RESUMO
The inactive X chromosome (Xi) is inherently susceptible to genomic aberrations. Replication stress (RS) has been proposed as an underlying cause, but the mechanisms that protect from Xi instability remain unknown. Here, we show that macroH2A1.2, an RS-protective histone variant enriched on the Xi, is required for Xi integrity and female survival. Mechanistically, macroH2A1.2 counteracts its structurally distinct and equally Xi-enriched alternative splice variant, macroH2A1.1. Comparative proteomics identified a role for macroH2A1.1 in alternative end joining (alt-EJ), which accounts for Xi anaphase defects in the absence of macroH2A1.2. Genomic instability was rescued by simultaneous depletion of macroH2A1.1 or alt-EJ factors, and mice deficient for both macroH2A1 variants harbor no overt female defects. Notably, macroH2A1 splice variant imbalance affected alt-EJ capacity also in tumor cells. Together, these findings identify macroH2A1 splicing as a modulator of genome maintenance that ensures Xi integrity and may, more broadly, predict DNA repair outcome in malignant cells.
Assuntos
Processamento Alternativo , Reparo do DNA , Epigênese Genética , Instabilidade Genômica , Histonas/fisiologia , Anáfase , Animais , Linhagem Celular , Instabilidade Cromossômica , Cromossomos Humanos X , Feminino , Histonas/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Treatment and relevant targets for breast cancer (BC) remain limited, especially for triple-negative BC (TNBC). We identified 6091 proteins of 76 human BC cell lines using data-independent acquisition (DIA). Integrating our proteomic findings with prior multi-omics datasets, we found that including proteomics data improved drug sensitivity predictions and provided insights into the mechanisms of action. We subsequently profiled the proteomic changes in nine cell lines (five TNBC and four non-TNBC) treated with EGFR/AKT/mTOR inhibitors. In TNBC, metabolism pathways were dysregulated after EGFR/mTOR inhibitor treatment, while RNA modification and cell cycle pathways were affected by AKT inhibitor. This systematic multi-omics and in-depth analysis of the proteome of BC cells can help prioritize potential therapeutic targets and provide insights into adaptive resistance in TNBC.
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Transdução de Sinais , Neoplasias de Mama Triplo Negativas , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteômica , Proliferação de Células , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Receptores ErbB/metabolismoRESUMO
CellMiner Cross-Database (CellMinerCDB, discover.nci.nih.gov/cellminercdb) allows integration and analysis of molecular and pharmacological data within and across cancer cell line datasets from the National Cancer Institute (NCI), Broad Institute, Sanger/MGH and MD Anderson Cancer Center (MDACC). We present CellMinerCDB 1.2 with updates to datasets from NCI-60, Broad Cancer Cell Line Encyclopedia and Sanger/MGH, and the addition of new datasets, including NCI-ALMANAC drug combination, MDACC Cell Line Project proteomic, NCI-SCLC DNA copy number and methylation data, and Broad methylation, genetic dependency and metabolomic datasets. CellMinerCDB (v1.2) includes several improvements over the previously published version: (i) new and updated datasets; (ii) support for pattern comparisons and multivariate analyses across data sources; (iii) updated annotations with drug mechanism of action information and biologically relevant multigene signatures; (iv) analysis speedups via caching; (v) a new dataset download feature; (vi) improved visualization of subsets of multiple tissue types; (vii) breakdown of univariate associations by tissue type; and (viii) enhanced help information. The curation and common annotations (e.g. tissues of origin and identifiers) provided here across pharmacogenomic datasets increase the utility of the individual datasets to address multiple researcher question types, including data reproducibility, biomarker discovery and multivariate analysis of drug activity.
Assuntos
Biologia Computacional/métodos , Bases de Dados Factuais , Neoplasias/metabolismo , Farmacogenética/métodos , Proteômica/métodos , Linhagem Celular Tumoral , Curadoria de Dados/métodos , Mineração de Dados/métodos , Tratamento Farmacológico/métodos , Genômica/métodos , Humanos , Internet , Neoplasias/tratamento farmacológico , Neoplasias/genéticaRESUMO
One of the hallmarks of cancer is chromosome instability (CIN), which leads to aneuploidy, translocations, and other chromosome aberrations. However, in the vast majority of human tumors the molecular basis of CIN remains unknown, partly because not all genes controlling chromosome transmission have yet been identified. To address this question, we developed an experimental high-throughput imaging (HTI) siRNA assay that allows the identification of novel CIN genes. Our method uses a human artificial chromosome (HAC) expressing the GFP transgene. When this assay was applied to screen an siRNA library of protein kinases, we identified PINK1, TRIO, IRAK1, PNCK, and TAOK1 as potential novel genes whose knockdown induces various mitotic abnormalities and results in chromosome loss. The HAC-based assay can be applied for screening different siRNA libraries (cell cycle regulation, DNA damage response, epigenetics, and transcription factors) to identify additional genes involved in CIN. Identification of the complete spectrum of CIN genes will reveal new insights into mechanisms of chromosome segregation and may expedite the development of novel therapeutic strategies to target the CIN phenotype in cancer cells.
Assuntos
Instabilidade Cromossômica/genética , Cromossomos Humanos/genética , Proteínas Quinases/genética , RNA Interferente Pequeno/genética , Aneuploidia , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/genética , Linhagem Celular Tumoral , Cromossomos Artificiais Humanos/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Quinases Associadas a Receptores de Interleucina-1/genética , Mitose/genética , Proteínas Quinases/isolamento & purificação , Proteínas Serina-Treonina Quinases/genética , RNA de Cadeia Dupla/genética , Transgenes , Translocação Genética/genéticaRESUMO
Six new macrophilone-type pyrroloiminoquines were isolated and identified from an extract of the marine hydroid Macrorhynchia philippina. The proton-deficient and heteroatom-rich structures of macrophilones B-G (2-7) were elucidated by spectroscopic analysis and comparison of their data with those of the previously reported metabolite macrophilone A (1). Compounds 1-7 are the first pyrroloiminoquines to be reported from a hydroid. The macrophilones were shown to inhibit the enzymatic conjugation of SUMO to peptide substrates, and macrophilones A (1) and C (3) exhibit potent and selective cytotoxic properties in the NCI-60 anticancer screen. Bioinformatic analysis revealed a close association of the cytotoxicity profiles of 1 and 3 with two known B-Raf kinase inhibitory drugs. While compounds 1 and 3 showed no kinase inhibitory activity, they resulted in a dramatic decrease in cellular protein levels of selected components of the ERK signal cascade. As such, the chemical scaffold of the macrophilones could provide small-molecule therapeutic leads that target the ERK signal transduction pathway.
Assuntos
Hidrozoários/química , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Pirroliminoquinonas/isolamento & purificação , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Pirroliminoquinonas/farmacologia , Sumoilação/efeitos dos fármacosRESUMO
The current convergence of molecular and pharmacological data provides unprecedented opportunities to gain insights into the relationships between the two types of data. Multiple forms of large-scale molecular data, including but not limited to gene and microRNA transcript expression, DNA somatic and germline variations from next-generation DNA and RNA sequencing, and DNA copy number from array comparative genomic hybridization are all potentially informative when one attempts to recognize the panoply of potentially influential events both for cancer progression and therapeutic outcome. Concurrently, there has also been a substantial expansion of the pharmacological data being accrued in a systematic fashion. For cancer cell lines, the National Cancer Institute cell line panel (NCI-60), the Cancer Cell Line Encyclopedia (CCLE), and the collaborative Genomics of Drug Sensitivity in Cancer (GDSC) databases all provide subsets of these forms of data. For the patient-derived data, The Cancer Genome Atlas (TCGA) provides analogous forms of genomic information along with treatment histories. Integration of these data in turn relies on the fields of statistics and statistical learning. Multiple algorithmic approaches may be chosen, depending on the data being considered, and the nature of the question being asked. Combining these algorithms with prior biological knowledge, the results of molecular biological studies, and the consideration of genes as pathways or functional groups provides both the challenge and the potential of the field. The ultimate goal is to provide a paradigm shift in the way that drugs are selected to provide a more targeted and efficacious outcome for the patient.
Assuntos
Algoritmos , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica , Neoplasias/tratamento farmacológico , Neoplasias/genética , Farmacogenética , Humanos , Medicina de PrecisãoRESUMO
DNA-damaging agents (DDAs) constitute the backbone of treatment for most human tumors. Here we used the National Cancer Institute Antitumor Cell Line Panel (the NCI-60) to identify predictors of cancer cell response to topoisomerase I (Top1) inhibitors, a widely used class of DDAs. We assessed the NCI-60 transcriptome using Affymetrix Human Exon 1.0 ST microarrays and correlated the in vitro activity of four Top1 inhibitors with gene expression in the 60 cell lines. A single gene, Schlafen-11 (SLFN11), showed an extremely significant positive correlation with the response not only to Top1 inhibitors, but also to Top2 inhibitors, alkylating agents, and DNA synthesis inhibitors. Using cells with endogenously high and low SLFN11 expression and siRNA-mediated silencing, we show that SLFN11 is causative in determining cell death and cell cycle arrest in response to DDAs in cancer cells from different tissues of origin. We next analyzed SLFN11 expression in ovarian and colorectal cancers and normal corresponding tissues from The Cancer Genome Atlas database and observed that SLFN11 has a wide expression range. We also observed that high SLFN11 expression independently predicts overall survival in a group of ovarian cancer patients treated with cisplatin-containing regimens. We conclude that SLFN11 expression is causally associated with the activity of DDAs in cancer cells, has a broad expression range in colon and ovarian adenocarcinomas, and may behave as a biomarker for prediction of response to DDAs in the clinical setting.
Assuntos
Dano ao DNA/efeitos dos fármacos , DNA Helicases/metabolismo , Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Inibidores da Topoisomerase I/farmacologia , Linhagem Celular Tumoral , Ensaio de Unidades Formadoras de Colônias , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Análise em Microsséries , Microscopia Confocal , Interferência de RNARESUMO
Core binding factor (CBF) leukemias, those with translocations or inversions that affect transcription factor genes RUNX1 or CBFB, account for ~24% of adult acute myeloid leukemia (AML) and 25% of pediatric acute lymphocytic leukemia (ALL). Current treatments for CBF leukemias are associated with significant morbidity and mortality, with a 5-y survival rate of ~50%. We hypothesize that the interaction between RUNX1 and CBFß is critical for CBF leukemia and can be targeted for drug development. We developed high-throughput AlphaScreen and time-resolved fluorescence resonance energy transfer (TR-FRET) methods to quantify the RUNX1-CBFß interaction and screen a library collection of 243,398 compounds. Ro5-3335, a benzodiazepine identified from the screen, was able to interact with RUNX1 and CBFß directly, repress RUNX1/CBFB-dependent transactivation in reporter assays, and repress runx1-dependent hematopoiesis in zebrafish embryos. Ro5-3335 preferentially killed human CBF leukemia cell lines, rescued preleukemic phenotype in a RUNX1-ETO transgenic zebrafish, and reduced leukemia burden in a mouse CBFB-MYH11 leukemia model. Our data thus confirmed that RUNX1-CBFß interaction can be targeted for leukemia treatment and we have identified a promising lead compound for this purpose.
Assuntos
Benzodiazepinas/farmacologia , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Subunidade beta de Fator de Ligação ao Core/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Leucemia Mieloide Aguda/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Ativação Transcricional/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Western Blotting , Subunidade beta de Fator de Ligação ao Core/genética , Ensaio de Desvio de Mobilidade Eletroforética , Citometria de Fluxo , Transferência Ressonante de Energia de Fluorescência/métodos , Vetores Genéticos/genética , Hematopoese/efeitos dos fármacos , Técnicas Histológicas , Humanos , Imunoprecipitação , Células Jurkat , Camundongos , Dados de Sequência Molecular , Mapeamento de Interação de Proteínas/métodos , Ressonância de Plasmônio de Superfície , Peixe-ZebraRESUMO
This report investigates the mechanisms by which mammalian cells coordinate DNA replication with transcription and chromatin assembly. In yeast, DNA replication initiates within nucleosome-free regions, but studies in mammalian cells have not revealed a similar relationship. Here, we have used genome-wide massively parallel sequencing to map replication initiation events, thereby creating a database of all replication initiation sites within nonrepetitive DNA in two human cell lines. Mining this database revealed that genomic regions transcribed at moderate levels were generally associated with high replication initiation frequency. In genomic regions with high rates of transcription, very few replication initiation events were detected. High-resolution mapping of replication initiation sites showed that replication initiation events were absent from transcription start sites but were highly enriched in adjacent, downstream sequences. Methylation of CpG sequences strongly affected the location of replication initiation events, whereas histone modifications had minimal effects. These observations suggest that high levels of transcription interfere with formation of pre-replication protein complexes. Data presented here identify replication initiation sites throughout the genome, providing a foundation for further analyses of DNA-replication dynamics and cell-cycle progression.
Assuntos
Replicação do DNA , Genoma Humano , Origem de Replicação , Transcrição Gênica , Linhagem Celular Tumoral , Cromatina/metabolismo , Ilhas de CpG , Metilação de DNA , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Células K562 , Sítio de Iniciação de TranscriçãoRESUMO
Sarcomas are a diverse group of rare malignancies composed of multiple different clinical and molecular subtypes. Due to their rarity and heterogeneity, basic, translational, and clinical research in sarcoma has trailed behind that of other cancers. Outcomes for patients remain generally poor due to an incomplete understanding of disease biology and a lack of novel therapies. To address some of the limitations impeding preclinical sarcoma research, we have developed Sarcoma_CellMinerCDB, a publicly available interactive tool that merges publicly available sarcoma cell line data and newly generated omics data to create a comprehensive database of genomic, transcriptomic, methylomic, proteomic, metabolic, and pharmacologic data on 133 annotated sarcoma cell lines. The reproducibility, functionality, biological relevance, and therapeutic applications of Sarcoma_CellMinerCDB described herein are powerful tools to address and generate biological questions and test hypotheses for translational research. Sarcoma_CellMinerCDB (https://discover.nci.nih.gov/SarcomaCellMinerCDB) aims to contribute to advancing the preclinical study of sarcoma.
RESUMO
Triple-negative breast cancer (TNBC) is clinically aggressive and relatively unresponsive to current therapies. Therefore, the development of new anticancer agents is needed to satisfy clinical needs. Oxyphenisatin acetate (Acetalax), which had been used as a laxative, has recently been reported to have anticancer activity in murine models. In this study, we demonstrate that Acetalax and its diphenolic laxative structural analogue bisacodyl (Dulcolax) exhibit potent antiproliferative activity in TNBC cell lines and cause oncosis, a nonapoptotic cell death characterized by cellular and nuclear swelling and cell membrane blebbing, leading to mitochondrial dysfunction, ATP depletion, and enhanced immune and inflammatory responses. Mechanistically, we provide evidence that transient receptor potential melastatin member 4 (TRPM4) is poisoned by Acetalax and bisacodyl in MDA-MB468, BT549, and HS578T TNBC cells. MDA-MB231 and MDA-MB436 TNBC cells without endogenous TRPM4 expression as well as TRPM4-knockout TNBC cells were found to be Acetalax- and bisacodyl-resistant. Conversely, ectopic expression of TRPM4 sensitized MDA-MB231 and MDA-MB436 cells to Acetalax. TRPM4 was also lost in cells with acquired Acetalax resistance. Moreover, TRPM4 is rapidly degraded by the ubiquitin-proteasome system upon acute exposure to Acetalax and bisacodyl. Together, these results demonstrate that TRPM4 is a previously unknown target of Acetalax and bisacodyl and that TRPM4 expression in cancer cells is a predictor of Acetalax and bisacodyl efficacy and could be used for the clinical development of these drugs as anticancer agents. SIGNIFICANCE: Acetalax and bisacodyl kill cancer cells by causing oncosis following poisoning of the plasma membrane sodium transporter TRPM4 and represent a new therapeutic approach for TNBC.
Assuntos
Canais de Cátion TRPM , Neoplasias de Mama Triplo Negativas , Canais de Cátion TRPM/genética , Canais de Cátion TRPM/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/genética , Humanos , Linhagem Celular Tumoral , Feminino , Proliferação de Células/efeitos dos fármacos , Animais , Camundongos , Antineoplásicos/farmacologiaRESUMO
Adrenocortical carcinoma (ACC) is a rare and highly heterogeneous disease with a notably poor prognosis due to significant challenges in diagnosis and treatment. Emphasising on the importance of precision medicine, there is an increasing need for comprehensive genomic resources alongside well-developed experimental models to devise personalized therapeutic strategies. We present ACC_CellMinerCDB, a substantive genomic and drug sensitivity database (available at https://discover.nci.nih.gov/acc_cellminercdb) comprising ACC cell lines, patient-derived xenografts, surgical samples, combined with responses to over 2,400 drugs examined by NCI and NCATS. This database exposes shared genomic pathways among ACC cell lines and surgical samples, thus authenticating the cell lines as research models. It also allows exploration of pertinent treatment markers such as MDR-1, SOAT1, MGMT, MMR and SLFN11, and introduces the potential to repurpose agents like temozolomide for ACC therapy. ACC_CellMinerCDB provides the foundation for exploring larger preclinical ACC models.
RESUMO
The RNA Pol II transcription complex pauses just downstream of the promoter in a significant fraction of human genes. The local features of genomic structure that contribute to pausing have not been defined. Here, we show that genes that pause are more G-rich within the region flanking the transcription start site (TSS) than RefSeq genes or non-paused genes. We show that enrichment of binding motifs for common transcription factors, such as SP1, may account for G-richness upstream but not downstream of the TSS. We further show that pausing correlates with the presence of a GrIn1 element, an element bearing one or more G4 motifs at the 5'-end of the first intron, on the non-template DNA strand. These results suggest potential roles for dynamic G4 DNA and G4 RNA structures in cis-regulation of pausing, and thus genome-wide regulation of gene expression, in human cells.
Assuntos
Guanina/análise , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Transcrição Gênica , Sítios de Ligação , Linhagem Celular Tumoral , Ilhas de CpG , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Íntrons , RNA Polimerase II/metabolismo , Fatores de Transcrição/metabolismo , Sítio de Iniciação de TranscriçãoRESUMO
Several linkage studies provided evidence for the presence of the hereditary prostate cancer locus, HPCX1, at Xq27-q28. The strongest linkage peak of prostate cancer overlies a variable region of ~750 kb at Xq27 enriched by segmental duplications (SDs), suggesting that the predisposition to prostate cancer may be a genomic disorder caused by recombinational interaction between SDs. The large size of SDs and their sequence similarity make it difficult to examine this region for possible rearrangements using standard methods. To overcome this problem, direct isolation of a set of genomic segments by in vivo recombination in yeast (a TAR cloning technique) was used to perform a mutational analysis of the 750 kb region in X-linked families. We did not detect disease-specific rearrangements within this region. In addition, transcriptome and computational analyses were performed to search for nonannotated genes within the Xq27 region, which may be associated with genetic predisposition to prostate cancer. Two candidate genes were identified, one of which is a novel gene termed SPANXL that represents a highly diverged member of the SPANX gene family, and the previously described CDR1 gene that is expressed at a high level in both normal and malignant prostate cells, and mapped 210 kb of upstream the SPANX gene cluster. No disease-specific alterations were identified in these genes. Our results exclude the 750-kb genetically unstable region at Xq27 as a candidate locus for prostate malignancy. Adjacent regions appear to be the most likely candidates to identify the elusive HPCX1 locus.
Assuntos
Cromossomos Humanos X/genética , DNA de Neoplasias/genética , Loci Gênicos , Neoplasias da Próstata/genética , Autoantígenos/genética , Mapeamento Cromossômico , Cromossomos Humanos X/química , Análise Mutacional de DNA , Família , Feminino , Ligação Genética , Predisposição Genética para Doença , Humanos , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Recombinação Genética , Saccharomyces cerevisiae/genética , Duplicações Segmentares GenômicasRESUMO
Major advances have been made in the field of precision medicine for treating cancer. However, many open questions remain that need to be answered to realize the goal of matching every patient with cancer to the most efficacious therapy. To facilitate these efforts, we have developed CellMinerCDB: National Center for Advancing Translational Sciences (NCATS; https://discover.nci.nih.gov/rsconnect/cellminercdb_ncats/), which makes available activity information for 2,675 drugs and compounds, including multiple nononcology drugs and 1,866 drugs and compounds unique to the NCATS. CellMinerCDB: NCATS comprises 183 cancer cell lines, with 72 unique to NCATS, including some from previously understudied tissues of origin. Multiple forms of data from different institutes are integrated, including single and combination drug activity, DNA copy number, methylation and mutation, transcriptome, protein levels, histone acetylation and methylation, metabolites, CRISPR, and miscellaneous signatures. Curation of cell lines and drug names enables cross-database (CDB) analyses. Comparison of the datasets is made possible by the overlap between cell lines and drugs across databases. Multiple univariate and multivariate analysis tools are built-in, including linear regression and LASSO. Examples have been presented here for the clinical topoisomerase I (TOP1) inhibitors topotecan and irinotecan/SN-38. This web application provides both substantial new data and significant pharmacogenomic integration, allowing exploration of interrelationships. SIGNIFICANCE: CellMinerCDB: NCATS provides activity information for 2,675 drugs in 183 cancer cell lines and analysis tools to facilitate pharmacogenomic research and to identify determinants of response.
Assuntos
National Center for Advancing Translational Sciences (U.S.) , Neoplasia de Células Basais , Estados Unidos , Humanos , Farmacogenética , Linhagem Celular Tumoral , Bases de Dados Factuais , Irinotecano , InternetRESUMO
Nuclear factor (NF)-YB, a subunit of the transcription factor nuclear factor Y (NF-Y) complex, binds and activates CCAAT-containing promoters. Our previous work suggested that NF-YB may be a mediator of topoisomerase IIα (Top2α), working through the Top2α promoter. DNA topoisomerase II (Top2) is an essential nuclear enzyme and the primary target for several clinically important anticancer drugs. Our teniposide-resistant human lymphoblastic leukemia CEM cells (CEM/VM-1-5) express reduced Top2α protein compared with parental CEM cells. To study the regulation of Top2α during the development of drug resistance, we found that NF-YB protein expression is increased in CEM/VM-1-5 cells compared with parental CEM cells. This further suggests that increased NF-YB may be a negative regulator of Top2α in CEM/VM-1-5 cells. We asked what causes the up-regulation of NF-YB in CEM/VM-1-5 cells. We found by microRNA profiling that hsa-miR-485-3p is lower in CEM/VM-1-5 cells compared with CEM cells. MicroRNA target prediction programs revealed that the 3'-untranslated region (3'-UTR) of NF-YB harbors a putative hsa-miR-485-3p binding site. We thus hypothesized that hsa-miR-485-3p mediates drug responsiveness by decreasing NF-YB expression, which in turn negatively regulates Top2α expression. To test this, we overexpressed miR-485-3p in CEM/VM-1-5 cells and found that this led to reduced expression of NF-YB, a corresponding up-regulation of Top2α, and increased sensitivity to the Top2 inhibitors. Results in CEM cells were replicated in drug-sensitive and -resistant human rhabdomyosarcoma Rh30 cells, suggesting that our findings represent a general phenomenon. Ours is the first study to show that miR-485-3p mediates Top2α down-regulation in part by altered regulation of NF-YB.
Assuntos
Antígenos de Neoplasias/biossíntese , Fator de Ligação a CCAAT/metabolismo , DNA Topoisomerases Tipo II/biossíntese , Proteínas de Ligação a DNA/biossíntese , Etoposídeo/toxicidade , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , MicroRNAs/fisiologia , Antígenos de Neoplasias/genética , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Regulação Enzimológica da Expressão Gênica/fisiologia , Humanos , Proteínas de Ligação a Poli-ADP-Ribose , Teniposídeo/toxicidade , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND: Altered DNA methylation patterns play important roles in cancer development and progression. We examined whether expression levels of genes directly or indirectly involved in DNA methylation and demethylation may be associated with response of cancer cell lines to chemotherapy treatment with a variety of antitumor agents. RESULTS: We analyzed 72 genes encoding epigenetic factors directly or indirectly involved in DNA methylation and demethylation processes. We examined association of their pretreatment expression levels with methylation beta-values of individual DNA methylation probes, DNA methylation averaged within gene regions, and average epigenome-wide methylation levels. We analyzed data from 645 cancer cell lines and 23 cancer types from the Cancer Cell Line Encyclopedia and Genomics of Drug Sensitivity in Cancer datasets. We observed numerous correlations between expression of genes encoding epigenetic factors and response to chemotherapeutic agents. Expression of genes encoding a variety of epigenetic factors, including KDM2B, DNMT1, EHMT2, SETDB1, EZH2, APOBEC3G, and other genes, was correlated with response to multiple agents. DNA methylation of numerous target probes and gene regions was associated with expression of multiple genes encoding epigenetic factors, underscoring complex regulation of epigenome methylation by multiple intersecting molecular pathways. The genes whose expression was associated with methylation of multiple epigenome targets encode DNA methyltransferases, TET DNA methylcytosine dioxygenases, the methylated DNA-binding protein ZBTB38, KDM2B, SETDB1, and other molecular factors which are involved in diverse epigenetic processes affecting DNA methylation. While baseline DNA methylation of numerous epigenome targets was correlated with cell line response to antitumor agents, the complex relationships between the overlapping effects of each epigenetic factor on methylation of specific targets and the importance of such influences in tumor response to individual agents require further investigation. CONCLUSIONS: Expression of multiple genes encoding epigenetic factors is associated with drug response and with DNA methylation of numerous epigenome targets that may affect response to therapeutic agents. Our findings suggest complex and interconnected pathways regulating DNA methylation in the epigenome, which may both directly and indirectly affect response to chemotherapy.
Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Farmacológicos/metabolismo , Linhagem Celular/metabolismo , Neoplasias/genética , Desaminase APOBEC-3G , Linhagem Celular/efeitos dos fármacos , DNA (Citosina-5-)-Metiltransferase 1 , Metilação de DNA , Proteínas de Ligação a DNA/genética , Dioxigenases/genética , Proteína Potenciadora do Homólogo 2 de Zeste , Epigenoma , Epigenômica , Proteínas F-Box , Regulação Neoplásica da Expressão Gênica/genética , Antígenos de Histocompatibilidade , Histona-Lisina N-Metiltransferase , Humanos , Histona Desmetilases com o Domínio Jumonji , Neoplasias/tratamento farmacológico , Regiões Promotoras Genéticas , Proteínas RepressorasRESUMO
Histone deacetylase inhibitors (HDACi) induce hyperacetylation of histones by blocking HDAC catalytic sites. Despite regulatory approvals in hematological malignancies, limited solid tumor clinical activity has constrained their potential, arguing for better understanding of mechanisms of action (MOA). Multiple activities of HDACis have been demonstrated, dependent on cell context, beyond the canonical induction of gene expression. Here, using a clinically relevant exposure duration, we established DNA damage as the dominant signature using the NCI-60 cell line database and then focused on the mechanism by which hyperacetylation induces DNA damage. We identified accumulation of DNA-RNA hybrids (R-loops) following romidepsin-induced histone hyperacetylation, with single-stranded DNA (ssDNA) breaks detected by single-cell electrophoresis. Our data suggest that transcription-coupled base excision repair (BER) is involved in resolving ssDNA breaks that, when overwhelmed, evolve to lethal dsDNA breaks. We show that inhibition of BER proteins such as PARP will increase dsDNA breaks in this context. These studies establish accumulation of R-loops as a consequence of romidepsin-mediated histone hyperacetylation. We believe that the insights provided will inform design of more effective combination therapy with HDACis for treatment of solid tumors. IMPLICATIONS: Key HDAC inhibitor mechanisms of action remain unknown; we identify accumulation of DNA-RNA hybrids (R-loops) due to chromatin hyperacetylation that provokes single-stranded DNA damage as a first step toward cell death.
Assuntos
DNA de Cadeia Simples/efeitos dos fármacos , Depsipeptídeos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Estruturas R-Loop/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , DNA de Cadeia Simples/genética , Humanos , Células PC-3 , Estruturas R-Loop/genéticaRESUMO
The National Cancer Institute's NCI-60 cell line panel, the most extensively characterized set of cells in existence and a public resource, is frequently used as a screening tool for drug discovery. Because many laboratories around the world rely on data from the NCI-60 cells, confirmation of their genetic identities represents an essential step in validating results from them. Given the consequences of cell line contamination or misidentification, quality control measures should routinely include DNA fingerprinting. We have, therefore, used standard DNA microsatellite short tandem repeats to profile the NCI-60, and the resulting DNA fingerprints are provided here as a reference. Consistent with previous reports, the fingerprints suggest that several NCI-60 lines have common origins: the melanoma lines MDA-MB-435, MDA-N, and M14; the central nervous system lines U251 and SNB-19; the ovarian lines OVCAR-8 and OVCAR-8/ADR (also called NCI/ADR); and the prostate lines DU-145, DU-145 (ATCC), and RC0.1. Those lines also show that the ability to connect two fingerprints to the same origin is not affected by stable transfection or by the development of multidrug resistance. As expected, DNA fingerprints were not able to distinguish different tissues-of-origin. The fingerprints serve principally as a barcodes.
Assuntos
Impressões Digitais de DNA , DNA de Neoplasias/análise , Neoplasias/genética , Linhagem Celular Tumoral , DNA de Neoplasias/genética , Humanos , Repetições de Microssatélites , National Cancer Institute (U.S.) , Neoplasias/classificação , Reação em Cadeia da Polimerase , Estados UnidosRESUMO
Importance: It is not well understood whether prognostic factors in breast cancer are affected by specific treatment and vary by clinical outcome type compared with untreated patients. Objective: To identify independent clinical and molecular measurements associated with overall survival (OS) and recurrence-free survival (RFS) by homogeneous treatment in women with breast cancer. Design, Setting, and Participants: This prognostic study included 956 patients diagnosed with invasive breast cancer from hospital centers across 4 geographical regions of the United States who participated in the accreditation program of the Commission on Cancer of the American College of Surgeons from 1985 to 1997. The duration of follow-up ranged from 1 to 282 months. The study analysis was conducted from June 10, 2019, to March 18, 2020. Main Outcomes and Measures: Analysis of OS and RFS in patients who underwent chemotherapy, radiotherapy, or endocrine therapy alone compared with no systemic or locoregional therapy. Cox proportional hazards regression models were used to estimate independent performance and 95% CI of age, tumor size, number of positive nodes (nodal status), tumor grades 2 and 3, p53 status, estrogen receptor (ER) status, and ERBB2 (formerly HER2) status. Results: Among 956 participants, median age was 61 (range, 25-96) years. Age (adjusted hazard ratio [AHR], 2.24; 95% CI, 1.27-3.94; P = .01) and high grade (AHR, 2.05; 95% CI, 1.09-3.86; P = .02), in addition to nodal status and tumor size, were independently associated with OS and RFS, respectively, in untreated patients. p53 status (AHR, 2.11; 95% CI, 1.07-4.18; P = .03) and ER status (AHR, 0.46; 95% CI, 0.23-0.92; P = .03) were associated with higher and lower risks of death, respectively, whereas nodal status (AHR, 1.13; 95% CI, 1.06-1.20; P < .005), high grade (AHR, 4.01; 95% CI, 1.51-10.70; P = .01), and ERBB2 positivity (AHR, 2.67; 95% CI, 1.25-5.70; P = .01) were associated with the risk of recurrence after endocrine therapy. Tumor size (AHR for OS, 2.76 [95% CI, 1.79-4.31; P < .005]; AHR for RFS, 2.27 [95% CI, 1.23-4.18; P = .01]) and ERBB2 status (AHR for OS, 5.35 [95% CI, 1.31-21.98; P = .02]; AHR for RFS, 6.05 [95% CI, 1.48-24.78; P = .01]) were independently associated with radiotherapy outcomes, and nodal status was significantly associated with chemotherapy outcomes (AHR for OS, 1.06 [95% CI, 1.02-1.09; P < .005]; AHR for RFS, 1.05 [95% CI, 1.01-1.09; P = .01]). Conclusions and Relevance: In this study, independent prognostic factors were associated with specific treatment and weighted by the outcome category with reference to untreated patients within biological and clinical contexts.