ADAM10 mediates the cell invasion and metastasis of human esophageal squamous cell carcinoma via regulation of E-cadherin activity

ADAM10-cleaved ephrin-A5 contributes to prostate cancer metastasis

A disintegrin and metalloprotease-10(ADAM10) promotes the metastasis of prostate cancer (PCa), but the specific mechanism is indistinct. Herein, DU145 cell lines with stable overexpression and knockdown of ADAM10 were constructed. We found that ectopic expression of ADAM10 not only significantly facilitated cell proliferation, migration, invasion, and inhibited apoptosis, but also could specifically hydrolyze ephrin-A5 and release the ephrin-A5 soluble ectodomain into extracellular media in vitro. These effects were reversed by ADAM10 depletion or treatment of GI254023X. Meanwhile, the co-location and physical interaction among EphA3, ephrin-A5, and ADAM10 were observed in PCa cells using immunofluorescence and immunoprecipitation techniques. Interestingly, overexpression of EphA3 exerted opposite effects in DU145 (ephrin-A5 + ) cells and PC-3 (ephrin-A5 ± ) cells. In addition, the pro-tumor function of EphA3 was reversed by the treatment with the exogenous ephrin-A5-Fc, which increased the phosphorylation level of EphA3 in PC-3 (ephrin-A5 ± ) cells. In nude mice, ADAM10 accelerated growth of the primary tumor, decreased the level of ephrin-A5 in the tumor tissue, but increased the level of ephrin-A5 in the peripheral blood, accompanied with an increase in the expression of CD31 and VEGF (vascular endothelial growth factor) in the tissue. What is more, the serum ephrin-A5 content of patients with metastatic PCa was significantly higher than that of the non-metastatic group (P < 0.05). The receiver operating characteristic curve(ROC) showed that the area under the curve(AUC) of serum ephrin-A5 as a marker of PCa metastasis was 0.843, with a sensitivity of 93.5% and a specificity of 75%. It is concluded that ADAM10-mediated ephrin-A5 shedding promotes PCa metastasis via transforming the role of EphA3 from ligand-dependent tumor suppressor to ligand-independent promoter, and ephrin-A5 in the blood can be used as a new biomarker for PCa metastasis.

ADAM9 functions as a transcriptional regulator to drive angiogenesis in esophageal squamous cell carcinoma

Hypoxia and angiogenesis play key roles in the pathogenesis of esophageal squamous cell carcinoma (ESCC), but regulators linking these two pathways to drive tumor progression remain elusive. Here we provide evidence of ADAM9's novel function in ESCC progression. Increasing expression of ADAM9 was correlated with poor clinical outcomes in ESCC patients. Suppression of ADAM9 function diminished ESCC cell migration and in vivo metastasis in ESCC xenograft mouse models. Using cellular fractionation and imaging, we found a fraction of ADAM9 was present in the nucleus and was uniquely associated with gene loci known to be linked to the angiogenesis pathway demonstrated by genome-wide ChIP-seq. Mechanistically, nuclear ADAM9, triggered by hypoxia-induced translocation, functions as a transcriptional repressor by binding to promoters of genes involved in the negative regulation of angiogenesis, and thereby promotes tumor angiogenesis in plasminogen/plasmin pathway. Moreover, ADAM9 suppresses plasminogen activator inhibitor-1 gene transcription by interacting with its transcription factors at the promoter. Our findings uncover a novel regulatory mechanism of ADAM9 as a transcriptional regulator in angiogenesis and highlight ADAM9 as a promising therapeutic target for ESCC treatment.

GADD45G Interacts with E-cadherin to Suppress the Migration and Invasion of Esophageal Squamous Cell Carcinoma

BACKGROUND/AIMS

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent cancers with poor prognosis. Metastasis is the leading cause of cancer-related deaths. The growth arrest and DNA damage-inducible 45 gamma (GADD45G) has been reported to correlate with survival, invasion, and metastasis of ESCC. This study was aimed to investigate the role and mechanism of GADD45G in ESCC cell migration and invasion.

METHODS

Both the effects of GADD45G and its need for E-cadherin to function on ESCC cell migration and invasion were determined through loss- and gain-of-function approaches via Transwell assays. The interaction between GADD45G and E-cadherin was detected by GST-pull down and IP assays. The expression of E-cadherin upon GADD45G overexpression was evaluated by RT-qPCR and western blot. The level of E-cadherin in cytoplasmic, nuclear, and membrane fractions was examined by western blot following subcellular fractionation.

RESULTS

Knockdown of GADD45G increased the migration and invasion abilities of KYSE150 cells, while overexpression of GADD45G showed the opposite effects on YES2 and KYSE30 cells. GADD45G could interact with E-cadherin and enhanced its membrane level. Knockdown of E-cadherin abolished the inhibitory effects of GADD45G on ESCC cell migration and invasion. Intriguingly, dimer-dissociating mutant of GADD45G could not interact with E-cadherin and almost lost its ability to suppress the ESCC cell migration and invasion.

CONCLUSIONS

This study reveals a novel role for GADD45G in inhibiting the ESCC cell migration and invasion, which will provide a new insight in understanding the ESCC metastatic mechanism.

Soluble AXL is ubiquitously present in malignant serous effusions

OBJECTIVE

The objective of this study was to analyze the expression level and clinical role of soluble AXL (sAXL) in cancers affecting the serosal surfaces, with focus on ovarian carcinoma.

METHODS

sAXL protein expression by ELISA was analyzed in 572 effusion supernatants, including 424 peritoneal, 147 pleural and 1 pericardial specimens.

RESULTS

sAXL was overexpressed in peritoneal effusions compared to pleural and pericardial specimens (p < 0.001). sAXL levels were additionally significantly higher in effusions from patients with ovarian carcinoma, malignant mesothelioma and breast carcinoma compared to specimens from patients with other cancers (predominantly carcinomas of lung, gastrointestinal or uterine corpus/cervix origin) or benign reactive effusions (p < 0.001). sAXL was further overexpressed in high-grade serous carcinoma (HGSC; n = 373) compared to low-grade serous carcinoma (LGSC; n = 32; p = 0.036). In HGSC, sAXL levels were significantly lower in post-chemotherapy effusions compared to primary diagnosis pre-chemotherapy specimens (p = 0.002). sAXL levels in HGSC were unrelated to chemoresponse at diagnosis, progression-free survival or overall survival. Levels were similarly unrelated to survival in LGSC and breast carcinoma.

CONCLUSIONS

sAXL is widely expressed in malignant effusions, particularly in ovarian and breast carcinoma and in malignant mesothelioma. sAXL is overexpressed in HGSC compared to LGSC and its levels are lower following exposure to chemotherapy. However, sAXL levels are not informative of chemoresponse or survival.

Renal ADAM10 and 17: Their Physiological and Medical Meanings

A disintegrin and metalloproteinases (ADAMs) are a Zn²⁺-dependent transmembrane and secreted metalloprotease superfamily, so-called “molecular scissors,” and they consist of an N-terminal signal sequence, a prodomain, zinc-binding metalloprotease domain, disintegrin domain, cysteine-rich domain, transmembrane domain and cytoplasmic tail. ADAMs perform proteolytic processing of the ectodomains of diverse transmembrane molecules into bioactive mediators. This review summarizes on their most well-known members, ADAM10 and 17, focusing on the kidneys. ADAM10 is expressed in renal tubular cells and affects the expression of specific brush border genes, and its activation is involved in some renal diseases. ADAM17 is weakly expressed in normal kidneys, but its expression is markedly induced in the tubules, capillaries, glomeruli, and mesangium, and it is involved in interstitial fibrosis and tubular atrophy. So far, the various substrates have been identified in the kidneys. Shedding fragments become released ligands, such as Notch and EGFR ligands, and act as the chemoattractant factors including CXCL16. Their ectodomain shedding is closely correlated with pathological factors, which include inflammation, interstitial fibrosis, and renal injury. Also, the substrates of both ADAMs contain the molecules that play important roles at the plasma membrane, such as meaprin, E-cadherin, Klotho, and CADM1. By being released into urine, the shedding products could be useful for biomarkers of renal diseases, but ADAM10 and 17 per se are also notable as biomarkers. Furthermore, ADAM10 and/or 17 inhibitions based on various strategies such as small molecules, antibodies, and their recombinant prodomains are valuable, because they potentially protect renal tissues and promote renal regeneration. Although temporal and spatial regulations of inhibitors are problems to be solved, their inhibitors could be useful for renal diseases.

Downregulation of long non-coding RNA GAS5 promotes cell proliferation, migration and invasion in esophageal squamous cell carcinoma

The present study aimed to investigate the potential role of long non-coding RNA growth arrest-specific transcript 5 (lncRNA GAS5) in the progression of esophageal squamous cell carcinoma (ESCC) and to reveal its possible regulatory mechanism. The expression of lncRNA GAS5 in ESCC tissues and cell lines was analyzed using reverse transcription-quantitative polymerase chain reaction and western blot analysis. The overexpression vector pc-GAS5 and control vector pc-negative control (NC), containing no GAS5 sequence, were transfected into ESCC cells. The effects of lncRNA GAS5 overexpression on cell proliferation, cell cycle distribution, cell migration and invasion were then analyzed. Besides, the expression levels of ATM-CHK2 pathway-associated proteins and epithelial-mesenchymal transition (EMT)-associated proteins were measured. Expression of lncRNA GAS5 was downregulated in the ESCC tissues compared with adjacent normal tissues, and was also downregulated in ESCC Kyse450 cells compared with the human esophageal epithelial HET-1A cell line. Additionally, lncRNA GAS5 was successfully overexpressed in ESCC cells following transfection with pc-GAS5. Overexpression of lncRNA GAS5 significantly inhibited cell proliferation, induced cell cycle arrest at G2/M phase and suppressed cellular migration and invasion. When cells were transfected with pc-GAS5, the levels of phosphorylated (p)-ATM serine/threonine protein kinase, p-checkpoint kinase 2 (CHK2), p-cell division cycle 25C, p-cyclin-dependent kinase 1, N-cadherin, vimentin and Snail were significantly increased, whereas that of E-cadherin were markedly decreased. The results of the present study indicate that overexpression of lncRNA GAS5 may inhibit cell proliferation, migration and invasion in ESCC. lncRNA GAS5 overexpression may induce cell cycle arrest at G2/M stage by activating the ATM-CHK2 pathway. The results of the current study further indicate that lncRNA GAS5 overexpression may suppress cell migration and invasion via EMT-associated proteins. lncRNA GAS5 could therefore serve as a potential target for ESCC therapy.

Impact of ADAM10 gene polymorphisms on hepatocellular carcinoma development and clinical characteristics

A disintegrin and metalloprotease (ADAM) family proteins are type-I transmembrane glycoproteins with multiple functions in cell adhesion, migration, proteolysis and signaling. ADAM10 is a member of the ADAM family reportedly involved in cancer progression and has been shown to be overexpressed in hepatocellular carcinoma (HCC) tissues and significantly associated with tumor progression and shortened survival. This study investigated ADAM10's single nucleotide polymorphisms (SNPs) and their association to HCC development and regulation. Real-time polymerase chain reaction was used to analyze five SNPs of ADAM10 in 333 patients with HCC and 1196 controls without cancer. The results indicated that of the 333 patients with HCC, those who carried ADAM10 rs514049 (AC + CC) variants had a higher risk of developing lymph node metastasis (odds ratio [OR] = 5.087, p = 0.027), and those who carried ADAM10 rs653765 (GA + AA) variants had a higher risk of developing distant metastasis (OR = 3.346, p = 0.020) and higher levels of α-fetoprotein. In conclusion, our study demonstrated that the SNPs of ADAM10 are involved in HCC progression. ADAM10 SNPs may be used as therapeutic targets to evaluate poor prognoses for HCC.

Cytoplasmic fragment of CD147 generated by regulated intramembrane proteolysis contributes to HCC by promoting autophagy

Hepatocellular carcinoma (HCC) is one of the most lethal and prevalent cancers worldwide. CD147 (EMMPRIN or basigin) is a leading gene relating to hepatocarcinogenesis and metastasis, and is detected in transmembrane, exosome or circulating forms in HCC patients. The endosome recycling of CD147 further enhances the function of this oncoprotein from a dynamic perspective. However, previous studies about CD147 mainly focused on one separate form, and little attention has been paid to how the different forms of tumor-derived CD147 changes. Moreover, uncovering the roles of the residual C-terminal portion of CD147 after shedding is inevitable to fully understand CD147 promoting tumor progression. In this study, we discovered that under low-cholesterol condition, CD147 endocytosis is inhibited but its shedding mediated by ADAM10 is enhanced. Further procession of residual CD147 in the lysosome produces nuclear-localized CD147-ICD (intracellular domain of CD147), which contributes to autophagy through NF-κB–TRAIL–caspase8–ATG3 axis. As autophagy endows cancer cells with increased adaptability to chemotherapy, and HAb 18 (a specific antibody targeting CD147) inhibits CD147 shedding and sequential CD147-ICD enhances autophagy, we found the combination of HAb 18 and cisplatin exhibited marked antitumor efficiency.

Mast cell chymase affects the proliferation and metastasis of lung carcinoma cells in vitro

Metastasis of lung carcinoma cells is a major cause of organ failure and mortality of patients with lung cancer. Lung mast cells are a type of immune cell which reside in the respiratory mucosa. High numbers of mast cells are associated with the majority of common types of cancer; however, the effects of mast cells on cancer remain unclear. In the present study, the effects of mast cell chymase (MCC) on the proliferation and adhesion of the lung carcinoma cell lines A549 and H520 was investigated. After 24 h of treatment, the highest dose of MCC (50 mU/ml) decreased the proliferation rate of A549 and H520 cells, whereas the lowest dose of MCC (5 mU/ml) resulted in a small increase in the viability. A549 cells treated with MCC lost adhesion ability in a MCC dose-dependent manner; however, these detached cells were able to regrow when transferred to a fresh culture. The protein expression of epithelial (E-) cadherin, p53 and p21 in A549 lung carcinoma cells were detected by western blot analysis. The results of the present study revealed that, following 24 h of treatment, the expression level of E-cadherin was decreased, the p53 tumor suppressor protein was expressed in limited quantities and the expression of p21 was decreased. Zymography was used to examine the effects of MCC on the expression and activation of matrix metalloproteinase-9 (MMP-9) in A549 and H520 cells. The expression of MMP-9 in the two cell lines was time- and MCC dose-dependent. The results of the present study demonstrated that MCC stimulated lung carcinoma cell proliferation and adhesion, as well as regulated E-cadherin expression and the cell cycle, all of which are associated with cancer metastasis. Therefore, MCC may be a potential candidate for lung carcinoma therapy.

Role of MicroRNA-103a Targeting ADAM10 in Abdominal Aortic Aneurysm

MicroRNAs (miRNAs) are deregulated in various vascular ailments including abdominal aortic aneurysm (AAA). MiR-103 is involved in vascular, metabolic, and malignant diseases, but whether it participates in the pathogenesis of AAA remains elusive. ADAM10 plays a vital role in the formation of aneurysm, but whether miRs modulate its activity during AAA formation is totally unknown. In this study, we detected the significantly increased protein expression of ADAM10 in angiotensin II induced murine AAA specimens, while the mRNA expression of ADAM10 was similar between AAA and control, suggesting the posttranscriptional regulation. The ADAM10 specific inhibitor GI254023X dramatically reduced the macrophage infiltration of murine abdominal aorta. Bioinformatic predictions suggest that ADAM10 is the target of miR-103a/107 but the binding site is exclusive. At the cellular level, miR-103a-1 suppressed the protein expression of ADAM10, while antisense miR-103a-1 increased its expression. Particularly, with the progression of murine AAA, the mRNA expression of miR-103a/107 substantially decreased and the protein expression of ADAM10 greatly increased. Together, our data afford the new insight that miR-103a inhibited AAA growth via targeting ADAM10, which might be a promising therapeutic strategy to alleviate AAA.

Fine Tuning Cell Migration by a Disintegrin and Metalloproteinases

Cell migration is an instrumental process involved in organ development, tissue homeostasis, and various physiological processes and also in numerous pathologies. Both basic cell migration and migration towards chemotactic stimulus consist of changes in cell polarity and cytoskeletal rearrangement, cell detachment from, invasion through, and reattachment to their neighboring cells, and numerous interactions with the extracellular matrix. The different steps of immune cell, tissue cell, or cancer cell migration are tightly coordinated in time and place by growth factors, cytokines/chemokines, adhesion molecules, and receptors for these ligands. This review describes how a disintegrin and metalloproteinases interfere with several steps of cell migration, either by proteolytic cleavage of such molecules or by functions independent of proteolytic activity.