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1.
J Control Release ; 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38908756

ABSTRACT

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate of their parental fibroblasts, and TRAIL produced by iNSCs was naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed that Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays demonstrated that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts by approximately 3000-fold compared to treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a novel, easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

2.
bioRxiv ; 2024 May 29.
Article in English | MEDLINE | ID: mdl-38854085

ABSTRACT

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate as their parental fibroblasts, and the TRAIL produced by iNSCs were naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays showed that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts around 3000-fold greater than treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a new easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

3.
Nature ; 623(7987): 633-642, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37938770

ABSTRACT

Trimethylation of histone H3 lysine 9 (H3K9me3) is crucial for the regulation of gene repression and heterochromatin formation, cell-fate determination and organismal development1. H3K9me3 also provides an essential mechanism for silencing transposable elements1-4. However, previous studies have shown that canonical H3K9me3 readers (for example, HP1 (refs. 5-9) and MPP8 (refs. 10-12)) have limited roles in silencing endogenous retroviruses (ERVs), one of the main transposable element classes in the mammalian genome13. Here we report that trinucleotide-repeat-containing 18 (TNRC18), a poorly understood chromatin regulator, recognizes H3K9me3 to mediate the silencing of ERV class I (ERV1) elements such as LTR12 (ref. 14). Biochemical, biophysical and structural studies identified the carboxy-terminal bromo-adjacent homology (BAH) domain of TNRC18 (TNRC18(BAH)) as an H3K9me3-specific reader. Moreover, the amino-terminal segment of TNRC18 is a platform for the direct recruitment of co-repressors such as HDAC-Sin3-NCoR complexes, thus enforcing optimal repression of the H3K9me3-demarcated ERVs. Point mutagenesis that disrupts the TNRC18(BAH)-mediated H3K9me3 engagement caused neonatal death in mice and, in multiple mammalian cell models, led to derepressed expression of ERVs, which affected the landscape of cis-regulatory elements and, therefore, gene-expression programmes. Collectively, we describe a new H3K9me3-sensing and regulatory pathway that operates to epigenetically silence evolutionarily young ERVs and exert substantial effects on host genome integrity, transcriptomic regulation, immunity and development.


Subject(s)
Endogenous Retroviruses , Gene Silencing , Histones , Intracellular Signaling Peptides and Proteins , Lysine , Retroelements , Animals , Humans , Mice , Chromatin/genetics , Chromatin/metabolism , Co-Repressor Proteins/metabolism , Endogenous Retroviruses/genetics , Epigenesis, Genetic , Gene Expression Profiling , Genome/genetics , Histone Deacetylases/metabolism , Histones/metabolism , Intracellular Signaling Peptides and Proteins/chemistry , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Lysine/metabolism , Methylation , Protein Domains , Retroelements/genetics , Terminal Repeat Sequences/genetics , Animals, Newborn , Cell Line
4.
Cell Rep Med ; 4(6): 101042, 2023 06 20.
Article in English | MEDLINE | ID: mdl-37192626

ABSTRACT

Functional precision medicine platforms are emerging as promising strategies to improve pre-clinical drug testing and guide clinical decisions. We have developed an organotypic brain slice culture (OBSC)-based platform and multi-parametric algorithm that enable rapid engraftment, treatment, and analysis of uncultured patient brain tumor tissue and patient-derived cell lines. The platform has supported engraftment of every patient tumor tested to this point: high- and low-grade adult and pediatric tumor tissue rapidly establishes on OBSCs among endogenous astrocytes and microglia while maintaining the tumor's original DNA profile. Our algorithm calculates dose-response relationships of both tumor kill and OBSC toxicity, generating summarized drug sensitivity scores on the basis of therapeutic window and allowing us to normalize response profiles across a panel of U.S. Food and Drug Administration (FDA)-approved and exploratory agents. Summarized patient tumor scores after OBSC treatment show positive associations to clinical outcomes, suggesting that the OBSC platform can provide rapid, accurate, functional testing to ultimately guide patient care.


Subject(s)
Brain Neoplasms , Humans , Child , Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Brain Neoplasms/therapy , Brain
5.
J Virol ; 96(17): e0095722, 2022 09 14.
Article in English | MEDLINE | ID: mdl-35975998

ABSTRACT

HIV-1 infection within the central nervous system (CNS) includes evolution of the virus, damaging inflammatory cascades, and the involvement of multiple cell types; however, our understanding of how Env tropism and inflammation can influence CNS infectivity is incomplete. In this study, we utilize macrophage-tropic and T cell-tropic HIV-1 Env proteins to establish accurate infection profiles for multiple CNS cells under basal and interferon alpha (IFN-α) or lipopolysaccharide (LPS)-induced inflammatory states. We found that macrophage-tropic viruses confer entry advantages in primary myeloid cells, including monocyte-derived macrophage, microglia, and induced pluripotent stem cell (iPSC)-derived microglia. However, neither macrophage-tropic or T cell-tropic HIV-1 Env proteins could mediate infection of astrocytes or neurons, and infection was not potentiated by induction of an inflammatory state in these cells. Additionally, we found that IFN-α and LPS restricted replication in myeloid cells, and IFN-α treatment prior to infection with vesicular stomatitis virus G protein (VSV G) Envs resulted in a conserved antiviral response across all CNS cell types. Further, using RNA sequencing (RNA-seq), we found that only myeloid cells express HIV-1 entry receptor/coreceptor transcripts at a significant level and that these transcripts in select cell types responded only modestly to inflammatory signals. We profiled the transcriptional response of multiple CNS cells to inflammation and found 57 IFN-induced genes that were differentially expressed across all cell types. Taken together, these data focus attention on the cells in the CNS that are truly permissive to HIV-1, further highlight the role of HIV-1 Env evolution in mediating infection in the CNS, and point to limitations in using model cell types versus primary cells to explore features of virus-host interaction. IMPORTANCE The major feature of HIV-1 pathogenesis is the induction of an immunodeficient state in the face of an enhanced state of inflammation. However, for many of those infected, there can be an impact on the central nervous system (CNS) resulting in a wide range of neurocognitive defects. Here, we use a highly sensitive and quantitative assay for viral infectivity to explore primary and model cell types of the brain for their susceptibility to infection using viral entry proteins derived from the CNS. In addition, we examine the ability of an inflammatory state to alter infectivity of these cells. We find that myeloid cells are the only cell types in the CNS that can be infected and that induction of an inflammatory state negatively impacts viral infection across all cell types.


Subject(s)
Central Nervous System , HIV Infections , HIV-1 , Inflammation , Macrophages , Central Nervous System/immunology , Central Nervous System/pathology , Central Nervous System/virology , HIV Infections/complications , HIV Infections/immunology , HIV Infections/pathology , HIV Infections/virology , HIV-1/physiology , Humans , Induced Pluripotent Stem Cells/cytology , Inflammation/complications , Inflammation/immunology , Inflammation/pathology , Inflammation/virology , Interferon-alpha/immunology , Lipopolysaccharides/immunology , Macrophages/cytology , Macrophages/virology , Membrane Glycoproteins/metabolism , Microglia/cytology , Microglia/virology , RNA-Seq , Receptors, HIV/metabolism , Viral Envelope Proteins/metabolism , Virus Internalization , env Gene Products, Human Immunodeficiency Virus/metabolism
6.
J Clin Invest ; 132(4)2022 02 15.
Article in English | MEDLINE | ID: mdl-34990404

ABSTRACT

BACKGROUNDThe KRAS proto-oncogene is among the most frequently mutated genes in cancer, yet for 40 years it remained an elusive therapeutic target. Recently, allosteric inhibitors that covalently bind to KRAS G12C mutations have been approved for use in lung adenocarcinomas. Although responses are observed, they are often short-lived, thus making in-depth characterization of the mechanisms of resistance of paramount importance.METHODSHere, we present a rapid-autopsy case of a patient who had a KRASG12C-mutant lung adenocarcinoma who initially responded to a KRAS G12C inhibitor but then rapidly developed resistance. Using deep-RNA and whole-exome sequencing comparing pretreatment, posttreatment, and matched normal tissues, we uncover numerous mechanisms of resistance to direct KRAS inhibition.RESULTSIn addition to decreased KRAS G12C-mutant allele frequency in refractory tumors, we also found reactivation of the MAPK pathway despite no new mutations in KRAS or its downstream mediators. Tumor cell-intrinsic and non-cell autonomous mechanisms included increased complement activation, coagulation, and tumor angiogenesis, and several lines of evidence of immunologic evasion.CONCLUSIONTogether, our findings reveal numerous mechanisms of resistance to current KRAS G12C inhibitors through enrichment of clonal populations, KRAS-independent downstream signaling, and diverse remodeling of the tumor microenvironment.FUNDINGRichard and Fran Duley, Jimmy and Kay Mann, the NIH, and the North Carolina Biotechnology Center.


Subject(s)
Adenocarcinoma of Lung , Drug Resistance, Neoplasm/genetics , Lung Neoplasms , Mutation, Missense , Proto-Oncogene Proteins p21(ras) , Signal Transduction/genetics , Tumor Microenvironment/genetics , Adenocarcinoma of Lung/enzymology , Adenocarcinoma of Lung/genetics , Amino Acid Substitution , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism
7.
Hum Genomics ; 15(1): 34, 2021 06 07.
Article in English | MEDLINE | ID: mdl-34099068

ABSTRACT

BACKGROUND: Mitochondrial genome copy number (MT-CN) varies among humans and across tissues and is highly heritable, but its causes and consequences are not well understood. When measured by bulk DNA sequencing in blood, MT-CN may reflect a combination of the number of mitochondria per cell and cell-type composition. Here, we studied MT-CN variation in blood-derived DNA from 19184 Finnish individuals using a combination of genome (N = 4163) and exome sequencing (N = 19034) data as well as imputed genotypes (N = 17718). RESULTS: We identified two loci significantly associated with MT-CN variation: a common variant at the MYB-HBS1L locus (P = 1.6 × 10-8), which has previously been associated with numerous hematological parameters; and a burden of rare variants in the TMBIM1 gene (P = 3.0 × 10-8), which has been reported to protect against non-alcoholic fatty liver disease. We also found that MT-CN is strongly associated with insulin levels (P = 2.0 × 10-21) and other metabolic syndrome (metS)-related traits. Using a Mendelian randomization framework, we show evidence that MT-CN measured in blood is causally related to insulin levels. We then applied an MT-CN polygenic risk score (PRS) derived from Finnish data to the UK Biobank, where the association between the PRS and metS traits was replicated. Adjusting for cell counts largely eliminated these signals, suggesting that MT-CN affects metS via cell-type composition. CONCLUSION: These results suggest that measurements of MT-CN in blood-derived DNA partially reflect differences in cell-type composition and that these differences are causally linked to insulin and related traits.


Subject(s)
Apoptosis Regulatory Proteins/genetics , DNA Copy Number Variations/genetics , DNA, Mitochondrial/blood , GTP-Binding Proteins/genetics , Membrane Proteins/genetics , Proto-Oncogene Proteins c-myb/genetics , Adult , Aged , Cell Lineage/genetics , DNA, Mitochondrial/genetics , Female , Genetic Predisposition to Disease , Genome, Mitochondrial/genetics , Genome-Wide Association Study , Humans , Male , Mendelian Randomization Analysis , Middle Aged , Phenotype , Polymorphism, Single Nucleotide/genetics , Sequence Analysis, DNA , Exome Sequencing
8.
Am J Hum Genet ; 108(4): 583-596, 2021 04 01.
Article in English | MEDLINE | ID: mdl-33798444

ABSTRACT

The contribution of genome structural variation (SV) to quantitative traits associated with cardiometabolic diseases remains largely unknown. Here, we present the results of a study examining genetic association between SVs and cardiometabolic traits in the Finnish population. We used sensitive methods to identify and genotype 129,166 high-confidence SVs from deep whole-genome sequencing (WGS) data of 4,848 individuals. We tested the 64,572 common and low-frequency SVs for association with 116 quantitative traits and tested candidate associations using exome sequencing and array genotype data from an additional 15,205 individuals. We discovered 31 genome-wide significant associations at 15 loci, including 2 loci at which SVs have strong phenotypic effects: (1) a deletion of the ALB promoter that is greatly enriched in the Finnish population and causes decreased serum albumin level in carriers (p = 1.47 × 10-54) and is also associated with increased levels of total cholesterol (p = 1.22 × 10-28) and 14 additional cholesterol-related traits, and (2) a multi-allelic copy number variant (CNV) at PDPR that is strongly associated with pyruvate (p = 4.81 × 10-21) and alanine (p = 6.14 × 10-12) levels and resides within a structurally complex genomic region that has accumulated many rearrangements over evolutionary time. We also confirmed six previously reported associations, including five led by stronger signals in single nucleotide variants (SNVs) and one linking recurrent HP gene deletion and cholesterol levels (p = 6.24 × 10-10), which was also found to be strongly associated with increased glycoprotein level (p = 3.53 × 10-35). Our study confirms that integrating SVs in trait-mapping studies will expand our knowledge of genetic factors underlying disease risk.


Subject(s)
Cardiovascular Diseases/genetics , Genomic Structural Variation/genetics , Alleles , Cholesterol/blood , DNA Copy Number Variations/genetics , Female , Finland , Genome, Human/genetics , Genotype , High-Throughput Nucleotide Sequencing , Humans , Male , Mitochondrial Proteins/genetics , Promoter Regions, Genetic/genetics , Pyruvate Dehydrogenase (Lipoamide)-Phosphatase/genetics , Pyruvic Acid/metabolism , Serum Albumin, Human/genetics
9.
Nature ; 583(7814): 83-89, 2020 07.
Article in English | MEDLINE | ID: mdl-32460305

ABSTRACT

A key goal of whole-genome sequencing for studies of human genetics is to interrogate all forms of variation, including single-nucleotide variants, small insertion or deletion (indel) variants and structural variants. However, tools and resources for the study of structural variants have lagged behind those for smaller variants. Here we used a scalable pipeline1 to map and characterize structural variants in 17,795 deeply sequenced human genomes. We publicly release site-frequency data to create the largest, to our knowledge, whole-genome-sequencing-based structural variant resource so far. On average, individuals carry 2.9 rare structural variants that alter coding regions; these variants affect the dosage or structure of 4.2 genes and account for 4.0-11.2% of rare high-impact coding alleles. Using a computational model, we estimate that structural variants account for 17.2% of rare alleles genome-wide, with predicted deleterious effects that are equivalent to loss-of-function coding alleles; approximately 90% of such structural variants are noncoding deletions (mean 19.1 per genome). We report 158,991 ultra-rare structural variants and show that 2% of individuals carry ultra-rare megabase-scale structural variants, nearly half of which are balanced or complex rearrangements. Finally, we infer the dosage sensitivity of genes and noncoding elements, and reveal trends that relate to element class and conservation. This work will help to guide the analysis and interpretation of structural variants in the era of whole-genome sequencing.


Subject(s)
Genetic Variation , Genome, Human/genetics , Whole Genome Sequencing , Alleles , Case-Control Studies , Epigenesis, Genetic , Female , Gene Dosage/genetics , Genetics, Population , High-Throughput Nucleotide Sequencing , Humans , Male , Molecular Sequence Annotation , Quantitative Trait Loci , Racial Groups/genetics , Software
11.
Nature ; 572(7769): 323-328, 2019 08.
Article in English | MEDLINE | ID: mdl-31367044

ABSTRACT

Exome-sequencing studies have generally been underpowered to identify deleterious alleles with a large effect on complex traits as such alleles are mostly rare. Because the population of northern and eastern Finland has expanded considerably and in isolation following a series of bottlenecks, individuals of these populations have numerous deleterious alleles at a relatively high frequency. Here, using exome sequencing of nearly 20,000 individuals from these regions, we investigate the role of rare coding variants in clinically relevant quantitative cardiometabolic traits. Exome-wide association studies for 64 quantitative traits identified 26 newly associated deleterious alleles. Of these 26 alleles, 19 are either unique to or more than 20 times more frequent in Finnish individuals than in other Europeans and show geographical clustering comparable to Mendelian disease mutations that are characteristic of the Finnish population. We estimate that sequencing studies of populations without this unique history would require hundreds of thousands to millions of participants to achieve comparable association power.


Subject(s)
Exome Sequencing , Genetic Association Studies/methods , Genetic Predisposition to Disease/genetics , Genetic Variation/genetics , Quantitative Trait Loci/genetics , Alleles , Cholesterol, HDL/genetics , Cluster Analysis , Endpoint Determination , Finland , Geographic Mapping , Humans , Multifactorial Inheritance/genetics , Reproducibility of Results
13.
PLoS Med ; 13(12): e1002174, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27923045

ABSTRACT

BACKGROUND: Metastasis is the main cause of cancer patient deaths and remains a poorly characterized process. It is still unclear when in tumor progression the ability to metastasize arises and whether this ability is inherent to the primary tumor or is acquired well after primary tumor formation. Next-generation sequencing and analytical methods to define clonal heterogeneity provide a means for identifying genetic events and the temporal relationships between these events in the primary and metastatic tumors within an individual. METHODS AND FINDINGS: We performed DNA whole genome and mRNA sequencing on two primary tumors, each with either four or five distinct tissue site-specific metastases, from two individuals with triple-negative/basal-like breast cancers. As evidenced by their case histories, each patient had an aggressive disease course with abbreviated survival. In each patient, the overall gene expression signatures, DNA copy number patterns, and somatic mutation patterns were highly similar across each primary tumor and its associated metastases. Almost every mutation found in the primary was found in a metastasis (for the two patients, 52/54 and 75/75). Many of these mutations were found in every tumor (11/54 and 65/75, respectively). In addition, each metastasis had fewer metastatic-specific events and shared at least 50% of its somatic mutation repertoire with the primary tumor, and all samples from each patient grouped together by gene expression clustering analysis. TP53 was the only mutated gene in common between both patients and was present in every tumor in this study. Strikingly, each metastasis resulted from multiclonal seeding instead of from a single cell of origin, and few of the new mutations, present only in the metastases, were expressed in mRNAs. Because of the clinical differences between these two patients and the small sample size of our study, the generalizability of these findings will need to be further examined in larger cohorts of patients. CONCLUSIONS: Our findings suggest that multiclonal seeding may be common amongst basal-like breast cancers. In these two patients, mutations and DNA copy number changes in the primary tumors appear to have had a biologic impact on metastatic potential, whereas mutations arising in the metastases were much more likely to be passengers.


Subject(s)
Breast Neoplasms/genetics , Disease Progression , Neoplasms, Basal Cell/genetics , Aged , Breast Neoplasms/secondary , Female , Genomics , Humans , Middle Aged , Mutation , Neoplasms, Basal Cell/secondary , Retrospective Studies
14.
Cell Rep ; 17(1): 249-260, 2016 09 27.
Article in English | MEDLINE | ID: mdl-27681435

ABSTRACT

Estrogen receptor alpha-positive (ERα+) luminal tumors are the most frequent subtype of breast cancer. Stat1(-/-) mice develop mammary tumors that closely recapitulate the biological characteristics of this cancer subtype. To identify transforming events that contribute to tumorigenesis, we performed whole genome sequencing of Stat1(-/-) primary mammary tumors and matched normal tissues. This investigation identified somatic truncating mutations affecting the prolactin receptor (PRLR) in all tumor and no normal samples. Targeted sequencing confirmed the presence of these mutations in precancerous lesions, indicating that this is an early event in tumorigenesis. Functional evaluation of these heterozygous mutations in Stat1(-/-) mouse embryonic fibroblasts showed that co-expression of truncated and wild-type PRLR led to aberrant STAT3 and STAT5 activation downstream of the receptor, cellular transformation in vitro, and tumor formation in vivo. In conclusion, truncating mutations of PRLR promote tumor growth in a model of human ERα+ breast cancer and warrant further investigation.


Subject(s)
Carcinoma/genetics , Estrogen Receptor alpha/genetics , Gene Expression Regulation, Neoplastic , Mammary Neoplasms, Animal/genetics , Mutation , Receptors, Prolactin/genetics , Animals , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carcinoma/metabolism , Carcinoma/pathology , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Cell Transformation, Neoplastic/pathology , Embryo, Mammalian , Estrogen Receptor alpha/metabolism , Female , Fibroblasts/cytology , Fibroblasts/metabolism , Humans , Mammary Neoplasms, Animal/metabolism , Mammary Neoplasms, Animal/pathology , Mice , Mice, Knockout , Receptors, Prolactin/metabolism , STAT1 Transcription Factor/deficiency , STAT1 Transcription Factor/genetics , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , STAT5 Transcription Factor/genetics , STAT5 Transcription Factor/metabolism , Signal Transduction
15.
Cancer Epidemiol Biomarkers Prev ; 25(11): 1456-1463, 2016 11.
Article in English | MEDLINE | ID: mdl-27486019

ABSTRACT

BACKGROUND: Common variants have been associated with prostate cancer risk. Unfortunately, few are reproducibly linked to aggressive disease, the phenotype of greatest clinical relevance. One possible explanation is that rare genetic variants underlie a significant proportion of the risk for aggressive disease. METHOD: To identify such variants, we performed a two-stage approach using whole-exome sequencing followed by targeted sequencing of 800 genes in 652 aggressive prostate cancer patients and 752 disease-free controls in both African and European Americans. In each population, we tested rare variants for association using two gene-based aggregation tests. We established a study-wide significance threshold of 3.125 × 10-5 to correct for multiple testing. RESULTS: TET2 in African Americans was associated with aggressive disease, with 24.4% of cases harboring a rare deleterious variant compared with 9.6% of controls (FET P = 1.84 × 10-5, OR = 3.0; SKAT-O P = 2.74 × 10-5). We report 8 additional genes with suggestive evidence of association, including the DNA repair genes PARP2 and MSH6 Finally, we observed an excess of rare truncation variants in 5 genes, including the DNA repair genes MSH6, BRCA1, and BRCA2 This adds to the growing body of evidence that DNA repair pathway defects may influence susceptibility to aggressive prostate cancer. CONCLUSIONS: Our findings suggest that rare variants influence risk of clinically relevant prostate cancer and, if validated, could serve to identify men for screening, prophylaxis, and treatment. IMPACT: This study provides evidence that rare variants in TET2 may help identify African American men at increased risk for clinically relevant prostate cancer. Cancer Epidemiol Biomarkers Prev; 25(11); 1456-63. ©2016 AACR.


Subject(s)
DNA-Binding Proteins/genetics , Genetic Predisposition to Disease , Polymorphism, Genetic , Prostatic Neoplasms/metabolism , Proto-Oncogene Proteins/genetics , Black or African American/genetics , Aged , BRCA1 Protein/genetics , BRCA2 Protein/genetics , DNA Mutational Analysis , DNA Repair , Dioxygenases , Humans , Male , Poly(ADP-ribose) Polymerases/genetics , Prostatic Neoplasms/genetics , White People/genetics
16.
Dis Model Mech ; 9(7): 749-57, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27149990

ABSTRACT

Targeted therapies against basal-like breast tumors, which are typically 'triple-negative breast cancers (TNBCs)', remain an important unmet clinical need. Somatic TP53 mutations are the most common genetic event in basal-like breast tumors and TNBC. To identify additional drivers and possible drug targets of this subtype, a comparative study between human and murine tumors was performed by utilizing a murine Trp53-null mammary transplant tumor model. We show that two subsets of murine Trp53-null mammary transplant tumors resemble aspects of the human basal-like subtype. DNA-microarray, whole-genome and exome-based sequencing approaches were used to interrogate the secondary genetic aberrations of these tumors, which were then compared to human basal-like tumors to identify conserved somatic genetic features. DNA copy-number variation produced the largest number of conserved candidate personalized drug targets. These candidates were filtered using a DNA-RNA Pearson correlation cut-off and a requirement that the gene was deemed essential in at least 5% of human breast cancer cell lines from an RNA-mediated interference screen database. Five potential personalized drug target genes, which were spontaneously amplified loci in both murine and human basal-like tumors, were identified: Cul4a, Lamp1, Met, Pnpla6 and Tubgcp3 As a proof of concept, inhibition of Met using crizotinib caused Met-amplified murine tumors to initially undergo complete regression. This study identifies Met as a promising drug target in a subset of murine Trp53-null tumors, thus identifying a potential shared driver with a subset of human basal-like breast cancers. Our results also highlight the importance of comparative genomic studies for discovering personalized drug targets and for providing a preclinical model for further investigations of key tumor signaling pathways.


Subject(s)
Gene Expression Profiling , Mammary Neoplasms, Animal/drug therapy , Mammary Neoplasms, Animal/genetics , Molecular Targeted Therapy , Precision Medicine , Tumor Suppressor Protein p53/deficiency , Animals , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Chromosomes, Mammalian/genetics , Crizotinib , DNA Copy Number Variations/genetics , Female , Humans , Mammary Neoplasms, Animal/pathology , Mice, Inbred BALB C , Pyrazoles/pharmacology , Pyrazoles/therapeutic use , Pyridines/pharmacology , Pyridines/therapeutic use , Tumor Suppressor Protein p53/metabolism
17.
Oncotarget ; 7(17): 23885-96, 2016 Apr 26.
Article in English | MEDLINE | ID: mdl-26993606

ABSTRACT

Inactivation of Ras GTPase activating proteins (RasGAPs) can activate Ras, increasing the risk for tumor development. Utilizing a melanoma whole genome sequencing (WGS) data from 13 patients, we identified two novel, clustered somatic missense mutations (Y472H and L481F) in RASA1 (RAS p21 protein activator 1, also called p120RasGAP). We have shown that wild type RASA1, but not identified mutants, suppresses soft agar colony formation and tumor growth of BRAF mutated melanoma cell lines via its RasGAP activity toward R-Ras (related RAS viral (r-ras) oncogene homolog) isoform. Moreover, R-Ras increased and RASA1 suppressed Ral-A activation among Ras downstream effectors. In addition to mutations, loss of RASA1 expression was frequently observed in metastatic melanoma samples on melanoma tissue microarray (TMA) and a low level of RASA1 mRNA expression was associated with decreased overall survival in melanoma patients with BRAF mutations. Thus, these data support that RASA1 is inactivated by mutation or by suppressed expression in melanoma and that RASA1 plays a tumor suppressive role by inhibiting R-Ras, a previously less appreciated member of the Ras small GTPases.


Subject(s)
Biomarkers, Tumor/metabolism , Cell Transformation, Neoplastic/pathology , Melanoma/pathology , Mutation , p120 GTPase Activating Protein/metabolism , ras Proteins/metabolism , Amino Acid Sequence , Animals , Apoptosis , Biomarkers, Tumor/genetics , Cell Proliferation , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Follow-Up Studies , Humans , Melanoma/genetics , Melanoma/metabolism , Mice , Mice, Nude , Prognosis , Retrospective Studies , Signal Transduction , Survival Rate , Tumor Cells, Cultured , Xenograft Model Antitumor Assays , p120 GTPase Activating Protein/antagonists & inhibitors , p120 GTPase Activating Protein/genetics , ras Proteins/genetics
18.
Nat Commun ; 6: 10086, 2015 Dec 22.
Article in English | MEDLINE | ID: mdl-26689913

ABSTRACT

Large-scale cancer sequencing data enable discovery of rare germline cancer susceptibility variants. Here we systematically analyse 4,034 cases from The Cancer Genome Atlas cancer cases representing 12 cancer types. We find that the frequency of rare germline truncations in 114 cancer-susceptibility-associated genes varies widely, from 4% (acute myeloid leukaemia (AML)) to 19% (ovarian cancer), with a notably high frequency of 11% in stomach cancer. Burden testing identifies 13 cancer genes with significant enrichment of rare truncations, some associated with specific cancers (for example, RAD51C, PALB2 and MSH6 in AML, stomach and endometrial cancers, respectively). Significant, tumour-specific loss of heterozygosity occurs in nine genes (ATM, BAP1, BRCA1/2, BRIP1, FANCM, PALB2 and RAD51C/D). Moreover, our homology-directed repair assay of 68 BRCA1 rare missense variants supports the utility of allelic enrichment analysis for characterizing variants of unknown significance. The scale of this analysis and the somatic-germline integration enable the detection of rare variants that may affect individual susceptibility to tumour development, a critical step toward precision medicine.


Subject(s)
Genetic Variation , Neoplasms/genetics , Neoplasms/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Mutation , Neoplasms/classification , Neoplasms/epidemiology , United States/epidemiology , Young Adult
19.
Blood ; 126(22): 2484-90, 2015 Nov 26.
Article in English | MEDLINE | ID: mdl-26492932

ABSTRACT

Familial clustering of myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML) can be caused by inherited factors. We screened 59 individuals from 17 families with 2 or more biological relatives with MDS/AML for variants in 12 genes with established roles in predisposition to MDS/AML, and identified a pathogenic germ line variant in 5 families (29%). Extending the screen with a panel of 264 genes that are recurrently mutated in de novo AML, we identified rare, nonsynonymous germ line variants in 4 genes, each segregating with MDS/AML in 2 families. Somatic mutations are required for progression to MDS/AML in these familial cases. Using a combination of targeted and exome sequencing of tumor and matched normal samples from 26 familial MDS/AML cases and asymptomatic carriers, we identified recurrent frameshift mutations in the cohesin-associated factor PDS5B, co-occurrence of somatic ASXL1 mutations with germ line GATA2 mutations, and recurrent mutations in other known MDS/AML drivers. Mutations in genes that are recurrently mutated in de novo AML were underrepresented in the familial MDS/AML cases, although the total number of somatic mutations per exome was the same. Lastly, clonal skewing of hematopoiesis was detected in 67% of young, asymptomatic RUNX1 carriers, providing a potential biomarker that could be used for surveillance in these high-risk families.


Subject(s)
Exome , Genetic Diseases, Inborn/genetics , Germ-Line Mutation , Leukemia, Myeloid, Acute/genetics , Myelodysplastic Syndromes/genetics , Neoplasm Proteins/genetics , Adolescent , Adult , Aged , Base Sequence , Child , Core Binding Factor Alpha 2 Subunit , DNA-Binding Proteins/genetics , Female , Hematopoiesis/genetics , Humans , Male , Middle Aged , Molecular Sequence Data , Repressor Proteins/genetics , Transcription Factors/genetics
20.
Genom Data ; 3: 61-62, 2015 Mar 01.
Article in English | MEDLINE | ID: mdl-25729643

ABSTRACT

To investigate the molecular basis underlying aggressive behavior in oral squamous cell carcinoma (OSCC), our laboratory developed a carcinogen-induced mouse oral cancer (MOC) cell line model that encompasses the growth and metastasis spectrum of its human counterpart. We performed next-generation sequencing (NGS) and gene expression microarray profiles to explore the genomic and transcriptional backgrounds of the differential MOC line phenotypes, as well as, the cross-species relevance of the model. Here we describe the comparative analysis of NGS (www.ncbi.nlm.nih.gov/biosample?LinkName=bioproject_biosample_all&from_uid=247825) and expression microarray (www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE50041) data from the MOC lines and corresponding human data, as described in our recent publication [1].

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