immunocompromised population. Matrix metalloproteinases (MMPs) have a central role in tumor initiation, invasion and metastasis. Our aim was to compare the expression of MMPs-10, -12 and -21 in SCCs from immunosuppressed (IS) and control patients and the contribution of MMPs-10 and -21 to SCC development in the FVB/N-Tg(KRT5-Nfkbia)3Rto mouse line. Immunohistochemical analysis of 25 matched pairs of SCCs, nine of Bowen's disease and timed back skin biopsies of mice with selective inhibition of Rel/NF-kappaB signalling were performed. Semiquantitatively assessed stromal MMP-10 expression was higher (P = 0.009) in the control group when compared with IS patients. Tumor cell-derived MMP-10, -12 and -21 expression did not differ between the groups but stromal fibroblasts of the control SCCs tended to express MMP-21 more abundantly. MMP-10 expression was observed already in Bowen's disease while MMP-21 was absent. MMP-10 and -21 were present in inflammatory or stromal cells in ageing mice while dysplastic keratinocytes and invasive cancer were negative. Our results suggest that MMP-10 may be important in the initial stages of SCC progression and induced in the stroma relating to the general host-response reaction to skin cancer. MMP-21 does not associate with invasion of SCC but may be involved in keratinocyte differentiation.

Role of matrix metalloproteinases in epithelial migration

In response to injury, epithelial cells migrate across the denuded tissue to rapidly close the wound and restore barrier, thereby preventing the entry of pathogens and leakage of fluids. Efficient, proper migration requires a range of processes, acting both inside and out of the cell. Among the extracellular responses is the expression of various matrix metalloproteinases (MMPs). Though long thought to ease cell migration simply by breaking down matrix barriers, findings from various models demonstrate that MMPs facilitate (and sometimes repress) cell movement by other means, such as affecting the state of cell-matrix interactions or proliferation. In this Prospect, we review some key data indicting how specific MMPs function via their activity as proteinases to control closure of epithelial wounds.

CCHCR1 is up-regulated in skin cancer and associated with EGFR expression

Despite chronic inflammation, psoriatic lesions hardly ever progress to skin cancer. Aberrant function of the CCHCR1 gene (Coiled-Coil α-Helical Rod protein 1, HCR) within the PSORS1 locus may contribute to the onset of psoriasis. As CCHCR1 is expressed in certain cancers and regulates keratinocyte (KC) proliferation in a transgenic mouse model, we studied its relation to proliferation in cutaneous squamous cell cancer (SCC) cell lines by expression arrays and quantitative RT-PCR and in skin tumors by immunohistochemistry. CCHCR1 protein was detected in the pushing border of SCC and lining basal cell carcinoma islands. Different from psoriasis, Ki67 had a similar expression pattern as CCHCR1. The most intense CCHCR1 staining occurred in areas positive for epidermal growth factor receptor (EGFR). Expression of CCHCR1 mRNA was upregulated 30–80% in SCC lines when compared to normal KCs and correlated positively with Ki67 expression. The most aggressive and invasive tumor cell lines (RT3, FaDu) expressed CCHCR1 mRNA less than non-tumorigenic HaCaT cells. Moreover, the tumor promoters okadaic acid and menadione downregulated CCHCR1 mRNA. We conclude that both in psoriasis and the early stages of KC transformation, CCHCR1 may function as a negative regulator of proliferation, but beyond a certain point in oncogenesis cannot control this phenomenon any longer.