IL-6 upregulates a disintegrin and metalloproteinase with thrombospondin motifs 2 (ADAMTS-2) in human osteosarcoma cells mediated by JNK pathway

STAT-3, ELK-1, and c- Jun contributes IL-6 mediated ADAMTS-8 upregulation in colorectal cancer

BACKGROUND

ADAMTSs are extracellular matrix metalloproteinases that mainly process extracellular matrix components and closely related tumorigenesis. ADAMTS-8 is an anti-angiogenic member of the family and is dysregulated in common cancers. The tumor suppressor function of the ADAMTS-8 has been demonstrated in colorectal cancer. Although ADAMTS-8 plays a critical role in tumor progression, transcriptional regulatory features haven't been studied yet.

MATERIALS AND METHODS

The human ADAMTS-8 promoter was cloned into the pMetLuc Reporter vector. Basal promoter activity and the effect of the IL-6 on ADAMTS-8 promoter activity were determined by transient transfection assays in SW480 cells. QRT-PCR and Western blot analyses assessed the impact of IL-6 on ADAMTS-8 mRNA and protein expressions. Functional binding of the specific transcription factors to the ADAMTS-8 promoter region was evaluated by ChIP qPCR and EMSA.

RESULTS

Our results demonstrated that the ADAMTS-8 promoter includes multiple binding sites for transcription factors that could be activated in the inflammatory pathways. IL-6 stimulation increased ADAMTS-8 promoter activity, also mRNA, and protein expressions. Pathway inhibition studies showed that IL-6-mediated induction of ADAMTS-8 was achieved through p38/MAPK, NF-κB, PI3K, and SAPK/JNK pathways. STATs, Elk-1, and c-Jun functionally bind to the ADAMTS-8 promoter region.

CONCLUSION

It can be concluded that inflammation is a strong positive regulator of the ADAMTS-8 gene.

Associations of SEMA7A, SEMA4D, ADAMTS10, and ADAM8 with KRAS, NRAS, BRAF, PIK3CA, and AKT Gene Mutations, Microsatellite Instability Status, and Cytokine Expression in Colorectal Cancer Tissue

Semaphorins (SEMAs), ADAM, and ADAMTS family members are implicated in various cancer progression events within the tumor microenvironment across different cancers. In this study, we aimed to evaluate the expression of SEMA7A, SEMA4D, ADAM8, and ADAMTS10 in colorectal cancer (CRC) in relation to the mutational landscape of KRAS, NRAS, BRAF, PIK3CA, and AKT genes, microsatellite instability (MSI) status, and clinicopathological features. We also examined the associations between the expression of these proteins and selected cytokines, chemokines, and growth factors, assessed using a multiplex assay. Protein concentrations were quantified using ELISA in CRC tumors and tumor-free surgical margin tissue homogenates. Gene mutations were evaluated via RT-PCR, and MSI status was determined using immunohistochemistry (IHC). GSEA and statistical analyses were performed using R Studio. We observed a significantly elevated expression of SEMA7A in BRAF-mutant CRC tumors and an overexpression of ADAM8 in KRAS 12/13-mutant tumors. The expression of ADAMTS10 was decreased in PIK3CA-mutant CRC tumors. No significant differences in the expression of the examined proteins were observed based on MSI status. The SEMA7A and SEMA4D expressions were correlated with the expression of numerous cytokines associated with various immune processes. The potential immunomodulatory functions of these molecules and their suitability as therapeutic targets require further investigation.

The Mechanism and Role of ADAMTS Protein Family in Osteoarthritis

Osteoarthritis (OA) is a principal cause of aches and disability worldwide. It is characterized by the inflammation of the bone leading to degeneration and loss of cartilage function. Factors, including diet, age, and obesity, impact and/or lead to osteoarthritis. In the past few years, OA has received considerable scholarly attention owing to its increasing prevalence, resulting in a cumbersome burden. At present, most of the interventions only relieve short-term symptoms, and some treatments and drugs can aggravate the disease in the long run. There is a pressing need to address the safety problems due to osteoarthritis. A disintegrin-like and metalloprotease domain with thrombospondin type 1 repeats (ADAMTS) metalloproteinase is a kind of secretory zinc endopeptidase, comprising 19 kinds of zinc endopeptidases. ADAMTS has been implicated in several human diseases, including OA. For example, aggrecanases, ADAMTS-4 and ADAMTS-5, participate in the cleavage of aggrecan in the extracellular matrix (ECM); ADAMTS-7 and ADAMTS-12 participate in the fission of Cartilage Oligomeric Matrix Protein (COMP) into COMP lyase, and ADAMTS-2, ADAMTS-3, and ADAMTS-14 promote the formation of collagen fibers. In this article, we principally review the role of ADAMTS metalloproteinases in osteoarthritis. From three different dimensions, we explain how ADAMTS participates in all the following aspects of osteoarthritis: ECM, cartilage degeneration, and synovial inflammation. Thus, ADAMTS may be a potential therapeutic target in osteoarthritis, and this article may render a theoretical basis for the study of new therapeutic methods for osteoarthritis.

Regulation of ADAMTS Proteases

A disintegrin and metalloprotease with thrombospondin type I motifs (ADAMTS) proteases are secreted metalloproteinases that play key roles in the formation, homeostasis and remodeling of the extracellular matrix (ECM). The substrate spectrum of ADAMTS proteases can range from individual ECM proteins to entire families of ECM proteins, such as the hyalectans. ADAMTS-mediated substrate cleavage is required for the formation, remodeling and physiological adaptation of the ECM to the needs of individual tissues and organ systems. However, ADAMTS proteases can also be involved in the destruction of tissues, resulting in pathologies such as arthritis. Specifically, ADAMTS4 and ADAMTS5 contribute to irreparable cartilage erosion by degrading aggrecan, which is a major constituent of cartilage. Arthritic joint damage is a major contributor to musculoskeletal morbidity and the most frequent clinical indication for total joint arthroplasty. Due to the high sequence homology of ADAMTS proteases in their catalytically active site, it remains a formidable challenge to design ADAMTS isotype-specific inhibitors that selectively inhibit ADAMTS proteases responsible for tissue destruction without affecting the beneficial functions of other ADAMTS proteases. In vivo, proteolytic activity of ADAMTS proteases is regulated on the transcriptional and posttranslational level. Here, we review the current knowledge of mechanisms that regulate ADAMTS protease activity in tissues including factors that induce ADAMTS gene expression, consequences of posttranslational modifications such as furin processing, the role of endogenous inhibitors and pharmacological approaches to limit ADAMTS protease activity in tissues, which almost exclusively focus on inhibiting the aggrecanase activity of ADAMTS4 and ADAMTS5.

TNF-α Induces URG-4/URGCP Gene Expression in Hepatoma Cells through Starvation Dependent Manner

URG-4/URGCP is a gene that may be associated with the onset of tumorigenesis and cell cycle regulation. In the literature, there is no study about inflammatory cytokine-mediated URG-4/URGCP regulation. In this study, the effect of TNF-α cytokine was investigated on URG-4/URGCP expression in serum-starved and serum-cultured hepatoma cells. The effect of TNF-α on hepatoma cells was shown using MTT and Annexin-V/PI staining with flow cytometer analyses. As a result, TNF-α leads to the cytotoxicity of hepatoma cells in serum-starved condition whereas no decrease was detected from serum-cultured condition. TNF-α-mediated URG-4/URGCP expression was determined at mRNA and protein level with qRT-PCR analyses and Western blotting method. URG-4URGCP mRNA expression was upregulated in both serum-starved and serum-cultured hepatoma cells. The transfection studies were carried out with URG-4/URGCP promoter constructs for determining the transcriptional activity. TNF-α caused to the upregulation of the activities of URG/URGCP promoter constructs. The basal activities of the URG-4/URGCP promoter conditions are differential according to serum conditions. In addition, some pathway inhibitors were added into hepatoma cells for blocking specific pathways to find out TNF-α-mediated URG-4/URGCP upregulation at mRNA and protein level. TNF-α used JNK and PI3K pathways for regulating URG-4/URGCP gene at serum-starved Hep3B cells. In serum-cultured condition, wortmannin (PI3K inhibitor), MEK-1 (MAPK inhibitor), and SP600125 (JNK inhibitor) did not inhibit the activation response of TNF-α on URGCP.

Expression of ADAMTS2 and ADAMTS5 in the salivary gland of rats after radioiodine therapy

OBJECTIVE

The aim of this study was to investigate the presence of ADAMTS2 and ADAMTS5 in the salivary gland (SG) of rats after high-dose radioiodine therapy.

METHODS

A total of 36 male Wistar albino rats were used for this study. Thirty-six male rats were divided randomly into six groups: control and five radioactive iodine (RAI) treatment groups of six rats each. All animals were killed. The evaluation of biodistribution and histopathological studies were carried out on the SGs removed. Real-time PCR and immunohistochemical analysis were carried out to determine mRNA and protein expression levels of ADAMTS genes. Differences between the groups were evaluated statistically.

RESULTS

In RAI-treated groups, ADAMTS2 and ADAMTS5 gene expression was observed to increase, whereas there was no mRNA or protein expression in the control group. There were statistically significant increases in the mRNA expression of ADAMTS2 (all RAI-administered groups in parathyroid gland and at 4, 24, and 48 h in submandibular gland) and ADAMTS5 (all RAI-administered groups, except on the 30th day in the parathyroid gland and all RAI groups in submandibular gland). Through immunohistochemical analysis, the staining pattern in the extracellular source was also observed in the overexpressed ADAMTS2 and ADAMTS5 groups. Nuclear coarsening and partial focal subnuclei vacuolization were determined in all RAI-administered groups with histopathological examinations.

CONCLUSION

An increase in the mRNA expression levels of ADAMTS2 and ADAMTS5 genes was detected in the RAI-administered groups. These results suggested that ADAMTS2 and ADAMTS5 genes might play a role in radiation exposure and radioiodine-induced SG changes.

SP1-mediated downregulation of ADAMTS3 gene expression in osteosarcoma models

ADAMTS3 is a member of procollagen N-proteinase subfamily of ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) gene family. It has an important function in the procollagen maturation process. The removal of N-peptidases is required for the accurate processing of fibrillar collagens. Otherwise, several disorders can occur that is related with the collagenous tissues. ADAMTS3 mainly maturates type II collagen molecule which is the main component of the bone and cartilage. There are several expression studies about ADAMTS3 gene however its transcriptional regulation has not been lightened up, yet. Here we first time cloned and functionally analyzed the promoter region of ADAMTS3 gene, approximately 1380 bp upstream of the transcription start site. Transient transfection experiments showed that all truncated promoter constructs are active and 171 bp fragment is sufficient to activate gene expression in both Saos-2 and MG63 cells. In silico analysis showed that ADAMTS3 has a TATA-less promoter and contains several SP1/GC box binding motifs and a CpG island. Therefore we mainly investigated the SP1 dependent regulation of ADAMTS3 promoter. SP1 downregulated ADAMTS3 transcriptional activity. As consistent with the transcriptional activity, mRNA, and protein expression levels were also decreased by SP1. On the other hand, functional binding of the SP1 on multiple regions of ADAMTS3 promoter was confirmed by EMSA studies. As ADAMTS3 is responsible for the collagen maturation and biosynthesis, further we investigated the effect of SP1 on type I-II and III collagen gene expressions. We point out that SP1 increased type II and III collagen expression and in contrast decreased type I collagen expression levels in Saos-2 cells. mRNA expression level was decreased for all collagen types in MG63 model. Decrease in the type II collagen expression was also demonstrated at the protein level by SP1. Collectively these results provide first findings for the SP1-related transcriptional regulation of ADAMTS3 and collagen genes in osteosarcoma cell lines.

Critical Role of ADAMTS2 (A Disintegrin and Metalloproteinase With Thrombospondin Motifs 2) in Cardiac Hypertrophy Induced by Pressure Overload

ADAMTS2 (A Disintegrin and Metalloproteinase With Thrombospondin Motifs 2) is recognized as a metalloproteinase that promotes the cleavage of amino propeptides of types I, II, III, and V procollagens. However, the role of ADAMTS2 in the heart has not yet been defined. Herein, we observed the upregulated expression of ADAMTS2 in failing human hearts and hypertrophic murine hearts. Mice lacking ADAMTS2 display exacerbated cardiac hypertrophy on pressure overload-induced hypertrophic response, whereas mice with cardiac-specific overexpression of ADAMTS2 display alleviation of this detrimental phenotype. Consistent with these results, in vitro loss or gain of function experiments in neonatal rat cardiomyocytes confirmed that ADAMTS2 negatively regulates cardiomyocyte hypertrophy in response to Ang II. Mechanistically, blockage of the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B)-dependent signaling pathway with specific inhibitors both in vivo and in vitro could rescue the aggravated hypertrophic response to the loss of ADAMTS2. Collectively, we propose that ADAMTS2 regulates the hypertrophic response through inhibiting the activation of the PI3K/AKT-dependent signaling pathway. Because ADAMTS2 is an extracellular protein, it could be effectively manipulated using pharmacological means to modulate cardiac hypertrophy.

SP1 is a transcriptional regulator of URG-4/URGCP gene in hepatocytes

URG-4/URGCP gene was implicated as an oncogene that contributes hepatocarcinogenesis regulated by Hepatitis-B-virus-encoded X antigen. However, the mechanism of transcriptional regulation of this gene remains largely unknown. For this reason, we focused on the functional analyses of URG4/URGCP promoter site. First, 545 bp of URG-4/URGCP, -482/+63, and three different 5'-truncated constructs, -109/+63, -261/+63, -344/+63 were cloned by PCR-based approach into pMetLuc luciferase reporter vector. Transient transfection assay showed that, -109/+63 construct has the highest activity. The promoter of URG-4/URGCP gene contained a CpG island region spanning 400 bp from translation start site. Many SP1/GC boxes, named GC-1 to GC-10 are present in 545 bp of URG-4/URGCP promoter. Because of presence of multiple SP1/GC boxes, promoter constructs were transiently co-transfected with SP1 expression vector to determine the effect of SP1 on URG-4/URGCP promoter activity. Co-transfection analyses induced the basal activity of -268/+63, -344/+63 and -482/+63 constructs. EMSA analysis of GC-4, GC-5, GC-6 and GC-7 binding sites located in -128/-148 bases, showed two DNA-protein binding complexes. Competition assay and super-shifted complexes indicated these complexes are resulted from SP1 binding. Also, site-directed mutagenesis of potential SP1 binding sites diminished both DNA-protein complexes and SP1-mediated upregulation of URG-4 promoter activity. These findings are valuable for understanding transcriptional regulation of URG4/URGCP that has a pivotal role in cancer progression.

The extracellular matrix in cancer progression: Role of hyalectan proteoglycans and ADAMTS enzymes

Remodelling of the extracellular matrix (ECM) has emerged as a key factor in cancer progression. Proteoglycans, including versican and other hyalectans, represent major structural elements of the ECM where they interact with other important molecules, including the glycosaminoglycan hyaluronan and the CD44 cell surface receptor. The hyalectan proteoglycans are regulated through cleavage by the proteolytic actions of A Disintegrin-like And Metalloproteinase domain with Thrombospondin-1 motif (ADAMTS) family members. Alteration in the balance between hyalectan proteoglycans and ADAMTS enzymes has been proposed to be a crucial factor in cancer progression either in a positive or negative manner depending on the context. Further complexity arises due to the formation of bioactive cleavage products, such as versikine, which may also play a role, and non-enzymatic functions for ADAMTS proteins. This research is providing fresh insights into cancer biology and opportunities for the development of new diagnostic and treatment strategies.

SP1 and USF differentially regulate ADAMTS1 gene expression under normoxic and hypoxic conditions in hepatoma cells

ADAM metallopeptidase with thrombospondin type I motif, 1 (ADAMTS1) that has both antiangiogenic and aggrecanase activity was dysregulated in many pathophysiologic circumstances. However, there is limited information available on the transcriptional regulation of ADAMTS1 gene. Therefore, this study mainly aimed to identify regulatory regions important for the regulation of ADAMTS1 gene under normoxic and hypoxic conditions in human hepatoma cells (HEP3B). Cultured HEP3B cells were exposed to normal oxygen condition, and Cobalt chloride (CoCl2) induced the hypoxic condition, which is an HIF-1 inducer. The cocl2-induced hypoxic condition led to the induced ADAMTS1 mRNA and protein expression in Hepatoma cells. Differential regulation of SP1 and USF transcription factors on ADAMTS1 gene expression was determined by transcriptional activity, mRNA and protein level of ADAMTS1 gene. Ectopic expression of SP1 and USF transcription factors resulted in the decrease in ADAMTS1 transcriptional activity of all promoter constructs consistent with mRNA and protein level in normoxic condition. However, overexpression of SP1 and USF led to the increase of ADAMTS1 gene expressions at mRNA and protein level in hypoxic condition. On the other hand, C/EBPα transcription factor didn't show any statistically significant effect on ADAMTS1 gene expression at mRNA, protein and transcriptional level under normoxic and hypoxic condition.

JNK pathway in osteosarcoma: pathogenesis and therapeutics

CONTEXT

The c-Jun NH2-terminal kinase (JNK) is a member of the mitogen-activated protein kinase super family. JNK can phosphorylate a number of activator protein-1 components, activating several transcription factors, and thus, JNK signaling pathway is being involved in several carcinogenic mechanisms.

OBJECTIVE

In this study, we have reviewed the recent updates of the association of JNK pathway with osteosarcoma (OS), which is one of the most common and aggressive bone malignancies.

METHODS

In this review, we have explored the databases like PubMed, Google Scholar, MEDLINE, etc., and collected the most relevant papers of JNK signaling pathway involved in the pathogenesis and therapeutics of OS.

RESULTS

Evidence showed that JNK is a master protein kinase that plays an important role in osteoblast proliferation, differentiation and apoptosis. Interesting reports showed that chemical JNK inhibitors reduce OS cell proliferation and metastasis. Many of the components of this pathway have now been identified and the application of JNK inhibitors has been proven to work in vivo in human and in animal models; however, JNK pathway has not been translated into clinical use.

CONCLUSION

Therapeutic interventions of potent and selective inhibitors of JNK might provide promising therapeutic approaches for the treatment of OS, and could improve the survival rate and quality of life of OS patients.

Induction of human ADAMTS-2 gene expression by IL-1α is mediated by a multiple crosstalk of MEK/JNK and PI3K pathways in osteoblast like cells

Up-regulation of ADAMTS genes with proinflammatory cytokines is important for some pathological conditions such as osteoarthritis (OA) that is a disease based on ECM degradation in cartilage. IL-1α is a proinflammatory cytokine and important both to normal and pathophysiologic conditions in cartilage and bone. Effects of some proinflammatory cytokines such as TNF-α and IL-1β on the some members of ADAMTS family have been investigated in some chondrocyte tissues or cell lines. However the effect of the IL-1α on the expression of ADAMTS-2 and ADAMTS-3 gene expression in osteoblast like cell lines, remains unclear. Therefore, the aim of this study is to investigate the effect of IL-1α on ADAMTS-2 and ADAMTS-3 gene expression in osteoblast like cells, Saos-2 and MG-63. The present study, for the first time, demonstrated that IL-1α increases ADAMTS-2 and ADAMTS-3 gene expressions in both Saos-2 and MG-63 cells. Having correlation to mRNA induction, the upregulation of ADAMTS-2,-3 protein levels by IL-1α stimulation is also observed. The inhibition studies showed that this upregulation occurred at the level of transcription, and there was no effect of IL-1α on ADAMTS-2 mRNA half-life in Saos-2 cells. Transactivation potential of IL-1α on ADAMTS-2 promoter was investigated by transient transfection assay. Specifically, IL-1α strongly increased -658/+112 and -530/+112 ADAMTS-2 promoter constructs. Further, we analyzed signaling pathways involved in ADAMTS-2 induction. Pathway inhibition studies revealed that this upregulation depends on the activation of MEK, JNK and PI3K pathways. These findings suggested that IL-1α is a strong positive regulator of ADAMTS-2 and ADAMTS-3 expression. These findings would provide novel insight into the pathophysiology of OA.