Expression of ADAMTS1 and its correlation with angiogenesis in primary gastric cancer and lymph node metastasis

Comprehensive analysis of a novel subtype of immune microenvironment-derived HPV-infected colorectal cancer

BACKGROUND

The current study proposed a novel subtype, Human papillomavirus (HPV)-infected colorectal cancer (CRC), to understand the impact of HPV on CRC.

METHODS

We assessed the prevalence and clinical implications of HPV in CRC by integrating a single cohort in Guangdong Provincial People's Hospital and public datasets. Differential gene, pathway enrichment, and immune infiltration analysis were conducted to explore the patterns in HPV-infected CRC. Quantitative polymerase chain reaction, cell proliferation, scratch, and flow cytometry assays were employed to validate the impact of HPV on CRC.

RESULTS

The study revealed a high prevalence of HPV infection in CRC, with infection rates ranging from 10% to 31%. There was also a significant increase in tumor proliferation in HPV-infected CRC. The study showed increased immune cell infiltration, including T cells, γδ T cells, cytotoxic cells, and plasmacytoid dendritic cells in HPV-infected CRC (P < 0.05). Furthermore, our findings confirmed that HPV infection promoted M1 polarization. Our results demonstrated that low ISM2 expression was associated with a less advanced clinical stage (P < 0.001) and better survival outcomes (P = 0.039). Low ISM2 expression correlated with a strong tumor immune response, potentially contributing to the improved survival observed in HPV-infected CRC.

CONCLUSIONS

These findings provided a novel subtype of HPV-infected CRC. The subtype with a better prognosis showed a "hot" tumor immune microenvironment that may be responsive to immunotherapy.

Cyclic increase in the ADAMTS1-L1CAM-EGFR axis promotes the EMT and cervical lymph node metastasis of oral squamous cell carcinoma

The matrix metalloprotease A disintegrin and metalloprotease with thrombospondin motifs 1 (ADAMTS1) was reported to be involved in tumor progression in several cancer types, but its contributions appear discrepant. At present, the role of ADAMTS1 in oral squamous cell carcinoma (SCC; OSCC) remains unclear. Herein, The Cancer Genome Atlas (TCGA) database showed that ADAMTS1 transcripts were downregulated in head and neck SCC (HNSCC) tissues compared to normal tissues, but ADAMTS1 levels were correlated with poorer prognoses of HNSCC patients. In vitro, we observed that ADAMTS1 expression levels were correlated with the invasive abilities of four OSCC cell lines, HSC-3, SCC9, HSC-3M, and SAS. Knockdown of ADAMTS1 in OSCC cells led to a decrease and its overexpression led to an increase in cell-invasive abilities in vitro as well as tumor growth and lymph node (LN) metastasis in OSCC xenografts. Mechanistic investigations showed that the cyclic increase in ADAMTS1-L1 cell adhesion molecule (L1CAM) axis-mediated epidermal growth factor receptor (EGFR) activation led to exacerbation of the invasive abilities of OSCC cells via inducing epithelial-mesenchymal transition (EMT) progression. Clinical analyses revealed that ADAMTS1, L1CAM, and EGFR levels were all correlated with worse prognoses of HNSCC patients, and patients with ADAMTS1high/L1CAMhigh or EGFRhigh tumors had the shortest overall and disease-specific survival times. As to therapeutic aspects, we discovered that an edible plant-derived flavonoid, apigenin (API), drastically inhibited expression of the ADAMTS1-L1CAM-EGFR axis and reduced the ADAMTS1-triggered invasion and LN metastasis of OSCC cells in vitro and in vivo. Most importantly, API treatment significantly prolonged survival rates of xenograft mice with OSCC. In summary, ADAMTS1 may be a useful biomarker for predicting OSCC progression, and API potentially retarded OSCC progression by targeting the ADAMTS1-L1CAM-EGFR signaling pathway.

Molecular Motifs in Vascular Morphogenesis: Vascular Endothelial Growth Factor A (VEGFA) as the Leading Promoter of Angiogenesis

Tissular hypoxia stimulates vascular morphogenesis. Vascular morphogenesis shapes the cell and, consecutively, tissue growth. The development of new blood vessels is intermediated substantially through the tyrosine kinase pathway. There are several types of receptors inferred to be located in the blood vessel structures. Vascular endothelial growth factor A (VEGF-A) is the leading protagonist of angiogenesis. VEGF-A's interactions with its receptors VEGFR1, VEGFR2, and VEGFR3, together with disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1), connective tissue growth factor (CTGF), and neuropilin-1 (NRP1), independently, are studied computationally. Peripheral artery disease (PAD), which results in tissue ischemia, is more prevalent in the senior population. Presently, medical curatives used to treat cases of PAD-antiplatelet and antithrombotic agents, statins, antihypertensive remedies with ACE (angiotensin-converting enzyme) impediments, angiotensin receptor blockers (ARB) or β- blockers, blood glucose control, and smoking cessation-are not effective. These curatives were largely established from the treatment of complaint cases of coronary disease. However, these medical curatives do not ameliorate lower limb perfusion in cases of PAD. Likewise, surgical or endovascular procedures may be ineffective in relieving symptoms. Eventually, after successful large vessel revascularization, the residual microvascular circulation may well limit the effectiveness of curatives in cases of PAD. It would thus feel rational to attempt to ameliorate perfusion in PAD by enhancing vascular rejuvenescence and function. Likewise, stimulating specific angiogenesis in these cases (PAD) can ameliorate the patient's symptomatology. Also, the quality of life of PAD patients can be improved by developing new vasodilative and angiogenetic molecules that stimulate the tyrosine kinase pathway. In this respect, the VEGFA angiogenetic pathway was explored computationally. Docking methodologies, molecular dynamics, and computational molecular design methodologies were used. VEGFA's interaction with its target was primarily studied. Common motifs in the vascular morphogenesis pathway are suggested using conformational energy and Riemann spaces. The results show that interaction with VEGFR2 and ADAMTS1 is pivotal in the angiogenetic process. Also, the informational content of two VEGFA complexes, VEGFR2 and ADAMTS1, is crucial in the angiogenesis process.

ADAM and ADAMTS disintegrin and metalloproteinases as major factors and molecular targets in vascular malfunction and disease

A Disintegrin and Metalloproteinase (ADAM) and A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) are two closely related families of proteolytic enzymes. ADAMs are largely membrane-bound enzymes that act as molecular scissors or sheddases of membrane-bound proteins, growth factors, cytokines, receptors and ligands, whereas ADAMTS are mainly secreted enzymes. ADAMs have a pro-domain, and a metalloproteinase, disintegrin, cysteine-rich and transmembrane domain. Similarly, ADAMTS family members have a pro-domain, and a metalloproteinase, disintegrin, and cysteine-rich domain, but instead of a transmembrane domain they have thrombospondin motifs. Most ADAMs and ADAMTS are activated by pro-protein convertases, and can be regulated by G-protein coupled receptor agonists, Ca²⁺ ionophores and protein kinase C. Activated ADAMs and ADAMTS participate in numerous vascular processes including angiogenesis, vascular smooth muscle cell proliferation and migration, vascular cell apoptosis, cell survival, tissue repair, and wound healing. ADAMs and ADAMTS also play a role in vascular malfunction and cardiovascular diseases such as hypertension, atherosclerosis, coronary artery disease, myocardial infarction, heart failure, peripheral artery disease, and vascular aneurysm. Decreased ADAMTS13 is involved in thrombotic thrombocytopenic purpura and microangiopathies. The activity of ADAMs and ADAMTS can be regulated by endogenous tissue inhibitors of metalloproteinases and other synthetic small molecule inhibitors. ADAMs and ADAMTS can be used as diagnostic biomarkers and molecular targets in cardiovascular disease, and modulators of ADAMs and ADAMTS activity may provide potential new approaches for the management of cardiovascular disorders.

Identification of prognosis-related genes in the tumor microenvironment of stomach adenocarcinoma by TCGA and GEO datasets

Accumulating evidence has demonstrated that tumor microenvironment (TME) plays a crucial role in stomach adenocarcinoma (STAD) development, progression, prognosis and immunotherapeutic responses. How the genes in TME interact and behave is extremely crucial for tumor investigation. In the present study, we used gene expression data of STAD available from TCGA and GEO datasets to infer tumor purity using ESTIMATE algorithms, and predicted the associations between tumor purity and clinical features and clinical outcomes. Next, we calculated the differentially expressed genes (DEGs) from the comparisons of immune and stromal scores, and postulated key biological processes and pathways that the DEGs mainly involved in. Then, we analyzed the prognostic values of DEGs in TCGA dataset, and validated the results by GEO dataset. Finally, we used CIBERSORT computational algorithm to estimate the 22 tumor infiltrating immune cells (TIICs) subsets in STAD tissues. We found that stromal and immune scores were significantly correlated with STAD subtypes, clinical stages, Helicobacter polyri infection, and stromal scores could predict the clinical outcomes in STAD patients. Moreover, we screened 307 common DEGs in TCGA and GSE51105 datasets. In the prognosis analyses, we only found OGN, JAM2, RERG, OLFML2B, and ADAMTS1 genes were significantly associated with overall survival in TCGA and GSE84437 datasets, and these genes were correlated with the fractions of T cells, B cells, macrophages, monocytes, NK cells and DC cells, respectively. Our comprehensive analyses for transcriptional data not only improved the understanding of characteristics of TME, but also provided the targets for individual therapy in STAD.

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.

Role of Extracellular Matrix in Gastrointestinal Cancer-Associated Angiogenesis

Gastrointestinal tumors are responsible for more cancer-related fatalities than any other type of tumors, and colorectal and gastric malignancies account for a large part of these diseases. Thus, there is an urgent need to develop new therapeutic approaches to improve the patients' outcome and the tumor microenvironment is a promising arena for the development of such treatments. In fact, the nature of the microenvironment in the different gastrointestinal tracts may significantly influence not only tumor development but also the therapy response. In particular, an important microenvironmental component and a potential therapeutic target is the vasculature. In this context, the extracellular matrix is a key component exerting an active effect in all the hallmarks of cancer, including angiogenesis. Here, we summarized the current knowledge on the role of extracellular matrix in affecting endothelial cell function and intratumoral vascularization in the context of colorectal and gastric cancer. The extracellular matrix acts both directly on endothelial cells and indirectly through its remodeling and the consequent release of growth factors. We envision that a deeper understanding of the role of extracellular matrix and of its remodeling during cancer progression is of chief importance for the development of new, more efficacious, targeted therapies.

A Disintegrin and Metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) family in vascular biology and disease

A Disintegrin and Metalloproteinase (ADAM) is a family of proteolytic enzymes that possess sheddase function and regulate shedding of membrane-bound proteins, growth factors, cytokines, ligands and receptors. Typically, ADAMs have a pro-domain, and a metalloproteinase, disintegrin, cysteine-rich and a characteristic transmembrane domain. Most ADAMs are activated by proprotein convertases, but can also be regulated by G-protein coupled receptor agonists, Ca²⁺ ionophores and protein kinase C activators. A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) is a family of secreted enzymes closely related to ADAMs. Like ADAMs, ADAMTS members have a pro-domain, and a metalloproteinase, disintegrin, and cysteine-rich domain, but they lack a transmembrane domain and instead have characteristic thrombospondin motifs. Activated ADAMs perform several functions and participate in multiple cardiovascular processes including vascular smooth muscle cell proliferation and migration, angiogenesis, vascular cell apoptosis, cell survival, tissue repair, and wound healing. ADAMs may also be involved in pathological conditions and cardiovascular diseases such as atherosclerosis, hypertension, aneurysm, coronary artery disease, myocardial infarction and heart failure. Like ADAMs, ADAMTS have a wide-spectrum role in vascular biology and cardiovascular pathophysiology. ADAMs and ADAMTS activity is naturally controlled by endogenous inhibitors such as tissue inhibitors of metalloproteinases (TIMPs), and their activity can also be suppressed by synthetic small molecule inhibitors. ADAMs and ADAMTS can serve as important diagnostic biomarkers and potential therapeutic targets for cardiovascular disorders. Natural and synthetic inhibitors of ADAMs and ADAMTS could be potential therapeutic tools for the management of cardiovascular diseases.

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.

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.

Genomic predictors of chemotherapy efficacy in advanced or recurrent gastric cancer in the GC0301/TOP002 phase III clinical trial

Recent gastric cancer clinical trials have aimed to establish the efficacy of combination therapy over monotherapy, however, the role for genomic biomarkers in these trials has remained largely unexplored. Here, using the NanoString expression platform, we analyzed 105 gastric tumors from a randomized phase III Japanese clinical trial (GC0301/TOP002) testing the efficacy of irinotecan plus S-1(IRI-S) versus S-1 therapy. We found that previously established proliferative subtype signatures, were associated with older patients (>65 years) and liver metastasis while mesenchymal subtype signatures were associated with younger patients (≤65 years) and peritoneal metastasis. Genes associated with tumor microenvironment (CD4, CD14, ADAMTS1, CCL5, CXCL12, CCL19), therapeutic implications (DPYD) and oncogenic signaling (Wnt5A, PTRF) were significantly associated with patient age, histology, tumor status, measurable lesions and metastasis. We identified Wnt5A downregulation as a candidate predictor of improved progression free survival (>8 weeks) in S-1 but not in IRI-S treatment. Although statistical significance was not achieved, mesenchymal subtype showed a trend for treatment interaction with IRI-S for efficacy. These findings highlight promising genomic markers that could be useful predictors of chemotherapy efficacy for better prognosis and survival outcome in gastric cancer.

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.

The Long Noncoding RNA MALAT-1 Is Highly Expressed in Ovarian Cancer and Induces Cell Growth and Migration

BACKGROUND

Metastasis associated in lung adenocarcinoma transcript-1 (MALAT-1) is overexpressed during cancer progression and promotes cell migration and invasion in many solid tumors. However, its role in ovarian cancer remains poorly understood.

METHODS

Expressions of MALAT-1 were detected in 37 normal ovarian tissues and 45 ovarian cancer tissues by reverse transcription polymerase chain reaction (RT-PCR). Cell proliferation was observed by CCK-8 assay; Flow cytometry was used to measure cell cycle and apoptosis; Cell migration was detected by transwell migration and invasion assay. In order to evaluate the function of MALAT-1, shRNA combined with DNA microarray and Functional enrichment analysis were performed to determine the transcriptional effects of MALAT-1 silencing in OVCAR3 cells. RNA and protein expression were measured by qRT-PCR and Western blotting, respectively.

RESULTS

We found that upregulation of MALAT-1 mRNA in ovarian cancer tissues and enhanced MALAT-1 expression was associated with FIGO stage. Knockdown of MALAT-1 expression in OVCAR3 cells inhibited cell proliferation, migration, and invasion, leading to G0/G1 cell cycle arrest and apoptosis. Overexpressed MALAT-1 expression in SKOV3 cells promoted cell proliferation, migration and invasion. Downregulation of MALAT-1 resulted in significant change of gene expression (at least 2-fold) in 449 genes, which regulate proliferation, cell cycle, and adhesion. As a consequence of MALAT-1 knockdown, MMP13 protein expression decreased, while the expression of MMP19 and ADAMTS1 was increased.

CONCLUSIONS

The present study found that MALAT-1 is highly expressed in ovarian tumors. MALAT-1 promotes the growth and migration of ovarian cancer cells, suggesting that MALAT-1 may be an important contributor to ovarian cancer development.

The roles of ADAMTS in angiogenesis and cancer

Angiogenesis is an indispensable mechanism involved in both physiological processes and various pathological conditions, such as inflammation, aberrant wound healing, tumor progression, and metastasis. Among many angiogenic stimulators and inhibitors, vascular endothelial growth factor (VEGF) is regarded as one of the most important members of the signaling protein family involved in blood vessel formation and maturation. The a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) proteins are a family of multifunctional proteinases. Such proteolytic enzymes are associated with various physiological processes, such as collagen maturation, organogenesis, angiogenesis, and reproduction. Importantly, deficiency or overexpression of certain ADAMTS proteinases has been shown to be directly involved in a number of serious diseases, including tumor progression and metastasis. This review explores in-depth the connections between ADAMTS proteinases as positive/negative mediators during angiogenesis and VEGF.

Downregulation of A disintegrin and metallopeptidase with thrombospondin motif type 1 by DNA hypermethylation in human gastric cancer

A disintegrin and metallopeptidase with thrombospondin motif type 1 (ADAMTS1) is a metalloproteinase with antiangiogenic activity. It was previously observed that the mRNA and protein levels of ADAMTS1 are downregulated in primary gastric tumors. The aim of the present study was to examine whether the reduction in the expression of ADAMTS1 is due to aberrant methylation of the gene in primary gastric tumor tissues and gastric cancer cell lines. In addition, the association between ADAMTS1 methylation and clinicopathological features in were investigated in patients with primary gastric cancer. The results revealed that the frequency of ADAMTS1 methylation in primary gastric tumor tissues was significantly higher, compared with the corresponding normal gastric tissues. The relative mRNA expression levels of ADAMTS1 were significantly lower in the methylated primary gastric tumor tissues, compared with the unmethylated primary gastric tumor tissuess. A significant association was observed between the ADAMTS1 methylation status and the depth of tumor invasion and tumor, node, metastasis stage in primary gastric cancer. The mRNA expression of ADAMTS1 was significantly lower in 60% (3 of 5) of the gastric cancer cell lines. The relative mRNA expression levels of ADAMTS1 were significantly lower in the methylated gastric cancer cell lines, compared with the unmethylated gastric cancer cell lines. Furthermore, the expression of ADAMTS1 was significantly restored following treatment with the 5-Aza-2′-deoxycytidine demethylating agent in the MGC-803, HGC-27 and AGS gastric cancer cell lines, and the demethylation of the MGC-803 cell line inhibited cell invasion. Together, these results suggested for the first time, to the best of our knowledge, ADAMTS1 as a novel antitumor protease, and this function was lost following epigenetic silencing in the gastric cancer cells and gastric tumor tissues. Therefore, the aberrant methylation of ADAMTS1 may be involved in the development and progression of gastric cancer.

ADAMTS1 inhibits lymphangiogenesis by attenuating phosphorylation of the lymphatic endothelial cell-specific VEGF receptor

Angiogenesis and lymphangiogenesis play roles in malignant tumor progression, dissemination, and metastasis. ADAMTS1, a member of the matrix metalloproteinase family, is known to inhibit angiogenesis. Recombinant ADAMTS1 was shown to strongly inhibit angiogenesis. We investigated whether ADAMTS1 inhibited lymphangiogenesis in the present study. We examined cell proliferation and cell migration in normal human dermal lymphatic microvascular endothelial cells (HMVEC-dLy) transduced with or without adenoviral human ADAMTS1 gene therapy. We then examined the VEGFC/VEGFR3 signal transduction pathway in ADAMTS1-transduced HMVEC-dLy. Cell proliferation and tube formation in Matrigel were significantly lower with transduced ADAMTS1 than with control (non-transduced HMVEC-dLy). The phosphorylation of VEGFR3 was also attenuated by ADAMTS1 gene therapy in HMVEC-dLy. Immunoprecipitation assays revealed that ADAMTS1 formed a complex with VEGFC. Our results demonstrated that ADAMTS1 inhibited lymphangiogenesis in vitro. The data highlight the new function of ADAMTS1 in the regulation of lymphangiogenesis and the therapeutic potential of ADAMTS1 in cancer therapy.

Effects of rosiglitazone on the growth and lymphangiogenesis of human gastric cancer transplanted in nude mice

Gastric cancer mainly metastasizes via lymphatic vessels. Thus, it is critical to identify efficacious chemopreventive agents for lymphangiogenesis. The present study was undertaken to explore the effects of rosiglitazone (ROSI) on the growth and lymphangiogenesis of human gastric cancer. We established a model of gastric cancer by subcutaneously inoculating the human gastric cancer cell line SGC-7901 into nude mice. Mice were randomly divided into 4 groups and each group received a different agent by oral gavage. The control group received normal saline and treatment groups received different doses of ROSI once every 2 days. The growth of the tumor in vivo was assessed by measuring tumor volume. After 42 days, the mice were sacrificed and the tumors were removed. H&E staining was used to observe the histomorphological features; immunohistochemistry staining for lymphatic vessel density (LVD) was used to evaluate tumor lymphangiogenesis, RT-PCR was performed to determine the mRNA expression of vascular endothelial growth factor C (VEGF-C) and VEGF receptor-3 (VEGFR-3), and western blotting was used to detect the protein expression of VEGF-C and VEGFR-3. Compared with the control group, all treatment groups had smaller tumor volume and higher tumor growth inhibitory rate every day. The number of typical tumor cells in the control group was higher compared to that in the treatment groups, and the highest level of LVD was found in the control group. Furthermore, both the expression of VEGF-C and VEGFR-3 mRNA and proteins in the control group were significantly higher compared to those in the treatment groups. Markedly, these changes were correlated in a dose-dependent manner with ROSI. These results demonstrated that, through simultaneously blocking the expression of VEGF-C and VEGFR-3, ROSI suppresses lymphangiogenesis. This may represent a powerful therapeutic approach for controlling gastric cancer cell growth and metastasis.

The metalloproteinase ADAMTS1: a comprehensive review of its role in tumorigenic and metastatic pathways

As it was first characterized in 1997, the ADAMTS (A Disintegrin and Metalloprotease with ThromboSpondin motifs) metalloprotease family has been associated with many physiological and pathological conditions. Of the 19 proteases belonging to this family, considerable attention has been devoted to the role of its first member ADAMTS1 in cancer. Elevated ADAMTS1 promotes pro-tumorigenic changes such as increased tumor cell proliferation, inhibited apoptosis and altered vascularization. Importantly, it facilitates significant peritumoral remodeling of the extracellular matrix environment to promote tumor progression and metastasis. However, discrepancy exists, as several studies also depict ADAMTS1 as a tumor suppressor. This article reviews the current understanding of ADAMTS1 regulation and the consequence of its dysregulation in primary cancer and ADAMTS1-mediated pathways of cancer progression and metastasis.