Project description:Drugs that target pre-mRNA splicing hold great therapeutic potential, but the mechanistic understanding of how these drugs function is limited. Here we introduce a biophysical modeling framework that can quantitatively describe the sequence-specific and concentration-dependent behavior of splice-modifying drugs. Using massively parallel splicing assays, RNA-seq experiments, and precision dose-response curves, we apply this framework to two drugs, risdiplam and branaplam, developed for treating spinal muscular atrophy. The results quantitatively define the specificities of risdiplam and branaplam for 5’ splice site sequences, suggest that branaplam recognizes 5’ splice sites via two distinct interaction modes, and disprove the prevailing two-site hypothesis for risdiplam activity at SMN2 exon 7. The results also show, more generally, that single-drug cooperativity and multi-drug synergy are widespread among splice-modifying drugs. Our biophysical modeling approach thus clarifies the mechanisms of existing splice-modifying treatments and provides a quantitative basis for the rational development of new therapies.
Project description:Drugs that target pre-mRNA splicing hold great therapeutic potential, but the quantitative understanding of how these drugs work is limited. Here we introduce mechanistically interpretable quantitative models for the sequence-specific and concentration-dependent behavior of splice-modifying drugs. Using massively parallel splicing assays, RNA-seq experiments, and precision dose-response curves, we obtain quantitative models for two small-molecule drugs, risdiplam and branaplam, developed for treating spinal muscular atrophy. The results quantitatively characterize the specificities of risdiplam and branaplam for 5' splice site sequences, suggest that branaplam recognizes 5' splice sites via two distinct interaction modes, and contradict the prevailing two-site hypothesis for risdiplam activity at SMN2 exon 7. The results also show that anomalous single-drug cooperativity, as well as multi-drug synergy, are widespread among small-molecule drugs and antisense-oligonucleotide drugs that promote exon inclusion. Our quantitative models thus clarify the mechanisms of existing treatments and provide a basis for the rational development of new therapies.
Project description:PPARγ is a member of the nuclear receptor family for which agonist ligands have anti-growth effects. However, clinical studies using PPARγ ligands as a monotherapy failed to show a beneficial effect. Here we have studied the effects of PPARγ activation with chemotherapeutic agents in current use for specific cancers. We observed a striking synergy between rosiglitazone and platinum-based drugs in several different cancers both in vitro and using transplantable and chemically induced “spontaneous” tumor models. The effect appears to be due in part to PPARγ-mediated downregulation of metallothioneins, proteins that have been shown to be involved in resistance to platinum-based therapy. These data strongly suggest combining PPARγ agonists and platinum-based drugs for the treatment of certain human cancers Keywords: Gene expression, change, synergy of interaction
Project description:miRNA expression profiling in human cancer cells after 5-aza-2'-deoxycytidine and 4-phenylbutyric acid treatment to investigate whether microRNA expression is controlled by these chromatin modifying drugs.
Project description:PPARγ is a member of the nuclear receptor family for which agonist ligands have anti-growth effects. However, clinical studies using PPARγ ligands as a monotherapy failed to show a beneficial effect. Here we have studied the effects of PPARγ activation with chemotherapeutic agents in current use for specific cancers. We observed a striking synergy between rosiglitazone and platinum-based drugs in several different cancers both in vitro and using transplantable and chemically induced âspontaneousâ tumor models. The effect appears to be due in part to PPARγ-mediated downregulation of metallothioneins, proteins that have been shown to be involved in resistance to platinum-based therapy. These data strongly suggest combining PPARγ agonists and platinum-based drugs for the treatment of certain human cancers Experiment Overall Design: Cells were treated with either DMSO/control, rosiglitazone, carboplatin or combination or rosiglitazone and carboplatin in duplicate for 24 hr. RNA was isolated and microarray analysis carried out by the Dana-Farber Cancer Institute Microarray Core.
Project description:The gas-1(fc21) mutation affects the 49 kD subunit of complex I, decreasing the rate of complex I-dependent oxidative phosphorylation. This is a model for human mitochondrial respiratory chain disease. NAD+ and PPAR-modifying drugs may confer benefits with respect to lifespan in these short-lived mutant worms. Analysis of gas-1(fc21) electron transport chain complex I mutants treated either starting in development or in young adulthood only with nicotinic acid (1 mM), resveratrol (50 microM), rosiglitazone (5 mM) or fenofibrate (14 microM) is presented. The goal is to detect transcriptional changes in clusters of genes using gene set enrichment analysis to explain treament effects in these mutant worms.
Project description:The gas-1(fc21) mutation affects the 49 kD subunit of complex I, decreasing the rate of complex I-dependent oxidative phosphorylation. This is a model for human mitochondrial respiratory chain disease. NAD+ and PPAR-modifying drugs may confer benefits with respect to lifespan in these short-lived mutant worms. Analysis of gas-1(fc21) electron transport chain complex I mutants treated either starting in development or in young adulthood only with nicotinic acid (1 mM), resveratrol (50 microM), rosiglitazone (5 mM) or fenofibrate (14 microM) is presented. The goal is to detect transcriptional changes in clusters of genes using gene set enrichment analysis to explain treament effects in these mutant worms. Four biological replicates were performed for each treatment condition (nicotinic acid, resveratrol, rosiglitazone, and fenofibrate) for each drug beginning either in development or in young adulthood for gas-1 mutant worms, i.e., 8 treated samples in total. At most one outlier was excluded from each analysis. Untreated N2 and gas-1 in each of the control solvents (S-basal, for nicotinic acid, and 1% DMSO, for resveratrol, rosiglitazone, and fenofibrate) were also analyzed; at least 3 replicates of each were included. These were used as sources of total RNA, each for hybridization to a single Affymetrix whole-genome microarray. Analysis was performed to reveal transcriptional changes related to mutantion and/or drug treatment effects.
Project description:Invasive fungal infections (IFIs) are difficult to treat. Few effective antifungal drugs are available and many have problems with toxicity, efficacy and drug-resistance. To overcome these challenges, existing therapies may be enhanced using more than one agent acting in synergy. Previously, we have found amphotericin B (AMB) and the iron chelator, lactoferrin (LF), were synergistic against Cryptococcus neoformans and Saccharomyces cerevisiae. This study investigates the mechanism of AMB+LF synergy using RNA-seq in Cryptococcus neoformans H99.
Project description:Peripheral blood cellular dynamics of Rheumatoid arthritis treatment informs about efficacy of response to disease modifying drugs.