Identification of an ASC oligomerization inhibitor for the treatment of inflammatory diseases.

The ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD)) protein is an scaffold component of different inflammasomes, intracellular multiprotein platforms of the innate immune system that are activated in response to pathogens or intracellular damage. The formation of ASC specks, initiated by different inflammasome receptors, promotes the recruitment and activation of procaspase-1, thereby triggering pyroptotic inflammatory cell death and pro-inflammatory cytokine release. Here we describe MM01 as the first-in-class small-molecule inhibitor of ASC that interferes with ASC speck formation. MM01 inhibition of ASC oligomerization prevents activation of procaspase-1 in vitro and inhibits the activation of different ASC-dependent inflammasomes in cell lines and primary cultures. Furthermore, MM01 inhibits inflammation in vivo in a mouse model of inflammasome-induced peritonitis. Overall, we highlight MM01 as a novel broad-spectrum inflammasome inhibitor for the potential treatment of multifactorial diseases involving the dysregulation of multiple inflammasomes.

Structure-Based Discovery of Potent CARM1 Inhibitors for Solid Tumor and Cancer Immunology Therapy.

CARM1 is a protein arginine methyltransferase and acts as a transcriptional coactivator regulating multiple biological processes. Aberrant expression of CARM1 has been related to the progression of multiple types of cancers, and therefore CARM1 was considered as a promising drug target. In the present work, we report the structure-based discovery of a series of N1-(3-(pyrimidin-2-yl)benzyl)ethane-1,2-diamines as potent CARM1 inhibitors, in which compound 43 displays high potency and selectivity. With the advantage of excellent tissue distribution, compound 43 demonstrated good in vivo efficacy for solid tumors. Furthermore, from the detailed immuno-oncology study with MC38 C57BL/6J xenograft model, we confirmed that this chemical probe 43 has profound effects in tumor immunity, which paves the way for future studies on the modulation of arginine post-translational modification that could be utilized in solid tumor treatment and cancer immunotherapy.

Inhibition of ASC enhances the protective role of salvianolic acid A in traumatic brain injury via inhibition of inflammation and recovery of mitochondrial function.

More than 50 million people are affected by traumatic brain injury (TBI) each year around the world, and nearly half of the population worldwide will have one or more TBI(s) in their lifetime. And in 2017, more than 1.39 billion people in China suffered from TBI, representing nearly 18% of the world population; these were mainly caused by road traffic incidents. Salvianolic acid A is a compound obtained from Salvia miltiorrhiza Bunge, which is one of the active components of many traditional Chinese medicines for the treatment of cardiovascular and cerebrovascular disease, with the effect of inhibition of inflammatory response. ASC is a critical factor in the activation of inflammation response process via promoting the maturation of caspase-1, and activation of NLPR3 under bacterial infection promotes the necrosis of cells in an ASC-dependent manner. However, few studies focus on the effect of ASC in a TBI model. In this study, we found that inhibition of ASC reduced the expression of inflammatory cytokines, and the concentration of calcium and ROS, while it increased the expression of mitochondrial function-related proteins. We further noticed that these effects were regulated by DLK2/MLK3/JNK signalling pathway and might contribute to the treatment of TBI.

Safranal inhibits NLRP3 inflammasome activation by preventing ASC oligomerization.

NLRP3 inflammasome is involved in several chronic inflammatory diseases. The inflammatory effect of the NLRP3 inflammasome is executed through IL-1ß and IL-18. Therefore, IL-1ß is one of the primary targets in chronic inflammatory conditions. However, current treatment regimens are dependent on anti- IL-1ß biologicals. The therapies targeting IL-1ß through inhibition of NLRP3 inflammasome are thus being actively explored. We identified safranal, a small molecule responsible for the essence of saffron as a potential inhibitor of the NLRP3 inflammasome. Safranal significantly suppressed the release of IL-1ß from ATP stimulated J774A.1 and bone marrow-derived macrophages (BMDMs) by regulating CASP1 and CASP8 dependent cleavage of pro-IL-1ß. Safranal markedly suppressed the expression of NLRP3 and its ATPase activity. Safranal treatment enhanced the expression of NRF2, whereas, si-RNA mediated silencing of Nrf2 abrogated the anti-NLRP3 effect of safranal. Furthermore, safranal inhibited ASC oligomerization and formation of ASC specks. Safranal also displayed anti-NLRP3 activity in multiple mice models. Treatment of animals with safranal reduced the production of IL-1ß in ATP elicited peritoneal inflammation, MSU induced air pouch inflammation, and MSU injected foot paw edema in mice. Thus, our data projects safranal as a potential preclinical drug candidate against NLRP3 inflammasome triggered chronic inflammation.

Discovery and characterization of small-molecule inhibitors of NLRP3 and NLRC4 inflammasomes.

Inflammasomes are macromolecular complexes involved in the host response to external and endogenous danger signals. Inflammasome-mediated sterile inflammation plays a central role in several human conditions such as autoimmune diseases, type-2 diabetes, and neurodegenerative disorders, indicating inflammasomes could be appealing therapeutic targets. Previous work has demonstrated that inhibiting the ATPase activity of the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3), disrupts inflammasome assembly and function. However, there is a necessity to find new potent compounds with therapeutic potential. Here we combine computational modeling of the target and virtual screening to discover a group of novel compounds predicted to inhibit NLRP3. We characterized the best compounds and determined their potency, specificity, and ability to inhibit processes downstream from NLRP3 activation. Moreover, we analyzed in mice the competence of a lead candidate to reduce lipopolysaccharide-induced inflammation. We also validated the active pharmacophore shared among all the NLRP3 inhibitors, and through computational docking, we clarify key structural features for compound positioning within the inflammasome ATP-binding site. Our study sets the basis for rational design and optimization of inflammasome-targeting probes and drugs.

The inhibitor effect of RKIP on inflammasome activation and inflammasome-dependent diseases.

Aberrant inflammasome activation contributes to the pathogenesis of various human diseases, including atherosclerosis, gout, and metabolic disorders. Elucidation of the underlying mechanism involved in the negative regulation of the inflammasome is important for developing new therapeutic targets for these diseases. Here, we showed that Raf kinase inhibitor protein (RKIP) negatively regulates the activation of the NLRP1, NLRP3, and NLRC4 inflammasomes. RKIP deficiency enhanced caspase-1 activation and IL-1ß secretion via NLRP1, NLRP3, and NLRC4 inflammasome activation in primary macrophages. The overexpression of RKIP in THP-1 cells inhibited NLRP1, NLRP3, and NLRC4 inflammasome activation. RKIP-deficient mice showed increased sensitivity to Alum-induced peritonitis and Salmonella typhimurium-induced inflammation, indicating that RKIP inhibits NLRP3 and NLRC4 inflammasome activation in vivo. Mechanistically, RKIP directly binds to apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and competes with NLRP1, NLRP3, or NLRC4 to interact with ASC, thus interrupting inflammasome assembly and activation. The depletion of RKIP aggravated inflammasome-related diseases such as monosodium urate (MSU)-induced gouty arthritis and high-fat diet (HFD)-induced metabolic disorders. Furthermore, the expression of RKIP was substantially downregulated in patients with gouty arthritis or type 2 diabetes (T2D) compared to healthy controls. Collectively, our findings suggest that RKIP negatively regulates NLRP1, NLRP3, and NLRC4 inflammasome activation and is a potential therapeutic target for the treatment of inflammasome-related diseases.

Role of CARD9 in inflammatory signal pathway of peritoneal macrophages in severe acute pancreatitis.

Previous studies revealed that caspase recruitment domain protein 9 (CARD9) was involved in severe acute pancreatitis (SAP) inflammation and that interfering with its expression in vivo could inhibit inflammation. However, the specific mechanism is unknown. This study aimed to discover the related signal pathways of CARD9 in macrophages. SiRNA interference technology was used in vivo and in vitro to detect CARD9-related signal pathways in peritoneal macrophages. Furthermore, Toll-like receptor 4 (TLR4) and membrane-associated C-type lectin-1 (Dectin-1) pathways in macrophages were activated specially to looking for the upstream signal path of CARD9. Results showed up-regulation of CARD9 expression in peritoneal macrophages of SAP rats (P < .05). CARD9 siRNA alleviated inflammatory cytokines, and inhibited the phosphorylation of NF-κB and p38MAPK in peritoneal macrophages in vivo or in vitro. Meanwhile, CARD9 siRNA reduced the concentration of CARD9 and Bcl10 in peritoneal macrophages, and TLR4 and Dectin-1 took part in CARD9 signal pathways in macrophages. In conclusion, there is an inflammation signal pathway comprised of TLR4/Dectin-1-CARD9-NF-κB/p38MAPK activated in macrophages in SAP. Blockade of CARD9 expression in macrophages can effectively alleviate SAP inflammation.

CRID3, a blocker of apoptosis associated speck like protein containing a card, ameliorates murine spinal cord injury by improving local immune microenvironment.

BACKGROUND: After spinal cord injury (SCI), destructive immune cell subsets are dominant in the local microenvironment, which are the important mechanism of injury. Studies have shown that inflammasomes play an important role in the inflammation following SCI, and apoptosis-associated speck-like protein containing a card (ASC) is the adaptor protein shared by inflammasomes. Therefore, we speculated that inhibiting ASC may improve the local microenvironment of injured spinal cord. Here, CRID3, a blocker of ASC oligomerization, was used to study its effect on the local microenvironment and the possible role in neuroprotection following SCI. METHODS: Murine SCI model was created using an Infinite Horizon impactor at T9 vertebral level with a force of 50 kdynes and CRID3 (50 mg/kg) was intraperitoneally injected following injury. ASC and its downstream molecules in inflammasome signaling pathway were measured by western blot. The immune cell subsets were detected by immunohistofluorescence (IHF) and flow cytometry (FCM). The spinal cord fibrosis area, neuron survival, myelin preservation, and functional recovery were assessed. RESULTS: Following SCI, CRID3 administration inhibited inflammasome-related ASC and caspase-1, IL-1ß, and IL-18 activation, which consequently suppressed M1 microglia, Th1 and Th1Th17 differentiation, and increased M2 microglia and Th2 differentiation. Accordingly, the improved histology and behavior have also been found. CONCLUSIONS: CRID3 may ameliorate murine SCI by inhibiting inflammasome activation, reducing proinflammatory factor production, restoring immune cell subset balance, and improving local immune microenvironment, and early administration may be a promising therapeutic strategy for SCI.

IC100: a novel anti-ASC monoclonal antibody improves functional outcomes in an animal model of multiple sclerosis.

BACKGROUND: The inflammasome adaptor apoptosis-associated speck-like protein containing a CARD (ASC) is involved in immune signaling by bridging the interactions between inflammasome sensors and caspase-1. Strong experimental evidence has shown that ASC-/- mice are protected from disease progression in animal models of multiple sclerosis (MS), suggesting that targeting inflammasome activation via ASC inhibition may be a promising therapeutic strategy in MS. Thus, the goal of our study is to test the efficacy of IC100, a novel humanized antibody targeting ASC, in preventing and/or suppressing disease in the experimental autoimmune encephalomyelitis (EAE) model of MS. METHODS: We employed the EAE model of MS where disease was induced by immunization of C57BL/6 mice with myelin oligodendrocyte glycoprotein peptide 35-55 (MOG35-55). Mice were treated with vehicle or increasing doses of IC100 (10, 30, and 45 mg/kg) and clinical disease course was evaluated up to 35 days post EAE induction. Immune cell infiltration into the spinal cord and microglia responses were assessed. RESULTS: We show that IC100 treatment reduced the severity of EAE when compared to vehicle-treated controls. At a dose of 30 mg/kg, IC100 significantly reduced the number of CD4+ and CD8+ T cells and CD11b+MHCII+ activated myeloid cells entering the spinal cord from the periphery, and reduced the number of total and activated microglia. CONCLUSIONS: These data indicate that IC100 suppresses the immune-inflammatory response that drives EAE development and progression, thereby identifying ASC as a promising target for the treatment of MS as well as other neurological diseases with a neuroinflammatory component.

Gallic Acid Impedes Non-Small Cell Lung Cancer Progression via Suppression of EGFR-Dependent CARM1-PELP1 Complex.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a common cause of cancer-related deaths. This study identified the regulatory pattern of gallic acid in NSCLC. METHODS: Human NSCLC cells were treated with different doses of gallic acid, after which, MTT assay and flow cytometry were performed to determine the survival and apoptotic rate of human NSCLC cells. Then, co-immunoprecipitation assay was performed to analyze the relationships between gallic acid, epidermal growth factor receptor (EGFR), and CARM1-PELP1. Next, we analyzed whether PELP1, CARM1 and EGFR were associated with the effects of gallic acid on NSCLC cells by conducting rescue experiments. The expression pattern of phosphorylated EGFR, EGFR, Ki67, as well as Fas, FasL and Caspase 3 proteins in cancer cells or xenografts was measured by Western blot analysis. Lastly, the role of gallic acid in the tumor growth was assessed in nude mice. RESULTS: The ideal dose of gallic acid that presented good suppressive effect on NSCLC cells were 30 µM, 50 µM and 75 µM, respectively. Gallic acid played an inhibiting role in the activation of EGFR, which further reduced the formation of CARM1-PELP1 complex, ultimately repressed the proliferation and elevated apoptosis of NSCLC cells. Meanwhile, CARM1 repression led to decreased growth, proliferation and migration abilities of NSCLC cells. Animal experiments confirmed that gallic acid contributed to the inhibition of tumor growth in vivo. CONCLUSION: To sum up, gallic acid could potentially prevent NSCLC progression via inhibition of EGFR activation and impairment of the binding of CARM1 to PELP1, highlighting a novel therapy to dampen NSCLC progression.

Dehydrocostus lactone inhibits NLRP3 inflammasome activation by blocking ASC oligomerization and prevents LPS-mediated inflammation in vivo.

Uncontrolled activation of NLRP3 inflammasome initiates a series of human inflammatory diseases. Targeting NLRP3 inflammasome has attracted considerable attention in developing potential therapeutic interventions. Here, we reported that dehydrocostus lactone (DCL), a main component of Saussurea lappa from the traditional Chinese medicine, inhibited NLRP3 inflammasome-mediated caspase-1 activation and subsequent interleukin (IL)-1ß production in primary mouse macrophages and human peripheral blood mononuclear cells and exerted an inhibitory effect on NLRP3-driven inflammation. Mechanistically, DCL significantly blocked the ASC oligomerization, which is essential for the assembly of activated inflammasome. Importantly, in vivo experiments showed that DCL reduced IL-1ß secretion and peritoneal neutrophils recruitment in LPS-mediated inflammation mouse model, which is demonstrated to be NLRP3 dependent. These results suggest that DCL is a potent pharmacological inhibitor of NLRP3 inflammasome and may be developed as a therapeutic drug for treating NLRP3-associated diseases.

CARMA3/NF-κB signaling contributes to tumorigenesis of hepatocellular carcinoma and is inhibited by sodium aescinate.

BACKGROUND: Primary hepatocellular carcinoma (HCC) is a very malignant tumor in the world. CARMA3 plays an oncogenic role in the pathogenesis of various tumors. However, the function of CARMA3 in HCC has not been fully clarified. AIM: To study the biological function of CAEMA3 in HCC. METHODS: Tissue microarray slides including tissues form 100 HCC patients were applied to access the expression of CARMA3 in HCC and its clinical relevance. Knockdown and overexpression of CARMA3 were conducted with plasmid transfection. MTT, colony formation, and apoptosis assays were performed to check the biological activity of cells. RESULTS: Higher expression of CARMA3 in HCC was relevant to poor prognostic survival (P < 0.05). Down-regulation of CARMA3 inhibited proliferation and colony formation and induced apoptosis in HCC cell lines, while increasing its expression promoted tumorigenesis. We also found that sodium aescinate (SA), a natural herb extract, exerted anti-proliferation effects in HCC cells by suppressing the CARMA3/nuclear factor kappa-B (NF-κB) pathway. CONCLUSION: Overexpression of CARMA3 in HCC tissues correlates with a poor prognosis in HCC patients. CARMA3 acts pro-tumorigenic effects partly through activation of CARMA3/NF-κB. SA inhibits HCC growth by targeting CARMA3/NF-κB.

Host CARD11 Inhibits Newcastle Disease Virus Replication by Suppressing Viral Polymerase Activity in Neurons.

Host factors play multiple essential roles in the replication and pathogenesis of mammalian neurotropic viruses. However, the cellular proteins of the central nervous system (CNS) involved in avian neurotropic virus infection have not been completely elucidated. Here, we employed a gene microarray to identify caspase recruitment domain-containing protein 11 (CARD11), a lymphoma-associated scaffold protein presenting brain-specific upregulated expression in a virulent neurotropic Newcastle disease virus (NDV)-infected natural host. Chicken primary neuronal cells infected with NDV appeared slightly syncytial and died quickly. CARD11 overexpression inhibited viral replication and delayed cytopathic effects; conversely, depletion of CARD11 enhanced viral replication and cytopathic effects in chicken primary neuronal cells. The inhibition of viral replication by CARD11 could not be blocked with CARD11-Bcl10-MALT1 (CBM) signalosome and NF-κB signaling inhibitors. CARD11 was found to interact directly with the viral phosphoprotein (P) through its CC1 domain and the X domain of P; this X domain also mediated the interaction between P and the viral large polymerase protein (L). The CARD11 CC1 domain and L competitively bound to P via the X domain that hindered the P-L interaction of the viral ribonucleoprotein (RNP) complex, resulting in a reduction of viral polymerase activity in a minigenome assay and inhibition of viral replication. Animal experiments further revealed that CARD11 contributed to viral replication inhibition and neuropathology in infected chicken brains. Taken together, our findings identify CARD11 as a brain-specific antiviral factor of NDV infection in avian species.IMPORTANCE Newcastle disease virus (NDV) substantially impacts the poultry industry worldwide and causes viral encephalitis and neurological disorders leading to brain damage, paralysis, and death. The mechanism of interaction between this neurotropic virus and the avian central nervous system (CNS) is largely unknown. Here, we report that host protein CARD11 presented brain-specific upregulated expression that inhibited NDV replication, which was not due to CARD11-Bcl10-MALT1 (CBM) complex-triggered activation of its downstream signaling pathways. The inhibitory mechanism of viral replication is through the CARD11 CC1 domain, and the viral large polymerase protein (L) competitively interacts with the X domain of the viral phosphoprotein (P), which hampers the P-L interaction, suppressing the viral polymerase activity and viral replication. An in vivo study indicated that CARD11 alleviated neuropathological lesions and reduced viral replication in chicken brains. These results provide insight into the interaction between NDV infection and the host defense in the CNS and a potential antiviral target for viral neural diseases.

Targeting the CBM complex causes Treg cells to prime tumours for immune checkpoint therapy.

Solid tumours are infiltrated by effector T cells with the potential to control or reject them, as well as by regulatory T (Treg) cells that restrict the function of effector T cells and thereby promote tumour growth1. The anti-tumour activity of effector T cells can be therapeutically unleashed, and is now being exploited for the treatment of some forms of human cancer. However, weak tumour-associated inflammatory responses and the immune-suppressive function of Treg cells remain major hurdles to broader effectiveness of tumour immunotherapy2. Here we show that, after disruption of the CARMA1-BCL10-MALT1 (CBM) signalosome complex, most tumour-infiltrating Treg cells produce IFNγ, resulting in stunted tumour growth. Notably, genetic deletion of both or even just one allele of CARMA1 (also known as Card11) in only a fraction of Treg cells-which avoided systemic autoimmunity-was sufficient to produce this anti-tumour effect, showing that it is not the mere loss of suppressive function but the gain of effector activity by Treg cells that initiates tumour control. The production of IFNγ by Treg cells was accompanied by activation of macrophages and upregulation of class I molecules of the major histocompatibility complex on tumour cells. However, tumour cells also upregulated the expression of PD-L1, which indicates activation of adaptive immune resistance3. Consequently, blockade of PD-1 together with CARMA1 deletion caused rejection of tumours that otherwise do not respond to anti-PD-1 monotherapy. This effect was reproduced by pharmacological inhibition of the CBM protein MALT1. Our results demonstrate that partial disruption of the CBM complex and induction of IFNγ secretion in the preferentially self-reactive Treg cell pool does not cause systemic autoimmunity but is sufficient to prime the tumour environment for successful immune checkpoint therapy.

Inhibition of NLRP3 inflammasome activation by cell-permeable stapled peptides.

Interleukin-1ß (IL-1ß) is a major cytokine that initiates and enhances inflammatory responses. Excessive IL-1ß production is a characteristic of most chronic inflammatory diseases, including atherosclerosis, type 2 diabetes, and obesity, which affect a large proportion of the global population. The production of bioactive IL-1ß is mediated by a caspase-1-activating complex known as an 'inflammasome'. The NLRP3 inflammasome has been associated with several human inflammatory and autoimmune diseases and represents a potential therapeutic target for disrupting IL-1ß production. We used molecular modeling guided by molecular dynamics simulations to design α-helical stapled peptides targeting the pyrin domain of the adaptor protein ASC to interrupt the development of its filament, which is crucial for NLRP3 inflammasome formation. The peptides were effectively internalized by human monocytic cells and efficiently suppressed the release of the inflammasome-regulated cytokines IL-1ß and IL-18, following exogenous activation of the NLRP3 inflammasome. The peptides reduced ASC speck formation and caspase-1 processing thereby suppressing pro-IL-1ß processing and release of active IL-1ß. This is the first demonstration of the successful use of stapled peptides designed to target the adaptor protein ASC, and can be extended to other inflammatory pathways to disrupt excessive IL-1ß production.

Preventive effect of bergenin against the development of TNBS-induced acute colitis in rats is associated with inflammatory mediators inhibition and NLRP3/ASC inflammasome signaling pathways.

Ulcerative colitis is an idiopathic inflammatory bowel disease characterized by intestinal inflammation; blocking this inflammatory process may be the key to the development of new naturally occurring anti-inflammatory drugs, with greater efficiency and lower side effects. The objective of this study is to explore the effects of bergenin (BG) in TNBS (2,4,6-trinitrobenzenesulfonic acid)-induced acute colitis model in rats in order to assist in the studies for the development of novel natural product therapies for inflammatory bowel disease. 48 Wistar rats were randomized into six groups: (i) Control and (ii) TNBS control; (iii) 5-ASA 100 mg/kg/day (iv) BG 12 mg/kg/day (v) BG 25 mg/kg/day and (vi) BG 50 mg/kg/day. Colitis was induced by instillation of TNBS. Colitis was evaluated by an independent observer who was blinded to the treatment. Our results revealed that bergenin decreased the macroscopic and microscopic damage signs of colitis, and reduced the degree of neutrophilic infiltration in the colon tissue; also, it was capable to down-regulate COX-2, iNOS, IkB-α, and pSTAT3 protein expression. Similarly, using a protocol for indirect ELISA quantification of cytokines, bergenin treatment reduced IL-1ß, IFN-γ and IL-10 levels, and inhibited both canonical (IL-1) and non-canonical (IL-11) NLRP3/ASC inflammasome signaling pathways in TNBS-induced acute colitis. Conclusion: Our study has provided evidence that administration of bergenin reduced the damage caused by TNBS in an experimental model of acute colitis in rats, reduced levels of pro-inflammatory proteins and cytokines probably by modulation of pSTAT3 and NF-κB signaling and blocking canonical and non-canonical NLRP3/ASC inflammasome pathways.

Long Non-Coding RNA LINC01260 Inhibits the Proliferation, Migration and Invasion of Spinal Cord Glioma Cells by Targeting CARD11 Via the NF-κB Signaling Pathway.

BACKGROUND/AIMS: Spinal cord glioma is a highly aggressive malignancy that commonly results in high mortality due to metastasis, high recurrence and limited treatment regimens. This study aims to elucidate the effects of long non-coding RNA LINC01260 (LINC01260) on the proliferation, migration and invasion of spinal cord glioma cells by targeting Caspase recruitment domain family, member 11 (CARD11) via nuclear factor kappa B (NF-κB) signaling. METHODS: The Multi Experiment Matrix (MEM) website was used for target gene prediction, and the DAVID database was used for analysis of the relationship between CARD11 and the NF-κB pathway. In total, 60 cases of glioma tissues and adjacent normal tissues were collected. Human U251 glioma cells were grouped into blank, negative control (NC), LINC01260 vector, CARD11 vector, siRNA-LINC01260, siRNA-CARD11, LINC01260 vector + CARD11 vector and LINC01260 + siRNA-CARD11 groups. A dual-luciferase reporter assay was conducted to verify the target relationship between LINC01260 and CARD11. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were employed to assess expression of LINC01260, E-cadherin, p53, CARD11, Ki67, N-cadherin, matrix metalloproteinase (MMP)-9, NF-κBp65 and NF-κBp50. MTT, flow cytometry, wound-healing and Transwell assays were performed to examine cell viability, the cell cycle, apoptosis, invasion and migration. Tumor growth was assessed through xenografts in nude mice. RESULTS: CARD11 was confirmed to be a target gene of LINC01260 and was found to be involved in regulating the NF-κB pathway. Compared with adjacent normal tissues, glioma tissues showed reduced expression of LINC01260 and elevated expression of CARD11 and genes related to apoptosis, invasion and migration; activation of NF-κB signaling was also observed. In contrast to the blank and NC groups, an elevated number of cells arrested in G1 phase, increased apoptosis and reduced cell proliferation, invasion and number of cells arrested in S and G2 phases, as well as tumor growth were found for the LINC01260 vector and siRNA-CARD11 groups. CONCLUSIONS: Our findings demonstrate that overexpression of LINC01260 inhibits spinal cord glioma cell proliferation, migration and invasion by targeting CARD11 via NF-κB signaling suppression.

The CARMA3-Bcl10-MALT1 Signalosome Drives NFκB Activation and Promotes Aggressiveness in Angiotensin II Receptor-Positive Breast Cancer.

The angiotensin II receptor AGTR1, which mediates vasoconstrictive and inflammatory signaling in vascular disease, is overexpressed aberrantly in some breast cancers. In this study, we established the significance of an AGTR1-responsive NFκB signaling pathway in this breast cancer subset. We documented that AGTR1 overexpression occurred in the luminal A and B subtypes of breast cancer, was mutually exclusive of HER2 expression, and correlated with aggressive features that include increased lymph node metastasis, reduced responsiveness to neoadjuvant therapy, and reduced overall survival. Mechanistically, AGTR1 overexpression directed both ligand-independent and ligand-dependent activation of NFκB, mediated by a signaling pathway that requires the triad of CARMA3, Bcl10, and MALT1 (CBM signalosome). Activation of this pathway drove cancer cell-intrinsic responses that include proliferation, migration, and invasion. In addition, CBM-dependent activation of NFκB elicited cancer cell-extrinsic effects, impacting endothelial cells of the tumor microenvironment to promote tumor angiogenesis. CBM/NFκB signaling in AGTR1+ breast cancer therefore conspires to promote aggressive behavior through pleiotropic effects. Overall, our results point to the prognostic and therapeutic value of identifying AGTR1 overexpression in a subset of HER2-negative breast cancers, and they provide a mechanistic rationale to explore the repurposing of drugs that target angiotensin II-dependent NFκB signaling pathways to improve the treatment of this breast cancer subset.Significance: These findings offer a mechanistic rationale to explore the repurposing of drugs that target angiotensin action to improve the treatment of AGTR1-expressing breast cancers. Cancer Res; 78(5); 1225-40. ©2017 AACR.

Identification of a CARM1 Inhibitor with Potent In Vitro and In Vivo Activity in Preclinical Models of Multiple Myeloma.

CARM1 is an arginine methyltransferase with diverse histone and non-histone substrates implicated in the regulation of cellular processes including transcriptional co-activation and RNA processing. CARM1 overexpression has been reported in multiple cancer types and has been shown to modulate oncogenic pathways in in vitro studies. Detailed understanding of the mechanism of action of CARM1 in oncogenesis has been limited by a lack of selective tool compounds, particularly for in vivo studies. We describe the identification and characterization of, to our knowledge, the first potent and selective inhibitor of CARM1 that exhibits anti-proliferative effects both in vitro and in vivo and, to our knowledge, the first demonstration of a role for CARM1 in multiple myeloma (MM). EZM2302 (GSK3359088) is an inhibitor of CARM1 enzymatic activity in biochemical assays (IC50 = 6 nM) with broad selectivity against other histone methyltransferases. Treatment of MM cell lines with EZM2302 leads to inhibition of PABP1 and SMB methylation and cell stasis with IC50 values in the nanomolar range. Oral dosing of EZM2302 demonstrates dose-dependent in vivo CARM1 inhibition and anti-tumor activity in an MM xenograft model. EZM2302 is a validated chemical probe suitable for further understanding the biological role CARM1 plays in cancer and other diseases.

Small-molecule inhibitors directly target CARD9 and mimic its protective variant in inflammatory bowel disease.

Advances in human genetics have dramatically expanded our understanding of complex heritable diseases. Genome-wide association studies have identified an allelic series of CARD9 variants associated with increased risk of or protection from inflammatory bowel disease (IBD). The predisposing variant of CARD9 is associated with increased NF-κB-mediated cytokine production. Conversely, the protective variant lacks a functional C-terminal domain and is unable to recruit the E3 ubiquitin ligase TRIM62. Here, we used biochemical insights into CARD9 variant proteins to create a blueprint for IBD therapeutics and recapitulated the mechanism of the CARD9 protective variant using small molecules. We developed a multiplexed bead-based technology to screen compounds for disruption of the CARD9-TRIM62 interaction. We identified compounds that directly and selectively bind CARD9, disrupt TRIM62 recruitment, inhibit TRIM62-mediated ubiquitinylation of CARD9, and demonstrate cellular activity and selectivity in CARD9-dependent pathways. Taken together, small molecules targeting CARD9 illustrate a path toward improved IBD therapeutics.