ADAM23 is downregulated in side population and suppresses lung metastasis of lung carcinoma cells

ADAM12 as a Clinical Prognostic Indicator Associated with Tumor Immune Infiltration in Lung Adenocarcinoma

Twenty-two functional α-disintegrin and metalloproteinases (ADAMs) have been identified in humans, 12 of which have proteolytic activity. The role of ADAMs in cancer has attracted increasing attention. However, the expression and significance of ADAMs in lung adenocarcinoma (LUAD) remain unclear. Most recently, we investigated the transcriptional data of ADAMs and related overall survival in patients with LUAD based on several databases, including TCGA, cBioPortal, Kaplan-Meier Plotter, LinkedOmics, KEGG, TIMER, and TISIDB. Knockdown of ADAM12 was performed in vitro to verify its biological function. According to our findings, 10 ADAMs exhibited significant differential expression in LUAD compared with cancer-adjacent normal tissues. ADAM12 expression was significantly higher in LUAD tissues than in paracancerous tissues, and lower ADAM12 expression was associated with better survival. Genetic alterations of ADAM12 mainly included missense mutations, amplifications, and deep deletions. ADAM12 and positively correlated genes were mainly enriched in protein digestion and absorption, extracellular matrix-receptor interaction, and adhesion plaques. ADAM12 had a moderate correlation with immune cell markers EBIP1, CCNB1, EXO1, KNTC1, PRC1, and FAM198B. Prognostic model was established based on ADAM12 and immune-related genes. In vitro experiments revealed that knocking down ADAM12 inhibited cell proliferation, migration, and invasion. ADAM12 potentially plays an important role in the occurrence of LUAD and may be utilized as an immunotherapy target and a valuable prognostic biomarker for LUAD.

Mechanism and Role of the Neuropeptide LGI1 Receptor ADAM23 in Regulating Biomarkers of Ferroptosis and Progression of Esophageal Cancer

Background

According to recent studies, ferroptosis is closely related to the efficacy and prognosis of tumour treatment. However, the role of ferroptosis in esophageal squamous cell carcinoma (ESCC) has not been explored comprehensively.

Materials and Methods

The esophageal cancer (EC) transcriptome data was downloaded from The Cancer Genome Atlas (TCGA), then analyzed, to obtain the differentially expressed messenger RNA (mRNA), microRNA (miRNA), and long noncoding RNA (lncRNA) between groups with the low and high Ferroptosis Potential Index (FPI) and construct a ferroptosis-associated ceRNA network. In addition, the expression of ARHGEF26-AS1 and miR-372-3p in ESCC cell lines was assessed, and the appropriate cell lines were selected. The interaction between ARHGEF26-AS1, miR-372-3p, and ADAM23 was also determined through a dual-luciferase reporter assay. Moreover, the Western blot, Cell Counting Kit-8 (CCK-8), wound healing, cell viability, and cell death assays were conducted to establish the biological functions of the ARHGEF26-AS1/miR-372-3p/ADAM23 pathway in ESCCs.

Results

An FPI scoring model reflecting the activity of the ferroptosis pathway was constructed, and a ferroptosis-associated ceRNA network was established. The findings revealed that low expression of ADAM23 and ARHGEF26-AS1 as well as high expression of miR-372-3p was associated with poor prognosis and a lower FPI score in EC patients. Functionally, overexpression of ADAM23 and ARHGEF26-AS1 and the miR-372-3p inhibitor not only promoted ferroptosis in ESCC cells in vitro but also inhibited the proliferation and migration of cells. Mechanistically, ARHGEF26-AS1 upregulated the expression of ADAM23 by competitively binding to miR-372-3p.

Conclusions

The study showed that the lncRNA, ARHGEF26-AS1 acts as a miR-372-3p sponge that regulates the neuropeptide LGI1 receptor ADAM23 expression. This in turn not only inhibits the proliferation and migration of ESCC cells but also upregulates the ferroptosis pathway. A neuropeptide-related ferroptosis regulatory pathway was identified in this study.

Proteases Regulate Cancer Stem Cell Properties and Remodel Their Microenvironment

Proteolytic activity is perturbed in tumors and their microenvironment, and proteases also affect cancer stem cells (CSCs). CSCs are the therapy-resistant subpopulation of cancer cells with tumor-initiating capacity that reside in specialized tumor microenvironment niches. In this review, we briefly summarize the significance of proteases in regulating CSC activities with a focus on brain tumor glioblastoma. A plethora of proteases and their inhibitors participate in CSC invasiveness and affect intercellular interactions, enhancing CSC immune, irradiation, and chemotherapy resilience. Apart from their role in degrading the extracellular matrix enabling CSC migration in and out of their niches, we review the ability of proteases to modulate CSC properties, which prevents their elimination. When designing protease-oriented therapies, the multifaceted roles of proteases should be thoroughly investigated.

Transcriptome signature of miRNA-26b KO mouse model suggests novel targets

Background

MicroRNAs (miRNAs) are short (20–24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. One of the miRNAs that has been shown to play a role in various pathologies like cancer, neurological disorders and cardiovascular diseases is miRNA-26b. However, these studies only demonstrated rather ambiguous associations without revealing a causal relationship. Therefore, the aim of this study is to establish and validate a mouse model which enables the elucidation of the exact role of miRNA-26b in various pathologies.

Results

A miRNA-26b-deficient mouse model was established using homologous recombination and validated using PCR. miRNA-26b-deficient mice did not show any physiological abnormalities and no effects on systemic lipid levels, blood parameters or tissue leukocytes. Using next generation sequencing, the gene expression patterns in miRNA-26b-deficient mice were analyzed and compared to wild type controls. This supported the already suggested role of miRNA-26b in cancer and neurological processes, but also revealed novel associations of miRNA-26b with thermogenesis and allergic reactions. In addition, detailed analysis identified several genes that seem to be highly regulated by miRNA-26b, which are linked to the same pathological conditions, further confirming the role of miRNA-26b in these pathologies and providing a strong validation of our mouse model.

Conclusions

miRNA-26b plays an important role in various pathologies, although causal relationships still have to be established. The described mouse model of miRNA-26b deficiency is a crucial first step towards the identification of the exact role of miRNA-26b in various diseases that could identify miRNA-26b as a promising novel diagnostic or even therapeutic target in a broad range of pathologies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-021-00976-1.

Prognostic value of tumour microenvironment-related genes by TCGA database in rectal cancer

Rectal cancer is a common malignant tumour and the progression is highly affected by the tumour microenvironment (TME). This study intended to assess the relationship between TME and prognosis, and explore prognostic genes of rectal cancer. The gene expression profile of rectal cancer was obtained from TCGA and immune/stromal scores were calculated by Estimation of Stromal and Immune cells in Malignant Tumors using Expression data (ESTIMATE) algorithm. The correlation between immune/stromal scores and survival time as well as clinical characteristics were evaluated. Differentially expressed genes (DEGs) were identified according to the stromal/immune scores, and the functional enrichment analyses were conducted to explore functions and pathways of DEGs. The survival analyses were conducted to clarify the DEGs with prognostic value, and the protein‐protein interaction (PPI) network was performed to explore the interrelation of prognostic DEGs. Finally, we validated prognostic DEGs using data from the Gene Expression Omnibus (GEO) database by PrognoScan, and we verified these genes at the protein levels using the Human Protein Atlas (HPA) databases. We downloaded gene expression profiles of 83 rectal cancer patients from The Cancer Genome Atlas (TCGA) database. The Kaplan‐Meier plot demonstrated that low‐immune score was associated with worse clinical outcome (P = .034), metastasis (M1 vs. M0, P = .031) and lymphatic invasion (+ vs. ‐, P < .001). A total of 540 genes were screened as DEGs with 539 up‐regulated genes and 1 down‐regulated gene. In addition, 60 DEGs were identified associated with overall survival. Functional enrichment analyses and PPI networks showed that the DEGs are mainly participated in immune process, and cytokine‐cytokine receptor interaction. Finally, 19 prognostic genes were verified by GSE17536 and GSE17537 from GEO, and five genes (ADAM23, ARHGAP20, ICOS, IRF4,MMRN1) were significantly different in tumour tissues compared with normal tissues at the protein level. In summary, our study demonstrated the associations between TME and prognosis as well as clinical characteristics of rectal cancer. Moreover, we explored and verified microenvironment‐related genes, which may be the potential key prognostic genes of rectal cancer. Further clinical samples and functional studies are needed to validate this finding.

Broad proteomic screen reveals shared serum proteomic signature in patients with psoriatic arthritis and psoriasis without arthritis

OBJECTIVE

To identify novel serum proteins involved in the pathogenesis of PsA as compared with healthy controls, psoriasis (Pso) and AS, and to explore which proteins best correlated to major clinical features of the disease.

METHODS

A high-throughput serum biomarker platform (Olink) was used to assess the level of 951 unique proteins in serum of patients with PsA (n = 20), Pso (n = 18) and AS (n = 19), as well as healthy controls (HC, n = 20). Pso and PsA were matched for Psoriasis Area and Severity Index (PASI) and other clinical parameters.

RESULTS

We found 68 differentially expressed proteins (DEPs) in PsA as compared with HC. Of those DEPs, 48 proteins (71%) were also dysregulated in Pso and/or AS. Strikingly, there were no DEPs when comparing PsA with Pso directly. On the contrary, hierarchical cluster analysis and multidimensional scaling revealed that HC clustered distinctly from all patients, and that PsA and Pso grouped together. The number of swollen joints had the strongest positive correlation to ICAM-1 (r = 0.81, P < 0.001) and CCL18 (0.76, P < 0.001). PASI score was best correlated to PI3 (r = 0.54, P < 0.001) and IL-17 receptor A (r = -0.51, P < 0.01). There were more proteins correlated to PASI score when analysing Pso and PsA patients separately, as compared with analysing Pso and PsA patients pooled together.

CONCLUSION

PsA and Pso patients share a serum proteomic signature, which supports the concept of a single psoriatic spectrum of disease. Future studies should target skin and synovial tissues to uncover differences in local factors driving arthritis development in Pso.

Endocytosis of the non-catalytic ADAM23: Recycling and long half-life properties

A Disintegrin And Metalloprotease 23 (ADAM23) is a member of the ADAMs family of transmembrane proteins, mostly expressed in nervous system, and involved in traffic and stabilization of Kv1-potassium channels, synaptic transmission, neurite outgrowth, neuronal morphology and cell adhesion. Also, ADAM23 has been linked to human pathological conditions, such as epilepsy, cancer metastasis and cardiomyopathy. ADAM23 functionality depends on the molecule presence at the cell surface and along the secretory pathway, as expected for a cell surface receptor. Because endocytosis is an important functional regulatory mechanism of plasma membrane receptors and no information is available about the traffic or turnover of non-catalytic ADAMs, we investigated ADAM23 internalization, recycling and half-life properties. Here, we show that ADAM23 undergoes constitutive internalization from the plasma membrane, a process that depends on lipid raft integrity, and is redistributed to intracellular vesicles, especially early and recycling endosomes. Furthermore, we observed that ADAM23 is recycled from intracellular compartments back to the plasma membrane and thus has longer half-life and higher cell surface stability compared with other ADAMs. Our findings suggest that regulation of ADAM23 endocytosis/stability could be exploited therapeutically in diseases in which ADAM23 is directly involved, such as epilepsy, cancer progression and cardiac hypertrophy.

Role of Transmembrane 4 L Six Family 1 in the Development and Progression of Cancer

Transmembrane 4 L six family 1 (TM4SF1) is a protein with four transmembrane domains that belongs to the transmembrane 4 L six family members (TM4SFs). Structurally, TM4SF1 consists of four transmembrane domains (TM1–4), N- and C-terminal intracellular domains, two extracellular domains, a smaller domain between TM1 and TM2, and a larger domain between TM3 and TM4. Within the cell, TM4SF1 is located at the cell surface where it transmits extracellular signals into the cytoplasm. TM4SF1 interacts with tetraspanins, integrin, receptor tyrosine kinases, and other proteins to form tetraspanin-enriched microdomains. This interaction affects the pro-migratory activity of the cells, and thus it plays important roles in the development and progression of cancer. TM4SF1 has been shown to be overexpressed in many malignant tumors, including gliomas; malignant melanomas; and liver, prostate, breast, pancreatic, bladder, colon, lung, gastric, ovarian, and thyroid cancers. TM4SF1 promotes the migration and invasion of cancer cells by inducing epithelial-mesenchymal transition, self-renewal ability, tumor angiogenesis, invadopodia formation, and regulating the related signaling pathway. TM4SF1 is an independent prognostic indicator and biomarker in several cancers. It also promotes drug resistance, which is a major cause of therapeutic failure. These characteristics make TM4SF1 an attractive target for antibody-based immunotherapy. Here, we review the many functions of TM4SF1 in malignant tumors, with the aim to understand the interaction between its expression and the biological behaviors of cancer and to supply a basis for exploring new therapeutic targets.

Infiltration of tumor-associated macrophages is involved in tumor programmed death-ligand 1 expression in early lung adenocarcinoma

Programmed death-ligand 1 (PD-L1) is an immune modulator that promotes immunosuppression by binding to programmed death-1 of T-lymphocytes. Although tumor cell PD-L1 expression has been shown to be associated with the clinical response to anti-PD-L1 antibodies, its concise regulatory mechanisms remain elusive. In this study, we evaluated the associations of tumor PD-L1 expression and immune cell infiltrating patterns in 146 cases of early lung adenocarcinoma (AC) to investigate the possible extrinsic regulation of tumor PD-L1 by immune cells. Using immunohistochemistry, cell surface PD-L1 expression in tumor cells was observed in 18.5% of stage 0-IA lung AC patients. Tumor PD-L1 positivity was significantly associated with stromal invasion, which was accompanied by increased tumor-associated macrophages (TAM), CD8⁺ cytotoxic T cells and FoxP3⁺ regulatory T cells. Among these immune cells, TAM and CD8⁺ T cells significantly accumulated in PD-L1-positive carcinoma cell areas, which showed a tumor cell nest-infiltrating pattern. Although CD8⁺ T cells are known to induce tumor PD-L1 expression via interferon-ɣ production, the increased TAM within tumors were also associated with tumor cell PD-L1 positivity, independently of CD8⁺ T cell infiltration. Our in vitro experiments revealed that PD-L1 expression in lung cancer cell lines was significantly upregulated by co-culture with M2-differentiated macrophages; expression of PD-L1 was reduced to baseline levels following treatment with a transforming growth factor-β inhibitor. These results demonstrated that tumor-infiltrating TAM are extrinsic regulators of tumor PD-L1 expression, indicating that combination therapy targeting both tumor PD-L1 and stromal TAM might be a possible strategy for effective treatment of lung cancer.

Dysregulation of adenosine kinase isoforms in breast cancer

Dysregulated adenosine signaling pathway has been evidenced in the pathogenesis of breast cancer. However, the role of adenosine kinase (ADK) in tumorigenesis remains unclear while it crucially regulates the removal and availability of adenosine. ADK has two isoforms that localize to discrete subcellular spaces: i.e., nuclear, long-isoform (ADK-L) and cytosolic, short-isoform (ADK-S). We hypothesized that these two ADK isoforms would be differentially expressed in breast cancer and may contribute to divergent cellular actions in cancer. In this study, we examined the expression profiles of ADK isoforms in breast cancer tissues from 46 patient and followed up with an in vitro investigation by knocking down the expression of ADK-L or ADK-S using CRISPR gene editing to evaluate the role of ADK isoform in cancer progression and metastasis of cultured triple-negative breast cancer cell line MDA-MB-231. We demonstrated that (i) ADK-L expression level was significantly increased in breast cancer tissues versus paired normal tissues adjacent to tumor, whereas the ADK-S expression levels were not significantly different between cancerous and normal tissues; (ii) CRISPR/Cas9-mediated downregulation of ADK isoforms, led to suppressed cellular proliferation, division, and migration of cultured breast cancer cells; (iii) ADK-L knockdown significantly upregulated gene expression of matrix metalloproteinase (ADAM23, 9.93-fold; MMP9, 24.58-fold) and downregulated expression of cyclin D2 (CCND2, -30.76-fold), adhesive glycoprotein THBS1 (-8.28-fold), and cystatin E/M (CST6, -16.32-fold). Our findings suggest a potential role of ADK-L in mitogenesis, tumorigenesis, and tumor-associated tissue remodeling and invasion; and the manipulation of ADK-L holds promise as a therapeutic strategy for aggressive breast cancer.

A disintegrin and metalloprotease 23 hypermethylation predicts decreased disease-free survival in low-risk breast cancer patients

A Disintegrin And Metalloprotease 23 (ADAM23), a member of the ADAM family, is involved in neuronal differentiation and cancer. ADAM23 is considered a possible tumor suppressor gene and is frequently downregulated in various types of malignancies. Its epigenetic silencing through promoter hypermethylation was observed in breast cancer (BC). In the present study, we evaluated the prognostic significance of ADAM23 promoter methylation for hematogenous spread and disease-free survival (DFS). Pyrosequencing was used to quantify ADAM23 methylation in tumors of 203 BC patients. Presence of circulating tumor cells (CTC) in their peripheral blood was detected by quantitative RT-PCR. Expression of epithelial (KRT19) or mesenchymal (epithelial-mesenchymal transition [EMT]-inducing transcription factors TWIST1, SNAI1, SLUG and ZEB1) mRNA transcripts was examined in CD45-depleted peripheral blood mononuclear cells. ADAM23 methylation was significantly lower in tumors of patients with the mesenchymal CTC (P = .006). It positively correlated with Ki-67 proliferation, especially in mesenchymal CTC-negative patients (P = .001). In low-risk patients, characterized by low Ki-67 and mesenchymal CTC absence, ADAM23 hypermethylation was an independent predictor of DFS (P = .006). Our results indicate that ADAM23 is likely involved in BC progression and dissemination of mesenchymal CTC. ADAM23 methylation has the potential to function as a novel prognostic marker and therapeutic target.

MTBP promotes migration and invasion by regulation of ZEB2-mediated epithelial-mesenchymal transition in lung cancer cells

Background

It is clearly necessary to discover prognostic biomarkers to identify stage I patients at risk of recurrence and give them timely postoperative treatment.

Materials and methods

Data of stage I lung adenocarcinoma were retrieved from four gene series in Gene Expression Omnibus (GEO) database (GSE50081, GSE30219, GSE37745, and GSE13213). Partek Genomics Suite software was used to identify survival-related genes for finding candidate indicators for early-stage patients at risk of recurrence. Differential expression of MTBP (MDM₂ binding protein) in early-stage lung adenocarcinoma tissues was determined by immunohistochemical staining. The effects of MTBP interference expression and overexpression on viability, migration, and invasion capacity of lung cells were evaluated using Cell Counting Kit-8, wound healing, and Transwell assays. The tumor growth and lung metastasis in vivo were observed in chick embryo chorioallantoic membrane model. Human Exon 2.0 ST Array was used to analyze downstream regulation genes of MTBP in lung cancer cells. Involvement of ZEB2 and epithelial–mesenchymal transition (EMT) markers was investigated by Western blot.

Results

By mining GEO database, we identified MTBP as a poor prognostic indicator of stage I lung adenocarcinomas. In addition, increased expression of MTBP was also associated with poor survival in our early-stage lung adenocarcinoma cohort. Further experiment suggested that knockdown of MTBP suppressed the migration and invasion of A549 and H1975 cells in vitro and in vivo, whereas overexpression of MTBP in HCC827 and PC9 cells promoted the migration and invasion in vitro and in vivo. Furthermore, ZEB2 upregulation directly activated EMT to mediate the downstream effects of MTBP involved in lung cancer cells metastasis.

Conclusion

MTBP is an independent indicator for poor prognosis in stage I lung adenocarcinomas and might promote the aggressive phenotype of non-small-cell lung cancer by inducing the EMT process through upregulating ZEB2 expression.

Low levels of ADAM23 expression in epithelial ovarian cancer are associated with poor survival

BACKGROUND

ADAM23, a member of the disintegrin and metalloprotease (ADAM) family, has been reported to be expressed in several types of tumours. Nevertheless, the exact role of ADAM23 in epithelial ovarian cancer (EOC) remains unclear. The aim of this study was to investigate ADAM23 expression in EOC and evaluate its clinicopathological and prognostic significance.

METHODS

Immunohistochemistry (IHC), western blot and real-time PCR (RT-PCR) were used to analyse ADAM23 expression in 133 EOC, 42 benign ovarian tumour and 35 healthy control samples. Moreover, we evaluated the expression of ADAM23 in both public database (Oncomine and Kaplan-Meier plotter). The association between ADAM23 expression and various clinicopathological parameters was analysed.

RESULTS

The levels of ADAM23 mRNA and protein expression were significantly lower in EOC tissues than in corresponding control tissues and benign ovarian tumours, verifying results from the Oncomine databases. The loss of ADAM23 expression was significantly correlated with an advanced International Federation of Gynecology and Obstetrics (FIGO) stage and lymph node metastasis. The IHC data in the EOC samples correlated with the RT-PCR data. Furthermore, patients with low ADAM23 expression had shorter progression-free survival (PFS) and overall survival (OS) than patients with high ADAM23 expression. The multivariate analysis indicated that ADAM23 was an independent predictor in patients with EOC.

CONCLUSIONS

Our results demonstrate that ADAM23 expression is likely involved in the progression of EOC and may provide potential diagnostic and prognostic information regarding EOC.

SOX4, an epithelial-mesenchymal transition inducer, transactivates ADAM28 gene expression and co-localizes with ADAM28 at the invasive front of human breast and lung carcinomas

ADAM28 (a disintegrin and metalloproteinase 28) is abundantly expressed by carcinoma cells in the human breast and non-small cell lung carcinomas, and plays a role in carcinoma cell growth and metastasis. Although Src is an inducer of ADAM28 gene expression through the PI3K/AKT/mTOR and MEK/ERK pathways, direct transcriptional regulators for ADAM28 gene expression remain unknown. In this study, we performed the luciferase reporter assay and found that SOX4 (SRY-related HMG-box 4), an inducer of epithelial-mesenchymal transition (EMT), is a transcriptional activator for the ADAM28 gene. This activation required the SOX4-binding consensus sequence at the 5'-untranslated region of the mouse and human ADAM28 genes. Forced expression of SOX4 promoted the ADAM28 gene expression and migration in human breast and lung carcinoma cell lines. In the human breast and lung carcinoma tissues, ADAM28 and SOX4 were co-expressed at the invasive front of carcinoma cell nests. Our data demonstrate that SOX4 transactivates ADAM28 gene expression through direct binding to the ADAM28 promoter region and suggest the possibility that ADAM28 plays a role in invasion through SOX4-mediated EMT in the human breast and lung carcinomas.

Isolation of Cancer Stem Cells by Side Population Method

The Hoechst side population (SP) method is a flow cytometry technique used to obtain stem cells based on the dye efflux properties of the ATP-binding cassette (ABC) transporters. The SP cells are characterized by their capability to efflux the fluorescent DNA-binding dye Hoechst 33342 through their ABC transporters and are enriched in stem cells, which are endowed with a self-renewal capacity and multilineage differentiation potential and express the stemness genes including ABC multidrug transporters. The protocols outlined in this book chapter describe the isolation method of the SP cells from human lung carcinoma cell lines by using Hoechst 33342. In addition, we refer to the propagation method of SP cells by successive rounds of fluorescence-activated cell sorting analysis for SP cells. These approaches will be helpful for the establishment of novel in vitro and in vivo models using cancer stem cells, which may play a key role during carcinogenesis and/or tumor progression.

MicroRNA-130a-3p suppresses cell migration and invasion by inhibition of TBL1XR1-mediated EMT in human gastric carcinoma

MiR-130a-3p was found to play tumor suppressor role in most human cancers, except for gastric cancer. However, in this study, we demonstrated that miR-130a-3p was significantly down-regulated in gastric carcinoma (GC) tissues compared with adjacent non-neoplastic tissues, and decreased miR-130a-3p expression was associated with shorter overall survival (OS) and was an independent prognostic factor for OS in GC patients. Over-expression of miR-130a-3p remarkably inhibited not only GC cell migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro, but also tumorigenesis and lung metastasis in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Conversely, inhibition of miR-130a-3p resulted in opposite phenotype changes in GC cells. Furthermore, TBL1XR1 was identified as a direct target of miR-130a-3p, and reintroduction of TBL1XR1 into miR-130a-3p-transfected MGC-803 cells reversed the inhibitory effects of miR-130a-3p on GC cell migration, invasion and EMT. Taken together, our data suggested that miR-130a-3p suppressed aggressive phenotype of GC cells partially by direct targeting and decreasing TBL1XR1 and subsequent EMT process.

Expression of ADAMTS13 in Normal and Abnormal Placentae and Its Potential Role in Angiogenesis and Placenta Development

OBJECTIVE

ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 repeats, member 13) is primarily synthesized in liver. The biosynthesis of ADAMTS13 and its physiological role in placenta are not known.

APPROACH AND RESULTS

We used real-time polymerase chain reaction, immunohistochemistry, and Western blotting analyses, as well as proteolytic cleavage of FRETS (fluorescent resonance energy transfers)-VWF73, to determine ADAMTS13 expression in placenta and trophoblasts obtained from individuals with normal pregnancy and patients with severe preeclampsia. We also determined the role of ADAMTS13 in extravillous trophoblasts using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, wound scratch assay, transwell migration assay, tube formation assay, and tissue outgrowth assays. We showed that full-length and proteolytically active ADAMTS13 was expressed in normal human placenta, primarily in the trophoblasts and villous core fetal vessel endothelium during pregnancy. Placental expression of ADAMTS13 mRNA, protein, and proteolytic activity was at the highest levels during the first trimester and significantly reduced at the term of gestation. Additionally, significantly reduced levels of placental ADAMTS13 expression was detected under hypoxic conditions and in patients with preeclampsia. In addition, recombinant ADAMTS13 protease stimulated proliferation, migration, invasion, and network formation of trophoblastic cells in culture. Finally, knockdown of ADAMTS13 expression attenuated the ability of tube formation in trophoblast (HTR-8/SVNEO) cells and the extravillous trophoblast outgrowth in placental explants.

CONCLUSIONS

Our results demonstrate for the first time the expression of ADAMTS13 mRNA and protein in normal and abnormal placental tissues and its role in promoting angiogenesis and trophoblastic cell development. The findings support the potential role of the ADAMTS13-von Willebrand factor pathway in normal pregnancy and pathogenesis of preeclampsia.

Neuron-specific enolase, histopathological types, and age as risk factors for bone metastases in lung cancer

Lung cancer is a malignant tumor with high metastatic ability and bone is the most common site of distant metastasis of it. However, the independent risk factors for bone metastases of lung cancer remain largely to be elucidated. Here, we conducted a retrospective study to evaluate the correlation between clinical-pathological parameters, serum levels of neuron-specific enolase and CYFRA21-1, and bone metastases in lung cancer patients. The results revealed that patients with bone metastases were younger than those without metastases. Adenocarcinoma was the most frequent type of histopathology in patients with bone metastases. And the incidence of bone metastasis in patients with adenocarcinoma was significantly higher than those with other histopathological subtypes ( p < 0.001). Furthermore, the serum concentration of neuron-specific enolase was significantly higher in patients with bone lesions than those without bone metastases. Multivariate logistic regression analysis showed that patients' age (odds ratio = 1.024, p < 0.001), concentrations of neuron-specific enolase (odds ratio = 1.212, p = 0.004), and histopathological types (odds ratio = 0.995, p = 0.001) were the independent risk factors for bone metastases in patients with lung cancer. Thus, physicians should pay attention to these factors in order to identify bone metastasis earlier while patient was primarily diagnosed as having lung cancer.

SLC3A2, antigen of mAb 3G9, promotes migration and invasion by upregulating of mucins in gastric cancer

Solute carrier family 3 member 2 (SLC3A2) has been reported to be highly expressed in a variety of carcinomas. However, the function of SLC3A2 in gastric carcinoma (GC) has not been well explored. Monoclonal antibody (mAb) 3G9, generated from immunogen of various human GC cell lines, has been shown to bind to GC tissues specifically. In this study, we identified the target antigen of mAb 3G9 as SLC3A2, and detected the expression profile of SLC3A2 in a panel of gastric cancer cell lines and GC tumor tissues. We found that the increased expression of SLC3A2 was associated with serosal invasion in GC patients. Knockout of SLC3A2 suppressed the migration and invasion of BGC-823 cells in vitro and in vivo, whereas overexpression of SLC3A2 in NCI-N87 cells promoted the migration and invasion in vitro and in vivo. Mechanistic investigations suggested that MUC1, MUC16 and MUC5B were the downstream genes of SLC3A2 in GC cells. Taken together, our data suggested that SLC3A2 promoted the aggressive phenotype of GC by upregulating several mucin genes expression and may serve as a potential biomarker for diagnosis and target therapy.

microRNA-590 suppresses the tumorigenesis and invasiveness of non-small cell lung cancer cells by targeting ADAM9

microRNAs (miRNAs), a family of small non-coding RNA molecules, are implicated in cancer growth and progression. In the present study, we examined the expression and biological roles of miR-590 in non-small cell lung cancer (NSCLC). Compared to normal lung tissues, miR-590 expression was downregulated in primary NSCLCs and, to a greater extent, in corresponding brain metastases. NSCLC cell lines with high metastatic potential had significantly (P < 0.05) lower levels of miR-590 than those with low metastatic potential. Re-expression of miR-590 suppressed NSCLC cell proliferation, colony formation, migration, and invasion in vitro and tumorigenesis in vivo. In contrast, inhibition of miR-590 enhanced the migration and invasion of NSCLC cells. Mechanistic studies revealed that a disintegrin and metalloproteinase 9 (ADAM9) was a direct target of miR-590. Delivery of miR-590 mimic was found to decrease endogenous ADAM9 expression in NSCLC cells. Enforced expression of a miRNA-resistant form of ADAM9 significantly restored the aggressive behaviors in miR-590-overexpressing NSCLC cells. Taken together, our data reveal miR-590 as a tumor suppressor in NSCLC, which is at least partially mediated through targeting of ADAM9. Restoration of miR-590 may provide a promising therapeutic strategy for NSCLC.

ADAMTS13: more than a regulator of thrombosis

ADAMTS13, a plasma reprolysin-like metalloprotease, proteolyzes von Willebrand factor (VWF). ADAMTS13 is primarily synthesized by hepatic stellate cells (HSCs), and mainly regulates thrombogenesis by cleaving VWF. Recent studies demonstrate that ADAMTS13 also plays a role in the down-regulation of inflammation, regulation angiogenesis, and degradation of extracellular matrix. The purpose of this review is to introduce the state of progress with respect to some of the theorized roles of ADAMTS13.

ADAM23 is downregulated in side population and suppresses lung metastasis of lung carcinoma cells

Cancer cells contain a small population of cancer stem cells or cancer initiating cells, which can be enriched in the side population (SP) after fluorescence activated cell sorting. To examine the members of the ADAM, ADAMTS and MMP gene families related to phenotypes of the SP and the main population (MP), we screened the expression of all the members in the propagated SP and MP of A549 lung adenocarcinoma cells, and found that the relative expression ratio of ADAM23 in the MP to the SP is most highly increased, but none of them are increased in the SP. A similar result on the ADAM23 expression was obtained with another cell line, Calu‐3 cells. Overexpression of ADAM23 inhibited colony formation, cell adhesion and migration, and knockdown of ADAM23 by shRNA showed the reverse effects. ADAM23‐mediated suppression of colony formation, cell adhesion and migration was greatly reduced by treatment with neutralizing anti‐ADAM23 antibody, anti‐αvβ3 integrin antibody and/or ADAM23 disintegrin peptide. Expression of cancer stem cell‐related genes, including AKRC1/2, TM4SF1 and NR0B1, was increased by knockdown of ADAM23. In addition, lung metastasis of A549 transfectants with different levels of ADAM23 expression was negatively regulated by the ADAM23 expression levels. Our data provide evidence that ADAM23 plays a role in suppression of cancer cell progression through interaction with αvβ3 integrin, and suggest that downregulation of ADAM23 in SP cells may contribute toward providing a cancer stem cell phenotype by facilitating the activity of integrin αvβ3.