RESUMEN
Proteins are essential agents of biological processes. To date, large-scale profiling of cell line collections including the Cancer Cell Line Encyclopedia (CCLE) has focused primarily on genetic information whereas deep interrogation of the proteome has remained out of reach. Here, we expand the CCLE through quantitative profiling of thousands of proteins by mass spectrometry across 375 cell lines from diverse lineages to reveal information undiscovered by DNA and RNA methods. We observe unexpected correlations within and between pathways that are largely absent from RNA. An analysis of microsatellite instable (MSI) cell lines reveals the dysregulation of specific protein complexes associated with surveillance of mutation and translation. These and other protein complexes were associated with sensitivity to knockdown of several different genes. These data in conjunction with the wider CCLE are a broad resource to explore cellular behavior and facilitate cancer research.
Asunto(s)
Regulación Neoplásica de la Expresión Génica/genética , Neoplasias/metabolismo , Proteoma/metabolismo , Línea Celular Tumoral , Perfilación de la Expresión Génica/métodos , Humanos , Espectrometría de Masas/métodos , Inestabilidad de Microsatélites , Mutación/genética , Proteómica/métodosRESUMEN
Cancer genomes often harbor hundreds of somatic DNA rearrangement junctions, many of which cannot be easily classified into simple (e.g., deletion) or complex (e.g., chromothripsis) structural variant classes. Applying a novel genome graph computational paradigm to analyze the topology of junction copy number (JCN) across 2,778 tumor whole-genome sequences, we uncovered three novel complex rearrangement phenomena: pyrgo, rigma, and tyfonas. Pyrgo are "towers" of low-JCN duplications associated with early-replicating regions, superenhancers, and breast or ovarian cancers. Rigma comprise "chasms" of low-JCN deletions enriched in late-replicating fragile sites and gastrointestinal carcinomas. Tyfonas are "typhoons" of high-JCN junctions and fold-back inversions associated with expressed protein-coding fusions, breakend hypermutation, and acral, but not cutaneous, melanomas. Clustering of tumors according to genome graph-derived features identified subgroups associated with DNA repair defects and poor prognosis.
Asunto(s)
Variación Estructural del Genoma/genética , Genómica/métodos , Neoplasias/genética , Inversión Cromosómica/genética , Cromotripsis , Variaciones en el Número de Copia de ADN/genética , Reordenamiento Génico/genética , Genoma Humano/genética , Humanos , Mutación/genética , Secuenciación Completa del Genoma/métodosRESUMEN
Most human epithelial tumors harbor numerous alterations, making it difficult to predict which genes are required for tumor survival. To systematically identify cancer dependencies, we analyzed 501 genome-scale loss-of-function screens performed in diverse human cancer cell lines. We developed DEMETER, an analytical framework that segregates on- from off-target effects of RNAi. 769 genes were differentially required in subsets of these cell lines at a threshold of six SDs from the mean. We found predictive models for 426 dependencies (55%) by nonlinear regression modeling considering 66,646 molecular features. Many dependencies fall into a limited number of classes, and unexpectedly, in 82% of models, the top biomarkers were expression based. We demonstrated the basis behind one such predictive model linking hypermethylation of the UBB ubiquitin gene to a dependency on UBC. Together, these observations provide a foundation for a cancer dependency map that facilitates the prioritization of therapeutic targets.
Asunto(s)
Neoplasias/genética , Neoplasias/patología , Línea Celular Tumoral , Humanos , Interferencia de ARN , Programas Informáticos , Ubiquitina/genéticaRESUMEN
The analysis of exonic DNA from prostate cancers has identified recurrently mutated genes, but the spectrum of genome-wide alterations has not been profiled extensively in this disease. We sequenced the genomes of 57 prostate tumors and matched normal tissues to characterize somatic alterations and to study how they accumulate during oncogenesis and progression. By modeling the genesis of genomic rearrangements, we identified abundant DNA translocations and deletions that arise in a highly interdependent manner. This phenomenon, which we term "chromoplexy," frequently accounts for the dysregulation of prostate cancer genes and appears to disrupt multiple cancer genes coordinately. Our modeling suggests that chromoplexy may induce considerable genomic derangement over relatively few events in prostate cancer and other neoplasms, supporting a model of punctuated cancer evolution. By characterizing the clonal hierarchy of genomic lesions in prostate tumors, we charted a path of oncogenic events along which chromoplexy may drive prostate carcinogenesis.
Asunto(s)
Aberraciones Cromosómicas , Regulación Neoplásica de la Expresión Génica , Genoma Humano , Neoplasias de la Próstata/genética , Adenocarcinoma/genética , Adenocarcinoma/patología , Estudios de Cohortes , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Tumores Neuroendocrinos/genética , Tumores Neuroendocrinos/patología , Neoplasias de la Próstata/patologíaRESUMEN
Synthetic lethality-an interaction between two genetic events through which the co-occurrence of these two genetic events leads to cell death, but each event alone does not-can be exploited for cancer therapeutics1. DNA repair processes represent attractive synthetic lethal targets, because many cancers exhibit an impairment of a DNA repair pathway, which can lead to dependence on specific repair proteins2. The success of poly(ADP-ribose) polymerase 1 (PARP-1) inhibitors in cancers with deficiencies in homologous recombination highlights the potential of this approach3. Hypothesizing that other DNA repair defects would give rise to synthetic lethal relationships, we queried dependencies in cancers with microsatellite instability (MSI), which results from deficient DNA mismatch repair. Here we analysed data from large-scale silencing screens using CRISPR-Cas9-mediated knockout and RNA interference, and found that the RecQ DNA helicase WRN was selectively essential in MSI models in vitro and in vivo, yet dispensable in models of cancers that are microsatellite stable. Depletion of WRN induced double-stranded DNA breaks and promoted apoptosis and cell cycle arrest selectively in MSI models. MSI cancer models required the helicase activity of WRN, but not its exonuclease activity. These findings show that WRN is a synthetic lethal vulnerability and promising drug target for MSI cancers.
Asunto(s)
Inestabilidad de Microsatélites , Repeticiones de Microsatélite/genética , Neoplasias/genética , Mutaciones Letales Sintéticas/genética , Helicasa del Síndrome de Werner/genética , Apoptosis/genética , Sistemas CRISPR-Cas/genética , Puntos de Control del Ciclo Celular/genética , Línea Celular Tumoral , Roturas del ADN de Doble Cadena , Humanos , Modelos Genéticos , Neoplasias/patología , Interferencia de ARN , Proteína p53 Supresora de Tumor/metabolismo , Helicasa del Síndrome de Werner/deficienciaRESUMEN
Large panels of comprehensively characterized human cancer models, including the Cancer Cell Line Encyclopedia (CCLE), have provided a rigorous framework with which to study genetic variants, candidate targets, and small-molecule and biological therapeutics and to identify new marker-driven cancer dependencies. To improve our understanding of the molecular features that contribute to cancer phenotypes, including drug responses, here we have expanded the characterizations of cancer cell lines to include genetic, RNA splicing, DNA methylation, histone H3 modification, microRNA expression and reverse-phase protein array data for 1,072 cell lines from individuals of various lineages and ethnicities. Integration of these data with functional characterizations such as drug-sensitivity, short hairpin RNA knockdown and CRISPR-Cas9 knockout data reveals potential targets for cancer drugs and associated biomarkers. Together, this dataset and an accompanying public data portal provide a resource for the acceleration of cancer research using model cancer cell lines.
Asunto(s)
Línea Celular Tumoral , Neoplasias/genética , Neoplasias/patología , Antineoplásicos/farmacología , Biomarcadores de Tumor , Metilación de ADN , Resistencia a Antineoplásicos , Etnicidad/genética , Edición Génica , Histonas/metabolismo , Humanos , MicroARNs/genética , Terapia Molecular Dirigida , Neoplasias/metabolismo , Análisis por Matrices de Proteínas , Empalme del ARNRESUMEN
With the advances in sequencing technologies, a huge amount of biological data is extracted nowadays. Analyzing this amount of data is beyond the ability of human beings, creating a splendid opportunity for machine learning methods to grow. The methods, however, are practical only when the sequences are converted into feature vectors. Many tools target this task including iLearnPlus, a Python-based tool which supports a rich set of features. In this paper, we propose a holistic tool that extracts features from biological sequences (i.e. DNA, RNA and Protein). These features are the inputs to machine learning models that predict properties, structures or functions of the input sequences. Our tool not only supports all features in iLearnPlus but also 30 additional features which exist in the literature. Moreover, our tool is based on R language which makes an alternative for bioinformaticians to transform sequences into feature vectors. We have compared the conversion time of our tool with that of iLearnPlus: we transform the sequences much faster. We convert small nucleotides by a median of 2.8X faster, while we outperform iLearnPlus by a median of 6.3X for large sequences. Finally, in amino acids, our tool achieves a median speedup of 23.9X.
Asunto(s)
Aprendizaje Automático , Proteínas , ADN/genética , Humanos , Proteínas/química , ARN/genética , Análisis de Secuencia/métodosRESUMEN
Human cancer cell lines are the workhorse of cancer research. Although cell lines are known to evolve in culture, the extent of the resultant genetic and transcriptional heterogeneity and its functional consequences remain understudied. Here we use genomic analyses of 106 human cell lines grown in two laboratories to show extensive clonal diversity. Further comprehensive genomic characterization of 27 strains of the common breast cancer cell line MCF7 uncovered rapid genetic diversification. Similar results were obtained with multiple strains of 13 additional cell lines. Notably, genetic changes were associated with differential activation of gene expression programs and marked differences in cell morphology and proliferation. Barcoding experiments showed that cell line evolution occurs as a result of positive clonal selection that is highly sensitive to culture conditions. Analyses of single-cell-derived clones demonstrated that continuous instability quickly translates into heterogeneity of the cell line. When the 27 MCF7 strains were tested against 321 anti-cancer compounds, we uncovered considerably different drug responses: at least 75% of compounds that strongly inhibited some strains were completely inactive in others. This study documents the extent, origins and consequences of genetic variation within cell lines, and provides a framework for researchers to measure such variation in efforts to support maximally reproducible cancer research.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Evolución Molecular , Variación Genética/genética , Inestabilidad Genómica/genética , Transcripción Genética/genética , Neoplasias de la Mama/patología , Proliferación Celular , Forma de la Célula , Células Clonales/citología , Células Clonales/efectos de los fármacos , Células Clonales/metabolismo , Variación Genética/efectos de los fármacos , Inestabilidad Genómica/efectos de los fármacos , Humanos , Células MCF-7 , Reproducibilidad de los ResultadosRESUMEN
The use of proteasome inhibitors to target cancer's dependence on altered protein homeostasis has been greatly limited by intrinsic and acquired resistance. Analyzing data from thousands of cancer lines and tumors, we find that those with suppressed expression of one or more 19S proteasome subunits show intrinsic proteasome inhibitor resistance. Moreover, such proteasome subunit suppression is associated with poor outcome in myeloma patients, where proteasome inhibitors are a mainstay of treatment. Beyond conferring resistance to proteasome inhibitors, proteasome subunit suppression also serves as a sentinel of a more global remodeling of the transcriptome. This remodeling produces a distinct gene signature and new vulnerabilities to the proapoptotic drug, ABT-263. This frequent, naturally arising imbalance in 19S regulatory complex composition is achieved through a variety of mechanisms, including DNA methylation, and marks the emergence of a heritably altered and therapeutically relevant state in diverse cancers.
Asunto(s)
Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma/farmacología , Línea Celular Tumoral , Metilación de ADN/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , HumanosRESUMEN
Pediatric-type nodal follicular lymphoma (PTNFL) is a variant of follicular lymphoma (FL) characterized by limited-stage presentation and invariably benign behavior despite often high-grade histological appearance. It is important to distinguish PTNFL from typical FL in order to avoid unnecessary treatment; however, this distinction relies solely on clinical and pathological criteria, which may be variably applied. To define the genetic landscape of PTNFL, we performed copy number analysis and exome and/or targeted sequencing of 26 PTNFLs (16 pediatric and 10 adult). The most commonly mutated gene in PTNFL was MAP2K1, encoding MEK1, with a mutation frequency of 43%. All MAP2K1 mutations were activating missense mutations localized to exons 2 and 3, which encode negative regulatory and catalytic domains, respectively. Missense mutations in MAPK1 (2/22) and RRAS (1/22) were identified in cases that lacked MAP2K1 mutations. The second most commonly mutated gene in PTNFL was TNFRSF14, with a mutation frequency of 29%, similar to that seen in limited-stage typical FL (P = .35). PTNFL was otherwise genomically bland and specifically lacked recurrent mutations in epigenetic modifiers (eg, CREBBP, KMT2D). Copy number aberrations affected a mean of only 0.5% of PTNFL genomes, compared with 10% of limited-stage typical FL genomes (P < .02). Importantly, the mutational profiles of PTNFLs in children and adults were highly similar. Together, these findings define PTNFL as a biologically and clinically distinct indolent lymphoma of children and adults characterized by a high prevalence of MAPK pathway mutations and a near absence of mutations in epigenetic modifiers.
Asunto(s)
Linfoma Folicular/enzimología , Linfoma Folicular/genética , Sistema de Señalización de MAP Quinasas/genética , Mutación/genética , Adolescente , Factores de Edad , Forma de la Célula , Niño , Preescolar , Variaciones en el Número de Copia de ADN/genética , Epigénesis Genética , Femenino , Humanos , Inmunofenotipificación , Lactante , Linfoma Folicular/patología , MasculinoRESUMEN
UNLABELLED: We present a new R package for training gapped-kmer SVM classifiers for DNA and protein sequences. We describe an improved algorithm for kernel matrix calculation that speeds run time by about 2 to 5-fold over our original gkmSVM algorithm. This package supports several sequence kernels, including: gkmSVM, kmer-SVM, mismatch kernel and wildcard kernel. AVAILABILITY AND IMPLEMENTATION: gkmSVM package is freely available through the Comprehensive R Archive Network (CRAN), for Linux, Mac OS and Windows platforms. The C ++ implementation is available at www.beerlab.org/gkmsvm CONTACT: mghandi@gmail.com or mbeer@jhu.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Asunto(s)
Análisis de Secuencia de ADN/métodos , Análisis de Secuencia de Proteína/métodos , Programas Informáticos , Máquina de Vectores de Soporte , AlgoritmosRESUMEN
Oligomers of length k, or k-mers, are convenient and widely used features for modeling the properties and functions of DNA and protein sequences. However, k-mers suffer from the inherent limitation that if the parameter k is increased to resolve longer features, the probability of observing any specific k-mer becomes very small, and k-mer counts approach a binary variable, with most k-mers absent and a few present once. Thus, any statistical learning approach using k-mers as features becomes susceptible to noisy training set k-mer frequencies once k becomes large. To address this problem, we introduce alternative feature sets using gapped k-mers, a new classifier, gkm-SVM, and a general method for robust estimation of k-mer frequencies. To make the method applicable to large-scale genome wide applications, we develop an efficient tree data structure for computing the kernel matrix. We show that compared to our original kmer-SVM and alternative approaches, our gkm-SVM predicts functional genomic regulatory elements and tissue specific enhancers with significantly improved accuracy, increasing the precision by up to a factor of two. We then show that gkm-SVM consistently outperforms kmer-SVM on human ENCODE ChIP-seq datasets, and further demonstrate the general utility of our method using a Naïve-Bayes classifier. Although developed for regulatory sequence analysis, these methods can be applied to any sequence classification problem.
Asunto(s)
Biología Computacional/métodos , Modelos Genéticos , Secuencias Reguladoras de Ácidos Nucleicos/genética , Análisis de Secuencia de ADN/métodos , Secuencia de Bases , Teorema de Bayes , Inmunoprecipitación de Cromatina , Oligonucleótidos/genética , Especificidad de Órganos/genética , Máquina de Vectores de SoporteRESUMEN
Oligomers of fixed length, k, commonly known as k-mers, are often used as fundamental elements in the description of DNA sequence features of diverse biological function, or as intermediate elements in the constuction of more complex descriptors of sequence features such as position weight matrices. k-mers are very useful as general sequence features because they constitute a complete and unbiased feature set, and do not require parameterization based on incomplete knowledge of biological mechanisms. However, a fundamental limitation in the use of k-mers as sequence features is that as k is increased, larger spatial correlations in DNA sequence elements can be described, but the frequency of observing any specific k-mer becomes very small, and rapidly approaches a sparse matrix of binary counts. Thus any statistical learning approach using k-mers will be susceptible to noisy estimation of k-mer frequencies once k becomes large. Because all molecular DNA interactions have limited spatial extent, gapped k-mers often carry the relevant biological signal. Here we use gapped k-mer counts to more robustly estimate the ungapped k-mer frequencies, by deriving an equation for the minimum norm estimate of k-mer frequencies given an observed set of gapped k-mer frequencies. We demonstrate that this approach provides a more accurate estimate of the k-mer frequencies in real biological sequences using a sample of CTCF binding sites in the human genome.
Asunto(s)
ADN/química , Genoma Humano , Factores de Transcripción/química , Sitios de Unión , HumanosRESUMEN
Microsatellite instability-high (MSI-H) tumors are malignant tumors that, despite harboring a high mutational burden, often have intact TP53. One of the most frequent mutations in MSI-H tumors is a frameshift mutation in RPL22, a ribosomal protein. Here, we identified RPL22 as a modulator of MDM4 splicing through an alternative splicing switch in exon 6. RPL22 loss increases MDM4 exon 6 inclusion and cell proliferation and augments resistance to the MDM inhibitor Nutlin-3a. RPL22 represses the expression of its paralog, RPL22L1, by mediating the splicing of a cryptic exon corresponding to a truncated transcript. Therefore, damaging mutations in RPL22 drive oncogenic MDM4 induction and reveal a common splicing circuit in MSI-H tumors that may inform therapeutic targeting of the MDM4-p53 axis and oncogenic RPL22L1 induction.
Asunto(s)
Proteínas de Ciclo Celular , Proteínas Ribosómicas , Humanos , Proteínas Ribosómicas/metabolismo , Proteínas Ribosómicas/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética , Neoplasias/genética , Neoplasias/patología , Neoplasias/metabolismo , Línea Celular Tumoral , Empalme Alternativo/genética , Proliferación Celular/genética , Animales , Exones/genética , Ratones , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Regulación Neoplásica de la Expresión Génica , Piperazinas/farmacología , Imidazoles/farmacologíaRESUMEN
Here, we present FusionInspector for in silico characterization and interpretation of candidate fusion transcripts from RNA sequencing (RNA-seq) and exploration of their sequence and expression characteristics. We applied FusionInspector to thousands of tumor and normal transcriptomes and identified statistical and experimental features enriched among biologically impactful fusions. Through clustering and machine learning, we identified large collections of fusions potentially relevant to tumor and normal biological processes. We show that biologically relevant fusions are enriched for relatively high expression of the fusion transcript, imbalanced fusion allelic ratios, and canonical splicing patterns, and are deficient in sequence microhomologies between partner genes. We demonstrate that FusionInspector accurately validates fusion transcripts in silico and helps characterize numerous understudied fusions in tumor and normal tissue samples. FusionInspector is freely available as open source for screening, characterization, and visualization of candidate fusions via RNA-seq, and facilitates transparent explanation and interpretation of machine-learning predictions and their experimental sources.
Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Neoplasias , Humanos , Neoplasias/genética , Análisis de Secuencia de ARN , Transcriptoma/genéticaRESUMEN
Microsatellite instability high (MSI-H) tumors are malignant tumors that, despite harboring a high mutational burden, often have intact TP53. One of the most frequent mutations in MSI-H tumors is a frameshift mutation in RPL22, a ribosomal protein. Here, we identified RPL22 as a modulator of MDM4 splicing through an alternative splicing switch in exon 6. RPL22 loss increases MDM4 exon 6 inclusion, cell proliferation, and augments resistance to the MDM inhibitor Nutlin-3a. RPL22 represses expression of its paralog, RPL22L1, by mediating the splicing of a cryptic exon corresponding to a truncated transcript. Therefore, damaging mutations in RPL22 drive oncogenic MDM4 induction and reveal a common splicing circuit in MSI-H tumors that may inform therapeutic targeting of the MDM4-p53 axis and oncogenic RPL22L1 induction.
RESUMEN
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive leukemia of plasmacytoid dendritic cells (pDC). BPDCN occurs at least three times more frequently in men than in women, but the reasons for this sex bias are unknown. Here, studying genomics of primary BPDCN and modeling disease-associated mutations, we link acquired alterations in RNA splicing to abnormal pDC development and inflammatory response through Toll-like receptors. Loss-of-function mutations in ZRSR2, an X chromosome gene encoding a splicing factor, are enriched in BPDCN, and nearly all mutations occur in males. ZRSR2 mutation impairs pDC activation and apoptosis after inflammatory stimuli, associated with intron retention and inability to upregulate the transcription factor IRF7. In vivo, BPDCN-associated mutations promote pDC expansion and signatures of decreased activation. These data support a model in which male-biased mutations in hematopoietic progenitors alter pDC function and confer protection from apoptosis, which may impair immunity and predispose to leukemic transformation. SIGNIFICANCE: Sex bias in cancer is well recognized, but the underlying mechanisms are incompletely defined. We connect X chromosome mutations in ZRSR2 to an extremely male-predominant leukemia. Aberrant RNA splicing induced by ZRSR2 mutation impairs dendritic cell inflammatory signaling, interferon production, and apoptosis, revealing a sex- and lineage-related tumor suppressor pathway.This article is highlighted in the In This Issue feature, p. 275.
Asunto(s)
Células Dendríticas/metabolismo , Trastornos Mieloproliferativos/genética , Ribonucleoproteínas/genética , Apoptosis , Femenino , Identidad de Género , Humanos , Masculino , MutaciónRESUMEN
In cancer, telomere maintenance is critical for the development of replicative immortality. Using genome sequences from the Cancer Cell Line Encyclopedia and Genomics of Drug Sensitivity in Cancer Project, we calculated telomere content across 1299 cancer cell lines. We find that telomerase reverse transcriptase (TERT) expression correlates with telomere content in lung, central nervous system, and leukemia cell lines. Using CRISPR/Cas9 screening data, we show that lower telomeric content is associated with dependency of CST telomere maintenance genes. Increased dependencies of shelterin members are associated with wild-type TP53 status. Investigating the epigenetic regulation of TERT, we find widespread allele-specific expression in promoter-wildtype contexts. TERT promoter-mutant cell lines exhibit hypomethylation at PRC2-repressed regions, suggesting a cooperative global epigenetic state in the reactivation of telomerase. By incorporating telomere content with genomic features across comprehensively characterized cell lines, we provide further insights into the role of telomere regulation in cancer immortality.
Asunto(s)
Telomerasa/metabolismo , Homeostasis del Telómero , Telómero/metabolismo , Línea Celular Tumoral , Epigénesis Genética , Humanos , Neoplasias/genética , Telomerasa/genéticaRESUMEN
Assays to study cancer cell responses to pharmacologic or genetic perturbations are typically restricted to using simple phenotypic readouts such as proliferation rate. Information-rich assays, such as gene-expression profiling, have generally not permitted efficient profiling of a given perturbation across multiple cellular contexts. Here, we develop MIX-Seq, a method for multiplexed transcriptional profiling of post-perturbation responses across a mixture of samples with single-cell resolution, using SNP-based computational demultiplexing of single-cell RNA-sequencing data. We show that MIX-Seq can be used to profile responses to chemical or genetic perturbations across pools of 100 or more cancer cell lines. We combine it with Cell Hashing to further multiplex additional experimental conditions, such as post-treatment time points or drug doses. Analyzing the high-content readout of scRNA-seq reveals both shared and context-specific transcriptional response components that can identify drug mechanism of action and enable prediction of long-term cell viability from short-term transcriptional responses to treatment.
Asunto(s)
Perfilación de la Expresión Génica/métodos , Neoplasias/genética , Análisis de la Célula Individual/métodos , Antineoplásicos/farmacología , Secuencia de Bases , Línea Celular Tumoral , Supervivencia Celular/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Modelos Estadísticos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Polimorfismo de Nucleótido Simple , Piridonas/farmacología , Pirimidinonas/farmacologíaRESUMEN
The interleukin-3 receptor α subunit, CD123, is expressed in many hematologic malignancies including acute myeloid leukemia (AML) and blastic plasmacytoid dendritic cell neoplasm (BPDCN). Tagraxofusp (SL-401) is a CD123-targeted therapy consisting of interleukin-3 fused to a truncated diphtheria toxin payload. Factors influencing response to tagraxofusp other than CD123 expression are largely unknown. We interrogated tagraxofusp resistance in patients and experimental models and found that it was not associated with CD123 loss. Rather, resistant AML and BPDCN cells frequently acquired deficiencies in the diphthamide synthesis pathway, impairing tagraxofusp's ability to ADP-ribosylate cellular targets. Expression of DPH1, encoding a diphthamide pathway enzyme, was reduced by DNA CpG methylation in resistant cells. Treatment with the DNA methyltransferase inhibitor azacitidine restored DPH1 expression and tagraxofusp sensitivity. We also developed a drug-dependent ADP-ribosylation assay in primary cells that correlated with tagraxofusp activity and may represent an additional novel biomarker. As predicted by these results and our observation that resistance also increased mitochondrial apoptotic priming, we found that the combination of tagraxofusp and azacitidine was effective in patient-derived xenografts treated in vivo. These data have important implications for clinical use of tagraxofusp and led to a phase 1 study combining tagraxofusp and azacitidine in myeloid malignancies.