An Overview of ADAM9: Structure, Activation, and Regulation in Human Diseases.

ADAM9 (A disintegrin and a metalloprotease 9) is a membrane-anchored protein that participates in a variety of physiological functions, primarily through the disintegrin domain for adhesion and the metalloprotease domain for ectodomain shedding of a wide variety of cell surface proteins. ADAM9 influences the developmental process, inflammation, and degenerative diseases. Recently, increasing evidence has shown that ADAM9 plays an important role in tumor biology. Overexpression of ADAM9 has been found in several cancer types and is correlated with tumor aggressiveness and poor prognosis. In addition, through either proteolytic or non-proteolytic pathways, ADAM9 promotes tumor progression, therapeutic resistance, and metastasis of cancers. Therefore, comprehensively understanding the mechanism of ADAM9 is crucial for the development of therapeutic anti-cancer strategies. In this review, we summarize the current understanding of ADAM9 in biological function, pathophysiological diseases, and various cancers. Recent advances in therapeutic strategies using ADAM9-related pathways are presented as well.

Anti-IFN-γ autoantibodies in adults with disseminated nontuberculous mycobacterial infections are associated with HLA-DRB1*16:02 and HLA-DQB1*05:02 and the reactivation of latent varicella-zoster virus infection.

Adult patients with disseminated nontuberculous mycobacterial (dNTM) infections usually have severe immune system defects. Recently, several studies have shown that anti-IFN-γ autoantibodies may play an important role in the pathogenicity of dNTM infections. A considerable proportion of reported cases of anti-IFN-γ autoantibodies show either clinical or laboratory evidence of autoimmune disease. In the present study, we identified 19 formerly healthy adults who later developed dNTM infections, of whom 17 were further investigated immunologically. High-titer anti-IFN-γ autoantibodies capable of inhibiting IL-12 production in vitro were found in the plasma of all of these patients. In addition to dNTM infection, 35% and 71% of our patients also suffered from salmonellosis and herpes zoster, respectively. This observation suggests that IFN-γ may be crucial in controlling salmonella infection and reactivating latent varicella-zoster virus infection in humans. 2 HLA alleles, DRB1*16:02 DQB1*05:02 (odds ratio 8.68; 95% confidence interval, 3.47-21.90; P = 1.1 × 10(-6); Pc = 3.08 × 10(-5) and odds ratio 7.16; 95% confidence interval, 3.02-17.05; P = 1 × 10(-7); Pc = 1.4 × 10(-6), respectively), were found in 82% (14 of 17) of our patients. In conclusion, our data suggest that anti-IFN-γ autoantibodies may play a critical role in the pathogenesis of dNTM infections and reactivation of latent varicella-zoster virus infection and are associated with HLA-DRB1*16:02 and HLA-DQB1*05:02.

ADAM9 drives the immunosuppressive microenvironment by cholesterol biosynthesis-mediated activation of IL6-STAT3 signaling for lung tumor progression.

Chronic inflammation associated with lung cancers contributes to immunosuppressive tumor microenvironments, reducing CD8+ T-cell function and leading to poor patient outcomes. A disintegrin and metalloprotease domain 9 (ADAM9) promotes cancer progression. Here, we aim to elucidate the role of ADAM9 in the immunosuppressive tumor microenvironment. A bioinformatic analysis of TIMER2.0 was used to investigate the correlation of ADAM9 and to infiltrate immune cells in the human lung cancer database and mouse lung tumor samples. Flow cytometry, immunohistochemistry, and RNA sequencing (RNA-seq) were performed to investigate the ADAM9-mediated immunosuppressive microenvironment. The coculture system of lung cancer cells with immune cells, cytokine array assays, and proteomic approach was used to investigate the mechanism. By analyzing the human LUAD database and the mouse lung cancer models, we showed that ADAM9 was associated with the immunosuppressive microenvironment. Additionally, ADAM9 released IL6 protein from cancer cells to inhibit IL12p40 secretion from dendritic cells, therefore leading to dendritic cell dysfunction and further affecting T-cell functions. Proteomic analysis indicated that ADAM9 promoted cholesterol biosynthesis and increased IL6-STAT3 signaling. Mechanistically, ADAM9 reduced the protein stability of LDLR, resulting in reduced cholesterol uptake and induced cholesterol biosynthesis. Moreover, LDLR reduction enhanced IL6-STAT3 activation. We reveal that ADAM9 has a novel biological function that drives the immunosuppressive tumor microenvironment by linking lung cancer's metabolic and signaling axes. Thus, by targeting ADAM9 an innovative and promising therapeutic opportunity was indicated for regulating the immunosuppression of lung cancer.

Inhibition of CDCP1 by 8-isopentenylnaringenin synergizes with EGFR inhibitors in lung cancer treatment.

CUB domain-containing protein 1 (CDCP1) contributes to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) resistance by regulating EGFR signaling pathways and is a potential target in lung cancer treatment. This study aims to identify a CDCP1 reducer that synergistically improves TKI treatment. Utilizing a high-throughput drug screening system, a phytoestrogen 8-isopentenylnaringenin (8PN) was identified. Upon 8PN treatment, CDCP1 protein levels and malignant features were reduced. 8PN exposure caused the accumulation of lung cancer cells in G0/G1 phase and increased the proportion of senescent cells. In EGFR TKI-resistant lung cancer cells, the combination of 8PN and TKI synergistically reduced cell malignance, inhibited downstream EGFR pathway signaling, and exerted additive effects on cell death. Moreover, combination therapy effectively reduced tumor growth and enhanced tumor necrosis in tumor xenograft mice models. Mechanistically, 8PN increased interleukin (IL)6 and IL8 expression, induced neutrophil infiltration, and enhanced neutrophil-mediated cytotoxicity to attenuate lung cancer cell growth. In conclusion, 8PN enhances the anticancer efficacy of EGFR TKI on lung cancer and triggers neutrophil-dependent necrosis, highlighting the potential to overcome TKI resistance in lung cancer patients who have EGFR mutation.

ADAM9 promotes lung cancer progression through vascular remodeling by VEGFA, ANGPT2, and PLAT.

Lung cancer has a very high prevalence of brain metastasis, which results in a poor clinical outcome. Up-regulation of a disintegrin and metalloproteinase 9 (ADAM9) in lung cancer cells is correlated with metastasis to the brain. However, the molecular mechanism underlying this correlation remains to be elucidated. Since angiogenesis is an essential step for brain metastasis, microarray experiments were used to explore ADAM9-regulated genes that function in vascular remodeling. The results showed that the expression levels of vascular endothelial growth factor A (VEGFA), angiopoietin-2 (ANGPT2), and tissue plasminogen activator (PLAT) were suppressed in ADAM9-silenced cells, which in turn leads to decreases in angiogenesis, vascular remodeling, and tumor growth in vivo. Furthermore, simultaneous high expression of ADAM9 and VEGFA or of ADAM9 and ANGPT2 was correlated with poor prognosis in a clinical dataset. These findings suggest that ADAM9 promotes tumorigenesis through vascular remodeling, particularly by increasing the function of VEGFA, ANGPT2, and PLAT.

[Changes of erythrocyte rheology in rabbits with acute renal failure].

OBJECTIVE: To observe the change of erythrocyte theology in rabbits with acute renal failure (ARF). METHODS: Thirty-eight healthy rabbits were randomly divided into control group (n = 8), model group (establishing ARF model via intramuscular injection 1% HgCl2, and divided into 12 h, 24 h, 48 h subgroups, all n = 10), the arterial blood sample was taken out through carotid artery at corresponding times after anesthetization with urethane, for detecting the indices of renal function and erythrocyte rheology. RESULTS: The levels of urea and creatinine in plasma of model rabbits at 12 h, 24 h and 48 h were higher than those of control group, and there was a rise trend along with the time extension. The erythrocytes electrophoresis time at 12 h of model group was higher, the electrophoresis rate and migration rate of erythrocytes were lower compared with those of control group; the erythrocytes electrophoresis time at 24 h of model group was lower and the electrophoresis rate and migration rate were higher compared with those of model group at 12 h; and there were no statistical differences in erythrocytes electrophoresis indices between model group at 48 h and other groups. Meanwhile, there was a rise trend in erythrocyte sedimentation rate (ESR), K value of equation and emendation along with the time extension of ARF, but these indices only at 48 h of model group was lower significantly than that of control group. There were no statistical differences in aggregation index and deformability index of erythrocytes among groups. CONCLUSION: During the process of ARF, the erythrocytes electrophoresis time lengthen and electrophoresis rate and migration rate decrease at early stage, and these indices gradually return to normal; the indices of ESR increase gradually.