ChIP-PCR and ChIP-seq analyses revealed that histone H3 lysine 27 acetylation was enriched in the ALDH1A3 promoter in 5-Fluorouracil (5-FU)-tolerant persister PDCs. By chemical library screening, we found that the BET inhibitors OTX015/birabresib and I-BET-762/molibresib suppressed DTP-related ALDH1A3 expression and preferentially inhibited DTP cell growth...Combination therapy with 5-FU and OTX015 significantly suppressed in vivo tumor growth. These observations suggest that BET inhibitors are efficient DTP cell-targeting agents for gastric cancer treatment.

Through applying systematic bioinformatic analysis, we determined that out of 31 chromatin remodeling factors in six gastrointestinal cancers, only PR/SET domain 1 (PRDM1) showed both expression alteration and prognosis prediction. Analyses on pathways, therapies, and mediators showed that cell cycle, bromodomain inhibitor IBET151, and BET protein BRD4 were, respectively involved in PRDM1-high stomach cancer, while cell line experiments validated that PRDM1 knockdown in human stomach cancer cell line SNU-1 decreased its proliferation, BRD4 expression, and responsiveness to IBET151; accordingly, these results indicate the contribution by PRDM1 in stomach cancer formation and its association with BRD4 modulation as well as BET inhibitor treatment.

While NHWD-870 could inhibit IRF7 and phosphorylated-IRF7 expression in vivo and in vitro. These results indicate that NHWD-870 suppresses the maturation and activation of DCs by decreasing IRF7 proteins which finally alleviates psoriasis-like skin lesions, and NHWD-870 may be a potent therapeutic drug for psoriasis.

RNAseq analysis demonstrated that the inhibitors increased viral E1A expression, altered expression of cell cycle regulators and inflammatory factors, and attenuated expression levels of tumour cell oncogenes such as c-Myc and Myb. The data suggest that the tumour-selective Ad∆∆ and Ad-3∆-A20T combined with epigenetic inhibitors is a novel strategy for the treatment of PDAC by eliminating both cancer and associated stromal cells to pave the way for immune cell access even after systemic delivery of the virus.

Thus, we screened for inhibitors that repress YAP1 expression and identified multiple bromodomain and extra-terminal (BET) inhibitors, including NHWD-870, as hits. We identified a new vulnerability for MEK inhibitor-resistant melanomas, which activated Hippo pathway due to elevated YAP1 activity. Inhibition of BRD4 using BET inhibitors suppressed YAP1 expression and led to blunted melanoma growth when combined with treatment with the MEK inhibitor trametinib.

DW-71177 effectively inhibits oncogenes comparable to the pan-BET inhibitor OTX-015, but with a milder impact on housekeeping genes. It efficiently blocks cancer-associated transcriptional changes by targeting genes that are highly enriched with BRD4 and histone acetylation marks, suggesting that BD1-selective targeting could be an effective and safe therapeutic strategy against leukemia.

Pretreatment with the BRD4 inhibitors, OTX015 and MZ1, eliminated the enhanced inflammatory cytokine production. These findings suggest that persistent vIL-6 exposure may establish a chromatin landscape favorable for the reactivation of inflammatory responses in monocytes. This epigenetic memory may explain the greater risk of chronic inflammatory disease development in KSHV-infected individuals.

Patients with ER+ BC face high risk of late recurrence after definitive treatment and show poor response to immune CPIs. We show that combination of BET inhibition with RT induces anti-tumor immunity and completely prevents tumor growth. Clinical validation of this regimen is warranted to prevent late recurrences in ER+ BC patients.

In our group’s previous study, human cell lines NALM-6 and SEM responded to SYK inhibition by Entospletinib (Ento) with proliferation suppression and apoptosis induction. Herein, we evaluated the effect of combined inhibition with pan-BET inhibitor I-BET151 (IBET) and evaluated their synergistic potential in canine and human B-ALL in vitro models... Canine and human B-ALL cell lines had similar responses to Ento and IBET single treatments, showing anti-proliferative effects on NALM-6, SEM, and GL-1. The inhibition of proliferation induced by Ento may act through the induction of apoptosis rather than cell cycle arrest. IBET induced both, strong apoptosis (except NALM-6) and cell cycle arrest.

NHWD-870 demonstrated substantial nephroprotective effects in reducing renal damage induced by ischemia-reperfusion injury in rats. These effects may be attributed to the anti-apoptotic properties, as indicated by increased levels of the anti-apoptotic protein Bcl-2, and the reduction in oxidative stress marker PGF-2 through upregulation of the PI3K/AKT signaling pathway, along with the decrease in the inflammatory marker IL-1B.

In the PDA organoid-based screen, epigenetic inhibitors ITF2357 and I-BET151 are identified, which in combination with anti-PD-1 based therapy show considerably greater anti-tumor effect. The combinatorial treatment turns the TME from immunosuppressive to immunoactive, up-regulates the MHC-I antigen processing and presentation, and enhances the effector T cell activity. The standardized PDA organoid model has shown great promise to accelerate drug discovery for the immunosuppressive cancer.

Although their role in cancer progression has been extensively studied, very few information is known about their involvement in tumor immune microenvironment.Material and MethodsWe treated tumor-derived primary NKs or NK92 cell line with inhibitors of bromodomain and extra-terminal domain proteins (BETi) JQ1 or OTX-015, followed by co-culture with NSCLC cell lines or primary patient-derived 3D cultures. Among the deregulated genes, 15% are lncRNAs. We identified a set of 13 lncRNAs that may actively contribute to both the anti-tumor and cytotoxic activity of NK cells.

Integrative chromatin and transcriptional analysis following inhibition of RUNX1 and NOTCH1 revealed a surprisingly widespread role of RUNX1 in the establishment of global H3K27ac levels and that RUNX1 is required by NOTCH1 for cooperative transcription activation of key NOTCH1 target genes including MYC, DTX1, HES4, IL7R, and NOTCH3. Super-enhancers were preferentially sensitive to RUNX1 knockdown and RUNX1-dependent super-enhancers were disrupted following the treatment of a pan-BET inhibitor, I-BET151.

While BBC1115 does not structurally resemble OTX-015, a clinically active pan-BET inhibitor, our intensive biological characterization revealed that BBC1115 binds to BET proteins, including BRD4, and suppresses aberrant cell fate programs...Since epigenetic regulations are ubiquitously distributed across normal and malignant cells, it will be critical to evaluate if BBC1115 affects normal cell function. Nonetheless, our study shows integrating DEL-based small-molecule compound screening and multi-step biological validation represents a reliable strategy to discover new chemotypes with selectivity, efficacy, and safety profiles for targeting proteins involved in epigenetic regulation in human malignancies.

Through a high-throughput drug screening (HTS) we identified thioridazine (TDZ) as an efficacious compound, but its use is limited by the huge blood brain barriers crossing and cardiotoxic effects...In attempt to target it, we tested novel drug combinations of venetoclax (VEN), a BCL- 2 inhibitor, with KMT2A-specific drugs, revealing that the Bromodomain and Extra-Terminal Domain (BET) inhibitor I-BET151, and the kinase inhibitor sunitinib, decreased BCL-2 family protein expression and synergized with VEN enhancing KMT2A -r AML cell death, also in the 3D model... Overall, this study identified novel drug combinations of KMT2A -selective drugs together with VEN converging in different but all mitochondrial apoptotic networks activation, supporting the use of VEN in this AML setting. We demonstrate that TDZ6 reduces the AML growth in vitro and an enlarged in vivo study will support its efficacy andsafety. This study highlights the importance of having a bona-fide model to test drugs and produce reliable results, to accelerate the introduction of targeted therapies for the life-threatening KMT2A -AML subgroup of pediatric AML.

Overall, our ex vivo and in vitro studies indicate that i-BET858 represents an optimal candidate to pursue further clinical validation for the treatment of HGSC.

An X-ray structure of a CLICK chemistry-based BET PROTAC bound to BRD2(BD2) inspired synthesis of JQ1 derived heterocyclic amides. This effort led to the discovery of potent BET inhibitors displaying overall improved profiles when compared to JQ1 and birabresib...In addition, exploration of pharmacokinetic properties of this class of compounds suggest that the heterocyclic amide moiety improves drug-like features. Our study led to the discovery of potent and orally bioavailable BET inhibitor 1q (SJ1461) as a promising candidate for further development.

Cancer therapy continues to be plagued by modest therapeutic advances. The simulations included those based on global sensitivity analyses to identify fragile nodes - MDM2 and XIAP - in the network, and also how an epigenetic modifier (birabresib) could overcome a mechanism of TMZ resistance. The positive results of CSD therapy on TMZ activity supports continued efforts to develop CSD therapy as a new anticancer approach.

We recently reported that tegavivint (TV) (BC-2059), a disruptor of the nuclear TBL1/R1-β-catenin-TCF7L2 complex represses c-Myc, cyclin D1 and Survivin and inhibits growth and survival of AML LSCs. Notably, in the flank-implanted PDX of AML191 or tail-vein infused PDX of AML242 models in NSG mice, treatment with OTX015 and TV, compared to vehicle control or each drug alone, significantly reduced AML growth and improved survival, without any host toxicity. These findings highlight the promising pre-clinical efficacy of novel BETi-based combinations against AML models harboring 3q26 lesions and EVI1 overexpression.

Importantly, the combination of birabresib and a CDK4/6 kinase inhibitor (palbociclib) conferred the largest growth reduction of PDxOs expressing an ESR1-YAP1 fusion. Active ESR1 fusions cannot be treated with standard-of-care ET due to the lack of the LBD of ERα. Therefore, it is critical to investigate how active, in-frame ESR1 fusion proteins induce gene transcription and to develop molecular mechanism-based targeted therapies. Here, we revealed two groups of coactivators (BRDs and SRCs) as critical transcriptional regulators of active ESR1 fusion-driven tumor biology.

Herein, instead of using antibodies, we use MK-8628 (MK) to down-regulate both PD-L1 and CD47 simultaneously through halting the active transcription of oncogene c-MYC, leading to elicitation of the immune response...However, due to the local delivery and controlled release of inhibitors, HPDA@MK down-regulates c-MYC/PD-L1/CD47, promotes the activation and recruitment of cytotoxic T cells, regulates the M2 macrophages polarization in tumor sites, and especially boosts the combined therapeutic efficacy. Collectively, our work presents a simple but distinctive approach for c-MYC/PD-L1/CD47-targeted immunotherapy combined with PTT that may provide a desirable and feasible strategy for the treatment of other clinical solid tumors.

BRD4-targeted drug PFI-1 and (BRD2, BRD3, and BRD4)-targeted drug I-BET-151 may have good inhibitory effects on the SW13 cell line. The findings of this study provide a partial basis for the role of BRD2, BRD3, and BRD4 in the occurrence and development of ACC. In addition, this study also provides new potential therapeutic targets for ACC, which can serve as a reference for future basic and clinical research.

The results were validated by treating EBVaGC cells with bromodomain and the extra-terminal motif (BET) inhibitor, OTX015...Moreover, Spearman's correlation revealed that MAP3K8 expression was positively correlated with the expressions of notch pathway and EMT related genes, such as, Notch1, Notch2, C-terminal binding protein 2 (CTBP2), alpha smooth muscle actin isotype 2 (ACTA2), transforming growth factor beta receptor 1 (TGFβR1), and snail family transcriptional repressors 1/2 (SNAI1/SNAI2) in GC. Taken together, we are the first to functionally interrogate the mechanism of SE-mediated regulation of MAP3K8 in EBVaGC cell lines.

To this end, we employed an NMR-based metabolomics approach applied to the MYC-driven MB D283 and D458 cell lines before and after the treatment with the BETi OTX-015...These insights provide a metabolic characterisation of MYC-driven childhood MB cell lines, which could pave the way for the discovery of novel druggable pathways. Importantly, these findings will also contribute to understand the downstream effects of BETis on MYC-driven MB, potentially aiding the development of new therapeutic strategies to combat medulloblastoma.

Interestingly, chemoresistance against epidermal growth factor receptor (EGFR) inhibitors including erlotinib and gefitinib was also related to Met...Moreover, another BET protein inhibitor I-BET151, or BRD4 depletion, also inhibited NSCLC cell growth and downregulated Met...Moreover, JQ1 inhibited the growth of paired erlotinib-sensitive and resistant HCC827 cells in parallel with Met downregulation and PI3K/Akt signaling inactivation...These results suggested that targeting BET proteins inhibited NSCLC via downregulating Met and inactivating PI3K/AKT pathway. Our findings reveal a novel mechanism of BET proteins implicated in NSCLC progression with Met taken into consideration.

Together, our findings demonstrated that dual-inhibition of BET and HDAC proteins of the epigenetic pathway can be a novel therapeutic approach against MYC-driven MB.

Based on these observations, and clinical efficacy of the combination of venetoclax and decitabine/azacitidine, we determined the in vitro lethal activity of co-treatment with FHD-286 and venetoclax or decitabine against AML cell lines and PD AML cells. Additionally, co-treatment with FHD-286 and venetoclax or decitabine or OTX015, as compared to each drug alone or vehicle control, significantly reduced the AML burden and improved median and overall survival of the immune-depleted mice, without inducing significant toxicity. Taken together, these findings highlight the promise of FHD-286 treatment alone and in rational combinations in exerting significant anti-AML efficacy against cellular models of AML, especially those with MLL-r, mtNPM1 or chromosome 3q26 lesions and EVI1 overexpression.

Valosin-containing protein (VCP)/p97 or p97 is an AAA+ type ATPase involved in quality control of cellular proteins in normal and transformed cells, especially under cellular stress. Finally, in a tail-vein infused, luciferase transduced, aggressive xenograft model of MOLM13 cells, after AML engraftment, co-treatment for 3 weeks with CB-5339 (50 mg/kg/day, PO) and either venetoclax (30 mg/kg/day, PO) or OTX015 (30 mg/kg/day, PO), as compared to treatment with vehicle or each drug alone, significantly reduced the AML burden and improved median and overall survival of the NSG mice, without inducing significant toxicity. Taken together, these findings highlight that CB-5339 induces lethal ER stress in AML cells regardless of the TP53 status, and underscore the promise of CB-5339 treatment alone and in rational combinations in exerting efficacy against AML, including those with high-risk genetic alterations in TP53 or chromosome 3q26 lesions and EVI1 overexpression.

Covalent BTK inhibitors (BTKis), including ibrutinib and acalabrutinib, irreversibly bind to cysteine 481 in the kinase domain of BTK, inhibit growth, and induce loss of viability of MCL cells...In the present studies, we determined that in vitro exposure of human MCL cells, including MCL cell lines: REC1, Mino and JeKo-1, as well as patient-derived (PD) MCL cells, to NX-2127 (10 to 250 nM) for 2 to 24 hours markedly depleted BTK levels via proteasomal degradation, since co-treatment with the proteasome inhibitor carfilzomib restored BTK levels. NX-2127 but not NX-5948 treatment also degraded and depleted IKZF1 and IKZF3 levels...Co-treatment with NX-2127 (10 to 100 nM) and low nM levels of venetoclax or ABBV-744 was synergistically lethal against MCL cells (Delta synergy score above 1.0 by ZIP method). Collectively, these findings demonstrate that treatment with NX-2127 degrades and attenuates BTK and IKZF1/3 levels, as well as inhibits the downstream pro-growth and pro-survival signaling, resulting in loss of viability of MCL cells, including those resistant to covalent BTKi treatment. These findings also show promising anti-MCL activity of NX-2127-based combination with BCL2 or BET inhibitor which merits further in vivo validation.

We have recently reported that the nuclear TBL1/R1-β-catenin-TCF7L2 complex transcriptionally regulates c-Myc, cyclin D and Survivin and sustains AML stem cells, such that the undermining of this transcriptional axis by the TBL1/R1-β-catenin-binding disruptor tegavivint (BC-2059, Iterion) represses MYC, cyclin D1 and Survivin and inhibits growth and survival of AML stem-progenitor cells. Furthermore, in the tail-vein infused and engrafted PD AML191 PDX model, treatment with TV and OTX015 or venetoclax for 6 weeks, as compared to vehicle control or each drug alone, significantly improved overall survival of the NSG mice (p < 0.01), without inducing any toxicity. These findings highlight the promising pre-clinical efficacy of novel combinations of TV and BET protein or venetoclax against AML models harboring 3q26 lesions and EVI1 overexpression.

Our data provide insights into the prognostic role of BET family in GC and proposed BET inhibition as a therapeutic strategy for GC patients.

We evaluated the anti-lymphoma activity of the isoform-specific bivalent BET inhibitor AZD5153 (AZD) and the pan-BET inhibitor I-BET151 (I-BET) as single agents and in combination with SYK inhibitor Entospletinib (Ento) in vitro. Genes such as ADGRA2, MYB, TNFRSF11A, S100A10, PLEKHH3, DHRS2 and FOXP1-AS1 were identified as possible key regulators. Simultaneous inhibition of BET and SYK enhanced the anti-proliferative effects, and induced a combination-specific gene expression signature.

Thus, OTX015, a BET inhibitor with a favorable safety profile in early stage clinical trials, reverses both endocrine therapy resistance and radiation resistance in ER-positive breast cancer cells and tumors. Our findings are also consistent with reports that tamoxifen-resistant breast cancer cells are resistant to DNA damaging chemotherapeutic agents such as adriamycin and cisplatin...We also provide a molecularly targeted approach for reversing radiation resistance in such patients. Thus, our study provides a framework for advancing Precision Radiation Oncology in breast cancer patients.

When combined with abemaciclib, a CDK4/6 inhibitor, OTX015 induced more potent tumor regression than current standard-of-care treatment of abemaciclib + fulvestrant. OTX015 has preferential activity against Y537S mutant breast cancer cells and blocks their clonal selection in competition studies with wild-type cells. Thus, BET inhibition has the potential to both prevent and overcome ESR1 mutant-induced endocrine therapy resistance in breast cancer.

Thus, the goal of this study is to explore the molecular mechanisms behind promising epigenetic inhibitors in RMS, focusing on embryonal RMS, and to test these drugs in vivo in combination with vincristine. Our laboratory obtained a selection of epigenetic compounds from the Ontario Institute of Cancer Research (OICR) and Structural Genomics Consortium (SGC) that mainly target BET (BMS-986158, I-BET151, PLX51107) or HDAC (Apicidin, Domatinostat, Fimepinostat) proteins...Furthermore, the level of apoptosis in this cell line was higher after treatment with PLX51107 than after treatment with the positive control, doxorubicin (Figure 3)... Our data suggest that BET inhibitors may exploit an epigenetic weakness of ERMS, perhaps related to MYC amplification. In the future, we plan to conduct transcriptome assays to explore the mechanism of action of BET inhibitors in ERMS, and in vivo drug combination studies in an ERMS mosaic mouse model and patient-derived xenografts (PDXs).

The germinal center B-cell like diffuse large B-cell lymphoma (DLBCL) cell lines OCI-LY-19 and WSU-DLCL2 were exposed to 348 compounds given as single agents at two different concentrations and in combination with the BET inhibitor birabresib...The screening identified a series of compounds leading to a stronger antiproliferative activity when given in combination than as single agents: the histone deacetylase (HDAC) inhibitors panobinostat and dacinostat, the mTOR (mechanistic target of rapamycin) inhibitor everolimus, the ABL/SRC (ABL proto-oncogene/SRC proto oncogene) inhibitor dasatinib, the AKT1/2/3 inhibitor MK-2206, the JAK2 inhibitor TG101209...Genetic silencing demonstrated that LRRK2 sustains the proliferation of lymphoma cells, a finding paired with the association between high expression levels and inferior outcome in DLBCL patients. We identified combinations that can improve the response to BET inhibitors in lymphomas, and LRRK2 as a gene essential for lymphomas and as putative novel target for this type of tumors.

In vivo, when compared to idelalisib and GS-626510 single agents, the combo treatment arm underwent a 2-3 fold increase in relative tumor growth inhibition, reaching 85% after two weeks of daily dosing of the animals, with no detectable toxicity. Conclusion The combination of idelalisib and GS-626510 is able to disrupt GCB-DLBCL crosstalk with M2-macrophages, thereby modulating the secretion of several inflammatory cytokines involved in the regulation of tumor B cell apoptotic threshold.

Functional Assays : RNA interference and inhibitors that selectively target GLS (CB-839), DHODH (Teriflunomide, Leflunomide, Vidofludimus, Brequinar and BAY 2402234) or BRD4 (MZ-1; JQ1; AZD5153; Mivebresib and Birabresib) potently and specifically diminish the clonogenic potential of several SCCHN cell lines. However, none of these treatments induce comparable apoptosis in the ex vivo SCCHN tumour tissue. Conclusion The challenges presented by the tumour microenvironment in diminishing the potential of several promising therapies will have to be characterised further, which is the primary focus of our current studies.

Comprehensive proteomic and drug-screening studies across pan-cancer models confirm that FAT1-mutant HNSCC exhibits selective and higher sensitivity to BRD4 inhibition by JQ1. Epigenomic analysis reveals an active chromatin state in FAT1-mutant HNSCC cells that is driven by the YAP/TAZ transcriptional complex through recruitment of BRD4 to deposit active histone marks, thereby maintaining an oncogenic transcriptional state. This study reveals a detailed cooperative mechanism between YAP1 and BRD4 in HNSCC and suggests a specific therapeutic opportunity for the treatment of this subset of head and neck cancer patients.