High levels of MMP-1 expression in the absence of the 2G single nucleotide polymorphism is mediated by p38 and ERK1/2 mitogen-activated protein kinases in VMM5 melanoma cells

MMP-2 (-1306 C/T) Polymorphism Affects Serum Matrix Metalloproteinase (MMP)-2 Levels and Correlates with Chronic Obstructive Pulmonary Disease Severity: A Case-Control Study of MMP-1 and -2 in a Tunisian Population

OBJECTIVE

The aim of this study was to determine the role of MMP-1 (-1607 1G/2G; -519 A/G) and MMP-2 (-1306 C/T; -735 C/T) polymorphisms in the development and severity of chronic obstructive pulmonary disease (COPD) in Tunisian patients. We also evaluated the impact of these genetic variants on serum levels of the corresponding proteins.

METHODS

The study included 138 patients with COPD and 216 healthy controls. Pulmonary function was evaluated using body plethysmography, and COPD severity was determined based on forced expiratory volume in 1 s (FEV1%). MMP-1 and MMP-2 variants were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while serum matrix metalloproteinase (MMP)-1 and -2 levels were determined by enzyme-linked immunosorbent assay (ELISA) and activity of MMP-2 was determined by gelatin zymography.

RESULTS

No significant associations were found between genetic variations in MMP-1 and MMP-2 variants and the risk of development of COPD. Additionally, no significant impact of the MMP-1 (-1607 1G/2G; -519 A/G) and MMP-2 (-735 C/T) polymorphisms was observed on the respective protein levels and clinical parameters of the disease. Interestingly, a significant correlation was identified between the MMP-2 (-1306) C/T and disease severity [p = 0.01; Bonferroni corrected p value (p _c) = 0.04]. Increased levels of MMP-2 were also identified in patients with the MMP-2 (-1306) CC genotype compared with those with CT and TT genotypes (105 [84.69-121.5] vs. 86.29 [80.99-92.62] ng/ml; p = 0.01, p _c = 0.04). Additionally, MMP-2 activity was enhanced in patients carrying the CC genotype compared with those carrying the T variant (p = 0.01, p _c = 0.02).

CONCLUSION

Our data suggest that, although MMP-1 (-1607 1G/2G; -519 A/G) and MMP-2 (-735 C/T) may not affect COPD risk and clinical parameters, the MMP-2 (-1306C/T) variant was correlated to COPD severity. These findings could be related to alterations in the level and activity of MMP-2 in serum from patients carrying the (-1306) CC genotype.

Matrix metalloproteinase-1 promoter -1607 bp 1G/2G polymorphism associated with increased risk of spinal tuberculosis in Southern Chinese Han population

BACKGROUND

Spinal tuberculosis is the most common form of musculoskeletal tuberculosis. The expression of matrix metalloproteinase-1 (MMP-1) is increased in cells with Mycobacterium tuberculosis infection. MMP-1 plays a curial role in extracellular matrix degradation during the progression of tuberculosis. Although the 1G/2G polymorphism in MMP-1-1607 influences its transcription, its role in spinal tuberculosis remains unknown.

METHODS

Healthy controls and patients with spinal tuberculosis of Han ethnicity were recruited between January 2010 and May 2016. The MMP-1-1607 1G/2G polymorphism was genotyped using the Sequenom mass Array polymorphism analysis system.

RESULTS

The genotypes of 1G/1G, 1G/2G, and 2G/2G were found in 13.7%, 53.6%, and 32.8% of patients, and 12.2%, 37.4%, and 50.4% of controls, respectively. The 1G/2G genotype were more common in cases than in controls (P=2.05E-04). The 1G allele showed an association with an increased risk for spinal tuberculosis when compared to 2G allele (P=.004). 1G genotypes, having at least one 1G allele, were associated with the risk of developing spinal tuberculosis (1G/1G+1G/2G vs 2G/2G: OR=2.084, 95%CI=1.401-3.100, P=2.65E-04).

CONCLUSION

1G genotypes of the MMP-1-1607 may be associated with susceptibility to spinal tuberculosis in Southern Chinese Han population.

Understanding the role of ETS-mediated gene regulation in complex biological processes

Ets factors are members of one of the largest families of evolutionarily conserved transcription factors, regulating critical functions in normal cell homeostasis, which when perturbed contribute to tumor progression. The well-documented alterations in ETS factor expression and function during cancer progression result in pleiotropic effects manifested by the downstream effect on their target genes. Multiple ETS factors bind to the same regulatory sites present on target genes, suggesting redundant or competitive functions. The anti- and prometastatic signatures obtained by examining specific ETS regulatory networks will significantly improve our ability to accurately predict tumor progression and advance our understanding of gene regulation in cancer. Coordination of multiple ETS gene functions also mediates interactions between tumor and stromal cells and thus contributes to the cancer phenotype. As such, these new insights may provide a novel view of the ETS gene family as well as a focal point for studying the complex biological control involved in tumor progression. One of the goals of molecular biology is to elucidate the mechanisms that contribute to the development and progression of cancer. Such an understanding of the molecular basis of cancer will provide new possibilities for: (1) earlier detection, as well as better diagnosis and staging of disease; (2) detection of minimal residual disease recurrences and evaluation of response to therapy; (3) prevention; and (4) novel treatment strategies. Increased understanding of ETS-regulated biological pathways will directly impact these areas.

Matrix metalloproteinase-1 (MMP-1) Promoter polymorphisms are well linked with lower stomach tumor formation in eastern Indian population

Expression of matrix metalloproteinase-1 (MMP-1), an interstitial collagenase, plays a major role in cellular invasion during development of gastric cancer, a leading cause of death worldwide. A single-nucleotide polymorphism (SNP) −1607 1G/2G site of the MMP-1 gene promoter has been reported to alter transcription level. While the importance’s of other SNPs in the MMP-1 promoter have not yet been studied in gastric cancer, our aim was to investigate MMP-1 gene promoter polymorphisms and gastric cancer susceptibility in eastern Indian population. A total of 145 gastric cancer patients and 145 healthy controls were genotyped for MMP-1 −1607 1G/2G (rs1799750) by PCR-restriction fragment length polymorphism (RFLP), while MMP-1 −519 A/G (rs1144393), MMP-1 −422 T/A (rs475007), MMP-1 −340 T/C (rs514921) and MMP-1 −320 T/C (rs494379) were genotyped by DNA sequencing. A positive association was found with MMP-1 −422 T/A SNP that showed significant risk for regional lymph node metastasis (P = 0.021, Odd’s ratio (OR) = 3.044, Confidence intervals (CI) = 1.187–7.807). In addition, we found a significant association with lower stomach tumor formation among gastric cancer patients for three adjacent polymorphisms near the transcriptional start sites of [MMP-1 −422 T/A (P = 0.043, OR = 2.182, CI = 1.03–4.643), MMP-1 −340 T/C (P = 0.075, OR = 1.97, CI = 0.94–4.158) and MMP-1 −320 T/C (P = 0.034, OR = 2.224, CI = 1.064–40731)]. MMP-1 level in patients’ serum was correlated with MMP-1 promoter haplotypes conferring these three SNPs to evaluate the functional importance of these polymorphisms in lower stomach tumor formation and significant correlation was observed. Furthermore, MMP-1 −519 A/G polymorphism displayed poor cellular differentiation (P = 0.024, OR = 3.8, CI = 1.69–8.56) attributing a higher risk of cancer progression. In conclusion, MMP-1 proximal promoter SNPs are associated with the risk of lower stomach tumor formation and node metastasis in eastern Indian population.

Matrix metalloproteinase-1 polymorphism (-1607G) and disease severity in non-cystic fibrosis bronchiectasis in Taiwan

Objectives

Bronchiectasis is characterized by an irreversible dilatation of bronchi and is associated with lung fibrosis. MMP-1 polymorphism may alter its transcriptional activity, and differentially modulate bronchial destruction and lung fibrosis.

Design

To investigate the association of MMP-1 polymorphisms with disease severity in non-cystic fibrosis (CF) bronchiectasis patients, 51 normal subjects and 113 patients with bronchiectasis were studied. The associations between MMP-1 polymorphisms, lung function, and disease severity evaluated by high resolution computed tomography (HRCT) were analyzed.

Results

The frequency of MMP-1(-1607G) allele was significantly higher in patients with bronchiectasis than normal subjects (70.8% vs 45.1%, p<0.01). Forced expiratory volume in 1 second (FEV1) was decreased in bronchiectasis patients with 1G/1G (1.2±0.1 L, n = 14) and 1G/2G (1.3±0.1 L, n = 66) genotypes compared to the 2G/2G genotype (1.7±0.1 L, n = 33, p<0.01). Six minute walking distance was decreased in bronchiectasis patients with 1G/1G and 1G/2G compared to that of 2G/2G genotype. Disease severity evaluated by HRCT score significantly increased in bronchiectasis patients with 1G/1G and 1G/2G genotypes compared to that of 2G/2G genotype. Bronchiectasis patients with at least one MMP-1 (-1607G) allele showed increased tendency for hospitalization. Serum levels of pro-MMP-1, active MMP-1 and TGF-β1 were significantly increased in patients with bronchiectasis with 1G/1G and 1G/2G genotype compared with 2G/2G genotype or normal subjects. Under IL-1β stimulation, peripheral blood monocytes from subjects with 1G/2G or 1G/1G genotype secreted higher levels of TGF-β1compared to subjects with 2G/2G genotype.

Conclusion

This is the first report to address the influence of MMP-1 polymorphisms on lung function and airway destruction in non-CF bronchiectasis patients. Bronchiectasis patients with MMP-1(-1607G) polymorphism may be more vulnerable to permanent lung fibrosis or airway destruction due to the enhanced MMP-1 and TGF-β1 activity. Upregulated MMP-1 activity results in proteolytic destruction of matrix, and leads to subsequent fibrosis.

Honokiol induces cytotoxic and cytostatic effects in malignant melanoma cancer cells

BACKGROUND

Melanomas are aggressive neoplasms with limited therapeutic options. Therefore, developing new therapies with low toxicity is of utmost importance. Honokiol is a natural compound that recently has shown promise as an effective anticancer agent.

METHODS

The effect of honokiol on melanoma cancer cells was assessed in vitro. Proliferation and physiologic changes were determined using hexosaminidase assay and transmission electron microscopy. Protein expression was assessed by immunoblotting.

RESULTS

Honokiol treatment inhibited cell proliferation and induced death. Electron microscopy showed autophagosome formation. Reduced levels of cyclin D1 accompanied cell-cycle arrest. Honokiol also decreased phosphorylation of AKT (known as protein kinase B) and mammalian target of rapamycin, and inhibited γ-secretase activity by down-regulating the expression of γ-secretase complex proteins, especially anterior pharynx-defective 1.

CONCLUSIONS

Honokiol is highly effective in inhibiting melanoma cancer cells by attenuating AKT/mammalian target of rapamycin and Notch signaling. These studies warrant further clinical evaluation for honokiol alone or with present chemotherapeutic regimens for the treatment of melanomas.

Influence of single nucleotide polymorphisms in the MMP1 promoter region on cutaneous melanoma progression

Recently, we reported on the associations of seven single nucleotide polymorphisms (SNPs) in the promoter region of MMP1 gene with susceptibility to cutaneous melanoma (CM). Considering the reported correlation between MMP1 expression and melanoma progression, we hypothesized that these promoter SNPs might affect CM progression and prognosis. In this study, we examined the associations of seven SNPs with overall survival, as well as six clinicopathological factors in 754 patients with CM. After adjustment for 11 covariates, we observed significant associations of the SNP -422A>T (rs475007) with ulceration status (P=0.012), primary tumor thickness (P=0.040), and anatomic site (P=0.030). We also observed significant associations of the SNP -755T>G (rs498186) with ulceration status (P=0.038) and anatomic site (P=0.003). Two SNPs, -839G>A and -519A>G, were marginally associated with primary tumor thickness, ulceration status, and anatomic site. Furthermore, the frequency of haplotype 2G-G-G-A-A-G-T was higher in patients with ulceration (odds ratio=2.18, 95% confidence interval: 1.08-4.40, P=0.030) compared with those without ulceration. However, we did not find significant associations of these SNPs with overall survival and other clinical factors. As primary tumor thickness and ulceration status are two important indicators of tumor progression and have significant associations with melanoma prognosis, our results suggested that these promoter SNPs in MMP1 might have potential effects on melanoma progression and prognosis by influencing related clinical factors.

Molecular bases of cutaneous and uveal melanomas

Intensive research in recent years has begun to unlock the mysteries surrounding the molecular pathogenesis of melanoma, the deadliest of skin cancers. The high-penetrance, low-frequency susceptibility gene CDKN2A produces tumor suppressor proteins that function in concert with p53 and retinoblastoma protein to thwart melanomagenesis. Aberrant CDKN2A gene products have been implicated in a great many cases of familial cutaneous melanoma. Sporadic cases, on the other hand, often involve constitutive signal transduction along the mitogen-activated protein kinase (MAPK) pathway, with particular focus falling upon mutated RAS and RAF protooncogenes. The proliferative effects of the MAPK pathway may be complemented by the antiapoptotic signals of the PI3K/AKT pathway. After skin, melanoma most commonly affects the eye. Data for the constitutive activation of the MAPK pathway in uveal melanoma exists as well, however, not through mutations of RAS and RAF. Rather, evidence implicates the proto-oncogene GNAQ. In the following discussion, we review the major molecular pathways implicated in both familial and sporadic cutaneous melanomagenesis, the former accounting for approximately 10% of cases. Additionally, we discuss the molecular pathways for which preliminary evidence suggests a role in uveal melanomagenesis.

Understanding melanoma signaling networks as the basis for molecular targeted therapy

Despite years of research, there has been little improvement in survival for patients with disseminated melanoma. Recent work has identified mutations in BRAF and NRAS, leading to constitutive mitogen-activated protein kinase (MAPK) pathway as well as constitutive activity in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway, as being critical events in melanoma growth and progression. In the current review, we discuss how these complex mutational and signaling profiles can be understood using a network biology approach, and suggest how an understanding of the key signaling nodes involved in progression and survival will lead to improvements in melanoma therapy.

Identification of a cigarette smoke-responsive region in the distal MMP-1 promoter

Tobacco-related diseases are leading causes of death worldwide, and many are associated with expression of matrix metalloproteinase-1 (MMP-1). We have reported extracellular signal-regulated kinase (ERK)1/2-dependent induction of MMP-1 by cigarette smoke in lung epithelial cells. Our objectives were to define regions of the human MMP-1 promoter required for activation by smoke, to identify differences in responses of the 1G/2G -1607 polymorphic promoters to smoke, and to identify relevant transcription factors whose activity in airway epithelial cells is increased by smoke. The responses of deletion and mutant promoter constructs were measured in transfected cells during exposure to cigarette smoke extract (CSE). DNA oligonucleotide arrays were used to identify transcription factors activated after smoke exposure. CSE activated the MMP-1 promoter, and this induction was prevented by PD98059 blockade of ERK1/2 phosphorylation. Deletion studies revealed the distal 1kb promoter region (-4438 to -3280 upstream of the transcription start site) is essential for CSE induction of MMP-1, and confers activation of a minimal promoter. Studies of 1G and 2G MMP-1 polymorphic promoter variants revealed higher 2G allele basal and CSE-responsive activities than the 1G allele. Cotransfection, mithramycin, and electrophoretic mobility shift assay studies identified activating and repressive roles for Sp1 and PEA3 transcription factors, respectively. Oligonucleotide DNA arrays confirmed activation of Sp1 and PEA3 by CSE. These data demonstrate that the MMP-1 promoter is a direct target of cigarette smoke in lung epithelial cells. This characterization of a smoke response region in the distal MMP-1 promoter has implications for smoking-related diseases such as cancer, heart disease, and emphysema.

RAF may induce cell proliferation through hypermethylation of tumor suppressor gene promoter in gastric epithelial cells

The extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK-MAPK) is critical in human malignancies. It remained to be established whether DNA methyltransferases (Dnmt) and proliferating cell nuclear antigen (PCNA) involved in DNA methylation during RAF-transformed cell proliferation. The plasmid of constitutively active RAF was used to transfect gastric cell GES-1 and cancer cell AGS. RAF promoted cell proliferation, growth in soft agar and induced cell cycle progress faster than empty plasmid by accelerating G1/S transition in both cell lines, a massive induction of cyclin D1 and PCNA expression was observed, along with reduced expression of p16INK4A, p21WAF1 and p27KIP1. Methylation-specific polymerase chain reaction and bisulfite sequencing showed that the promoter of p16INK4A was methylated in RAF-transformed cells, treatment with 5-aza-dC or PD98059 restored the expression of p16INK4A, increased p21WAF1 and p27KIP1 partially, associated with upregulation of the activity of Dnmt in RAF-transformed cell GES-1, and also decreased the hypermethylation status of p16INK4A, but not all CpG islands of p21WAF1 and p27KIP1. These data suggest that RAF may induce cell proliferation through hypermethylation of tumor suppressor gene p16INK4A, while the epigenetic inactivation of p21WAF1 and p27KIP1 may be not a key factor in RAF-transformed cells.

Association between promoter -1607 polymorphism of MMP1 and lumbar disc disease in Southern Chinese

Background

Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix of the intervertebral disc. A SNP for guanine insertion/deletion (G/D), the -1607 promoter polymorphism, of the MMP1 gene was found significantly affecting promoter activity and corresponding transcription level. Hence it is a good candidate for genetic studies in DDD.

Methods

Southern Chinese volunteers between 18 and 55 years were recruited from the population. DDD in the lumbar spine was defined by MRI using Schneiderman's classification. Genomic DNA was isolated from the leukocytes and genotyping was performed using the Sequenom^® platform. Association and Hardy-Weinberg equilibrium checking were assessed by Chi-square test and Mann-Whitney U test.

Results

Our results showed substantial evidence of association between -1607 promoter polymorphism of MMP1 and DDD in the Southern Chinese subjects. D allelic was significantly associated with DDD (p value = 0.027, odds ratio = 1.41 with 95% CI = 1.04–1.90) while Genotypic association on the presence of D allele was also significantly associated with DDD (p value = 0.046, odds ratio = 1.50 with 95% CI = 1.01–2.24). Further age stratification showed significant genotypic as well as allelic association in the group of over 40 years (genotypic: p value = 0.035, odds ratio = 1.617 with 95% CI = 1.033–2.529; allelic: p value = 0.033, odds ratio = 1.445 with 95% CI = 1.029–2.029). Disc bulge, annular tears and the Schmorl's nodes were not associated with the D allele.

Conclusion

We demonstrated that individuals with the presence of D allele for the -1607 promoter polymorphism of MMP1 are about 1.5 times more susceptible to develop DDD when compared with those having G allele only. Further association was identified in individuals over 40 years of age. Disc bulge, annular tear as well as Schmorl's nodes were not associated with this polymorphism.

The mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor AZD6244 (ARRY-142886) induces growth arrest in melanoma cells and tumor regression when combined with docetaxel

PURPOSE

Disseminated melanoma is highly therapy resistant. The finding that 66% of melanomas harbor the activating BRAF(V600E) mutation has raised expectations for targeting the Ras/RAF/mitogen-activated protein (MAP)/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK pathway in melanoma. This study addresses the anti-melanoma activity of the MEK inhibitor AZD6244 (ARRY-142886).

EXPERIMENTAL DESIGN

We recently have shown that growing melanoma cells as three-dimensional collagen-implanted spheroids enhances resistance to the MEK inhibitor U0126. Here, we investigated the anti-melanoma activity of AZD6244 in two-dimensional cell culture, the three-dimensional spheroid model, and an in vivo model.

RESULTS

In two-dimensional cell culture, AZD6244 was cytostatic and reduced the growth of melanoma cells in a concentration-dependent fashion through the induction of G(1)-phase cell cycle arrest. In our three-dimensional spheroid model, the effects of AZD6244 were largely cytostatic and reversible, with drug washout leading to spheroid regrowth. Finally, 1205Lu cells were grown as tumor xenografts in severe combined immunodeficient mice. After tumor establishment, mice were dosed twice daily with 0, 10, or 30 mg/kg AZD6244 p.o. AZD6244 treatment decreased phospho-ERK in the tumors and significantly suppressed tumor growth. The original tumors remained viable, suggesting that AZD6244 monotherapy was largely cytostatic, and not proapoptotic in this model. Further studies showed that co-administration of AZD6244 (30 mg/kg) with docetaxel (15 mg/kg) led to tumor regression, indicating the potential for MEK inhibitor/chemotherapy drug combinations.

CONCLUSIONS

Inhibition of MEK is cytostatic as a monotherapy in melanoma, but cytotoxic when combined with docetaxel.

[Research progresses on nutrigenomics]

Nutrition science is an age-old subject, and offers important theoretic instructions for human health protection and disease prevention. With the development of molecular biology, it will be a key technique in the 21 century. Combination of molecular biology and nutrition, bio-nutrition is formed. While the combination of genome and nutrition, nutrigenomics is developed. Nutrigenomics covers a wide range of areas, which studies the interactive effects between nutrients and genes expression, and predicts the expressive response to the nutrients. Genomics technology can help us to identify some dis-ease-related genes, thereby people establish individual diet and make their heath attained the best status through adjusting diet. This paper focuses on the main research technology of nutrigenomics and its application.

Matrix metalloproteinase-1 polymorphism in Taiwanese patients with endobronchial tuberculosis

Endobronchial tuberculosis (TB) often leads to some degree of tracheobronchial stenosis. Because matrix metalloproteinases (MMPs) play an essential role in tissue remodeling in the airways, we investigated the role of MMP-1 polymorphism in patients with endobronchial TB. One hundred and one cases of pulmonary TB in Taiwanese patients were genotyped for the 1G/2G polymorphism of MMP-1 promoter (-1607 bp). Bronchoscopic examination was performed to determine the presence of endobronchial involvement. Levels of MMP-1 in peripheral blood monocytes and in bronchial biopsies were also determined. 1G genotypes of MMP-1 polymorphism, containing at least one 1G allele, were associated with the presence of endobronchial TB. Using multivariate analysis, 1G genotypes and female gender were independent predictors of the development of endobronchial TB. Endobronchial TB patients with 1G genotypes had a 9.86-fold greater risk of developing tracheobronchial stenosis. IL-1beta increased levels of MMP-1 in peripheral blood monocytes of TB patients with 1G genotypes. MMP-1 activity was also present in the endobronchial TB granuloma from patients with 1G/1G genotype. 1G genotypes of MMP-1 polymorphism were associated with a greater risk of developing tracheobronchial stenosis through up-regulation of MMP-1 activity.

Expression of collagenase-1 (MMP-1) promotes melanoma growth through the generation of active transforming growth factor-beta

Tumor cell invasion through basement membranes and into stromal tissue are key steps for promoting growth and metastasis. Tumor cells express various extracellular-matrix-degrading enzymes such as matrix metalloproteinases (MMPs) to degrade extracellular matrix components to facilitate tumor migration and invasion. Histological and clinical studies suggest a role for MMP-1 (collagenase-1) in malignant melanoma invasion. In this study, we evaluated MMP-1 in regulating malignant phenotypes of human melanoma cells by generating human melanoma cells stably transfected with pro-MMP-1 cDNA. The transfectants expressed the active form of MMP-1 associated with cells and showed enhanced invasive and growth abilities in type I collagen gel. Furthermore, MMP-1 expression promoted anchorage-independent growth, which was inhibited in the presence of type II transforming growth factor (TGF)-beta receptor:Fc fusion protein that scavenges TGF-beta receptors. Finally, we demonstrated that MMP-1 directly generated active TGF-beta from its latent form. Thus, these results suggest that MMP-1 produced from melanoma cells would play a role in tumor progression by both degrading matrix proteins and generating active growth factors such as TGF-beta in vivo.

Melanoma cell-derived vascular endothelial growth factor induces endothelial tubulogenesis within fibrin gels by a metalloproteinase-mediated mechanism

Angiogenesis is a process required not only for embryonal development but is encountered in wound healing and in pathological situations such as tumour growth. In vitro, formation of capillary-like structures can be induced by seeding human microvascular endothelial cells (HDMECs) on top of a fibrin matrix in the presence of phorbol 12-myristate 13-acetate (PMA) as a stimulating agent. In this study, we show that supernatants collected from high-invasive melanoma cells (BLM) induce the formation of tubular structures similar to PMA treatment whereas supernatants from low-invasive cells (WM164) did not. Analysis of proteins secreted into the supernatant of both melanoma cell lines identified differential expression of several pro-angiogenic proteins in high- and low-invasive melanoma cells. Vascular endothelial growth factor (VEGF) was strongly expressed by high- but not by low-invasive melanoma cells. Neutralisation of VEGF as well as inhibition of matrix metalloproteases (MMPs) using the broad spectrum MMP inhibitor 1,10-phenanthroline, both strongly reduced the melanoma-induced tube formation. PMA treatment of HDMECs on a fibrin matrix stimulated MT1-MMP synthesis, indicating that this protease is involved in PMA-induced angiogenesis. In addition, stimulation of HDMECs by supernatants of BLM melanoma cells resulted in a strong induction of ADAM-15, which is known to act as a metalloproteinase. In conclusion, these results show that VEGF released by melanoma cells is an important mediator of neo-vascularisation and that this process depends on the presence of metalloproteinases.

Increased Soluble E-Cadherin in Melanoma Patients

Cadherin switching is thought to contribute to melanoma progression. E-cadherin expression is downregulated, facilitating the release of contacts with keratinocytes, while N-cadherin expression is increased, potentially contributing to more migration. Proteolytic cleavage of the cadherin extracellular domain, a process called ectodomain shedding, is one way to decrease cadherin cell surface expression. In addition, the released ectodomain could actively contribute to a more invasive phenotype. To examine if melanoma progression correlates with increased cadherin ectodomain shedding, we tested the presence of N- and E-cadherin extracellular domains in different melanoma cell lines and the presence of E-cadherin in sera of patients. Shedding occurs and is regulated in several melanoma cell lines expressing these cadherins. No correlation could be found between cadherin shedding and invasive capacity of the cell lines. However, we did find a significant increase in serum E-cadherin levels of melanoma patients with advanced disease correlating with increased S100 tumor marker values, suggesting that increased cadherin shedding may contribute to melanoma progression.

The use of allelic expression differences to ascertain functional polymorphisms acting in cis: analysis of MMP1 transcripts in normal lung tissue

Summary Aberrant expression of matrix metalloproteinase 1 (MMP1) has been implicated in a number of pathological conditions of the lung. In vitro results and analysis of tumours and cell lines suggest that an insertion/deletion polymorphism at position -1607 in the promoter of the gene can influence expression levels. However, whether this polymorphism is associated with differences in expression in normal lung tissue remains to be established. Polymorphisms affecting expression in cis will lead to alleles with different expression levels and will result in unequal expression of both alleles in heterozygous individuals (allelic expression imbalance, AEI). This can be detected using a transcribed marker. Here we follow a new approach and use AEI to ascertain that the -1607 polymorphism is associated with allelic expression differences of MMP1 in normal lung tissue. This approach could be used to map the sites associated with inter-individual expression differences in other genes. This is of particular interest since such sites allow prediction of expression levels, and can be used to test whether genetically determined differences in expression influence inter-individual differences of a phenotype of interest, such as disease predisposition.

Absence of a Correlation between the Presence of a Single Nucleotide Polymorphism in the Matrix Metalloproteinase 1 Promoter and Outcome in Patients of Chondrosarcoma

PURPOSE

Increased levels of matrix metalloproteinase 1 (MMP-1) expression have been associated with poor outcome in chondrosarcoma. The existence of a single nucleotide polymorphism creating an Ets-binding site in the MMP-1 promoter may be one mechanism for elevated MMP-1 transcription. The aim of our study was to identify the prevalence of this single nucleotide polymorphism (SNP) in chondrosarcoma patients, to determine its correlation with disease outcome, and to discern whether it could serve as a prognostic marker in patients with chondrosarcoma.

EXPERIMENTAL DESIGN

Sixty-seven chondrosarcoma specimens were selected sequentially from an established tumor bank with a median duration of 47 months follow-up (range, 24 to 179 months). DNA was extracted, amplified with PCR, and sequenced to determine presence (GG) or absence of the Ets-binding site created by the SNP.

RESULTS

Eighteen (27%) samples were homozygous for the absence of the Ets site, 34 (51%) were heterozygous for the SNP, and 15 (22%) were homozygous for the SNP. The 5-year overall survival rate for patients was 78, 80, and 84%, respectively (P = 0.5527). The disease-free survival rate was 16, 63, and 76%, respectively (P = 0.0801). The 5-year disease-free survival rate for patients with the homozygous G/G genotype was 16%, compared with 71% for patients who were either homozygous or heterozygous for the GG allele (P = 0.0444).

CONCLUSIONS

Despite a statistical correlation between MMP-1 gene expression and outcome in chondrosarcoma, this study demonstrates an absence of a correlation between the presence of the SNP and prognosis in patients with chondrosarcoma.

Overexpression of Collagenase 1 (MMP-1) Is Mediated by the ERK Pathway in Invasive Melanoma Cells

Melanoma progresses as a multistep process where the thickness of the lesion and depth of tumor invasion are the best prognostic indicators of clinical outcome. Degradation of the interstitial collagens in the extracellular matrix is an integral component of tumor invasion and metastasis, and much of this degradation is mediated by collagenase-1 (MMP-1), a member of the matrix metalloproteinase (MMP) family. MMP-1 levels increase during melanoma progression where they are associated with shorter disease-free survival. The Ras/Raf/MEK/ERK mitogen-activated protein kinase (MAPK) pathway is a major regulator of melanoma cell proliferation. Recently, BRAF has been identified as a common site of activating mutations, and, although many reports focus on its growth-promoting effects, this pathway has also been implicated in progression toward metastatic disease. In this study, we describe four melanoma cell lines that produce high levels of MMP-1 constitutively. In each cell line the Ras/Raf/MEK/ERK pathway is constitutively active and is the dominant pathway driving the production of MMP-1. Activation of this pathway arises due to either an activating mutation in BRAF (three cell lines) or autocrine fibroblast growth factor signaling (one cell line). Furthermore, blocking MEK/ERK activity inhibits melanoma cell proliferation and abrogates collagen degradation, thus decreasing their metastatic potential. Importantly, this inhibition of invasive behavior can occur in the absence of any detectable changes in cell proliferation and survival. Thus, constitutive activation of this MAPK pathway not only promotes the increased proliferation of melanoma cells but is also important for the acquisition of an invasive phenotype.

c-Jun NH2-terminal kinase pathway is involved in constitutive matrix metalloproteinase-1 expression in a hepatocellular carcinoma-derived cell line

Transcription factor c-Jun serves for cellular proliferation, survival, differentiation and transformation and is recognized as an important factor in cancer development, including hepatocellular carcinoma (HCC). The purpose of present study is to determine the involvement of c-Jun in matrix metalloproteinase-1 (MMP-1) expression, which is previously reported by us to be expressed only in the early stage of human HCC showing stromal invasion. Of 5 human HCC cell lines examined, only HLE cells revealed mRNA and protein expression as well as enzymatic activity of MMP-1. Transient transfection of an MMP-1 promoter/luciferase construct (including 4.4 kb full promoter region) into HLE and HCC-T cells (MMP-1 nonproducer) showed that high promoter activity was observed only in HLE cells without inducers, and that this promoter activity was still observed when a shorter 0.6 kb proximal promoter construct was transfected. The 0.6 kb promoter region contained 3 AP-1 sites, and c-jun mRNA was constitutively expressed in HLE cells without inducers. Furthermore, phosphorylated c-Jun and c-Jun NH2-terminal kinase (JNK) were detected in HLE cells. Promoter activity of the 0.6 kb construct was suppressed with SP600125, a potent inhibitor of JNK, but not with PD98059 and SB203580, potent inhibitors of MEK1/2 and p38, respectively. The inhibitory effect of SP600125 was also observed at protein expression level and in enzymatic activity of MMP-1. Taken together, this study suggests that the JNK pathway is involved in the expression of MMP-1 in HCC cells and may represent a new functional role of c-Jun for HCC development.

The 2G single nucleotide polymorphism (SNP) in the MMP-1 promoter contributes to high levels of MMP-1 transcription in MCF-7/ADR breast cancer cells

Degradation of stromal collagens in the extracellular matrix is mediated largely by matrix metalloproteinase-1 (MMP-1; collagenase-1), and high constitutive levels of MMP-1 in breast cancer correlate with a poor prognosis and invasive disease. MMP-1 expression is, in part, controlled by the mitogen-activated protein kinase (MAPK) pathway(s), which may target several activator protein-1 (AP-1) and polyoma enhancing activity-3/E26 virus (PEA3/ETS) sites within the promoter. An additional ETS site in the MMP-1 promoter is conferred by a single nucleotide polymorphism (SNP) at -1607 bp, when two guanines (5'-GGAT-3'; '2G allele/SNP') are present instead of one guanine (5'-GAT-3'; '1G allele/SNP'). This SNP is adjacent to an AP-1 site at -1602 bp, and in the presence of the 2G allele (ETS site), these sites cooperate to induce higher levels of transcription. ERK 1/2 is one component of the MAPK pathway and is constitutively active in MCF-7/ADR breast cancer cells, which are 1G/2G heterozygotes. This study demonstrates that when these cells are treated with PD098059, an ERK-specific inhibitor, MMP-1 mRNA levels are significantly decreased, suggesting that high constitutive expression of MMP-1 in these cells results from continuous ERK 1/2 activation. Using transient transfection, we determined that this signaling pathway targets different AP-1/ETS sites, depending upon which allele is present. Furthermore, in these cells, the AP-1 site at -1602 bp enhances transcription in the presence of the 2G SNP, but represses transcription from the 1G SNP. Finally, inhibiting ERK signaling and MMP-1 expression blocks type I collagen degradation and reduces the invasive ability of the MCF-7/ADR cells. We conclude that ERK 1/2 signaling and the 2G SNP mediate high levels of MMP-1 expression, which may contribute to the invasive potential of these breast cancer cells.

The 2G single nucleotide polymorphism (SNP) in the MMP-1 promoter contributes to high levels of MMP-1 transcription in MCF-7/ADR breast cancer cells

Degradation of stromal collagens in the extracellular matrix is mediated largely by matrix metalloproteinase-1 (MMP-1; collagenase-1), and high constitutive levels of MMP-1 in breast cancer correlate with a poor prognosis and invasive disease. MMP-1 expression is, in part, controlled by the mitogen-activated protein kinase (MAPK) pathway(s), which may target several activator protein-1 (AP-1) and polyoma enhancing activity-3/E26 virus (PEA3/ETS) sites within the promoter. An additional ETS site in the MMP-1 promoter is conferred by a single nucleotide polymorphism (SNP) at -1607 bp, when two guanines (5'-GGAT-3'; '2G allele/SNP') are present instead of one guanine (5'-GAT-3'; '1G allele/SNP'). This SNP is adjacent to an AP-1 site at -1602 bp, and in the presence of the 2G allele (ETS site), these sites cooperate to induce higher levels of transcription. ERK 1/2 is one component of the MAPK pathway and is constitutively active in MCF-7/ADR breast cancer cells, which are 1G/2G heterozygotes. This study demonstrates that when these cells are treated with PD098059, an ERK-specific inhibitor, MMP-1 mRNA levels are significantly decreased, suggesting that high constitutive expression of MMP-1 in these cells results from continuous ERK 1/2 activation. Using transient transfection, we determined that this signaling pathway targets different AP-1/ETS sites, depending upon which allele is present. Furthermore, in these cells, the AP-1 site at -1602 bp enhances transcription in the presence of the 2G SNP, but represses transcription from the 1G SNP. Finally, inhibiting ERK signaling and MMP-1 expression blocks type I collagen degradation and reduces the invasive ability of the MCF-7/ADR cells. We conclude that ERK 1/2 signaling and the 2G SNP mediate high levels of MMP-1 expression, which may contribute to the invasive potential of these breast cancer cells.

Topical Treatment with Inhibitors of the Phosphatidylinositol 3′-Kinase/Akt and Raf/Mitogen-Activated Protein Kinase Kinase/Extracellular Signal-Regulated Kinase Pathways Reduces Melanoma Development in Severe Combined Immunodeficient Mice

Topical treatment with inhibitors of the phosphatidylinositol 3'-kinase/Akt and Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathways inhibited the growth of TPras transgenic melanomas in severe combined immunodeficient mice, blocked invasive behavior, and reduced angiogenesis. The inhibitor Ly294002, which is specific for phosphatidylinositol 3'-kinase, effectively reduced melanoma cell growth both in vitro and in vivo. Both Ly294002 and U0126, a mitogen-activated protein kinase kinase 1/2 inhibitor, reduced invasion, which correlated with reduction of the metalloproteinase matrix metalloproteinase 2. Tumor angiogenesis was disrupted through inhibition of vascular endothelial growth factor production from the tumor cells and antiangiogenic effects on endothelial cells. Observations with TPras melanoma cells that express dominant negative Deltap85 or kinase-inactive Raf(301) supported the specificity of the phenomena observed with the chemical inhibitors. These studies demonstrate that topical treatment targeting Ras effectors is efficacious, without systemic toxicities, and may prove to be useful in treating and preventing the progression of cutaneous melanoma.

Nutritional genomics: the next frontier in the postgenomic era

The interface between the nutritional environment and cellular/genetic processes is being referred to as “nutrigenomics.” Nutrigenomics seeks to provide a molecular genetic understanding for how common dietary chemicals (i.e., nutrition) affect health by altering the expression and/or structure of an individual’s genetic makeup. The fundamental concepts of the field are that the progression from a healthy phenotype to a chronic disease phenotype must occur by changes in gene expression or by differences in activities of proteins and enzymes and that dietary chemicals directly or indirectly regulate the expression of genomic information. We present a conceptual basis and specific examples for this new branch of genomic research that focuses on the tenets of nutritional genomics: 1) common dietary chemicals act on the human genome, either directly or indirectly, to alter gene expression or structure; 2) under certain circumstances and in some individuals, diet can be a serious risk factor for a number of diseases; 3) some diet-regulated genes (and their normal, common variants) are likely to play a role in the onset, incidence, progression, and/or severity of chronic diseases; 4) the degree to which diet influences the balance between healthy and disease states may depend on an individual’s genetic makeup; and 5) dietary intervention based on knowledge of nutritional requirement, nutritional status, and genotype (i.e., “individualized nutrition”) can be used to prevent, mitigate, or cure chronic disease.

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The guanylate binding protein-1 GTPase controls the invasive and angiogenic capability of endothelial cells through inhibition of MMP-1 expression

Expression of the large GTPase guanylate binding protein-1 (GBP-1) is induced by inflammatory cytokines (ICs) in endothelial cells (ECs), and the helical domain of the molecule mediates the repression of EC proliferation by ICs. Here we show that the expression of GBP-1 and of the matrix metalloproteinase-1 (MMP-1) are inversely related in vitro and in vivo, and that GBP-1 selectively inhibits the expression of MMP-1 in ECs, but not the expression of other proteases. The GTPase activity of GBP-1 was necessary for this effect, which inhibited invasiveness and tube-forming capability of ECs in three-dimensional collagen-I matrices. A GTPase-deficient mutant (D184N-GBP-1) operated as a transdominant inhibitor of wild-type GBP-1 and rescued MMP-1 expression in the presence of ICs. Expression of D184N-GBP-1, as well as paracrine supplementation of MMP-1, restored the tube-forming capability of ECs in the presence of wild-type GBP-1. The latter finding indicated that the inhibition of capillary formation is specifically due to the repression of MMP-1 expression by GBP-1, and is not affected by the anti-proliferative activity of the helical domain of GBP-1. These findings substantiate the role of GBP-1 as a major regulator of the anti-angiogenic response of ECs to ICs.

A pivotal role for ERK in the oncogenic behaviour of malignant melanoma?

During the process of oncogenic transformation, melanoma cells escape from normal growth-control mechanisms and acquire the ability to invade surrounding tissues and organs. The Ras/Raf/MEK/ERK pathway is a major pathway involved in the control of growth signals, cell survival and invasion. Melanomas are known to harbour activating mutations of both Ras and BRAF, suggesting that the downstream effector ERK may be playing a major role in the oncogenic behaviour of these tumours. The past few years have seen a growth in the understanding of the role of ERK and the MAP kinase pathway in melanoma. The aim of the current review is to assess the role of ERK in melanoma behaviour and to determine whether modulation of these kinases could offer new therapeutic opportunities.