Project description:Chondrosarcomas are inherently resistant to chemotherapy and radiotherapy, pointing to an unmet need for new treatment options. Immune checkpoint inhibitors, which have shown remarkable promise in multiple solid cancer types, have limited efficacy in chondrosarcomas. Mutations in IDH1/2 genes, which result in progressive increases in DNA and histone methylation, are observed in 50% of conventional chondrosarcomas, suggesting that epigenetic dysregulation represents a potential barrier for tumor progression and target for therapeutic intervention. Here, we demonstrated that combined treatment of FDA-approved inhibitors of DNA methyltransferases (DNMTs) 5-aza-2'-deoxycytidine (5-aza), and histone deacetylases (HDACs) suberanilohydroxamic acid (SAHA) impaired the proliferation of chondrosarcoma cell lines in vitro and in xenograft studies. Transcriptomic analysis reveals that chondrosarcoma cells treated with 5-aza and SAHA markedly elevated the expression of IFN-stimulated genes including PD-L1, indicating that these epigenetic drugs induced a potent innate immune response. We demonstrated that 5-aza and SAHA resulted in both genomic and epigenomic instability, as shown by elevated DNA damage response and derepression of retrotransposons, respectively, which in turn activated pattern recognition receptors (PRRs) and the downstream IFN signaling pathways. Importantly, the cytotoxic effects of 5-aza and SAHA can be rescued by depletion of PRRs such as cGAS and MAVS, and potentiated by depletion of the RNA-editing enzyme ADAR1. Together, our results demonstrate preclinical activity of combined DNMT and HDAC inhibition against chondrosarcomas and suggest that targeted epigenetic therapies could represent a new therapeutic approach in the treatment of chondrosarcomas, and this is being tested in an ongoing clinical trial (NCT04340843).
Project description:In this study, our results demonstrated preclinical activity of combined DNMT and HDAC inhibition against chondrosarcomas and suggest that targeted epigenetic therapies could effectively augment the immune-reactivity of chondrosarcomas and may sensitize these immune-cold tumors to immune checkpoint blockade.
Project description:Sensing of microbial products by innate immune cells skew their transcriptional program to optimize anti-microbial defences. Chromatin remodeling by histone deacetylases (HDACs) plays a fundamental role in tailoring gene expression. HDAC inhibitors are among the most promising anti-cancer drugs and possess intrinsic anti-inflammatory properties. Yet, the influence of HDAC inhibition on innate immune responses to microbial infection is unknown. Here we show that HDAC inhibitors repress the expression of less than 10% of the genes expressed at baseline in BM-derived macrophages. In sharp contrast, HDAC inhibitors strongly interfere with transcriptome remodeling induced by LPS and Pam3CSK4, affecting the expression of 30-70% of genes modulated by microbial stimuli. Strikingly, HDAC inhibitors target the expression of numerous genes involved in anti-microbial host defences, encoding for microbial sensors, cytokines, chemokines, growth factors and their receptors, adhesion and signaling molecules, and molecules involved in antigen processing and presentation. At the molecular level, HDAC inhibitors do not impair mitogen-activated protein kinase, NF-kB, interferon-related factor signal and STAT1 transduction pathways, but inhibit NF-kB p65 recruitment to the promoter region of HDAC inhibitor-sensitive genes. HDAC inhibitors also inhibit the response of mouse and human DCs, splenocytes and whole blood to a broad range of microbial products and microorganisms. In agreement with these in vitro findings, HDAC inhibitors increase bacterial burden and sensitize mice to sub-lethal infection with Klebsiella pneumoniae and Candida albicans. Conversely, HDAC inhibitors confer protection in models of Pam3CSK4-induced fulminant toxic shock and severe sepsis following cecal ligation and puncture. Overall, these data substantiate the concept of immunomodulation by HDAC inhibitors, and suggest that these drugs could represent efficacious adjunctive therapy of severe sepsis. Mus musculus cells were grown in presence of LPS or LPS + TSA and pam or pam + TSA and hybrydised against a cRNA pool UMRR (from Mus musculus cells).
Project description:Treatment of established lines and primary ovarian cancer cultures with Src and MEK inhibitors, saracatinib and selumetinib, respectively, showed target kinase inhibition and synergistic induction of apoptosis and cell cycle arrest in vitro and tumor inhibition in xenografts.
Project description:Pharmacological small molecules that target fetal hemoglobin (HbF) repressors serve as potent, cost-effective, and accessible therapeutic strategies to β-globinopathies such as sickle cell disease (SCD). LSD1 inhibition has been shown to induce HbF levels both in vitro and in vivo. However, all potent LSD1 inhibitors in HbF induction in vivo are covalent irreversible compounds, which can cause some adverse effects. In this study, we utilized structure-aided drug design based on the scaffold of a reversible LSD1 inhibitor GSK-690, and developed potent new reversible LSD1 inhibitors that induce robust γ-globin expression in human primary erythroid differentiation culture. Moreover, in a transgenic mouse model of SCD, oral administration of the novel LSD1 inhibitors induces significant elevation of HbF levels and alleviates the disease pathologies resulted from SCD. In addition, combined treatment of an BRD4 degrader, BD-9136 with the LSD1 inhibitors represses the induction of RUNX1 and PU.1, therefore rescues the yield of erythroid cells caused by LSD1 inhibition. Our data indicate that our novel LSD1 inhibitors can effectively induce HbF levels and reduce disease pathologies in SCD mice, and are well-tolerated by oral administration. We anticipate that these new compounds will offer new therapeutic possibilities for treating SCD.
Project description:MEK and BRD4 inhibitors induce cell death of subset of KRAS-mutant lung tumors in vitro and in vivo We performed microarray analysis of MEK and BRD4 inhibition alone and in combination 24 hours after treatment, prior to the induction of cell death, to analyze transcriptional changes that might be mechanistic drivers of the therapeutic effect