Triple combination of BET plus pan-PI3K and NF-κB inhibitors exhibit synergistic activity in adult T cell leukemia/lymphoma
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ABSTRACT: We exploited the use of I-BET762, copanlisib, and bardoxolone methyl inhibitors as triple combination to understand the interactions between these three pathways in Adult T cell leukemia/lymphoma.
Project description:Adult T-cell leukemia/lymphoma (ATL) is an aggressive T-cell lymphoproliferative malignancy caused by human T-cell leukemia virus type 1 (HTLV-1). ATL is an orphan disease with no curative drug treatment regimens urgently needing new combination therapy. HTLV-1-infected cells rely on viral proteins, Tax and HBZ (HTLV-1-b-ZIP factor), to activate the transcription of various host genes that are critical for promoting leukemic transformation. Inhibition of bromodomain and extraterminal motif (BET) protein was previously shown to collapse the transcriptional network directed by BATF3 super-enhancer and thereby induced ATL cell apoptosis. In the current work, by using xenograft, ex vivo, and in vitro models, we demonstrated that I-BET762 (BETi) synergized with copanlisib (PI3Ki) and bardoxolone methyl (NF-κBi) to dramatically decrease the growth of ATL cells. Mechanistically, the triple combination exhibited synergistic activity by down-regulating the expression of c-MYC while upregulating the level of the glucocorticoid-induced leucine zipper (GILZ). The triple combination also enhanced apoptosis induction by elevating the expression of active caspase-3 and cleaved PARP. Importantly, the triple combination prolonged the survival of ATL-bearing xenograft mice and inhibited the proliferation of ATL cells from peripheral blood mononuclear cells (PBMCs) of both acute and smoldering/chronic ATL patients. Therefore, our data provide the rationale for a clinical trial exploring the multiagent combination of BET, PI3K/AKT, and NF-κB inhibitors for ATL patients and expands the potential treatments for this recalcitrant malignancy.
Project description:The bromodomain and extra-terminal domain inhibitors (BETi) are promising epigenetic drugs for the treatment of various cancers through suppression of oncogenic transcription factors. However, only a subset of colorectal cancer (CRC) cells response to BETi. We investigate additional agents that could be combined with BETi to overcome this obstacle. JQ1-resistant CRC cells were used for screening of the effective combination therapies with JQ1. RNA-seq was performed to explore the mechanism of synergistic effect. The efficacy of combinational treatment was tested in the CRC cell line- and patient-derived xenograft (PDX) models. In BETi-sensitive CRC cells, JQ1 also impaired tumor angiogenesis through the c-myc/miR-17-92/CTGF+THBS1 axis. CTGF knockdown moderately counteracted anti-angiogenic effect of JQ1 and led to partially attenuated tumor regression. JQ1 decreased c-myc expression and NF-κB activity in BETi-sensitive CRC cells but not in resistant cells. Bortezomib synergistically sensitized BETi-resistant cells to the JQ1 treatment, and JQ1+Bortezomib induced G2/M arrest in CRC cells. Mechanistically, inhibition of NF-κB by Bortezomib or NF-κB inhibitor or IKK1/2 siRNA all rendered BETi-resistant cells more sensitive to BETi by synergistic repression of c-myc, which in turn induces GADD45s' expression, and by synergistic repression of FOXM1 which in turn inhibit G2/M checkpoint genes' expression. Activation of NF-κB by IκBα siRNA induced resistance to JQ1 in BETi-sensitive CRC cells. Last, JQ1+Bortezomib inhibited tumor growth and angiogenesis in CRC cell line xenograft model and four PDX models. Our results indicate that anti-angiogenic effect of JQ1 plays a vital role in therapeutic effect of JQ1 in CRC, and provide a rationale for combined inhibition of BET proteins and NF-κB as a potential therapy for CRC.
Project description:Our previous finding that the BET inhibitor (BETi) JQ1 increases levels of the DNA damage marker γH2AX suggested that JQ1 might enhance the sensitivity of tumor cells to PARP inhibitors (PARPi), which are selectively toxic to cells that harbor relatively high levels of DNA damage. To address this hypothesis, we evaluated the effect of a BETi (JQ1 or I-BET762) combined with a PARPi (olaparib or veliparib) in KKU-055 and KKU-100 cholangiocarcinoma (CCA) cell lines and of JQ1 with olaparib in a xenograft model of CCA. Each combination was more effective than any of the four drugs as single agents. Combination indices ranged from 0.1 to 0.8 at the ED50 for all combinations, indicating synergy and demonstrating that synergy was not limited to a specific combination. Mechanistically, downregulation of BETi molecular targets BRD2 or BRD4 by shRNA sensitized CCA cells to BETi as single agents as well as to the combination of a BETi + a PARPi. Our data indicate that combinations of a BETi with a PARPi merit further evaluation as a promising strategy for CCA.
Project description:Background: Bromodomain and extra-terminal domain (BET) inhibitors have shown profound efficacy against hematologic malignancies and solid tumors in preclinical studies. However, the underlying molecular mechanism in melanoma is not well understood. Here we identified secreted phosphoprotein 1 (SPP1) as a melanoma driver and a crucial target of BET inhibitors in melanoma. Methods: Bioinformatics analysis and meta-analysis were used to evaluate the SPP1 expression in normal tissues, primary melanoma, and metastatic melanoma. Real-time PCR (RT-PCR) and Western blotting were employed to quantify SPP1 expression in melanoma cells and tissues. Cell proliferation, wound healing, and Transwell assays were carried out to evaluate the effects of SPP1 and BET inhibitors in melanoma cells in vitro. A xenograft mouse model was used to investigate the effect of SPP1 and BET inhibitors on melanoma in vivo. Chromatin immunoprecipitation (ChIP) assay was performed to evaluate the regulatory mechanism of BET inhibitors on SPP1. Results: SPP1 was identified as a melanoma driver by bioinformatics analysis, and meta-analysis determined it to be a diagnostic and prognostic biomarker for melanoma. SPP1 overexpression was associated with poor melanoma prognosis, and silencing SPP1 suppressed melanoma cell proliferation, migration, and invasion. Through a pilot drug screen, we identified BET inhibitors as ideal therapeutic agents that suppressed SPP1 expression. Also, SPP1 overexpression could partially reverse the suppressive effect of BET inhibitors on melanoma. We further demonstrated that bromodomain-containing 4 (BRD4) regulated SPP1 expression. Notably, BRD4 did not bind directly to the SPP1 promoter but regulated SPP1 expression through NFKB2. Silencing of NFKB2 resembled the phenotype of BET inhibitors treatment and SPP1 silencing in melanoma. Conclusion: Our findings highlight SPP1 as an essential target of BET inhibitors and provide a novel mechanism by which BET inhibitors suppress melanoma progression via the noncanonical NF-κB/SPP1 pathway.
Project description:BackgroundThe frequently occurred chemotherapy-induced diarrhea (CID) caused by irinotecan (CPT-11) administration has been the most representative side-effects of CPT-11, resulting in the chemotherapy suspension or failure. Our previous studies indicated that Gegen Qinlian formula exhibited a significant alleviation effect on CPT-11-induced diarrhea. However, referencing to Japanese Kampo medicine, the TCM standard decoction would supply the gap between ancient preparation application and modern industrial production.MethodsThe LC-MS technology combined with network pharmacology was employed to identify the active ingredients and mechanisms of GQD standard decoction for CPT-11-induced diarrhea. The anti-inflammatory activities associated with intestinal barrier function of GQD standard decoction were studied by SN-38 activated NCM460 cells in vitro and CPT-11-induced diarrhea in vivo. Proteins involved in inflammation, mRNA levels, disease severity scores, and histology involved in intestinal inflammation were analysed.ResultsThere were 37 active compounds were identified in GQD standard decoction. Network pharmacology analyses indicated that PI3K-AKT signaling pathway were probably the main pathway of GQD standard decoction in CPT-11-induced diarrhea treatment, and PIK3R1, AKT1, NF-κB1 were the core proteins. Moreover, we found that the key proteins and pathway predicted above was verified in vivo and in vitro experiments, and the GQD standard decoction could protect the cellular proliferation in vitro and ameliorate CPT-11-induced diarrhea in mice model.ConclusionsThis study demonstrated the molecular mechanism of 37 active ingredients in GQD standard decoction against CPT-11-induced diarrhea. And the core proteins and pathway were validated by experiment. This data establishes the groundwork for particular molecular mechanism of GQD standard decoction active components, and this research can provide a scientific reference for the TCM therapy of CID.
Project description:Latency reversal strategies for HIV cure using inhibitor of apoptosis protein (IAP) antagonists (IAPi) induce unprecedented levels of latent reservoir expression without immunotoxicity during suppressive antiretroviral therapy (ART). However, full targeting of the reservoir may require combinatorial approaches. A Jurkat latency model screen for IAPi combination partners demonstrated synergistic latency reversal with bromodomain (BD) and extraterminal domain protein inhibitors (BETi). Mechanistic investigations using CRISPR-CAS9 and single-cell RNA-Seq informed comprehensive ex vivo evaluations of IAPi plus pan-BET, bD-selective BET, or selective BET isoform targeting in CD4+ T cells from ART-suppressed donors. IAPi+BETi treatment resulted in striking induction of cell-associated HIV gag RNA, but lesser induction of fully elongated and tat-rev RNA compared with T cell activation-positive controls. IAPi+BETi resulted in HIV protein induction in bulk cultures of CD4+ T cells using an ultrasensitive p24 assay, but did not result in enhanced viral outgrowth frequency using a standard quantitative viral outgrowth assay. This study defines HIV transcriptional elongation and splicing as important barriers to latent HIV protein expression following latency reversal, delineates the roles of BET proteins and their BDs in HIV latency, and provides a rationale for exploration of IAPi+BETi in animal models of HIV latency.
Project description:Inflammation and apoptosis are main pathological processes that lead to the development of cardiac hypertrophy. Lupeol, a natural triterpenoid, has shown anti-inflammatory and anti-apoptotic activities as well as potential protective effects on cardiovascular diseases. In this study we investigated whether lupeol attenuated cardiac hypertrophy and fibrosis induced by pressure overload in vivo and in vitro, and explored the underlying mechanisms. Cardiac hypertrophy was induced in mice by transverse aortic constriction (TAC) surgery, and in neonatal rat cardiomyocytes (NRCMs) by stimulation with phenylephrine (PE) in vitro. We showed that administration of lupeol (50 mg ·kg-1· d-1, i.g., for 4 weeks) prevented the morphological changes and cardiac dysfunction and remodeling in TAC mice, and treatment with lupeol (50 μg/mL) significantly attenuated the hypertrophy of PE-stimulated NRCMs, and blunted the upregulated hypertrophic markers ANP, BNP, and β-MHC. Furthermore, lupeol treatment attenuated the apoptotic and inflammatory responses in the heart tissue. We revealed that lupeol attenuated the inflammatory responses including the reduction of inflammatory cytokines and inhibition of NF-κB p65 nuclear translocation, which was mediated by the TLR4-PI3K-Akt signaling. Administration of a PI3K/Akt agonist 740 Y-P reversed the protective effects of lupeol in TAC mice as well as in PE-stimulated NRCMs. Moreover, pre-treatment with a TLR4 agonist RS 09 abolished the protective effects of lupeol and restored the inhibition of PI3K-Akt-NF-κB signaling by lupeol in PE-stimulated NRCMs. Collectively, our results demonstrate that the lupeol protects against cardiac hypertrophy via anti-inflammatory mechanisms, which results from inhibiting the TLR4-PI3K-Akt-NF-κB signaling.
Project description:Immune checkpoint blockade (ICB) induces durable response in approximately 20% of patients with advanced bladder urothelial cancer (aUC). Over 50% of aUCs harbor genomic alterations along the phosphoinositide 3-kinase (PI3K) pathway. The goal of this project was to determine the synergistic effects and mechanisms of action of PI3K inhibition and ICB combination in aUC. Alterations affecting the PI3K pathway were examined in The Cancer Genome Atlas (TCGA) and the Cancer Dependency Map databases. Human and mouse cells with Pten deletion were used for in vitro studies. C57BL/6 mice carrying syngeneic tumors were used to determine in vivo activity, mechanisms of action and secondary resistance of pan-PI3K inhibition, ICB and combination. Alterations along the PI3K pathway occurred in 57% of aUCs in TCGA. CRISPR (clustered regularly interspaced short palindromic repeats) knockout of PIK3CA induced pronounced inhibition of cell proliferation (p=0.0046). PI3K inhibition suppressed cancer cell growth, migration and colony formation in vitro. Pan-PI3K inhibition, antiprogrammed death 1 (aPD1) therapy and combination improved the overall survival (OS) of syngeneic mice with PTEN-deleted tumors from 27 days of the control to 48, 37, and 65 days, respectively. In mice with tumors not containing a PI3K pathway alteration, OS was prolonged by the combination but not single treatments. Pan-PI3K inhibition significantly upregulated CD80, CD86, MHC-I, and MHC-II in dendritic cells, and downregulated the transforming growth factor beta pathway with a false discovery rate-adjusted q value of 0.001. Interferon alpha response was significantly upregulated with aPD1 therapy (q value: <0.001) and combination (q value: 0.027). Compared with the control, combination treatment increased CD8+ T-cell infiltration (p=0.005), decreased Treg-cell infiltration (p=0.036), and upregulated the expression of multiple immunostimulatory cytokines and granzyme B (p<0.01). Secondary resistance was associated with upregulation of the mammalian target of rapamycin (mTOR) pathway and multiple Sprr family genes. The combination Pan-PI3K inhibition and ICB has significant antitumor effects in aUC with or without activated PI3K pathway and warrants further clinical investigation. This combination creates an immunostimulatory tumor milieu. Secondary resistance is associated with upregulation of the mTOR pathway and Sprr family genes.