TGF-β and MMPs: A complex regulatory loop involved in tumor progression

Transforming growth factor-β (TGF-β) has a dual and contradictory role in cancer. It is a tumor suppressor at early stages of tumor formation by virtue of its growth inhibitory and pro-apoptotic functions. However, at later stages of tumor progression, tumor cells lose their sensitivity to be growth inhibited by this cytokine, and, then, TGF-β facilitates tumor invasion and metastasis by diverse mechanisms, including the induction of an epithelial-mesenchymal transition, the suppression of the immune system and the stimulation of angiogenesis. Matrix metalloproteinases (MMPs) have also been shown to play a pivotal function in tumor cell migration, invasion and angiogenesis. MMPs and TGF-β form an interplay loop that may attenuate or promote tumor progression. On one hand, latent TGF-β, an inactive TGF-β precursor that is sequestered by the extracellular matrix, is proteolytically activated by MMPs; the released active cytokine may, then, suppress or promote tumor cell growth and invasiveness depending on the tumor stage. On the other hand, TGF-β regulates the expression of MMPs and their tissue inhibitors TIMPs in both tumor and stromal cells. MMPs in the tumor microenvironment are involved in the control of tumor cell growth and survival by modulating the bioavailability of growth factors and chemokines, and they also influence inflammation and angiogenesis. Thus, by modulating the net balance of MMPs and TIMPs in both compartments: the tumor and stroma, TGF-β regulates malignant progression.The work developed in our laboratories is supported by grants of the Spanish Ministry of Science and Innovation (grant SAF2010-19152 to MQ) and the Ministry of Science and Technological Development of the Republic of Serbia (grant 175062 to JFS and JK). GC is the recipient of a contract from the Juan de la Cierva program of the Spanish Ministry of Science and Innovation.Peer Reviewe

Interleukin 17 inhibits myogenic and promotes osteogenic differentiation of C2C12 myoblasts by activating ERK1,2

The present study evaluated the role of interleukin (IL) 17 in multilineage commitment of C2C12 myoblastic cells and investigated associated signaling pathways. The results concerning the effects on cell function showed that IL-17 inhibits the migration of C2C12 cells, while not affecting their proliferation. The data regarding the influence on differentiation demonstrated that IL-17 inhibits myogenic differentiation of C2C12 cells by down-regulating the myogenin mRNA level, myosin heavy chain expression and myotube formation, but promotes their osteogenic differentiation by up-regulating the Runt-related transcription factor 2 mRNA level, cyclooxygenase-2 expression and alkaline phosphatase activity. IL-17 exerted these effects by activating ERK1,2 mitogen activated protein kinase signaling pathway, which in turn regulated the expression of relevant genes and proteins to inhibit myogenic differentiation and induce osteogenic differentiation. Additional analysis showed that the induction of osteogenic differentiation by IL-17 is independent of BMP signaling. The results obtained demonstrate the potential of IL-17 not only to inhibit the myogenic differentiation of C2C12 myoblasts but also to convert their differentiation pathway into that of osteoblast lineage providing new insight into the capacities of IL-17 to modulate the differentiation commitment

Distinctive Archaeal Composition of an Artisanal Crystallizer Pond and Functional Insights Into Salt-Saturated Hypersaline Environment Adaptation

Hypersaline environments represent some of the most challenging settings for life on Earth. Extremely halophilic microorganisms have been selected to colonize and thrive in these extreme environments by virtue of a broad spectrum of adaptations to counter high salinity and osmotic stress. Although there is substantial data on microbial taxonomic diversity in these challenging ecosystems and their primary osmoadaptation mechanisms, less is known about how hypersaline environments shape the genomes of microbial inhabitants at the functional level. In this study, we analyzed the microbial communities in five ponds along the discontinuous salinity gradient from brackish to salt-saturated environments and sequenced the metagenome of the salt (halite) precipitation pond in the artisanal Cáhuil Solar Saltern system. We combined field measurements with spectrophotometric pigment analysis and flow cytometry to characterize the microbial ecology of the pond ecosystems, including primary producers and applied metagenomic sequencing for analysis of archaeal and bacterial taxonomic diversity of the salt crystallizer harvest pond. Comparative metagenomic analysis of the Cáhuil salt crystallizer pond against microbial communities from other salt-saturated aquatic environments revealed a dominance of the archaeal genus Halorubrum and showed an unexpectedly low abundance of Haloquadratum in the Cáhuil system. Functional comparison of 26 hypersaline microbial metagenomes revealed a high proportion of sequences associated with nucleotide excision repair, helicases, replication and restriction-methylation systems in all of them. Moreover, we found distinctive functional signatures between the microbial communities from salt-saturated (>30% [w/v] total salinity) compared to sub-saturated hypersaline environments mainly due to a higher representation of sequences related to replication, recombination and DNA repair in the former. The current study expands our understanding of the diversity and distribution of halophilic microbial populations inhabiting salt-saturated habitats and the functional attributes that sustain them

Urokinase type plasminogen activator mediates Interleukin-17-induced peripheral blood mesenchymal stem cell motility and transendothelial migration

Mesenchymal stem cells (MSCs) have the potential to migrate toward damaged tissues increasing tissue regeneration. Interleukin-17 (IL-17) is a proinflammatory cytokine with pleiotropic effects associated with many inflammatory diseases. Although IL-17 can modulate MSC functions, its capacity to regulate MSC migration is not well elucidated so far. Here, we studied the role of IL-17 on peripheral blood (PB) derived MSC migration and transmigration across endothelial cells. IL-17 increased PB-MSC migration in a wound healing assay as well as cell mobilization from collagen gel. Concomitantly IL-17 induced the expression of urokinase type plasminogen activator (uPA) without affecting matrix metalloproteinase expression. The incremented uPA expression mediated the capacity of IL-17 to enhance PB-MSC migration in a ERK1,2 MAPK dependent way. Also, IL-17 induced PB-MSC migration alongside with changes in cell polarization and uPA localization in cell protrusions. Moreover, IL-17 increased PB-MSC adhesion to endothelial cells and transendothelial migration, as well as increased the capacity of PB-MSC adhesion to fibronectin, in an uPA-dependent fashion. Therefore, our data suggested that IL-17 may act as chemotropic factor for PB-MSCs by incrementing cell motility and uPA expression during inflammation development

Prevalence of high-risk HPV genotypes, categorised by their quadrivalent and nine-valent HPV vaccination coverage, and the genotype association with high-grade lesions

BACKGROUND: The new nine-valent vaccine against human papillomavirus (HPV) includes the four HPV genotypes (6, 11, 16, and 18) that are targeted by the older quadrivalent HPV vaccine, plus five additional oncogenic types (31, 33, 45, 52, and 58) remain significantly associated with high grade lesions. We aimed to determine the prevalence of high-risk HPV genotypes in unvaccinated subjects and the association of these genotypes with the incidence of high-grade lesions. We also assessed which, if either, of these two HPV vaccines could have prevented these cases. METHODS: This cross-sectional study, conducted from 4 January 2010 to 30 December 2011, was composed of 595 women attending the Hospital General Universitario de Elche (Spain) gynaecology department who were positively screened for opportunistic cervical cancer by pap smears and HPV detection during a routine gynaecological health check. The pap smear results were classified using the Bethesda system. HPV genotyping was performed with the Linear Array HPV genotyping test, and viruses were classified by the International Agency for Research on Cancer assessment of HPV carcinogenicity. Odds ratios (ORs) with their 95% confidence intervals (95% CI) were estimated by logistic regression, adjusting for age and immigrant status. The prevented fraction among those exposed (PFe-adjusted) was determined as a measure of impact. RESULTS: At least one of the additional five high-risk HPV genotypes present in the nine-valent HPV vaccine was detected in 20.5% of subjects. After excluding women with genotype 16 and/or 18 co-infection, high-risk genotypes (31, 33, 45, 52, and 58) were associated with a higher risk of intraepithelial lesion or malignancy: adjusted OR?=?3.51 (95% CI, 1.29-9.56), PFe-adjusted?=?0.72 (95% CI, 0.22-0.90). Genotypes that are still non-vaccine-targeted were detected in 17.98% of the women, but these were not significantly associated with high-grade lesions. CONCLUSION: The greater protection of the nine-valent HPV vaccine is likely to have a positive impact because, in the absence of genotype 16 or 18 infection, these five genotypes on their own remained significantly associated with high-grade lesions

Extracellular calcium modulates proliferation of factor dependent hemopoietic cells

Blockade of the calcium channel inhibited, in a dose‐dependent manner, the proliferation of the IL‐3 dependent FDCP‐1 cell line and normal murine bone marrow cells. Similar results were obtained by lowering the amount of extracellular calcium using specific chelators or a calcium‐free medium. These results suggest that factor‐dependent cell proliferation is highly sensitive to fluctuations in the concentration of extracellular calcium. Copyright © 1993 John Wiley & Sons Ltd

TGF-β1 and Smad4 overexpression induce a less invasive phenotype in highly invasive spindle carcinoma cells

We have examined the effect of transforming growth factor β1 (TGF-β1) and overexpression of the Smad4 gene on the phenotype of Car C, a ras mutated highly malignant spindle carcinoma cell line. TGF-β1-treated Car C cells overexpressing Smad4 spread with a flattened morphology with membrane ruffles abundant in vinculin and show a reduction in their invasive abilities. TGF-β1 treatment and overexpression of Smad4 also enhanced the production of PAI-1 measured by the activation of the p3TP-lux reporter gene containing a PAI-1-related promoter. This activation was abolished with a dominant-negative Smad4 construct. These results lead us to conclude that both TGF-β1 and Smad4 overexpression reduce the invasive potential of Car C cells, probably via the Smad pathway.This work was supported by Fondecyt 3000045 and post-graduate fellowship of Fundación Andes (to J.F.S.),1010703 (to J.M.) and by the Comisión Interministerial de Ciencia y Tecnología and Comunidad Autónoma de Madrid of Spain (Grants SAF98-0085-CO3-02 and 8.1/22/97,to M.Q.).Peer Reviewe

The secretion of urokinase‐like plasminogen activator is inhibited by microtubule‐interacting drugs

The secretion of proteinases into the extracellular matrix is one of the main features of tumour cells, as related to their invasive behaviour. Considering the role of the microtubule cytoskeleton, and particularly the action of microtubule‐associated protein (MAPs) in mediating protein secretion, the effects of the anti‐microtubule drugs estramustine and taxol, on the secretion of urokinase‐type plasminogen activator (u‐PA) and the 72 kDa gelatinase were investigated. Treatment of 5637 bladder carcinoma cells with estramustine and taxol inhibited u‐PA secretion into the conditioned medium in a drug concentration‐dependent fashion. This inhibition was confirmed by determinations of u‐PA enzymatic activities and by measurements of the levels of immunoreactive activator. Studies using gelatin zymograms also showed an inhibition of another tumoural proteinase namely the 72 kDa gelatinase. Time‐course uptake experiments showed that estramustine was incorporated into the cells, a process w

Urokinase expression and binding activity associated with the transforming growth factor β1-induced migratory and invasive phenotype of mouse epidermal keratinocytes

Transforming growth factor β1(TGF-β1) is a stimulator of malignant progression in mouse skin carcinogenesis. TGF-β1 exerts a differential effect on cultured nontumorigenic (MCA3D cell line) and transformed (PDV cell line) keratinocytes. Whereas MCA3D cells are growth arrested and committed to die in the presence of the factor, it induces a reversible epithelial- fibroblastic conversion in PDV cells. This conversion is associated in vivo with a squamous-spindle cell carcinoma transition. Here we have investigated the role of urokinase (uPA) during malignant progression of transformed epidermal keratinocytes. We show that the levels of uPA expression/secretion, and the uPA binding activity to the cell surface, correlate with the invasive and malignant potentials of mouse epidermal cell lines. TGF-β1 enhanced uPA production, the number of uPA cell surface binding sites, and the expression of the plasminogen activator inhibitor PAI-1, in transformed PDV cells, but had no major effect on nontumorigenic MCA3D keratinocytes. Increased uPA production depended on the presence of the factor in the culture medium and occurred concomitantly to the stimulation of the migratory and invasive abilities of PDV cells. Synthetic peptides containing the amino terminal sequence of the mature mouse uPA inhibited the binding of uPA to the cell surface and decreased TGF-β1-induced cell motility and invasiveness. These results demonstrate that the uPA system mediates at least part of the migratory and invasive phenotype induced by TGF-β1 in transformed keratinocytes, and suggest a role for uPA on the changes that lead to the appearance of spindle carcinomas.Funded by: Comisión Interministerial de Ciencia y Tecnología. Grant Number: SAF98–0085-C03–02; Comunidad Autónoma de Madrid. Grant Number: 8. 1/22/97 and Fondo Nacional de Ciencia y Tecnologia de Chile. Grant Number: 890028.Peer Reviewe