Epigenetic identification of ADAMTS18 as a novel 16q23.1 tumor suppressor frequently silenced in esophageal, nasopharyngeal and multiple other carcinomas

ADAMTS18 deficiency associates extracellular matrix dysfunction with a higher risk of HER2-positive mammary tumorigenesis and metastasis

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer accounts for about 20% of all breast cancer cases and is correlated with a high relapse rate and poor prognosis. ADAMTS18 is proposed as an important functional tumor suppressor gene involved in multiple malignancies, including breast cancer. It functions as an extracellular matrix (ECM) modifier. However, it remains unclear whether ADAMTS18 affects mammary tumorigenesis and malignant progression through its essential ECM regulatory function.

METHODS

To elucidate the role of ADAMTS18 in HER2-positive mammary tumorigenesis and metastasis in vivo, we compared the incidence of mammary tumor and metastasis between Adamts18-knockout (MMTV)-Her2/ErbB2/Neu+ transgenic mice (i.e., Her2t/w/Adamts18-/-) and Adamts18-wildtype (MMTV)-Her2/ErbB2/Neu+ transgenic mice (i.e., Her2t/w/Adamts18+/+). The underlying mechanisms by which ADAMTS18 regulates HER2-positive tumorigenesis and metastasis were investigated by pathology, cell culture, Western blot and immunochemistry.

RESULTS

Adamts18 mRNA is mainly expressed in myoepithelial cells of the mammary duct. ADAMTS18 deficiency leads to a significantly increased incidence of mammary tumors and metastasis, as well as mammary hyperplasia in mice, over 30 months of observation. The proliferation, migration and invasion capacities of primary Her2t/w/Adamts18-/- mammary tumor cells are significantly higher than those of primary Her2t/w/Adamts18+/+ mammary tumor cells in vitro. At 30 months of age, the expression levels of laminin (LNα5), fibronectin (FN) and type I collagen (ColI) in the mammary glands of Her2t/w/Adamts18-/- mice are significantly increased, and the activities of integrin-mediated PI3K/AKT, ERK and JNK signaling pathways are enhanced.

CONCLUSIONS

ADAMTS18 deficiency leads to alterations in mammary ECM components (e.g., LNα5, FN, ColI), which are associated with a higher risk of HER2-positive mammary tumorigenesis and metastasis.

Genome-wide identification of bovine ADAMTS gene family and analysis of its expression profile in the inflammatory process of mammary epithelial cells

ADAM metallopeptidase with thrombospondin type 1 motif (ADAMTS) are secreted, multi-domain matrix-related zinc endopeptidases that play a role in organogenesis, assembly and degradation of extracellular matrix (ECM), cancer and inflammation. Genome-wide identification and analysis of the bovine ADAMTS gene family has not yet been carried out. In this study, 19 ADAMTS family genes were identified in Bos taurus by genome-wide bioinformatics analysis, and they were unevenly distributed on 12 chromosomes. Phylogenetic analysis shows that the Bos taurus ADAMTS are divided into eight subfamilies, with highly consistent gene structures and motifs within the same subfamily. Collinearity analysis showed that the Bos taurus ADAMTS gene family is homologous to other bovine subfamily species, and many ADAMTS genes may be derived from tandem replication and segmental replication. In addition, based on the analysis of RNA-seq data, we found the expression pattern of ADAMTS gene in different tissues. Meanwhile, we also analyzed the expression profile of ADAMTS gene in the inflammatory response of bovine mammary epithelial cells (BMECs) stimulated by LPS by qRT-PCR. The results can provide ideas for understanding the evolutionary relationship and expression pattern of ADAMTS gene in Bovidae, and clarify the theoretical basis of the function of ADAMTS in inflammation.

The role of NF-κB in breast cancer initiation, growth, metastasis, and resistance to chemotherapy

Breast cancer (BC) is the second most fatal disease and is the prime cause of cancer allied female deaths. BC is caused by aberrant tumor suppressor genes and oncogenes regulated by transcription factors (TFs) like NF-κB. NF-κB is a pro-inflammatory TF that crucially alters the expressions of various genes associated with inflammation, cell progression, metastasis, and apoptosis and modulates a network of genes that underlie tumorigenesis. Herein, we focus on NF-κB signaling pathways, its regulators, and the rationale for targeting NF-κB. This review also includes TFs that maintain NF-κB crosstalk and their roles in promoting angiogenesis and metastasis. In addition, we discuss the importance of combination therapies, resistance to treatment, and potential novel therapeutic strategies including nanomedicine that targets NF-κB.

Secreted protease ADAMTS18 in development and disease

ADAMTS18 was identified in 2002 as a member of the ADAMTS family of 19 secreted Zinc-dependent metalloproteinases. Prior to 2016, ADAMTS18 was known as a candidate gene associated with a wide range of pathologies, particularly various malignancies and eye disorders. However, functions and substrates of ADAMTS18 in normal conditions were unknown. Since 2016, with the development of Adamts18 knockout models, many studies had been conducted on the Adamts18 gene in vivo. These studies revealed that ADAMTS18 is essential for the morphology and organogenesis of several epithelial organs (e.g., lung, kidney, breast, salivary glands, and lacrimal glands), vascular and neuronal systems, adipose tissue, and reproductive tracts. In this review, we describe the current understanding of ADAMTS18 and its substrates and regulators. Limitations in translating new findings on ADAMTS18 to clinical practice are also discussed.

The Biochemistry and Physiology of A Disintegrin and Metalloproteinases (ADAMs and ADAM-TSs) in Human Pathologies

Metalloproteinases are a group of proteinases that plays a substantial role in extracellular matrix remodeling and its molecular signaling. Among these metalloproteinases, ADAMs (a disintegrin and metalloproteinases) and ADAM-TSs (ADAMs with thrombospondin domains) have emerged as highly efficient contributors mediating proteolytic processing of various signaling molecules. ADAMs are transmembrane metalloenzymes that facilitate the extracellular domain shedding of membrane-anchored proteins, cytokines, growth factors, ligands, and their receptors and therefore modulate their biological functions. ADAM-TSs are secretory, and soluble extracellular proteinases that mediate the cleavage of non-fibrillar extracellular matrix proteins. ADAMs and ADAM-TSs possess pro-domain, metalloproteinase, disintegrin, and cysteine-rich domains in common, but ADAM-TSs have characteristic thrombospondin motifs instead of the transmembrane domain. Most ADAMs and ADAM-TSs are activated by cleavage of pro-domain via pro-protein convertases at their N-terminus, hence directing them to various signaling pathways. In this article, we are discussing not only the structure and regulation of ADAMs and ADAM-TSs, but also the importance of these metalloproteinases in various human pathophysiological conditions like cardiovascular diseases, colorectal cancer, autoinflammatory diseases (sepsis/rheumatoid arthritis), Alzheimer's disease, proliferative retinopathies, and infectious diseases. Therefore, based on the emerging role of ADAMs and ADAM-TSs in various human pathologies, as summarized in this review, these metalloproteases can be considered as critical therapeutic targets and diagnostic biomarkers.

Role of ADAM and ADAMTS Disintegrin and Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy (NP) involves intricate processes starting with egg fertilization, proceeding to embryo implantation, placentation and gestation, and culminating in parturition. These pregnancy-related processes require marked uteroplacental and vascular remodeling by proteolytic enzymes and metalloproteinases. A disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) are members of the zinc-dependent family of proteinases with highly conserved protein structure and sequence homology, which include a pro-domain, and a metalloproteinase, disintegrin and cysteine-rich domain. In NP, ADAMs and ADAMTS regulate sperm-egg fusion, embryo implantation, trophoblast invasion, placental angiogenesis and spiral arteries remodeling through their ectodomain proteolysis of cell surface cytokines, cadherins and growth factors as well as their adhesion with integrins and cell-cell junction proteins. Preeclampsia (PE) is a serious complication of pregnancy characterized by new-onset hypertension (HTN) in pregnancy (HTN-Preg) at or after 20 weeks of gestation, with or without proteinuria. Insufficient trophoblast invasion of the uterine wall, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia/hypoxia are major initiating events in the pathogenesis of PE. Placental ischemia/hypoxia increase the release of reactive oxygen species (ROS), which lead to aberrant expression/activity of certain ADAMs and ADAMTS. In PE, abnormal expression/activity of specific ADAMs and ADAMTS that function as proteolytic sheddases could alter proangiogenic and growth factors, and promote the release of antiangiogenic factors and inflammatory cytokines into the placenta and maternal circulation leading to generalized inflammation, endothelial cell injury and HTN-Preg, renal injury and proteinuria, and further decreases in uteroplacental blood flow, exaggeration of placental ischemia, and consequently fetal growth restriction. Identifying the role of ADAMs and ADAMTS in NP and PE has led to a better understanding of the underlying molecular and vascular pathways, and advanced the potential for novel biomarkers for prediction and early detection, and new approaches for the management of PE.

Downregulation of SLC27A6 by DNA Hypermethylation Promotes Proliferation but Suppresses Metastasis of Nasopharyngeal Carcinoma Through Modulating Lipid Metabolism

Lipid is the building block and an important source of energy, contributing to the malignant behavior of tumor cells. Recent studies suggested that lipid droplets (LDs) accumulations were associated with nasopharyngeal carcinoma (NPC) progression. Solute carrier family 27 member 6 (SLC27A6) mediates the cellular uptake of long-chain fatty acid (LCFA), a necessary lipid component. However, the functions of SLC27A6 in NPC remain unknown. Here, we found a significant reduction of SLC27A6 mRNA in NPC tissues compared with normal nasopharyngeal epithelia (NNE). The promoter methylation ratio of SLC27A6 was greater in NPC than in non-cancerous tissues. The demethylation reagent 5-aza-2'-deoxycytidine (5-aza-dC) remarkably restored the mRNA expression of SLC27A6, suggesting that this gene was downregulated in NPC owing to DNA promoter hypermethylation. Furthermore, SLC27A6 overexpression level in NPC cell lines led to significant suppression of cell proliferation, clonogenicity in vitro, and tumorigenesis in vivo. Higher SLC27A6 expression, on the other hand, promoted NPC cell migration and invasion. In particular, re-expression of SLC27A6 faciliated epithelial-mesenchymal transition (EMT) signals in xenograft tumors. Furthermore, we observed that SLC27A6 enhanced the intracellular amount of triglyceride (TG) and total cholesterol (T-CHO) in NPC cells, contributing to lipid biosynthesis and increasing metastatic potential. Notably, the mRNA level of SLC27A6 was positively correlated with cancer stem cell (CSC) markers, CD24 and CD44. In summary, DNA promoter hypermethylation downregulated the expression of SLC27A6. Furthermore, re-expression of SLC27A6 inhibited the growth capacity of NPC cells but strengthened the CSC markers. Our findings revealed the dual role of SLC27A6 in NPC and shed novel light on the link between lipid metabolism and CSC maintenance.

OKN-007 Alters Protein Expression Profiles in High-Grade Gliomas: Mass Spectral Analysis of Blood Sera

Current therapies for high-grade gliomas, particularly glioblastomas (GBM), do not extend patient survival beyond 16–22 months. OKN-007 (OKlahoma Nitrone 007), which is currently in phase II (multi-institutional) clinical trials for GBM patients, and has demonstrated efficacy in several rodent and human xenograft glioma models, shows some promise as an anti-glioma therapeutic, as it affects most aspects of tumorigenesis (tumor cell proliferation, angiogenesis, migration, and apoptosis). Combined with the chemotherapeutic agent temozolomide (TMZ), OKN-007 is even more effective by affecting chemo-resistant tumor cells. In this study, mass spectrometry (MS) methodology ESI-MS, mass peak analysis (Leave One Out Cross Validation (LOOCV) and tandem MS peptide sequence analyses), and bioinformatics analyses (Ingenuity^® Pathway Analysis (IPA^®)), were used to identify up- or down-regulated proteins in the blood sera of F98 glioma-bearing rats, that were either untreated or treated with OKN-007. Proteins of interest identified by tandem MS-MS that were decreased in sera from tumor-bearing rats that were either OKN-007-treated or untreated included ABCA2, ATP5B, CNTN2, ITGA3, KMT2D, MYCBP2, NOTCH3, and VCAN. Conversely, proteins of interest in tumor-bearing rats that were elevated following OKN-007 treatment included ABCA6, ADAMTS18, VWA8, MACF1, and LAMA5. These findings, in general, support our previous gene analysis, indicating that OKN-007 may be effective against the ECM. These findings also surmise that OKN-007 may be more effective against oligodendrogliomas, other brain tumors such as medulloblastoma, and possibly other types of cancers.

The expression of ADAMTS14 is regulated by promoter DNA methylation and is associated with poor prognosis in colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors of digestive system, and its main cause of death is tumor metastasis. The occurrence of CRC is a polygenic and multi-step complex process involving genetic and epigenetic alterations. It has been demonstrated that ADAMTS14 (A disintegrin and metalloproteinase with thrombospondin motifs 14) was hypermethylated in esophageal cancer using whole-genome methylation microarray in our previous report. The present study revealed that ADAMTS14 was highly methylated accompanied with low expression in CRC. In addition, demethylation agent 5-Aza-dC could demethylate ADAMTS14 promoter region and reactivate ADAMTS14 expression effectively in vitro. Therefore, promoter hypermethylation was probably contributed to ADAMTS14 epigenetic silencing in CRC. Furthermore, ADAMTS14 protein expression was higher at invasive tumor front than at the tumor center or other areas of tumor. Kaplan-meier survival analysis indicated that the high ADAMTS14 expression was correlated with poor prognosis in CRC patients, suggesting the possibility that ADAMTS14 is a promising indicator in the evaluation of CRC prognosis.

ADAMTS18 deficiency leads to preputial gland hypoplasia and fibrosis in male mice

ADAMTSs (A disintegrin and metalloproteinase with thrombospondin motifs) are a family of 19 secreted zinc metalloproteinases that play a major role in the assembly and degradation of the extracellular matrix (ECM) during development, morphogenesis, tissue repair, and remodeling. ADAMTS18 is a poorly characterized member of the ADAMTS family. Previously, ADAMTS18 was found to participate in the development of female reproductive tract in mice. However, whether ADAMTS18 also plays a role in the development of male reproductive system remains unclear. In this study, Adamts18 mRNA was found to be highly expressed in the basal cells of the developing preputial gland. Male Adamts18 knockout (Adamts18^-/-) mice exhibit abnormal preputial gland morphogenesis, including reduced size and sharp outline. Histological analyses of preputial gland from 2-week-old male Adamts18^-/- mice showed significant atrophy of the whole gland. Preputial glands from 7 months and older Adamts18^-/- mice appeared macroscopic swelling on their surface. Histologically, preputial gland swelling is characterized by tissue fibrosis and thicker keratinized squamous cell layer. Preputial gland lesions in age-matched male Adamts18^+/+ mice were barely detected. ADAMTS18 deficiency does not lead to significant changes in morphogenesis of prostate and testis in male mice. These results indicate that ADAMTS18 is required for normal morphogenesis and homeostasis of the preputial gland in male mice.

Adamts18 Deficiency Causes Spontaneous SMG Fibrogenesis in Adult Mice

Chronic sclerosing sialadenitis of the submandibular gland (also known as Küttner tumor) is characterized by concomitant swelling of the submandibular glands secondary to strong lymphocytic infiltration and fibrosis. The pathogenesis of this disease has been unclear, but it is associated with immune disorders. ADAMTS18 is a member of the ADAMTS superfamily of extracellular proteinases. In this study, we showed that Adamts18 is highly expressed in submandibular salivary gland (SMG) during embryonic development and decreases but is retained in adult SMG tissue in mice. Adamts18 deficiency led to reduced cleft formation and epithelial branching in embryonic SMG before embryonic day 15.5 in mice. No significant histologic changes in the later stages of branching or the morphology of SMG were detected in Adamts18^-/- mice. However, Adamts18 deficiency causes spontaneous SMG fibrogenesis and fibrosis in adult mice. At 8 wk of age, Adamts18^-/- mice began to manifest the first signs of pathologic changes of mild fibrosis and CD11b⁺ cell infiltration in SMG tissues. At ≥8 mo, all male and female Adamts18^-/- mice developed unilateral or bilateral SMG scleroma that is similar to patients with chronic sclerosing sialadenitis of the submandibular gland. Adamts18^-/- mice also showed secretory dysfunction and severe dental caries. Histologically, SMG scleroma is characterized by progressive periductal fibrosis, acinar atrophy, irregular duct ectasis, and dense infiltration of IgG-positive plasma cells. A significant infiltration of CD4⁺ T lymphocytes and CD11b⁺ monocytes and macrophages was also detected in the SMG scleroma of Adamts18^-/- mice. The levels of TGF-β1, IL-6, and IL-33 were significantly increased in Adamts18^-/- SMGs, which induces chronic inflammation and myofibroblast activation, ultimately leading to fibrosis. This study indicates that Adamts18 regulates the early branching morphogenesis of embryonic SMG and plays a role in protecting from spontaneous SMG fibrogenesis via modulating local inflammation, autoimmune reaction, and myofibroblast activation in adult mice.

Characterization of a functional endothelial super-enhancer that regulates ADAMTS18 and angiogenesis

Super-enhancers are clusters of enhancers associated with cell lineage. They can be powerful gene-regulators and may be useful in cell-type specific viral-vector development. Here, we have screened for endothelial super-enhancers and identified an enhancer from within a cluster that conferred 5–70-fold increase in transgene expression. Importantly, CRISPR/Cas9 deletion of enhancers demonstrated regulation of ADAMTS18, corresponding to evidence of chromatin contacts between these genomic regions. Cell division-related pathways were primarily affected by the enhancer deletions, which correlated with significant reduction in cell proliferation. Furthermore, we observed changes in angiogenesis-related genes consistent with the endothelial specificity of this SE. Indeed, deletion of the enhancers affected tube formation, resulting in reduced or shortened sprouts. The super-enhancer angiogenic role is at least partly due to its regulation of ADAMTS18, as siRNA knockdown of ADAMTS18 resulted in significantly shortened endothelial sprouts. Hence, functional characterization of a novel endothelial super-enhancer has revealed substantial downstream effects from single enhancer deletions and led to the discovery of the cis-target gene ADAMTS18 and its role in endothelial function.

ADAMTS18 regulates vaginal opening through influencing the fusion of Mullerian duct and apoptosis of vaginal epithelial cells in mice

The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin Motifs) enzymes are secreted metalloproteinases with major roles in development, morphogenesis, and tissue repair via the assembly and degradation of extracellular matrix (ECM). In this study, we investigated the role of ADAMTS18 in the development of the reproductive tract in female mice by phenotyping Adamts18 knockout (Adamts18^-/-) mice. The results showed that Adamst18 mRNAs were abundantly expressed in vaginal epithelial cells and muscularis cells of the developing vagina. At the time of vaginal opening (5 weeks of age), about 41 % of Adamts18^-/- females showed enlarged protrusions in the upper and middle parts of the vagina, reduced vaginal length, and simultaneously exhibited vaginal atresia. 6% Adamts18^-/- females exhibited vaginal septum. Histological analyses revealed that the paired Mullerian ducts in ∼33 % female Adamts18^-/- embryos failed to fuse at embryonic day 15.5 (E15.5) resulting in the formation of two vaginal cavities. Results of TUNEL assay and immunohistochemistry for caspase-3 showed that the number of apoptotic cells in the terminal portion of the vagina of 5-week-old Adamts18^-/- females with vaginal atresia was significantly decreased. Adamts18^-/- females also showed a significant decrease in serum estradiol E2 compared to age-matched Adamts18^+/+ females. Results of qRT-PCR showed that the expression level of the anti-apoptosis gene Bcl-2 was significantly increased and that of the apoptosis-related gene Epha1 was decreased in the vagina of 5-week-old Adamts18^-/- females. These results suggest that ADAMTS18 regulates vaginal opening through influencing the fusion of Mullerian ducts and apoptosis of vaginal cells in mice.

Adamts18 modulates the development of the aortic arch and common carotid artery

Members of a disintegrin and metalloproteinases with thrombospondin motif (ADAMTS) family have been implicated in various vascular diseases. However, their functional roles in early embryonic vascular development are unknown. In this study, we showed that Adamts18 is highly expressed at E11.5-E14.5 in cells surrounding the embryonic aortic arch (AOAR) and the common carotid artery (CCA) during branchial arch artery development in mice. Adamts18 deficiency was found to cause abnormal development of AOAR, CCA, and the third and fourth branchial arch appendages, leading to hypoplastic carotid body, thymus, and variation of middle cerebral artery. Adamts18 was shown to affect the accumulation of extracellular matrix (ECM) components, in particular fibronectin (Fn), around AOAR and CCA. As a result of increased Fn accumulation, the Notch3 signaling pathway was activated to promote the differentiation of cranial neural crest cells (CNCCs) to vascular smooth muscle cells. These data indicate that Adamts18-mediated ECM homeostasis is crucial for the differentiation of CNCCs.

New physiological insights into the phenomena of deer antler: A unique model for skeletal tissue regeneration

Generally, mammals are unable to regenerate complex tissues and organs however the deer antler provides a rare anomaly to this rule. This osseous cranial appendage which is located on the frontal bone of male deer is capable of stem cell-based organogenesis, annual casting, and cyclic de novo regeneration. A series of recent studies have classified this form of regeneration as epimorphic stem cell based. Antler renewal is initiated by the activation of neural crest derived pedicle periosteal cells (PPCs) found residing within the pedicle periosteum (PP), these PPCs have the potential to differentiate into multiple lineages. Other antler stem cells (ASCs) are the reserve mesenchymal cells (RMCs) located in the antlers tip, which develop into cartilage tissue. Antlerogenic periosteal cells (APCs) found within the antlerogenic periosteum (AP) form the tissues of both the pedicle and first set of antlers. Antler stem cells (ASCs) further appear to progress through various stages of activation, this coordinated transition is considered imperative for stem cell-based mammalian regeneration. The latest developments have shown that the rapid elongation of the main beam and antler branches are a controlled form of tumour growth, regulated by the tumour suppressing genes TP73 and ADAMTS18. Both osteoclastogenesis, as well as osteogenic and chondrogenic differentiation are also involved. While there remains much to uncover this review both summarises and comprehensively evaluates our existing knowledge of tissue regeneration in the deer antler. This will assist in achieving the goal of in vitro organ regeneration in humans by furthering the field of modern regenerative medicine.

The Translational potential of this article

As a unique stem cell-based organ regeneration process in mammals, the deer antler represents a prime model system for investigating mechanisms of regeneration in mammalian tissues. Novel ASCs could provide cell-based therapies for regenerative medicine and bone remodelling for clinical application. A greater understanding of this process and a more in-depth defining of ASCs will potentiate improved clinical outcomes.

Genome-wide association study of the TP53 R249S mutation in hepatocellular carcinoma with aflatoxin B1 exposure and infection with hepatitis B virus

BACKGROUND

Exposure to dietary aflatoxin B1 (AFB1) induces DNA damage and mutation in the TP53 gene at codon 249, known as the TP53 R249S mutation, and is a major risk factor for hepatocellular carcinoma (HCC). AFB1 and the hepatitis B virus (HBV) together exert synergistic effects that promote carcinogenesis and TP53 R249S mutation in HCC.

METHODS

A genome-wide association study (GWAS) of whole genome exons was conducted using 485 HCC patients with chronic HBV infection. This was followed by an independent replication study conducted using 270 patients with chronic HBV infection. Immunohistochemistry was used to evaluate TP53 expression in all samples. This showed a correlation between codon 249 mutations and TP53 expression. Susceptibility variants for the TP53 R249S mutation in HCC were identified based on both the GWAS and replication study. The associations between identified variants and the expression levels of their located genes were analyzed in 20 paired independent samples.

RESULTS

The likelihood of positive TP53 expression was found to be higher in HCC patients with the R249S mutation both in the GWAS (P<0.001) and the replication study (P=0.006). The combined analyses showed that the TP53 R249S mutation was significantly associated with three single nucleotide polymorphisms (SNPs): ADAMTS18 rs9930984 (adjusted P=4.84×10-6), WDR49 rs75218075 (adjusted P=7.36×10-5), and SLC8A3 rs8022091 (adjusted P=0.042). The TP53 R249S mutation was found to be highly associated with the TT genotypes of rs9930984 (additive model, P=0.01; dominant model, P=6.43×10-5) and rs75218075 (additive model, P=0.002; dominant model, P=2.16×10-4). Additionally, ADAMTS18 mRNA expression was significantly higher in HCC tissue compared with its expression in paired non-tumor tissue (P=0.041), and patients carrying the TT genotype at rs9930984 showed lower ADAMTS18 expression in non-tumor tissue compared with patients carrying the GT genotype (P=0.0028). WDR49 expression was markedly lower in HCC tissue compared with paired non-tumor tissue (P=0.0011).

CONCLUSIONS

TP53 expression is significantly associated with the R249S mutation in HCC. Our collective results suggest that rs9930984, rs75218075, and rs8022091 are associated with R249S mutation susceptibility in HCC patients exposed to AFB1 and HBV infection.

ADAMTS18 Deficiency Leads to Pulmonary Hypoplasia and Bronchial Microfibril Accumulation

ADAMTSs (a disintegrin and metalloproteinase with thrombospondin motifs) are secreted metalloproteinases that play a major role in the assembly and degradation of the extracellular matrix (ECM). In this study, we show that ADAMTS18, produced by the epithelial cells of distal airways and mesenchymal cells in lung apex at early embryonic stages, serves as a morphogen in lung development. ADAMTS18 deficiency leads to reduced number and length of bronchi, tipped lung apexes, and dilated alveoli. These developmental defects worsen lipopolysaccharide-induced acute lung injury and bleomycin-induced lung fibrosis in adult Adamts18-deficient mice. ADAMTS18 deficiency also causes increased levels of fibrillin1 and fibrillin2, bronchial microfibril accumulation, decreased focal adhesion kinase signaling, and disruption of F-actin organization. Our findings indicate that ECM homeostasis mediated by ADAMTS18 is pivotal in airway branching morphogenesis.

High ADAMTS18 expression is associated with poor prognosis in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is the most pathological type of gastric cancer. ADAM metallopeptidase with thrombospondin type 1 motif 18 (ADAMTS18) plays an essential role in organ development and tumorigenesis; however, its function in STAD, and its impact on clinical outcome remain unclear. Thus, the present study aimed to investigate the association between ADAMTS18 expression and the prognosis of patients with STAD. Data from 300 patients with STAD in The Cancer Genome Atlas (TCGA) database were analyzed, and the median survival time and overall survival (OS) rate of these patients were assessed. Subsequently, 40 paired tumor and non-tumor tissue samples from patients with STAD were collected, and the relative ADAMTS18 mRNA expression levels were determined. Results from TCGA database demonstrated that high tumor ADAMTS18 expression was associated with a poorer prognosis in patients with STAD. Similarly, results from the assessed patient cohort indicated that ADAMTS18 expression was significantly higher in STAD tissues compared with non-tumor tissues. Furthermore, ADAMTS18 expression was significantly associated with tumor differentiation, lymph node metastasis and tumor node metastasis stage. Taken together, these results suggest that ADAMTS18 is highly expressed in STAD tissues, and thus may act as a potential indicator of poor prognosis in patients with STAD.

ADAMTS8 Inhibits Cell Proliferation and Invasion, and Induces Apoptosis in Breast Cancer

Introduction

A disintegrin and metallopeptidase with thrombospondin motifs (ADAMTSs), whose expression is dysregulated in various cancers, is implicated in cancer development. Herein, we aimed to investigate the functional role of ADAMTS8 in breast cancer (BC) and explore the underlying mechanisms.

Methods

The protein expression of ADAMTS8 in BC cell lines and tumor tissues from BC patients was quantified by Western blot. ADAMTS8 overexpression was induced by transfection with pEZ-M90-ADAMTS8 plasmid using lipofectamine 2000. To generate ADAMTS8 stable knockdown cells, MDA-MB-231 cells were transfected with psi-H1-ADAMTS8siRNA plasmids. Cell counting kit-8 (CCK-8) assay, wound-healing assay, transwell assay and flow cytometry assay were employed to analyze the effects of ADAMTS8 on the proliferation, migration, invasion and apoptosis of BC cells. Chemosensitivity also was assessed using CCK-8 assay. The expressions of β-catenin, MMP-7 and c-Myc were measured by Western blot.

Results

Our results showed that ADAMTS8 expression was significantly lower in BC tissues than that in adjacent non-tumor tissues. Overexpression of ADAMTS8 in MDA-MB-453 cells could inhibit the cell proliferation, migration and invasion and promote apoptosis. ADAMTS8 knockdown displayed the reverse effect in MDA-MB-231 cells. Consistently, in vivo data showed that ADAMTS8 overexpression led to a reduction in tumor growth. In addition, chemosensitivity testing in MDA-MB-453 cells transfected with pEZ-M90-ADAMTS8 plasmid indicated that cisplatin inhibited cell growth dramatically. Furthermore, attenuated β-catenin, MMP-7 and c-Myc level was detected after ADAMTS8 overexpression.

Conclusion

These results indicate that increased ADAMTS8 expression could modify the progression of BC by inhibiting cell proliferation and invasion while promoting the apoptosis of BC cells. Thus, ADAMTS8 represents a potential therapeutic target for BC therapy.

Prognostic Values for the mRNA Expression of the ADAMTS Family of Genes in Gastric Cancer

The “A Disintegrin and Metalloproteinase with Thrombospondin Motif” (ADAMTS) family of genes is involved in the occurrence and development of different cancers. However, the prognostic value of these genes in gastric cancer (GC) has not been revealed. The present study was thus conducted to determine the prognostic value for the ADAMTS family of genes in GC. First, we evaluated the mRNA expression levels of the ADAMTS family in GC patients using a GEPIA dataset. Thereafter, we determined the prognostic value of these genes by analyzing their mRNA level using the Kaplan–Meier Plotter database. The mRNA expression level of ADAMTS12 was randomly validated by qRT-PCR and meta-analysis while its coexpression genes were derived using Coexpedia. Finally, we performed Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses using the OmicShare Tools. Compared to normal tissues, expression of ADAMTS2 and 12 was significantly higher while that of ADAMTS1, 13, and 15 was significantly lower in GC tissues. According to the RNA-seq and gene chip data, the ADAMTS family (6, 7, 12, 15, and 18) of genes was closely related to the prognosis of GC, and their high expression levels were associated with poor prognosis and survival time. In addition, ADAMTS12 was highly expressed in 20 pairs of GC tissues based on RT-PCR (P=0.016) and meta-analysis (SMD: 0.73, 95% CI: 0.32–1.14, P < 0.001). GO and KEGG pathway analyses indicated that the ADAMTS12 coexpressed genes were enriched in the pathways of extracellular matrix organization, extracellular matrix structural constituent, extracellular matrix, and protein digestion and absorption. Herein, we discovered the prognostic values and biological roles of the ADAMTS genes in GC.

Genetic basis of ruminant headgear and rapid antler regeneration

Ruminants are the only extant mammalian group possessing bony (osseous) headgear. We obtained 221 transcriptomes from bovids and cervids and sequenced three genomes representing the only two pecoran lineages that convergently lack headgear. Comparative analyses reveal that bovid horns and cervid antlers share similar gene expression profiles and a common cellular basis developed from neural crest stem cells. The rapid regenerative properties of antler tissue involve exploitation of oncogenetic pathways, and at the same time some tumor suppressor genes are under strong selection in deer. These results provide insights into the evolutionary origin of ruminant headgear as well as mammalian organ regeneration and oncogenesis.

Identification of somatic copy number variations in plasma cell free DNA correlating with intrinsic resistances to EGFR targeted therapy in T790M negative non-small cell lung cancer

Background

About 20–30% EGFR-mutant non-small lung cancer show intrinsic resistance to EGFR targeted therapies. Compared to T790M positive in acquired resistance patients, little is known about EGFR-TKI intrinsic resistance for T790M negative patients.

Methods

Thirty-one patients with advanced stage lung cancer, including 18 patients with intrinsic resistance (PFS <6 months) and 13 patients with acquired resistance (PFS >36 months) but are negative for plasma T790M were recruited in the study. Plasma cell free DNA was profiled by low coverage whole genome sequencing with median genome coverage of 1.86X by Illumina X10. Sequencing coverage across chromosomes was summarized by samtools, and normalized by segmentation analysis as provided by R package ‘DNACopy’.

Results

The most frequent chromosomal changes were found on chr7, chr1 and chr8. Among them, chr7p gains were found in 12 (66.7%) intrinsic resistance and 4 (30.7%) acquired resistance patients. The gene EGFR was found located on the focal amplification peak of chr7p. The performance of 7p gain to predict intrinsic resistance reaches AUC =0.902. Similarly, focal amplifications were also found on chromosome 5, 16 and 22, where tumor related gene PCDHA^@, ADAMTS18 and CRKL were located. Focal deletions were also found in chr1, 8, 10 and 16, where genes SFTPA1/2, DLC1, PTEN and CDH1 are located.

Conclusions

The results suggest cell free DNA copy number might be a useful peripheral blood tumor biomarker for predicting intrinsic resistance of EGFR targeted therapy and prognosis.

Adamts18 deficiency in zebrafish embryo causes defective trunk angiogenesis and caudal vein plexus formation

ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin type I motifs) enzymes play an important role in various morphogenesis processes. To determine the functions of Adamts18 in the early stages of organogenesis, we created Adamts18 deficient zebrafish using morpholino antisense oligonucleotides (MO) to generate exon 3 skipped adamts18 mRNA transcripts. Results showed that Adamts18 deficiency in zebrafish embryos caused developmental defects, including expanded brain ventricle and hindbrain edema, eye defects, and accumulation of blood in the caudal vein. Adamts18 deficiency also led to impaired trunk angiogenesis and formation of the caudal vein plexus (CVP). Consequently, Adamts18 deficient zebrafish embryos exhibited incomplete formation of intersegment vessels (ISVs), disruption of the honeycomb structure of CVP, and reduced CVP area and loop number. Furthermore, Adamts18 deficiency resulted in impaired blood circulation in major trunk, caudal vein (CV), and common cardinal vein (CCV). These aberrant vascular phenotypes in mutant zebrafish embryos were shown to be associated with a decreased expression of multiple angiogenesis-related signaling genes, including slit/robo, dll4/Notch, cox2, and fgfr. These findings indicate the critical role of Adamts18 in the early stages of vascular network development.

Downregulation of ADAMTS18 May Serve as a Poor Prognostic Biomarker for Cervical Cancer Patients

ADAMTS18 is a member of ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin motifs) family proteins which have been found to play important roles in cancer progression and metastasis in different cancer types. The present study aims at evaluating the prognostic significance of ADAMTS18 in cervical cancer. The expression levels of ADAMTS18 was evaluated by real-time PCR in normal (N=28) and cervical cancer tissues from patients at different stages as well as in tumor tissues from 35 cervical cancer patients with primary cancer and 29 patients with metastasis. The correlation between serum ADAMTS18 expression levels and clinicopathologic features or overall survival of cervical cancer patients was analyzed. ADAMTS18 expression levels were significantly decreased in cervical cancer tissues compared with normal tissues and it decreased gradually from early stage to late stage. Low expression of ADAMTS18 was positively associated with high tumor stage (P=0.0239), positive lymph node metastasis (P=0.0388), and distant metastasis (P=0.0004). Tissue levels of ADAMTS18 in patients with primary cancer were significantly lower compared with those with metastasis. Moreover, patients with low ADAMTS18 expression levels had shorter overall survival (P=0.0119) or disease-free survival (P=0.0033). Multivariate analysis demonstrated that ADAMTS18 was an independent prognostic factor for cervical cancer. Our study suggests that ADAMTS18 is downregulated in cervical cancer and ADAMTS18 may serve as a potential prognostic biomarker for cervical cancer.

Morphogenesis of the kidney and lung requires branch-tip directed activity of the Adamts18 metalloprotease

Adamts18 encodes a secreted metalloprotease restricted to branch-tip progenitor pools directing the morphogenesis of multiple mammalian organs. Adamts18 was targeted to explore a potential role in branching morphogenesis. In the kidney, an arborized collecting system develops through extensive branching morphogenesis of an initial epithelial outgrowth of the mesonephric duct, the ureteric bud. Adamts18 mutants displayed a weakly penetrant phenotype: duplicated ureteric outgrowths forming enlarged, bi-lobed kidneys with an increased nephron endowment. In contrast, Adamts18 mutants showed a fully penetrant lung phenotype: epithelial growth was markedly reduced and early secondary branching scaled to the reduced length of the primary airways. Furthermore, there was a pronounced delay in the appearance of differentiated cell types in both proximal and distally positions of the developing airways. Adamts18 is closely related to Adamts16. In the kidney but not the lung, broad epithelial Adamts16 expression overlaps Adamts18 in branch tips. However, compound Adamts16/18 mutants displayed a comparable low penetrance duplicated ureteric phenotype, ruling out a possible role for Adamts16 as a functional modifier of the Adamts18 kidney phenotype. Given the predicted action of secreted Adamts18 metalloprotease, and broad expression of Adamts18 in branching organ systems, these findings suggest distinct requirements for matrix modelling in the morphogenesis of epithelial networks.

ADAMTS18 Deficiency Affects Neuronal Morphogenesis and Reduces the Levels of Depression-like Behaviors in Mice

The ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) enzymes are secreted, multi-domain matrix-associated zinc metalloendopeptidases that modify extracellular matrix components and play crucial roles in development and numerous diseases. ADAMTS18 is a member of the ADAMTS family, and genome-wide association studies made an initial association of ADAMTS18 with white matter integrity in healthy people of 72-74 years old. However, the potential roles of ADAMTS18 in central nervous system remain unclear. In this study, we showed that Adamts18 mRNA is highly abundant in developing brains, especially in the cerebellum granular cell layer and the hippocampus dentate gyrus (DG) granular cell layer. Adamts18 knockout (KO) mice displayed higher dendritic branching complexity and spine density on hippocampal DG granular cells. Behavioral tests showed that Adamts18 KO mice had reduced levels of depression-like behaviors compared to their wild-type (WT) littermates. The increased neurite formation could be attributed in part to reduced phosphorylation levels of the collapsin response mediator protein-2 (CRMP2) due to activation of the laminin/PI3K/AKT/GSK-3β signaling pathway. Our findings revealed a critical role of ADAMTS18 in neuronal morphogenesis and emotional control in mice.

Inactivation of ADAMTS18 by aberrant promoter hypermethylation contribute to lung cancer progression

Lung cancer is the most frequently diagnosed cancer worldwide. Epigenetic regulation contributes to lung cancer pathogenesis. The ADAMTS18 tumor suppressor gene is inactivated in some cancers, but its involvement in lung cancer has not been shown. Immunohistochemistry, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and methylation-specific PCR were used to assay ADAMTS18 expression and promoter methylation in lung tumor tissues and adjacent tissues. Cell viability, transwell, and wound-healing assays, as well as flow cytometry were used to characterize the biological activity of ADAMTS18. The influence of ADAMTS18 on protein expression was assayed using western blots analysis, and its effect on chemosensitivity was assayed by the response to cisplatin. We found that ADAMTS18 was silenced in lung cancer cells by promoter methylation. Demethylation by the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine, with or without the histone deacetylase inhibitor trichostatin A, restored ADAMTS18 expression. Compared with normal lung tissue, ADAMTS18 in lung tumors was frequently methylated. Overexpression of ADAMTS18 in lung cancer cells inhibited cell proliferation, migration, and invasiveness and induced G0/G1 cell cycle arrest. Furthermore, ADAMTS18 suppressed epidermal growth factor receptor/protein kinase B (EGFR/AKT) signaling, which sensitized lung cancer cells to cisplatin. Thus, our results demonstrated that the tumor suppressor gene ADAMTS18 was downregulated in lung cancer by promoter CpG methylation, and it promoted sensitivity to cisplatin via EGFR/AKT signaling. Our study suggests that ADAMTS18 promoter methylation is a potential epigenetic biomarker for early detection of lung cancer and warrants investigation as a therapeutic target for early-stage lung cancer.

ADAMTS8 targets ERK to suppress cell proliferation, invasion, and metastasis of hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors of the digestive system. A disintegrin and metallopeptidase with thrombospondin motif (ADAMTS) has been identified as a secreted metalloproteinase that participates in the inhibition of tumor cell growth and invasion. The aims of the present study were to investigate the clinical significance of ADAMTS8 in patients with HCC and to determine the effect of ADAMTS8 on HCC cell biological activity in vitro and in vivo.

Methods

The tumor tissues and matched adjacent non-tumor tissues were collected from 61 patients with HCC, and ADAMTS8 expression was detected with immunohistochemistry. Flow cytometry and MTT assays were used to assess cell apoptosis and cell viability, respectively, and ERK, p-ERK, Stat3, p-Stat3, Akt, and p-Akt protein expressions were measured by Western blot.

Results

The results showed that ADAMTS8 expression was significantly lower in HCC tissues than that in adjacent non-tumor tissues. Moreover, ADAMTS8 expression was inversely associated with clinical stages and metastasis in patients with HCC. Furthermore, we found that transfection with exogenous ADAMTS8 inhibited proliferation and migration and induced apoptosis in HepG2 cells. In the in vivo study, tumor growth of upregulated HepG2 cells in nude mice was significantly slower. Moreover, decreased ERK activity was detected after transfection with ADAMTS8.

Conclusion

These results indicate that low ADAMTS8 expression is a predictor of a poor prognosis in patients with HCC and that ADAMTS8 plays an important role in regulating HCC growth, invasion, and apoptosis by modulating the ERK signaling pathway. ADAMTS8 maybe a new target in HCC treatment.

Aberrant DNA methylation of ADAMTS16 in colorectal and other epithelial cancers

BACKGROUND

ADAMs (a disintegrin and metalloproteinase) have long been associated with tumor progression. Recent findings indicate that members of the closely related ADAMTS (ADAMs with thrombospondin motifs) family are also critically involved in carcinogenesis. Gene silencing through DNA methylation at CpG loci around e.g. transcription start or enhancer sites is a major mechanism in cancer development. Here, we aimed at identifying genes of the ADAM and ADAMTS family showing altered DNA methylation in the development or colorectal cancer (CRC) and other epithelial tumors.

METHODS

We investigated potential changes of DNA methylation affecting ADAM and ADAMTS genes in 117 CRC, 40 lung cancer (LC) and 15 oral squamous-cell carcinoma (SCC) samples. Tumor tissue was analyzed in comparison to adjacent non-malignant tissue of the same patients. The methylation status of 1145 CpGs in 51 ADAM and ADAMTS genes was measured with the HumanMethylation450 BeadChip Array. ADAMTS16 protein expression was analyzed in CRC samples by immunohistochemistry.

RESULTS

In CRC, we identified 72 CpGs in 18 genes which were significantly affected by hyper- or hypomethylation in the tumor tissue compared to the adjacent non-malignant tissue. While notable/frequent alterations in methylation patterns within ADAM genes were not observed, conspicuous changes were found in ADAMTS16 and ADAMTS2. To figure out whether these differences would be CRC specific, additional LC and SCC tissue samples were analyzed. Overall, 78 differentially methylated CpGs were found in LC and 29 in SCC. Strikingly, 8 CpGs located in the ADAMTS16 gene were commonly differentially methylated in all three cancer entities. Six CpGs in the promoter region were hypermethylated, whereas 2 CpGs in the gene body were hypomethylated indicative of gene silencing. In line with these findings, ADAMTS16 protein was strongly expressed in globlet cells and colonocytes in control tissue but not in CRC samples. Functional in vitro studies using the colorectal carcinoma cell line HT29 revealed that ADAMTS16 expression restrained tumor cell proliferation.

CONCLUSIONS

We identified ADAMTS16 as novel gene with cancer-specific promoter hypermethylation in CRC, LC and SCC patients implicating ADAMTS16 as potential biomarker for these tumors. Moreover, our results provide evidence that ADAMTS16 may have tumor suppressor properties.

TET1 exerts its anti-tumor functions via demethylating DACT2 and SFRP2 to antagonize Wnt/β-catenin signaling pathway in nasopharyngeal carcinoma cells

BACKGROUND

TET1 is a tumor suppressor gene (TSG) that codes for ten-eleven translocation methyl cytosine dioxygenase1 (TET1) catalyzing the conversion of 5-methylcytosine to 5-hydroxy methyl cytosine as a first step of TSG demethylation. Its hypermethylation has been associated with cancer pathogenesis. However, whether TET1 plays any role in nasopharyngeal carcinoma (NPC) remains unclear. This study investigated the expression and methylation of TET1 in NPC and confirmed its role and mechanism as a TSG.

RESULTS

TET1 expression was downregulated in NPC tissues compared with nasal septum deviation tissues. Demethylation of TET1 in HONE1 and HNE1 cells restored its expression with downregulated methylation, implying that TET1 was silenced by promoter hypermethylation. Ectopic expression of TET1 suppressed the growth of NPC cells, induced apoptosis, arrested cell division in G0/G1 phase, and inhibited cell migration and invasion, confirming TET1 TSG activity. TET1 decreased the expression of nuclear β-catenin and downstream target genes. Furthermore, TET1 could cause Wnt antagonists (DACT2, SFRP2) promoter demethylation and restore its expression in NPC cells.

CONCLUSIONS

Collectively, we conclude that TET1 exerts its anti-tumor functions in NPC cells by suppressing Wnt/β-catenin signaling via demethylation of Wnt antagonists (DACT2 and SFRP2).

Relationship Between ADAMTS8, ADAMTS18, and ADAMTS20 (A Disintegrin and Metalloproteinase with Thrombospondin Motifs) Expressions and Tumor Molecular Classification, Clinical Pathological Parameters, and Prognosis in Breast Invasive Ductal Carcinoma

BACKGROUND The aim of this study was to investigate the correlations between ADAMTSs expression and breast invasive ductal carcinoma (IDC), and to offer a theoretical basis for novel treatment methods for IDC patients. MATERIAL AND METHODS Non-proliferative catheter of breast fibroadenoma (FA) and IDC were used as the normal control and experimental group, respectively. Immunohistochemical (IHC) staining and Western blot (WB) analysis was used to assess protein expression levels of ADAMTS8, ADAMTS18, and ADAMTS20 in both FA and IDC tissues. The results of IHC, the relationship between the protein expression and the tumor molecular classification, and clinical pathological parameters were all evaluated. RESULTS IHC and WB results showed that the expression of ADAMTS8/18 in IDC samples was higher than in FA samples, while the expression of ADAMTS20 in IDC samples was lower than that in FA samples. According to the results of WB, the level of ADAMTS8 was higher in the HER2+ group than in the HER2- group and FA group. The expression of ADAMTS18 in the HR+ (including ER+ and PR+) group was significantly higher than in the HR- group and FA group. The expression of ADAMTS18 protein was also higher in the Ki67+ group than in the Ki67- group. ADAMTS20 was higher in HER2+ IDC compared with the basal subtype of IDC. CONCLUSIONS ADAMTS8/18/20 levels were not significantly correlated to the molecular subtype of IDC. ADAMTS18/20 was significantly associated with histological grade of IDC. ADAMTS8 may predict poor prognosis results of IDC patients.

Differentially regulated ADAMTS1, 8, 9, and 18 in pancreas adenocarcinoma

Introduction

Despite recent diagnostic and therapeutic improvements, pancreas cancer remains one of the highly lethal cancers. The extracellular matrix (ECM) is a physiological barrier that limits the spread of cancer cells into surrounding tissues and distant organs. Disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) is a family of 19 proteases, which is involved in various biological processes such as ECM remodelling and anti-angiogenesis.

Aim

To investigate the expression of ADAMTS1, 8, 9, and 18 proteinases in pancreas adenocarcinoma and its nodal metastasis.

Material and methods

The immunostaining status of ADAMTS1, 8, 9, and 18 were investigated in formalin-fixed paraffin-embedded samples of 25 patients who underwent pancreaticoduodenectomy for an adenocarcinoma located at the head of the pancreas.

Results

In semi-quantitive grading pathologically, ADAMTS1, 8, 9, and 18 were found to be highly stained in all cancerous pancreas samples compared with normal pancreas. In addition, the immune positivity of ADAMTS1, 9, and 18 was found to be higher in metastatic lymph nodes than in non-metastatic lymph tissue. Tumour size was correlated with ADAMTS9 and 18 expressions in cancerous pancreas.

Conclusions

According to the data obtained from the study, we suggest that these four ADAMTSs may have significant roles in the tumorigenesis and nodal spread of pancreas adenocarcinoma.

The 3p14.2 tumour suppressor ADAMTS9 is inactivated by promoter CpG methylation and inhibits tumour cell growth in breast cancer

Chromosome region 3p12‐14 is an important tumour suppressor gene (TSG) locus for multiple cancers. ADAMTS9, a member of the metalloprotease large family, has been identified as a candidate 3p14.2 TSG inactivated by aberrant promoter CpG methylation in several carcinomas, but little known about its expression and function in breast cancer. In this report, ADAMTS9 expression and methylation was analysed in breast cancer cell lines and tissue samples. ADAMTS9 RNA was significantly down‐regulated in breast cancer cell lines (6/8). After treating the cells with demethylation agent Aza and TSA,ADAMTS9 expression was dramatically increased. Bisulphite genomic sequencing and methylation‐specific PCR detected promoter methylation, which was associated with decreased ADAMTS9 expression. Hypermethylation was also detected in 130/219 (59.4%) of primary tumours but only in 4.5% (2/44) of paired surgical margin tissues. Ectopic expression of ADAMTS9 in tumor cells induced significant growth suppression, cell cycle arrest at the G0/G1 phase, enhanced apoptosis and reduced cell migration and invasion. Conditioned culture medium from ADAMTS9‐transfected BT549 cells markedly disrupted tube formation ability of human umbilical vein endothelial cell (HUVEC) in Matrigel. Furthermore, ADAMTS9 inhibited AKT signaling and its downstream targets (MDM2, p53, p21, p27, E‐cadherin, VIM, SNAIL, VEGFA, NFκB‐p65 and MMP2). In addition, we demonstrated, for the first time, that ADAMTS9 inhibits AKT signaling, through suppressing its upstream activators EGFR and TGFβ1/TβR(I/II) in breast cancer cells. Our results suggest that ADAMTS9 is a TSG epigenetically inactivated in breast cancer, which functions through blocking EGFR‐ and TGFβ1/TβR(I/II)‐activated AKT signaling.

A Disintegrin and Metalloproteinase with Thrombospondin Motifs 18 Deficiency Leads to Visceral Adiposity and Associated Metabolic Syndrome in Mice

Visceral adiposity is of greater risk than obesity in s.c. adipose tissue for diabetes and cardiovascular disease. Its pathogenesis remains unclear, but it is associated with extracellular matrix (ECM) remodeling. A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) are a family of secreted zinc-dependent metalloproteinases that play crucial roles in development and various diseases because of their ECM remodeling activity. ADAMTS18 is an orphan ADAMTS whose function and substrate remain unclear. Herein, we showed that Adamts18 mRNA was abundantly expressed in visceral (gonadal) white adipose tissue (vWAT) during the early stage of development after birth. Adamts18 knockout (KO) mice showed increased body fat percentage and larger adipocyte size in vWAT relative to wild-type littermates. These findings may be partly attributed to ECM remodeling, especially increased expression of laminin 1 and adipokine thrombospondin 1 in vWAT. Attenuated extracellular signal-regulated kinase 1 and 2 activity, along with increased expression of adipocyte-specific transcription factors peroxisome proliferator-activated receptor-γ, CCAAT/enhancer binding protein β, and marker gene Fabp4, was detected in vWAT of Adamts18 KO mice. Furthermore, Adamts18 KO mice showed early metabolic syndrome, including hyperlipidemia, blood glucose metabolic disorder, and hypertension. ADAMTS18 deficiency promotes atherosclerosis in apolipoprotein E-deficient mice. These results indicate a novel function of ADAMTS18 in vWAT development and associated metabolic disorders.

Adamts18 deficiency promotes colon carcinogenesis by enhancing β-catenin and p38MAPK/ERK1/2 signaling in the mouse model of AOM/DSS-induced colitis-associated colorectal cancer

ADAMTS18 is a novel tumor suppressor and is critical to the pathology of human colorectal cancer. However, the underlying mechanism is not clear. Here we generated an Adamts18-deficient mouse strain as an in vivo model to investigate the role of ADAMTS18 in the pathogenesis of colorectal cancer. In AOM/DSS-induced colitis-associated colorectal cancer, the deficiency of Adamts18 in mice resulted in enhanced tumorigenesis and colon inflammation that could be attributed in part to enhanced nuclear translocation of β-catenin and elevated expression of its downstream target genes, cyclin D1 and c-myc. Moreover, increased p38MAPK and ERK1/2 activities were detected in colon cancer cells from Adamts18-deficient mice. Further studies revealed that ADAMTS18 deficiency reduced intestinal E-cadherin levels in mice, which ultimately led to intestinal barrier dysfunction. These data indicate that Adamts18 deficiency enhances tumorigenesis and intestinal inflammation through elevated Wnt/β-catenin and p38MAPK/ERK1/2 signaling and promotes colon cancer in this mouse model.

Epigenetic silencing of ADAMTS18 promotes cell migration and invasion of breast cancer through AKT and NF-κB signaling

ADAMTS18 dysregulation plays an important role in many disease processes including cancer. We previously found ADAMTS18 as frequently methylated tumor suppressor gene (TSG) for multiple carcinomas, however, its biological functions and underlying molecular mechanisms in breast carcinogenesis remain unknown. Here, we found that ADAMTS18 was silenced or downregulated in breast cancer cell lines. ADAMTS18 was reduced in primary breast tumor tissues as compared with their adjacent noncancer tissues. ADAMTS18 promoter methylation was detected in 70.8% of tumor tissues by methylation-specific PCR, but none of the normal tissues. Demethylation treatment restored ADAMTS18 expression in silenced breast cell lines. Ectopic expression of ADAMTS18 in breast tumor cells resulted in inhibition of cell migration and invasion. Nude mouse model further confirmed that ADAMTS18 suppressed breast cancer metastasis in vivo. Further mechanistic studies showed that ADAMTS18 suppressed epithelial-mesenchymal transition (EMT), further inhibited migration and invasion of breast cancer cells. ADAMT18 deregulated AKT and NF-κB signaling, through inhibiting phosphorylation levels of AKT and p65. Thus, ADAMTS18 as an antimetastatic tumor suppressor antagonizes AKT and NF-κB signaling in breast tumorigenesis. Its methylation could be a potential tumor biomarker for breast cancer.

Epigenomic and Functional Characterization of Junctophilin 3 (JPH3) as a Novel Tumor Suppressor Being Frequently Inactivated by Promoter CpG Methylation in Digestive Cancers

Junctophilin (JPH) proteins stabilize junctional membrane complexes between plasma membrane and endoplasmic reticulum, also implicated in some human diseases. JPH3 mutations are linked to Huntington's disease-like 2 syndrome. Through epigenomic study of a colon cancer cell line pair (HCT116 and DKO), we identified JPH3 as a methylated novel tumor suppressor gene (TSG) candidate at 16q24. We further studied its epigenetic alterations and functions in digestive tumorigenesis. JPH3 expression at the RNA level was found to be frequently silenced or reduced in colorectal and gastric cancers due to its promoter CpG methylation, which is associated with tumor progression and poor survival of digestive cancer patients. Ectopic expression of JPH3 inhibited tumor cell growth in vitro and in vivo. JPH3 expression upregulated the cytosolic Ca²⁺ levels, and unfolded protein response gene expression upon endoplasmic reticulum stress. JPH3 also induced calpain activation and subsequent mitochondrial membrane depolarization and cell apoptosis. Thus, JPH3 was identified as a novel TSG methylated in colorectal and gastric tumors which promotes mitochondrial-mediated apoptosis, also as a potential metastasis and survival biomarker for digestive cancers.

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.

Chromosome 16q genes CDH1, CDH13 and ADAMTS18 are correlated and frequently methylated in human lymphoma

The products of the E-cadherin (CDH1), H-cadherin (CDH13) and a disintegrin and metalloproteinase with thrombospondin motif 18 (ADAMTS18) genes are proteins displaying structural features and functions on the cell surface membrane, and have been reported to be involved in cancer progression. Using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and methylation-specific PCR (MSP) analysis, the promoter methylation status and messenger RNA (mRNA) expression levels of CDH1, CDH13 and ADAMTS18, which are putative tumor-suppressor genes located on chromosome 16q, were evaluated. In addition, the mRNA expression levels of DNA methyltransferases (DNMTs) 1, 3A and 3B were examined, and the correlations among the different parameters analyzed were studied in 36 lymphomas and 16 non-malignant lymphoid tissue samples. A significant positive correlation was identified between the expression levels of CDH1 and CDH13 (r=0.735, P<0.01). ADAMTS18 expression also exhibited a significant positive correlation with both CDH1 and CDH13 mRNA expression levels (r=0.625, P<0.01; and r=0.720, P<0.01, respectively). Our results indicated that CDH1, CDH13 and ADAMTS18, which are localized on chromosome 16q, are remarkably correlated and frequently methylated in human lymphomas, and their methylation could not be explained solely by the mRNA expression level of DNMTs.

Downregulation of ADAMTS8 by DNA Hypermethylation in Gastric Cancer and Its Clinical Significance

A disintegrin and metallopeptidase with thrombospondin motif type 8 (ADAMTS8), a member of the ADAMTS family, was discovered as a novel angiogenesis inhibitor. We analyzed the expression and methylation of ADAMTS8 in primary gastric tumors and gastric cancer cell lines. We also examined the relationship between ADAMTS8 expression and methylation and clinicopathologic features. The results showed that the significant downregulation of ADAMTS8 mRNA expression was observed in gastric cancer cell lines and tissues, and its expression was related to invasive depth and lymph node metastasis. CpG was hypermethylated in gastric cancer cell lines MKN45, MGC803, and BGC823, as well as primary gastric cancer specimens. ADAMTS8 mRNA expression was significantly lower in methylated primary gastric tumors. A significant association was found between ADAMTS8 methylation status and lymph node metastasis in primary gastric cancer. Moreover, ADAMTS8 expression was upregulated in the gastric cancer cell lines MGC803, BGC823, and MKN45 after treatment with 5-aza-2′-deoxycytidine. Thus, our results demonstrate that expression of ADAMTS8 mRNA is significantly decreased and DNA methylation is frequent in gastric cancer. ADAMTS8 hypermethylation is associated with decreased expression in gastric cancer and may play an important role in the invasion and metastasis of gastric cancer.

Association of Somatic Mutations of ADAMTS Genes With Chemotherapy Sensitivity and Survival in High-Grade Serous Ovarian Carcinoma

IMPORTANCE

Chemotherapy response in the majority of patients with ovarian cancer remains unpredictable.

OBJECTIVE

To identify novel molecular markers for predicting chemotherapy response in patients with ovarian cancer.

DESIGN, SETTING, AND PARTICIPANTS

Observational study of genomics and clinical data of high-grade serous ovarian cancer cases with genomic and clinical data made public between 2009 and 2014 via the Cancer Genome Atlas project.

MAIN OUTCOMES AND MEASURES

Chemotherapy response (primary outcome) and overall survival (OS), progression-free survival (PFS), and platinum-free duration (secondary outcome).

RESULTS

In 512 patients with ovarian cancer with available whole-exome sequencing data, mutations from 8 members of the ADAMTS family (ADAMTS mutations) with an overall mutation rate of approximately 10.4% were associated with a significantly higher chemotherapy sensitivity (100% for ADAMTS-mutated vs 64% for ADAMTS wild-type cases; P < .001) and longer platinum-free duration (median platinum-free duration, 21.7 months for ADAMTS-mutated vs 10.1 months for ADAMTS wild-type cases; P = .001). Moreover, ADAMTS mutations were associated with significantly better OS (hazard ratio [HR], 0.54 [95% CI, 0.42-0.89]; P = .01 and median OS, 58.0 months for ADAMTS-mutated vs 41.3 months for ADAMTS wild-type cases) and PFS (HR, 0.42 [95% CI, 0.38-0.70]; P < .001 and median PFS, 31.8 for ADAMTS-mutated vs 15.3 months for ADAMTS wild-type cases). After adjustment by BRCA1 or BRCA2 mutation, surgical stage, residual tumor, and patient age, ADAMTS mutations were significantly associated with better OS (HR, 0.53 [95% CI, 0.32-0.87]; P = .01), PFS (HR, 0.40 [95% CI, 0.25-0.62]; P < .001), and platinum-free survival (HR, 0.45 [95% CI, 0.28-0.73]; P = .001). ADAMTS-mutated cases exhibited a distinct mutation spectrum and were significantly associated with tumors with a higher genome-wide mutation rate than ADAMTS wild-type cases across the whole exome (median mutation number per sample, 121 for ADAMTS-mutated vs 69 for ADAMTS wild-type cases; P < .001).

CONCLUSIONS AND RELEVANCE

ADAMTS mutations may contribute to outcomes in ovarian cancer cases without BRCA1 or BRCA2 mutations and may have important clinical implications.

ADAMTS-18 in the host tissues exerts little effect on breast tumor progress in a murine 4T1 breast cancer model

BACKGROUND

In this study, we aimed to identify a novel extracellular proteinase ADAMTS-18 that could be a potential tumor suppressor gene.

RESULTS

We successfully constructed Adamts-18 knockout mice with BALB / c background. RT-PCR analysis showed syngeneic mammary tumor cell line 4 T1 per se has weakly endogenous ADAMTS-18 expression. Orthotopic inoculation of 4 T1 cells within the mammary fat pad of host mice, we found no significant difference in tumor growth and metastasis between Adamts-18 knockout mice and widetype control.

CONCLUSIONS

We did not confirm that ADAMTS-18 in the host tissues is relevant for breast tumor progress in a murine 4 T1 breast cancer model.

Epigenetic inactivation of the extracellular matrix metallopeptidase ADAMTS19 gene and the metastatic spread in colorectal cancer

BACKGROUND

ADAMTS19 encodes a member of the ADAMTS (a disintegrin and metalloproteinase domain with thrombospondin motifs) protein family with emerging roles in carcinogenesis and metastasis. ADAMTS shares several distinct protein modules including a propeptide region, a metalloproteinase domain, a disintegrin-like domain, and a thrombospondin type 1 (TS) motif. In a previous work, we found ADAMTS19 frequently hypermethylated in colorectal cancer (CRC). We explored the association of methylation with tumor genotype and phenotype.

RESULTS

The methylation status of the CpG island in the promoter of ADAMTS19 was determined in 252 colorectal, 65 pancreatic, 33 breast and 169 ovarian primary tumors, 70 CRC metastases, and 10 CRC cell lines. Tumor-specific methylation of ADAMTS19 was significantly more frequent in gastrointestinal than in gynecological cancers (odds ratio (OR) = 2.9, confidence interval (CI) = (1.9-4.7), p = 5.2 × 10(-7)) and was independent of the methylation of adjacent loci in CRC. Hypermethylation associated with CRC with mutated BRAF oncogene (OR = 10.1, CI = (3.1-42.9), p = 6.3 × 10(-6)) and with the mucinous phenotype in CRC (OR = 2.1, CI = (1.1-4.1), p = 0.023) and ovarian cancer (OR = 60, CI = (16-346), p = 4 × 10(-16)). Methylation was significantly more frequent in CRC metastases homing to the ovary and omentum than in those homing to the liver and lung (OR = 6.1, CI = (1.8-22.2), p = 0.001). Differentiating local from distant metastatic spread, methylation negatively associated with tumor progression (p = 0.031) but positively with depth of invasion (p = 0.030). Hypermethylation associated with transcriptional repression in CRC cell lines, and treatment with 5'-AZA-2'-deoxycytidine led to reactivation of mRNA expression. shRNA-mediated silencing of ADAMTS19 had no effect on the in vitro proliferation rate of CRC cells but significantly diminished their collective migration speed (56 %, p = 3.3 × 10(-4)) and potential to migrate in collagen I (64 %, p = 4.3 × 10(-10)).

CONCLUSIONS

Our results highlight the frequent involvement of ADAMTS19 epigenetic silencing in CRC and mucinous ovarian cancer. The mechanistic preferences for the target organ of metastatic spread may lead to the development of diagnostic CRC biomarkers. The association with the mucinous phenotype also may have diagnostic applications for ovarian cancer.

The Function and Roles of ADAMTS-7 in Inflammatory Diseases

The ADAMTS proteinases are a group of multidomain and secreted metalloproteinases containing the thrombospondin motifs. ADAMTS-7 is a member of ADAMTS family and plays a crucial role in the pathogenesis of arthritis. Overexpression of ADAMTS-7 gene promotes the breakdown of cartilage oligomeric matrix protein (COMP) matrix and accelerates the progression of both surgically induced osteoarthritis and collagen-induced arthritis. Moreover, ADAMTS-7 and tumor necrosis factor-α (TNF-α) form a positive feedback loop in osteoarthritis. More significantly, granulin-epithelin precursor, a growth factor has important roles in bone development and bone-associated diseases, disturbs the interaction between ADAMTS-7 and COMP, and prevents COMP degradation. This review is based on our results and provides an overview of current knowledge of ADAMTS-7, including its structure, function, gene regulation, and inflammatory diseases involvement.

ADAMs family and relatives in cardiovascular physiology and pathology

A disintegrin and metalloproteinases (ADAMs) are a family of membrane-bound proteases. ADAM-TSs (ADAMs with thrombospondin domains) are a close relative of ADAMs that are present in soluble form in the extracellular space. Dysregulated production or function of these enzymes has been associated with pathologies such as cancer, asthma, Alzheimer's and cardiovascular diseases. ADAMs contribute to angiogenesis, hypertrophy and apoptosis in a stimulus- and cell type-dependent manner. Among the ADAMs identified so far (34 in mouse, 21 in human), ADAMs 8, 9, 10, 12, 17 and 19 have been shown to be involved in cardiovascular development or cardiomyopathies; and among the 19 ADAM-TSs, ADAM-TS1, 5, 7 and 9 are important in development of the cardiovascular system, while ADAM-TS13 can contribute to vascular disorders. Meanwhile, there remain a number of ADAMs and ADAM-TSs whose function in the cardiovascular system has not been yet explored. The current knowledge about the role of ADAMs and ADAM-TSs in the cardiovascular pathologies is still quite limited. The most detailed studies have been performed in other cell types (e.g. cancer cells) and organs (nervous system) which can provide valuable insight into the potential functions of ADAMs and ADAM-TSs, their mechanism of action and therapeutic potentials in cardiomyopathies. Here, we review what is currently known about the structure and function of ADAMs and ADAM-TSs, and their roles in development, physiology and pathology of the cardiovascular system.