ADAM10 inhibition of human CD30 shedding increases specificity of targeted immunotherapy in vitro

The biology of classical Hodgkin lymphoma

Classical Hodgkin lymphoma (cHL) is distinguished by several important biological characteristics. The presence of Hodgkin Reed Sternberg (HRS) cells is a defining feature of this disease. The tumor microenvironment with relatively few HRS cells in an expansive infiltrate of immune cells is another key feature. Numerous cell-cell mediated interactions and a plethora of cytokines in the tumor microenvironment collectively work to promote HRS cell growth and survival. Aberrancy and constitutive activation of core signal transduction pathways are a hallmark trait of cHL. Genetic lesions contribute to these dysregulated pathways and evasion of the immune system through a variety of mechanisms is another notable feature of cHL. While substantial elucidation of the biology of cHL has enabled advancements in therapy, increased understanding in the future of additional mechanisms driving cHL may lead to new treatment opportunities.

Circulating soluble CD30 is associated with renal tertiary lymphoid structures and the progression of IgA nephropathy

BACKGROUND

Renal tertiary lymphoid structures (TLSs) are involved in renal pathology and prognosis of IgA nephropathy (IgAN). CD30 and its ligands participate in the formation of renal TLSs. However, the relationship between circulating CD30 and renal prognosis is unclear. The objective of this study was to evaluate the relationship between circulating CD30 and prognosis in patients with IgAN.

METHODS

We conducted a retrospective study including 351 patients with biopsy proved IgAN. We collected clinical and pathologic features at the time of biopsy and recorded renal follow-up outcomes. Circulating CD30 levels in IgAN patients at the time of biopsy were measured via enzyme-linked immunosorbent assay (ELISA). The association between elevated CD30 levels and the composite endpoint (defined as a ≥ 50 % decline in eGFR from baseline, end-stage renal disease, or death) was investigated using Cox regression analysis.

RESULTS

During a median follow-up period of 5.12 years, 44 (12.5 %) patients in the cohort reached the composite endpoint. Kaplan-Meier survival curve analysis revealed a significant association between higher circulating CD30 levels and a poorer renal prognosis (log-rank P < 0.001). Cox regression analysis showed that high CD30 was an independent factor for the composite endpoints in multivariable-adjusted models (HR 3.397, 95 % CI: 1.230-9.384, P = 0.018). These associations were also observed in a subgroup of patients with concomitant renal TLSs formation (10.443, 95 % CI: 1.680-65.545, P = 0.012), proteinuria > 1 g/d (HR 12.287, 95 % CI: 1.499-100.711, P = 0.019), and female patients (HR 22.372, 95 % CI: 1.797-278.520, P = 0.016).

CONCLUSION

Elevated level of circulating CD30 is an independent risk factor for renal disease progression in patients with IgAN.

Inhibitors of ADAM10 reduce Hodgkin lymphoma cell growth in 3D microenvironments and enhance brentuximab-vedotin effect

Shedding of ADAM10 substrates, like TNFa or CD30, can affect both anti-tumor immune response and antibody-drug-conjugate (ADC)-based immunotherapy. We have published two new ADAM10 inhibitors, LT4 and MN8 able to prevent such shedding in Hodgkin lymphoma (HL). Since tumor tissue architecture deeply influences the outcome of anti-cancer treatments, we set up a new threedimensional (3D) culture systems to verify whether ADAM10 inhibitors can contribute to, or enhance, the anti-lymphoma effects of the ADC brentuximab-vedotin (BtxVed). In order to recapitulate some aspects of lymphoma structure and architecture, we assembled two 3D culture models: mixed spheroids made of HL lymph node (LN) mesenchymal stromal cells (MSC) and Reed Sternberg/Hodgkin lymphoma cells (HL cells) or collagen scaffolds repopulated with LN-MSC and HL cells. In these 3D systems we found that: i) the ADAM10 inhibitors LT4 and MN8 reduce ATP content or glucose consumption, related to cell proliferation, increasing lactate dehydrogenase release as a cell damage hallmark; ii) these events are paralleled by mixed spheroids size reduction and inhibition of CD30 and TNFa shedding; iii) the effects observed can be reproduced in repopulated HL LN-derived matrix or collagen scaffolds; iv) ADAM10 inhibitors enhance the anti-lymphoma effect of the anti-CD30 ADC BtxVed both in conventional cultures and in repopulated scaffolds. Thus, we provide evidence for a direct and combined antilymphoma effect of ADAM10 inhibitors with BtxVed, leading to the improvement of ADC effects; this is documented in 3D models recapitulating features of the LN microenvironment, that can be proposed as a reliable tool for anti-lymphoma drug testing.

CD153-CD30 signaling promotes age-dependent tertiary lymphoid tissue expansion and kidney injury

Tertiary lymphoid tissues (TLTs) facilitate local T and B cell interactions in chronically inflamed organs. However, the cells and molecular pathways that govern TLT formation are poorly defined. Here, we identified TNF superfamily CD153/CD30 signaling between 2 unique age-dependent lymphocyte subpopulations, CD153⁺PD-1⁺CD4⁺ senescence-associated T (SAT) cells and CD30⁺T-bet⁺ age-associated B cells (ABCs), as a driver for TLT expansion. SAT cells, which produced ABC-inducing factors IL-21 and IFN-γ, and ABCs progressively accumulated within TLTs in aged kidneys after injury. Notably, in kidney injury models, CD153 or CD30 deficiency impaired functional SAT cell induction, which resulted in reduced ABC numbers and attenuated TLT formation with improved inflammation, fibrosis, and renal function. Attenuated TLT formation after transplantation of CD153-deficient bone marrow further supported the importance of CD153 in immune cells. Clonal analysis revealed that SAT cells and ABCs in the kidneys arose from both local differentiation and recruitment from the spleen. In the synovium of aged rheumatoid arthritis patients, T peripheral helper/T follicular helper cells and ABCs also expressed CD153 and CD30, respectively. Together, our data reveal a previously unappreciated function of CD153/CD30 signaling in TLT formation and propose targeting the CD153/CD30 signaling pathway as a therapeutic target for slowing kidney disease progression.

Impact of Endocytosis Mechanisms for the Receptors Targeted by the Currently Approved Antibody-Drug Conjugates (ADCs)-A Necessity for Future ADC Research and Development

Biologically-based therapies increasingly rely on the endocytic cycle of internalization and exocytosis of target receptors for cancer therapies. However, receptor trafficking pathways (endosomal sorting (recycling, lysosome localization) and lateral membrane movement) are often dysfunctional in cancer. Antibody-drug conjugates (ADCs) have revitalized the concept of targeted chemotherapy by coupling inhibitory antibodies to cytotoxic payloads. Significant advances in ADC technology and format, and target biology have hastened the FDA approval of nine ADCs (four since 2019). Although the links between aberrant endocytic machinery and cancer are emerging, the impact of dysregulated internalization processes of ADC targets and response rates or resistance have not been well studied. This is despite the reliance on ADC uptake and trafficking to lysosomes for linker cleavage and payload release. In this review, we describe what is known about all the target antigens for the currently approved ADCs. Specifically, internalization efficiency and relevant intracellular sorting activities are described for each receptor under normal processes, and when complexed to an ADC. In addition, we discuss aberrant endocytic processes that have been directly linked to preclinical ADC resistance mechanisms. The implications of endocytosis in regard to therapeutic effectiveness in the clinic are also described. Unexpectedly, information on endocytosis is scarce (absent for two receptors). Moreover, much of what is known about endocytosis is not in the context of receptor-ADC/antibody complexes. This review provides a deeper understanding of the pertinent principles of receptor endocytosis for the currently approved ADCs.

Aberrant Methylation of Tumour Suppressor Gene ADAM12 in Chronic Lympocytic Leukemia Patients: Application of Methylation Specific-PCR Technique

Objective:

Chronic Lymphocytic Leukemia (CLL) is a common leukemia among Caucasians but rare in Asians population. We postulated that aberrant methylation either hypermethylation or partial methylation might be one of the silencing mechanisms that inactivates the tumour suppressor genes in CLL. This study aimed to compare the methylation status of tumour suppressor gene, ADAM12, among CLL patients and normal individuals. We also evaluated the association between methylation of ADAM12 and clinical and demographic characteristics of the participants.

Methods:

A total of 25 CLL patients and 25 normal individuals were recruited in this study. The methylation status of ADAM12 was determined using Methylation-Specific PCR (MSP); whereas, DNA sequencing method was applied for validation of the MSP results.

Results:

Among CLL patients, 12 (48%) were partially methylated and 13 (52%) were unmethylated. Meanwhile, 5 (20%) and 20 (80.6%) of healthy individuals were partially methylated and unmethylated, respectively. There was a statistically significant association between the status of methylation at ADAM12 and the presence of CLL (p=0.037).

Conclusion:

The aberrant methylation of ADAM12 found in this study using MSP assay may provide new exposure to CLL that may improve the gaps involved in genetic epigenetic study in CLL.

Unveiling the Physical and Functional Niches of FAM26F by Analyzing Its Subcellular Localization and Novel Interacting Partners

The knowledge of a protein's subcellular localization and interacting partners are crucial for elucidating its cellular function and associated regulatory networks. Although FAM26F (family with sequence similarity 26, member F) has been recognized as a vital player in various infections, stimulation studies, cancer, and immune pathogenesis, the precise location and function of FAM26F are not well understood. The current study is the first to focus on functional characterization of FAM26F by analyzing its subcellular localization and identifying its novel interacting partners using advanced proteome approaches. The immunofluorescence and confocal microscopy results revealed FAM26F to be largely localized within the Golgi apparatus of the cell. However, its minor presence in endoplasmic reticulum (ER) pointed toward the probable retrograde transfer of FAM26F from Golgi to ER during adverse conditions. Moreover, co-immunoprecipitation and MS/MS results demonstrated a total of 85 proteins, 44 of which significantly copurified with FAM26F. Interestingly, out of these 44 MS/MS identified proteins, almost 52% were involved in innate immunity, 38.6% in neutrophil degranulation, and remaining 10% were either involved in phosphorylation, degradation, or regulation of apoptosis. Further characterization through Ingenuity Pathway Analysis showed that majority of these proteins was involved in maintaining calcium homeostasis of cell. Consequently, the validation of selected proteins uncovered the key interaction of FAM26F with Thioredoxin, which essentially paved the way for depicting its mechanism of action under stress or disease conditions. It is proposed that activation and inhibition of the cellular immune response is essentially dependent on whether FAM26F or Thioredoxin considerably interact with CD30R.

Levels of Soluble CD30 and CD26 and Their Clinical Significance in Patients with Primary Immune Thrombocytopenia

Background

sCD30 and sCD26 are correlated with autoimmune diseases. However, little research has been done on the relationship between them and primary immune thrombocytopenia (ITP).

Methods

This study enrolled 47 patients diagnosed with ITP in the Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences (Tianjin, China), from January 2015 to August 2015. The peripheral blood of all subjects was collected. The mRNA expression of CD30 was quantified by RT-PCR, and concentrations of sCD30 and sCD26 were measured by ELISA. Patient characteristics, CD30 mRNA levels, and sCD30 and sCD26 concentrations were analyzed.

Results

The concentration of sCD30 was higher in active ITP patients (median, 35.82 ng/mL) than in remission ITP patients (median, 23.12 ng/mL; P = 0.021) and healthy controls (median, 25.11 ng/mL; P = 0.002). Plasma sCD26 levels decreased in remission ITP patients compared with that in healthy controls (median, 599.4 ng/mL vs. 964.23 ng/mL; P = 0.004). Ratios of sCD26/sCD30 in active ITP patients decreased compared with those in controls (P = 0.005). Increased sCD30 was positively correlated with hemorrhage (r = 0.493, P = 0.017) in ITP patients while little relationship was identified between sCD26 and ITP.

Conclusion

Since sCD30 levels and sCD26/sCD30 ratios may contribute to the activity of the disease, they may be used to assess ITP disease activity.

Role of ADAM10 as a CD30 Sheddase in Classical Hodgkin Lymphoma

Cancer cells generally recruit and influence non-malignant immune cells to support the tumor growth. Classical Hodgkin lymphoma (cHL) is a good example because the affected lymphoid tissue contains only a few malignant Hodgkin and Reed-Sternberg (H-RS) cells, which are supported by a massive infiltrate of lymphocytes, fibroblasts, and innate immune cells. The transmembrane receptor CD30, which is selectively expressed on the H-RS cells, plays an important role, not only in cell stimulation and intercellular communication but also in tumor diagnosis and targeted tumor therapy. Different protein processing pathways influence its functionality. Depending on the conditions, the receptor is internalized or released. The release of CD30 occurs either as an intact molecule, embedded in the membrane of extracellular vesicles (EVs), or as a cleaved soluble ectodomain (sCD30). CD30 cleavage is predominantly catalyzed by ADAM10. The enzyme is catalytically active in cells as well as in EVs and gradually releases sCD30. Because the circulation contains no CD30⁺ donor cells, this mechanism explains that the cleaved ectodomain represents the predominant form of CD30 in the plasma of cHL patients. CD30 processing might influence the impact of CD30 antibody-drug conjugates, such as Brentuximab Vedotin (BV). Whereas, ADAM10-degraded CD30 impedes the BV efficacy, tumor-derived EVs load bystander cells with CD30 and generate new targets among supporter cells. This crossfire effect might contribute to the enormous clinical impact of BV, whereas the ADAM10-dependent cleavage to the mild systemic off-target effects of the treatment with BV.

NKG2D Ligand Shedding in Response to Stress: Role of ADAM10

NKG2D is an activating receptor expressed by NK cells and some subsets of T cells and represents a major recognition receptor for detection and elimination of cancer cells. The ligands of NKG2D are stress-induced self-proteins that can be secreted as soluble molecules by protease-mediated cleavage. The release of NKG2D ligands in the extracellular milieu is considered a mode of finely controlling their surface expression levels and represents a relevant immune evasion mechanism employed by cancer cells to elude NKG2D-mediated immune surveillance. A disintegrin and metalloproteinase 10 (ADAM10), a catalytically active member of the ADAM family of proteases, is involved in the cleavage of some NKG2D ligands in various types of cancer cells either in steady state conditions and in response to an ample variety of stress stimuli. Appealing immunotherapeutic strategies devoted to promoting NK cell-mediated recognition and elimination of cancer cells are based on the upregulation of NK cell activating ligands. In particular, activation of DNA damage response (DDR) and the induction of cellular senescence by chemotherapeutic agents are associated with increased expression of NKG2D ligands on cancer cell surface. Herein, we will review advances on the protease-mediated cleavage of NKG2D ligands in response to chemotherapy-induced stress focusing on: (i) the role played by ADAM10 in this process and (ii) the implications of NKG2D ligand shedding in the course of cancer therapy and in senescent cells.

ADAM Metalloproteinases as Potential Drug Targets

The ADAMs, together with ADAMTSs and snake venom metalloproteases (SVMPs), are members of the Adamalysin family. Differences in structural organization, functions and localization are known and their domains, catalytic or non-catalytic, show key roles in the substrate recognition and protease activity. Some ADAMs, as membrane-bound enzymes, show sheddase activity. Sheddases are key to modulation of functional proteins such as the tumor necrosis factor, growth factors, cytokines and their receptors, adhesion proteins, signaling molecules and stress molecules involved in immunity. These activities take part in the regulation of several physiological and pathological processes including inflammation, tumor growth, metastatic progression and infectious diseases. On these bases, some ADAMs are currently investigated as drug targets to develop new alternative therapies in many fields of medicine. This review will be focused on these aspects.

Influence of immunosuppressive drugs on the CD30 molecule in kidney transplanted patients

BACKGROUND

Soluble CD30 (sCD30) is a suggested marker for kidney transplantation outcomes. We investigated whether sCD30 serum levels are influenced by immunosuppression and whether they correlate with findings in protocol biopsies and with CD30 gene expression in peripheral blood mononuclear cells (PBMC).

METHODS

We studied 118 kidney transplant recipients that initially received tacrolimus (TAC) and, at month-3, were converted or not to sirolimus (SRL).

RESULTS

sCD30 serum levels gradually declined after transplantation, being the decline more pronounced in the SRL group. CD30 gene expression in PBMC was higher in the SRL group than in the TAC group. Patients with IF/TA ≥ I in the month-24 protocol biopsy had higher sCD30 levels than patients without IF/TA, in the SRL group (P = .03) and in the TAC group (P = .07). CD30⁺ cells were observed in three out of 10 biopsies with inflammatory infiltrate from the SRL group. In mixed lymphocyte cultures, SRL and TAC diminished the number of CD30⁺ T cells and the sCD30 levels in the supernatant, but the effect of SRL was stronger.

CONCLUSIONS

Overall, sCD30 levels are lower in SRL-treated patients, but the association between increased sCD30 levels and IF/TA at month-24 post-transplantation is stronger in SRL than in TAC-treated patients.

The Many Facets of Metzincins and Their Endogenous Inhibitors: Perspectives on Ovarian Cancer Progression

Approximately sixty per cent of ovarian cancer patients die within the first five years of diagnosis due to recurrence associated with chemoresistance. The metzincin family of metalloproteinases is enzymes involved in matrix remodeling in response to normal physiological changes and diseased states. Recently, there has been a mounting awareness of these proteinases and their endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), as superb modulators of cellular communication and signaling regulating key biological processes in cancer progression. This review investigates the role of metzincins and their inhibitors in ovarian cancer. We propose that understanding the metzincins and TIMP biology in ovarian cancer may provide valuable insights in combating ovarian cancer progression and chemoresistance-mediated recurrence in patients.

Specific ADAM10 inhibitors localize in exosome-like vesicles released by Hodgkin lymphoma and stromal cells and prevent sheddase activity carried to bystander cells

Shedding of ADAM10 substrates, like TNFα, MICA or CD30, is reported to affect both anti-tumor immune response and antibody-drug-conjugate (ADC)-based immunotherapy. Soluble forms of these molecules and ADAM10 can be carried and spread in the microenvironment by exosomes released by tumor cells. We reported new ADAM10 inhibitors able to prevent MICA shedding in Hodgkin lymphoma (HL), leading to recognition of HL cells by cytotoxic lymphocytes. In this paper, we show that the mature bioactive form of ADAM10 is released in exosome-like vesicles (ExoV) by HL cells and lymph node mesenchymal stromal cells (MSC). We demonstrate that ADAM10 inhibitors are released in ExoV by MSC or HL cells, endocytosed by bystander cells and localized in the endolysosomal compartment in HL MSC. ExoV released by HL cells can enhance MICA shedding by MSC, while ExoV from MSC induce TNFα or CD30 shedding by HL cells. Of note, ADAM10 sheddase activity carried by ExoV is prevented with the ADAM10 inhibitors LT4 and CAM29, pretreating either the ExoV-producing or the ExoV-receiving cells. In particular, both inhibitors reduce CD30 shedding maintaining the anti-tumor effects of the ADC Brentuximab-Vedotin or the anti-CD30 Iratumumab on HL cells. Thus, spreading of ADAM10 activity due to ExoV can result in the release of cytokines, like TNFα, a lymphoma growth factor, or soluble molecules, like sMICA or sCD30, that potentially interfere with host immune surveillance or immunotherapy. ADAM10 blockers can interfere with this process, allowing the development of anti-lymphoma immune response and/or efficient ADC-based or human antibody-based immunotherapy.

CD30 on extracellular vesicles from malignant Hodgkin cells supports damaging of CD30 ligand-expressing bystander cells with Brentuximab-Vedotin, in vitro

The goal of targeted immunotherapy in cancer is to damage both malignant and tumor-supporting cells of the microenvironment but spare unaffected tissue. The malignant cells in classical Hodgkin lymphoma (cHL) selectively express CD30. They release this receptor on extracellular vesicles (EVs) for the tumor-supporting communication with CD30 ligand (CD30L)-positive bystander cells. Here, we investigated how CD30-positive EVs influence the efficacy of the CD30 antibody drug conjugate (ADC) Brentuximab Vedotin (SGN-35). The malignant cells and the EVs expressed the active sheddase ADAM10. ADAM10 cleaved and released the CD30 ectodomain (sCD30), causing a gradual depletion of SGN-35 binding sites on EVs and creating a soluble competitor of the ADC therapy. In a 3D semi-solid tumor microenvironment model, the EVs were retained in the matrix whereas sCD30 penetrated readily into the surrounding culture medium. This resulted in a lowered ratio of EV-associated CD30 (CD30EV) to sCD30 in the surrounding medium in comparison to non-embedded cultures. A low percentage of CD30EV was also detected in the plasma of cHL patients, supporting the clinical relevance of the model. The adherence of CD30EV but not sCD30 to CD30-/CD30L+ mast cells and eosinophils allowed the indirect binding of SGN-35. Moreover, SGN-35 damaged CD30-negative cells, provided they were loaded with CD30+ EVs.

ADAM10 new selective inhibitors reduce NKG2D ligand release sensitizing Hodgkin lymphoma cells to NKG2D-mediated killing

Hodgkin lymphoma (HL) resistant to conventional therapies is increasing, making of interest the search for new schemes of treatment. Members of the "A Disintegrin And Metalloproteases" (ADAMs) family, mainly ADAM10 or ADAM17, have been proposed as therapeutic targets in solid tumors and some ADAMs inhibitors have been shown to exert antitumor effects. We have previously described an overexpression of ADAM10 in HL, together with increased release of NKG2D ligands (NKG2D-L) and reduced activation of effector T lymphocytes with anti-lymphoma capacity. Aim of the present work was to verify whether inhibition of ADAM10 in HL cells could restore the triggering of NKG2D-dependent anti-lymphoma T cell response. As no selective ADAM10 blockers have been reported so far, we synthesized the two hydroxamate compounds LT4 and MN8 with selectivity for ADAM10 over metalloproteases (MMPs), LT4 showing higher specificity for ADAM10 over ADAM17. We show that (i) HL lymph nodes (LN) and cultured HL cells express high levels of the mature active membrane form of ADAM10; (ii) ADAM10 is the major sheddase for the NKG2D-L in HL cells; (iii) the new LT4 and MN8 compounds strongly reduce the shedding of NKG2D-L by HL cell lines and enhance the binding of NKG2D receptor; (iv) of note, these new ADAM10 inhibitors increase the sensitivity of HL cell lines to NKG2D-dependent cell killing exerted by natural killer and γδ T cells. Overall, the biologic activity of LT4 and MN8 appears to be more potent than that of the commercial inhibitor GI254023X.

Association of CD30 transcripts with Th1 responses and proinflammatory cytokines in patients with end-stage renal disease

High serum sCD30 levels are associated with inflammatory disorders and poor outcome in renal transplantation. The contribution to these phenomena of transcripts and proteins related to CD30-activation and -cleavage is unknown. We assessed in peripheral blood of end-stage renal disease patients (ESRDP) transcripts of CD30-activation proteins CD30 and CD30L, CD30-cleavage proteins ADAM10 and ADAM17, and Th1- and Th2-type immunity-related factors t-bet and GATA3. Additionally, we evaluated the same transcripts and release of sCD30 and 32 cytokines after allogeneic and polyclonal T-cell activation. In peripheral blood, ESRDP showed increased levels of t-bet and GATA3 transcripts compared to healthy controls (HC) (both P<0.01) whereas levels of CD30, CD30L, ADAM10 and ADAM17 transcripts were similar. Polyclonal and allogeneic stimulation induced higher levels of CD30 transcripts in ESRDP than in HC (both P<0.001). Principal component analysis (PCA) in allogeneic cultures of ESRDP identified two correlation clusters, one consisting of sCD30, the Th-1 cytokine IFN-γ, MIP-1α, RANTES, sIL-2Rα, MIP-1β, TNF-β, MDC, GM-CSF and IL-5, and another one consisting of CD30 and t-bet transcripts, IL-13 and proinflammatory proteins IP-10, IL-8, IL-1Rα and MCP-1. Reflecting an activated immune state, ESRDP exhibited after allostimulation upregulation of CD30 transcripts in T cells, which was associated with Th1 and proinflammatory responses.

Knockdown of ADAM10 inhibits migration and invasion of fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease with high rates of morbidity and mortality. Previous studies proposed that the A disintegrin and metalloprotease (ADAM) family is involved in the regulation of inflammation and arthritis. Thus, the present study investigated whether ADAM10 is involved in the progression of RA. The effects of ADAM10 small interfering (si)RNA on the expression levels of tumor necrosis factor (TNF)‑α, interleukin (IL)‑6, IL‑8 and chemokine (C-X-C motif) ligand 16 (CXCL16) were determined in fibroblast‑like synoviocytes (FLS). In addition, the effects of ADAM10 siRNA on cell proliferation, invasion and migration in human RA‑FLS were assessed in vitro. The therapeutic efficacy and side‑effects of ADAM10 siRNA were examined in a mouse model of collagen‑induced arthritis (CIA). In vitro, ADAM10 silencing suppressed the expression of TNF‑α, IL‑6, IL‑8 and CXCL16 in lipopolysaccharide (LPS)‑stimulated human RA‑FLS. LPS‑induced RA‑FLS proliferation, migration and invasion were significantly attenuated by ADAM10 knockdown. ADAM10 silencing inhibited the secretion of vascular endothelial growth factor A (VEGF‑A) and matrix metalloproteinase (MMP)‑3 and ‑9 from LPS‑stimulated human RA‑FLS, in addition to inhibiting the phosphoinositide 3‑kinase/AKT activation in LPS‑stimulated human RA‑FLS. In vivo, treatment with siRNA against ADAM10 for three weeks reduced the arthritis score. Serum levels of VEGF‑A, MMP‑3 and MMP‑9 were also reduced in CIA mice. These observations indicate that the inhibition of ADAM10 may be a viable therapeutic target in the amelioration of disease progression in RA by attenuating FLS proliferation, migration and invasion.

Post-transplant soluble CD30 levels are associated with early subclinical rejection in kidney transplantation

Several studies have shown association of high pre- or post-transplant levels of soluble CD30 (sCD30) with acute rejection and poor late kidney transplant outcome. Our goal was to investigate whether sCD30 levels at month-3 post-transplant are associated with subclinical rejection, presence of CD30(+) cells within the graft, and expression of immune response genes in peripheral blood mononuclear cells. The study comprised 118 adult first kidney graft recipients, transplanted at a single center, receiving tacrolimus in low concentration. All were submitted to a protocol biopsy at month-3. Subclinical rejection was identified in 10 biopsies and sCD30 levels ≥ 61.88 ng/mL (P = 0.004), younger recipient age (P = 0.030) and non-Caucasian ethnicity (P = 0.011) were independently associated with this outcome. Rare CD30(+) cells were present in only two biopsies. There was a correlation between sCD30 levels and CD30 gene expression in peripheral blood mononuclear cells (r = 0.385, P = 0.043). These results show that high sCD30 levels are independent predictors of graft dysfunction and may contribute to patient selection protocols by indicating those who could benefit from a more thorough evaluation.

CD30 in systemic mastocytosis

CD30 is a transmembrane receptor, normally not expressed by mast cells, which regulates proliferation/apoptosis and antibody responses. Aberrant expression of CD30 by mastocytosis mast cells and interaction with its ligand CD30L (CD153) appears to play an important role in the pathogenesis and clinical presentation of systemic mastocytosis. This article highlights the expression profile and role of CD30 and CD30L in physiologic and pathologic conditions, the applicability of CD30 as a marker for systemic mastocytosis, the consequences of mast cell-expressed CD30, and the possibility of future anti-CD30 based cytoreductive therapies.

A disintegrin and metalloproteinase-12 (ADAM12): function, roles in disease progression, and clinical implications

BACKGROUND

A disintegrin and metalloproteinase-12 (ADAM12) is a member of the greater ADAM family of enzymes: these are multifunctional, generally membrane-bound, zinc proteases for which there are forty genes known (21 of these appearing in humans). ADAM12 has been implicated in the pathogenesis of various cancers, liver fibrogenesis, hypertension, and asthma, and its elevation or decrease in human serum has been linked to these and other physiological/pathological conditions.

SCOPE

In this review, we begin with a brief overview of the ADAM family of enzymes and protein structure. We then discuss the role of ADAM12 in the progression and/or diagnosis of various disease conditions, and we will conclude with an exploration of currently known natural and synthetic inhibitors.

MAJOR CONCLUSION

ADAM12 has potential to emerge as a successful drug target, although targeting the metalloproteinase domain with any specificity will be difficult to achieve due to structural similarity between the members of the ADAM and MMP family of enzymes. Overall, more research is required to establish ADAM12 being as a highly desirable biomarker and drug target of different diseases, and their selective inhibitors as potential therapeutic agents.

GENERAL SIGNIFICANCE

Given the appearance of elevated levels of ADAM12 in various diseases, particularly breast cancer, our understanding of this enzyme both as a biomarker and a potential drug target could help make significant inroads into both early diagnosis and treatment of disease.

ADAM-10 is overexpressed in rheumatoid arthritis synovial tissue and mediates angiogenesis

OBJECTIVE

To examine the expression of ADAM-10 in rheumatoid arthritis (RA) synovial tissue (ST) and the role it plays in angiogenesis.

METHODS

ADAM-10 expression was determined using immunohistology, Western blotting, and quantitative polymerase chain reaction. In order to examine the role of ADAM-10 in angiogenesis, we performed in vitro Matrigel tube formation and chemotaxis assays using human microvascular endothelial cells (HMVECs) transfected with control or ADAM-10 small interfering RNA (siRNA). To determine whether ADAM-10 plays a role in angiogenesis in the context of RA, we performed Matrigel assays using a coculture system of HMVECs and RA synovial fibroblasts.

RESULTS

Endothelial cells and lining cells within RA ST expressed high levels of ADAM-10 compared with cells within osteoarthritis ST and normal ST. ADAM-10 expression was significantly elevated at the protein and messenger RNA levels in HMVECs and RA synovial fibroblasts stimulated with proinflammatory mediators compared with unstimulated cells. ADAM-10 siRNA-treated HMVECs had decreased endothelial cell tube formation and migration compared with control siRNA-treated HMVECs. In addition, ADAM-10 siRNA-treated HMVECs from the RA synovial fibroblast coculture system had decreased endothelial cell tube formation compared with control siRNA-treated HMVECs.

CONCLUSION

These data show that ADAM-10 is overexpressed in RA and suggest that ADAM-10 may play a role in RA angiogenesis. ADAM-10 may be a potential therapeutic target in inflammatory angiogenic diseases such as RA.

A novel role for reciprocal CD30-CD30L signaling in the cross-talk between natural killer and dendritic cells

The interplay between dendritic cells (DCs) and natural killer (NK) cells directs adaptive immune responses. The molecular basis of the cross-talk is largely undefined. Here, we provide evidence for a contribution of CD30 (TNFRSF8) and its ligand CD30L (TNFSF8) expressed on NK cells and DCs, respectively. We demonstrate that CD30-mediated engagement of CD30L induced cytokine secretion from immature DCs via the mitogen-activated protein kinase pathway. Moreover, CD30L engagement promoted differentiation to mature DCs. On the contrary, the engagement of CD30 on NK cells resulted in an NF-κB-dependent release of TNF-α/IFN-γ. These data uncover a novel and unexpected role for CD30/CD30L that contributes to proinflammatory immune responses.

Ectodomain shedding and ADAMs in development

Proteolytic enzymes belonging to the A Disintegin And Metalloproteinase (ADAM) family are able to cleave transmembrane proteins close to the cell surface, in a process referred to as ectodomain shedding. Substrates for ADAMs include growth factors, cytokines, chemokines and adhesion molecules, and, as such, many ADAM proteins play crucial roles in cell-cell adhesion, extracellular and intracellular signaling, cell differentiation and cell proliferation. In this Review, we summarize the fascinating roles of ADAMs in embryonic and adult tissue development in both vertebrates and invertebrates.

The potential role of thioredoxin 1 and CD30 systems as multiple pathway targets and biomarkers in tumor therapy

Our progress in understanding pathological disease mechanisms has led to the identification of biomarkers that have had a considerable impact on clinical practice. It is hoped that the move from generalized to stratified approaches, with the grouping of patients into clinical/therapeutic subgroups according to specific biomarkers, will lead to increasingly more effective clinical treatments in the near future. This success depends on the identification of biomarkers that reflect disease evolution and can be used to predict disease state and therapy response, or represent themselves a target for treatment. Biomarkers can be identified by studying relationships between serum, tissue, or tumor microenvironment parameters and clinical or therapeutic parameters at onset and during the progression of the disease, using systems biology. Given that multiple pathways, such as those responsible for redox and immune regulation, are deregulated or altered in tumors, the future of tumor therapy could lie in the simultaneous targeting of these pathways using extracellular and intracellular targets and biomarkers. With this aim in mind, we evaluated the role of thioredoxin 1, a key redox regulator, and CD30, a cell membrane receptor, in immune regulation. Our results lead us to suggest that the combined use of these biomarkers provides more detailed information concerning the multiple pathways affected in disease and hence the possibility of more effective treatment.

TNF-α induced apoptosis is accompanied with rapid CD30 and slower CD45 shedding from K-562 cells

TNF-α can induce cell death (apoptosis and necrosis), and these effects mostly depend on expression of TNF-receptor superfamily molecules. As determination of certain intracellular enzymes like LDH, released from cultured tumor cells, reflects early membrane alterations, we compared LDH release with changes in cell surface membrane molecule expression during culture of K-562 cells in the presence of TNF-α. TNF-α-mediated CD45 and CD30 shedding is shown to be to be time- and dose-dependent and associated with significant increase in LDH release, with maximal effects after 24 h of treatment. The percentage of decrease of all examined cell surface molecules on K-562 cells after TNF-α treatment was not uniform and appeared to depend on the respective constitutive level of expression and molecule type. The presence of these molecules was confirmed in supernatants using Western blot analyses. These results indicated the complexity of events on the cell membrane, including early LDH release that is associated with a difference in shedding of CD30 and CD45. Shedding of CD30 occurs before apoptosis induction, while shedding of CD45 is associated with apoptosis.

Mast cells enhance proliferation of B lymphocytes and drive their differentiation toward IgA-secreting plasma cells

The evidence of a tight spatial interaction between mast cells (MCs) and B lymphocytes in secondary lymphoid organs, along with the data regarding the abundance of MCs in several B-cell lymphoproliferative disorders prompted us to investigate whether MCs could affect the proliferation and differentiation of B cells. To this aim, we performed coculture assays using mouse splenic B cells and bone marrow-derived MCs. Both nonsensitized and activated MCs proved able to induce a significant inhibition of cell death and an increase in proliferation of naive B cells. Such proliferation was further enhanced in activated B cells. This effect relied on cell-cell contact and MC-derived interleukin-6 (IL-6). Activated MCs could regulate CD40 surface expression on unstimulated B cells and the interaction between CD40 with CD40 ligand (CD40L) on MCs, together with MC-derived cytokines, was involved in the differentiation of B cells into CD138(+) plasma cells and in selective immunoglobulin A (IgA) secretion. These data were corroborated by in vivo evidence of infiltrating MCs in close contact with IgA-expressing plasma cells within inflamed tissues. In conclusion, we reported here a novel role for MCs in sustaining B-cell expansion and driving the development of IgA-oriented humoral immune responses.

Heat shock protein 90 inhibitor BIIB021 (CNF2024) depletes NF-kappaB and sensitizes Hodgkin's lymphoma cells for natural killer cell-mediated cytotoxicity

PURPOSE

In Hodgkin's lymphoma, constitutive activation of NF-kappaB promotes tumor cell survival and proliferation. The molecular chaperone heat shock protein 90 (HSP90) has immune regulatory activity and supports the activation of NF-kappaB in Hodgkin's lymphoma cells.

EXPERIMENTAL DESIGN

We analyzed the effect of HSP90 inhibition on viability and NF-kappaB activity in Hodgkin's lymphoma cells and the consequences for their recognition and killing through natural killer (NK) cells.

RESULTS

The novel orally administrable HSP90 inhibitor BIIB021 (CNF2024) inhibited Hodgkin's lymphoma cell viability at low nanomolar concentrations in synergy with doxorubicin and gemcitabine. Annexin V/7-aminoactinomycin D binding assay revealed that BIIB021 selectively induced cell death in Hodgkin's lymphoma cells but not in lymphocytes from healthy individuals. We observed that BIIB021 inhibited the constitutive activity of NF-kappaB and this was independent of IkappaB mutations. Furthermore, we analyzed the effect of HSP90 inhibition on NK cell-mediated cytotoxicity. BIIB021 induced the expression of ligands for the activating NK cell receptor NKG2D on Hodgkin's lymphoma cells resulting in an increased susceptibility to NK cell-mediated killing. In a xenograft model of Hodgkin's lymphoma, HSP90 inhibition significantly delayed tumor growth.

CONCLUSIONS

HSP90 inhibition has direct antitumor activity in Hodgkin's lymphoma in vitro and in vivo. Moreover, HSP90 inhibition may sensitize Hodgkin's lymphoma cells for NK cell-mediated killing via up-regulation of ligands engaging activating NK cell receptors.

The disintegrin-metalloproteinases ADAM 10, 12 and 17 are upregulated in invading peripheral tumor cells of basal cell carcinomas

BACKGROUND

Members of the a disintegrin and metalloproteinase (ADAM) family are expressed in malignant tumors and participate in the pathogenesis of cancer. However, the presence of ADAM 10, 12, 17 and their role in basal cell carcinoma (BCC) have not been described. The purpose of this study was to investigate expression of ADAM 10, 12 and 17 in BCC.

METHODS

Expression of ADAM 10, 12 and 17 was analyzed by immunohistochemistry in skin tissues obtained from 25 patients with different types of BCC.

RESULTS

Immunoreactivity of ADAM 10, 12 and 17 was increased at the peripheral tumor margin compared with central areas of BCC tumor cell nests. Immunoreactivity of ADAM 10 and 12 was increased in the deep margin of invading tumor cell nests in mixed BCC. Focally increased expression of ADAM 12 was detected in squamous differentiated tumor cells of nodular BCC. In addition, immunoreactivity of ADAM 17 was increased in superficial BCC.

CONCLUSIONS

ADAM 10, 12 and 17 showed different expression pattern in BCC histologic subtypes, indicating their different role in the BCC pathogenesis. Overexpression of ADAM 10, 12 and 17 immunoreactivity in deep invasion area of BCC indicates that these three proteases may play an important role in the locally invasive and highly destructive growth behavior of BCC. Additionally, we suggest that ADAM 17 may play an important role in early development of BCC.

The "a disintegrin and metalloprotease" (ADAM) family of sheddases: physiological and cellular functions

There is an exciting increase of evidence that members of the disintegrin and metalloprotease (ADAM) family critically regulate cell adhesion, migration, development and signalling. ADAMs are involved in "ectodomain shedding" of various cell surface proteins such as growth factors, receptors and their ligands, cytokines, and cell adhesion molecules. The regulation of these proteases is complex and still poorly understood. Studies in ADAM knockout mice revealed their partially redundant roles in angiogenesis, neurogenesis, tissue development and cancer. ADAMs usually trigger the first step in regulated intramembrane proteolysis leading to activation of intracellular signalling pathways and the release of functional soluble ectodomains.

The ADAM metalloproteinases

The ADAMs (a disintegrin and metalloproteinase) are a fascinating family of transmembrane and secreted proteins with important roles in regulating cell phenotype via their effects on cell adhesion, migration, proteolysis and signalling. Though all ADAMs contain metalloproteinase domains, in humans only 13 of the 21 genes in the family encode functional proteases, indicating that at least for the other eight members, protein-protein interactions are critical aspects of their biological functions. The functional ADAM metalloproteinases are involved in "ectodomain shedding" of diverse growth factors, cytokines, receptors and adhesion molecules. The archetypal activity is shown by ADAM-17 (tumour necrosis factor-alpha convertase, TACE), which is the principal protease involved in the activation of pro-TNF-alpha, but whose sheddase functions cover a broad range of cell surface molecules. In particular, ADAM-17 is required for generation of the active forms of Epidermal Growth Factor Receptor (EGFR) ligands, and its function is essential for the development of epithelial tissues. Several other ADAMs have important sheddase functions in particular tissue contexts. Another major family member, ADAM-10, is a principal player in signalling via the Notch and Eph/ephrin pathways. For a growing number of substrates, foremost among them being Notch, cleavage by ADAM sheddases is essential for their subsequent "regulated intramembrane proteolysis" (RIP), which generates cleaved intracellular domains that translocate to the nucleus and regulate gene transcription. Several ADAMs play roles in spermatogenesis and sperm function, potentially by effecting maturation of sperm and their adhesion and migration in the uterus. Other non-catalytic ADAMs function in the CNS via effects on guidance mechanisms. The ADAM family are thus fundamental to many control processes in development and homeostasis, and unsurprisingly they are also linked to pathological states when their functions are dysregulated, including cancer, cardiovascular disease, asthma, Alzheimer's disease. This review will provide an overview of current knowledge of the human ADAMs, discussing their structure, function, regulation and disease involvement.

Molecular mechanisms of soluble cytokine receptor generation

Soluble cytokine receptors play key roles in regulating cytokine-mediated biological events by binding and modulating the activity of target ligands in either an antagonistic or agonistic fashion. This Minireview will provide an overview of the molecular mechanisms mediating the generation of soluble cytokine receptors, which include sheddase-mediated proteolytic cleavage of cell-surface receptors, generation of soluble receptors by alternative gene splicing, transcription and translation of cytokine-binding genes, and extracellular release of membrane-bound receptors within vesicles such as exosomes.

Pharmacologically enhanced expression of GPNMB increases the sensitivity of melanoma cells to the CR011-vcMMAE antibody-drug conjugate

GPNMB is a melanoma-associated glycoprotein that is targeted by the CR011-vcMMAE antibody-drug conjugate (ADC). Previous studies have shown that CR011-vcMMAE induces the apoptosis of GPNMB-expressing tumor cells in vitro and tumor regression in xenograft models. This ADC is currently in clinical trials for melanoma. In the present investigation, a variety of compounds were examined for their ability to increase the expression of GPNMB by cancer cells. These experiments lead to the identification of three distinct groups of compounds that increased GPNMB, some of which were shown to enhance the sensitivity of melanoma cells to CR011-vcMMAE. These data indicate that it may be possible to increase the anticancer activity of CR011-vcMMAE through pharmacological enhancement of GPNMB expression for potential therapeutic benefit.