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Khan, J.

Publications and source records attributed to Khan, J..

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Scalable, ultra-fast, and low-memory construction of compacted de Bruijn graphs with Cuttlefish 2

The de Bruijn graph is a key data structure in modern computational genomics, and construction of its compacted variant resides upstream of many genomic analyses. As the quantity of genomic data grows rapidly, this often forms a computational bottleneck. We present CO_SCPLOWUTTLEFISHC_SCPLOW 2, significantly advancing the state-of-the-art for this problem. On a commodity server, it reduces the graph construction time for 661K bacterial genomes, of size 2.58Tbp, from 4.5 days to 17-23 hours; and it constructs the graph for 1.52Tbp white spruce reads in [~]10 hours, while the closest competitor requires 54-58 hours, using considerably more memory.

bioinformatics↗

Dysregulated Protein Translation Control in Hidradenitis Suppurativa: Implication for Lesion-associated Squamous Cell Carcinoma Development

Hidradenitis Suppurativa (HS) is a proinflammatory painful skin disorder. This chronic disease is often associated with aggressive squamous cell carcinoma (SCC). The molecular pathogenesis of this disease progression remains undefined. The translation initiation factor eIF4E/4G/4A1 complex is overexpressed in a variety of human malignancies. In this study, we found that the expression of eIF4E/4G/4A1 as well as phosphorylated eIF4E were upregulated in HS skin. In the global transcription profiles derived from two public database, we were able to enrich 734 eIF4F-related genes. GSEA pathway enrichment analysis further demonstrated that RAS/MEK/ERK oncogene signaling pathway associated with inflammation signaling were significantly activated in HS lesion. The increase expression of eIF4 protein components was associated with enhanced eIF4E translation targets Cyclin D1 and c-Myc. Confocal fluorescence microscopy analysis further revealed that Cyclin D1 and c-Myc specifically co-localized in nuclei of certain cells in HS epithelium. We also found that many of the PCNA positive hyperproliferative cells were also positive for c-Myc expression. These data demonstrate that 5-cap{square}dependent translation is a potential pathway underlying the SCC pathogenesis in chronic HS lesions. Furthermore, being a druggable target, inhibition of eIF4F may block lesion-associated lethal SCCs in HS patients.

cancer biology↗

Ex Vivo Culture Models of Hidradenitis Suppurativa for defining molecular pathogenesis and treatment efficacy of novel drugs

Hidradenitis suppurativa (HS) is a complex inflammatory and debilitating skin disease for which no effective treatment is available. This is partly because of the unavailability of suitable human or animal models with which exact pathobiology of the disease can be defined. Here, we describe the development of air-liquid (A-L) interface, liquid-liquid/liquid-submersion (L-S) and bioreactor (Bio) ex vivo skin culture models. All three ex vivo platforms were effective for culturing skin samples up to day-14, with the tissue architecture and integrity remaining intact for at least 3 days for healthy skin while for 14 days for HS skin. Up to day-3, no significant differences were observed in % early apoptotic cells among all three platforms. However, an increase was observed in late apoptotic/necrotic cells in HS skin at day-3 in A-L and Bio culture of HS skin. These cultures efficiently support the growth of various cells populations, including keratinocytes and immune cells. Profiling of the inflammatory genes using HS skin from these ex vivo cultures showed dynamic expression changes at day-3 and day-14. All of these cultures are necessary to represent the inflammatory gene status of HS skin at day-0 suggesting that not all gene clusters are identically altered in each culture method. Similarly, cytokine/chemokine profiling of the supernatant from vehicle- and drug-treated ex vivo HS cultures again showed better prediction of drug efficacy against HS. Overall, development of these three systems collectively provide a powerful tool to uncover the pathobiology of HS progression and screen various drugs against HS.

pathology↗

MCKAT, a multi-dimensional copy numbervariant kernel association test

BackgroundCopy number variants (CNVs) are the gain or loss of DNA segments in the genome. Studies have shown that CNVs are linked to various disorders, including autism, intellectual disability, and schizophrenia. Consequently, the interest in studying a possible association of CNVs to specific disease traits is growing. However, due to the specific multi-dimensional characteristics of the CNVs, methods for testing the association between CNVs and the disease-related traits are still underdeveloped. We propose a novel multi-dimensional CNV kernel association test (MCKAT) in this paper. We aim to find significant associations between CNVs and disease-related traits using kernel-based methods. ResultsWe address the multi-dimensionality in CNV characteristics. We first design a single pair CNV kernel, which contains three sub-kernels to summarize the similarity between two CNVs considering all CNV characteristics. Then, aggregate single pair CNV kernel to the whole chromosome CNV kernel, which summarizes the similarity between CNVs in two or more chromosomes. Finally, the association between the CNVs and disease-related traits is evaluated by comparing the similarity in the trait with kernel-based similarity using a score test in a random effect model. We apply MCKAT on genome-wide CNV datasets to examine the association between CNVs and disease-related traits, which demonstrates the potential usefulness the proposed method has for the CNV association tests. We compare the performance of MCKAT with CKAT, a uni-dimensional kernel method. Based on the results, MCKAT indicates stronger evidence, smaller p-value, in detecting significant associations between CNVs and disease-related traits in both rare and common CNV datasets. ConclusionA multi-dimensional copy number variant kernel association test can detect significantly associated CNVs with any disease-related trait. MCKAT can help biologists detect significantly associated CNVs with any disease-related trait across a patient group instead of examining the CNVs case by case in each subject.

bioinformatics↗

An Incrementally Updatable and Scalable System for Large-Scale Sequence Search using LSM Trees

MotivationIn the past few years, researchers have proposed numerous indexing schemes for searching large databases of raw sequencing experiments. Most of these proposed indexes are approximate (i.e. with one-sided errors) in order to save space. Recently, researchers have published exact indexes--Mantis, VariMerge, and Bifrost--that can serve as colored de Bruijn graph representations in addition to serving as k-mer indexes. This new type of index is promising because it has the potential to support more complex analyses than simple searches. However, in order to be useful as indexes for large and growing repositories of raw sequencing data, they must scale to thousands of experiments and support efficient insertion of new data. ResultsIn this paper, we show how to build a scalable and updatable exact sequence-search index. Specifically, we extend Mantis using the Bentley-Saxe transformation to support efficient updates. We demonstrate Mantiss scalability by constructing an index of{approx} 40K samples from SRA by adding samples one at a time to an initial index of 10K samples. Compared to VariMerge and Bifrost, Mantis is more efficient in terms of index-construction time and memory, query time and memory, and index size. In our benchmarks, VariMerge and Bifrost scaled to only 5K and 80 samples, respectively, while Mantis scaled to more than 39K samples. Queries were over 24x faster in Mantis than in Bifrost (VariMerge does not immediately support general search queries we require). Mantis indexes were about 2.5x smaller than Bifrosts indexes and about half as big as VariMerges indexes. AvailabilityThe updatable Mantis implementation is available at https://github.com/splatlab/mantis/tree/mergeMSTs. Contactrob@cs.umd.edu Supplementary informationSupplementary data are available online.

bioinformatics↗

SNAI2-mediated direct repression of BIM protects rhabdomyosarcoma from ionizing radiation

Ionizing radiation (IR) and chemotherapy are the mainstays of treatment for patients with rhabdomyosarcoma (RMS). Yet, the molecular mechanisms that underlie the success or failure of radiotherapy remain unclear. The transcriptional repressor SNAI2 was previously identified as a key regulator of IR sensitivity in normal and malignant stem cells through its repression of the proapoptotic BH3-only gene PUMA. Here, we demonstrate a clear correlation between SNAI2 expression levels and radiosensitivity across multiple RMS cell lines. Moreover, modulating SNAI2 levels in RMS cells through its overexpression or knockdown can alter radiosensitivity in vitro and in vivo. SNAI2 expression reliably promotes overall cell growth and inhibits mitochondrial apoptosis following exposure to IR, with either variable or minimal effects on differentiation and senescence, respectively. Importantly, SNAI2 knockdown results in a striking increase in expression of the proapoptotic BH3-only gene BIM, and ChIP-seq experiments establish that SNAI2 is a direct repressor of BIM. Since the P53 pathway is nonfunctional in the RMS cells used in this study, we have identified a new, P53-independent SNAI2/BIM axis that could potentially predict clinical responses to IR treatment and be exploited to improve RMS therapy. HighlightsO_LISNAI2 expression levels are directly correlated with protection from radiation in rhabdomyosarcoma. C_LIO_LILoss of SNAI2 primes rhabdomyosarcomas for IR-induced apoptosis. C_LIO_LISNAI2 directly represses the expression of the proapoptotic BH3-only gene BIM. C_LI

cancer biology↗

Age-Associated Insolubility of Parkin in Human Midbrain is Linked to Redox Balance and Sequestration of Reactive Dopamine Metabolites

The mechanisms by which parkin protects the adult human brain from Parkinson disease remain incompletely understood. We hypothesized that parkin cysteines participate in redox reactions, which are reflected in its posttranslational modifications. We found that in human control brain, including the S. nigra, parkin is largely insoluble after age 40 years, which is linked to its oxidation, e.g., at Cys95 and Cys253. In mice, oxidative stress increases posttranslational modifications at parkin cysteines and reduces its solubility. Oxidation of recombinant parkin also promotes insolubility and aggregate formation, but in parallel, lowers hydrogen peroxide (H2O2). This thiol-based redox activity is diminished by parkin point mutants, e.g., p.C431F and p.G328E. Intriguingly, in parkin-deficient human brain H2O2 concentrations are elevated. In prkn-null mice, H2O2 levels are dysregulated under oxidative stress conditions, such as acutely by MPTP-toxin exposure or chronically due to a second genetic hit. In dopamine toxicity studies, wild-type parkin, but not disease-linked mutants, protects human dopaminergic M17 cells, in part through lowering H2O2. Parkin also neutralizes reactive, electrophilic dopamine metabolites via adduct formation, which occurs foremost at primate-specific Cys95. Further, wild-type but not p.C95A-mutant parkin augments melanin formation. In sections of normal, adult human midbrain, parkin specifically co-localizes with neuromelanin pigment, frequently within LAMP-3/CD63+ lysosomes. We conclude that oxidative modifications of parkin cysteines are associated with protective outcomes, which include the reduction of H2O2, conjugation of reactive dopamine metabolites, sequestration of radicals within insoluble aggregates, and increased melanin formation. The loss of these redox effects may augment oxidative stress in dopamine producing neurons of mutant PRKN allele carriers, thereby contributing to neurodegeneration.

neuroscience↗

Cuttlefish: Fast, parallel, and low-memory compaction of de Bruijn graphs from large-scale genome collections

MotivationThe construction of the compacted de Bruijn graph from collections of reference genomes is a task of increasing interest in genomic analyses. These graphs are increasingly used as sequence indices for short and long read alignment. Also, as we sequence and assemble a greater diversity of genomes, the colored compacted de Bruijn graph is being used as the basis for efficient methods to perform comparative genomic analyses on these genomes. Therefore, designing time and memory efficient algorithms for the construction of this graph from reference sequences is an important problem. ResultsWe introduce a new algorithm, implemented in the toolCuttlefish, to construct the (colored) compacted de Bruijn graph from a collection of one or more genome references. Cuttlefish introduces a novel approach of modeling de Bruijn graph vertices as finite-state automata; it constrains these automatas state-space to enable tracking their transitioning states with very low memory usage. Cuttlefish is fast and highly parallelizable. Experimental results demonstrate that it scales much better than existing approaches, especially as the number and the scale of the input references grow. On our test hardware, Cuttlefish constructed the graph for 100 human genomes in under 9 hours, using ~29 GB of memory while no other tested tool completed this task. On 11 diverse conifer genomes, the compacted graph was constructed by Cuttlefish in under 9 hours, using ~84 GB of memory, while the only other tested tool that completed this construction on our hardware took over 16 hours and ~289 GB of memory. AvailabilityCuttlefish is written in C++14, and is available under an open source license at https://github.com/COMBINE-lab/cuttlefish. Contactrob@cs.umd.edu Supplementary informationSupplementary text are available at Bioinformatics online.

bioinformatics↗

Discovery of tREP-18, a novel class of tRNA encoded peptide with potent leishmanicidal activity

In the post genomic era, tRNA-derived fragments have emerged as a new class of non-coding gene regulators, those play crucial roles both at the transcriptional and translational levels, in different cellular biogenesis. However, none of the studies has ever asked whether tRNAs can also be translated into peptides with any biological significance. Thus, we present a novel hypothesis which suggested that; design and synthesis of tRNA-derived peptides from prokaryotic genome can be exploited for developing unique chemotherapeutics against neglected tropical diseases, like Visceral leishmaniasis (VL) and its aggressive form known as post kalazar dermal leishmaniasis (PKDL). To achieve this aim, we have used a novel system biology-based strategy, which involved; i) mining of unique tRNAs from E. coli genome and their translation into peptide in silico, ii) designing of theoretical 3D models to evaluate their stability, iii) prediction of their biological activity by screening against anti-parasitic database to filter the lead peptide. Based on this strategy, a unique tRNA-derived peptide (tREP-18) was selected, chemically synthesized, and used in vitro for elucidating its therapeutic significance against L. donovani, a causative agent of VL and PKDL. Our findings demonstrated that, tREP-18 can impose high level toxicity to L. donovani promastigotes, by disrupting the ultrastructural cellular architect, destabilizing the mitochondrial membrane potential ({Delta}{Psi}m), thus leading to drastic reduction in cell viability and proliferation. It also imparted high level of toxicity to BS12 a clinical isolate of PKDL. Conceivably, we for the first time reports a novel tRNA-derived peptide "tREP18" with excellent anti-leishmanial property, which can be further utilized for developing it as antileishmanial drug. One Sentence SummaryHere we report a novel first-in-class tRNA encoded peptide and its super anti-leishmanial characteristics.

synthetic biology↗

Proteogenomic analysis unveils the HLA Class I presented immunopeptidome in melanoma and EGFR mutant lung adenocarcinoma

Immune checkpoint inhibitor and adoptive lymphocyte transfer-based therapies have shown great therapeutic potential for cancers with high tumor mutation burden (TMB). Here, we employed mass spectrometry (MS)-based proteogenomic large-scale profiling to identify potential immunogenic human leukocyte antigen (HLA) Class I-presented peptides in both melanoma, a "hot tumor" with high TMB, and EGFR mutant lung adenocarcinoma, a "cold tumor" with low TMB. We identified several classes of neopeptides, including mutated neoantigens and more than 1000 post-translationally modified peptides representing 58 different PTMs. We constructed a cancer germline (CG) antigen database with 285 antigens and identified 42 Class I-presented CG antigens. Finally, we developed a non-canonical peptide discovery pipeline to identify 44 lncRNA-derived peptides and validated Class I binding for select neopeptides. We provide direct evidence of HLA Class I presentation of a large number of neopeptides for potential vaccine or adoptive cell therapy in melanoma and mutant EGFR lung cancer.

immunology↗

Lineage specific transcription factor waves reprogram neuroblastoma from self-renewal to differentiation

Temporal regulation of super-enhancer (SE) driven lineage specific transcription factors (TFs) underlies normal developmental programs. Neuroblastoma (NB) arises from an inability of sympathoadrenal progenitors to exit a self-renewal program and terminally differentiate. To identify critical SEs driving TF regulators of NB, we utilized NB cells in which all-trans retinoic acid (ATRA) induces growth arrest and differentiation. H3K27ac ChIP-seq paired with RNA-seq over a time course of ATRA treatment revealed SEs moving in a coordinated manner with four distinct temporal patterns (clusters). SEs that decreased with ATRA linked to 24 TFs involved in stem cell development/specialization (MYCN, GATA3, SOX11) along with LMO1, a transcriptional coregulator and oncogene identified via a genome-wide association study (GWAS) of NB. H3K27ac levels and GATA3 binding at the NB-associated rs2168101 site of the LMO1 SE were reduced with ATRA treatment, resulting in 1.46 fold decreased LMO1 expression. The SOX11 SE was lost coincident with a 50% decrease in mRNA after 8 days of ATRA treatment. CRISPR-Cas9 screening and siRNA inhibition showed a dependency on SOX11 for cell growth in NB cell lines. Silencing of the SOX11 SE using dCAS9-KRAB targeted guides caused a 40% decrease in SOX11 mRNA and inhibited cell growth. Three other TF SE clusters had sequential waves of activation at 2, 4 and 8 days of ATRA treatment and involved TFs regulating neural development (GATA2 and SOX4). Silencing of the gained SOX4 SE using dCAS9-KRAB targeting, caused a 50% decrease in SOX4 expression and attenuated expression of ATRA-induced differentiation genes. Our study has identified candidate oncogenic lineage drivers of NB self-renewal and TFs critical for implementing a differentiation program.

cancer biology↗

Computational vaccinology based development of multi-epitope subunit vaccine for protection against the Norovirus infections

Human Norovirus belong to family Calciviridae, it was identified in the outbreak of gastroenteritis in Norwalk, due to its seasonal prevalence known as "winter vomiting disease". Treatment of Norovirus infection is still mysterious because there is no effective antiviral drugs or vaccine developed to protect against the infection, to eradicate the infection an effective vaccine should be developed. In this study capsid protein (A7YK10), small protein (A7YK11) and polyprotein (A7YK09) were utilized. These proteins were subjected to B and T cell epitopes prediction by using reliable immunoinformatics tools. The antigenic and non-allergenic epitopes were selected for subunit vaccine, which can activate cellular and humoral immune responses. Linkers joined these epitopes together. The vaccine structure was modelled and validated by using Errat, ProSA and rampage servers. The modelled vaccine was docked with TLR-7. Stability of the docked complex was evaluated by MD simulation. In order to apply the concept in a wet lab, the reverse translated vaccine sequence was cloned in pET28a (+). The vaccine developed in this study requires experimental validation to ensure its effectiveness against the disease.

immunology↗

Biosynthesis of Iron Oxide Nanoparticles via Crocus sativus and their Antifungal Efficacy against Verticillium Wilt Pathogen Verticillium dahliae

Plant diseases pose threat to global food security. The excessive use of synthetic agro-chemical engender pesticide resistance. The exploration of alternative sustainable diseases management practices are crucial to overcome the devastative plant diseases. In this study, a facile innocuous approach was adopted for biogenic synthesis of Fe2O3-CsNPs via Crocus sativus corm aqueous extract and was evaluated for their antifungal efficacy against the Verticillium wilt pathogen Verticillium dahliae. The physico-chemical characterization of biosynthesized nanoparticles were performed through UV-visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Energy Dispersive X-ray Spectroscopy, X-Ray Diffraction, and Scanning Electron Microscopy. The fungus mycelium growth was significantly inhibited in the media containing 3mg/mL Fe2O3-CsNPs. Degenerated, concentrated and shriveled hyphae were revealed in Scanning Electron Microscopy. The overall results demonstrated that the biogenic Fe2O3-CsNPs have the efficacy to control devastative phytopathogens.

plant biology↗

Miswired enhancer logic drives translocation positive rhabdomyosarcoma

Core regularity transcription factors (CR TFs) define cell identity and lineage through an exquisitely precise and logical order during embryogenesis and development. These CR TFs regulate one another in three-dimensional space via distal enhancers that serve as logic gates embedded in their TF recognition sequences. Aberrant chromatin organization resulting in miswired circuitry of enhancer logic is a newly recognized feature in many cancers. Here, we report that PAX3-FOXO1 expression is driven by a translocated FOXO1 distal super enhancer (SE). Using 4C-seq, a technique detecting all genomic regions that interact with the translocated FOXO1 SE, we demonstrate its physical interaction with the PAX3 promotor only in the presence of the oncogenic translocation. Furthermore, RNA-seq and ChIP-seq in tumors bearing rare PAX translocations implicate enhancer miswiring is a pervasive feature across all FP-RMS tumors. HiChIP of enhancer mark H3K27ac showed extended connectivity between the distal FOXO1 SE and additional intra-domain enhancers and the PAX3 promoter. We show by CRISPR-paired-ChIP-Rx that PAX3-FOXO1 transcription is diminished when this network of enhancers is selectively ablated. Therefore, our data reveal a mechanism of a translocated hijacked enhancer which disrupts the normal CR TF logic during skeletal muscle development (PAX3 to MYOD to MYOG), replacing it with an infinite loop logic that locks rhabdomyosarcoma cells in an undifferentiated proliferating stage.

cancer biology↗

MEK1/2 in Rhabdomyosarcoma

Alveolar and embryonal rhabdomyosarcoma (RMS) are soft-tissue cancers that affect children, adolescents, and young adults. Sometimes referred to as muscle cancer, RMS is a cancer of muscle and non-muscle origin that phenocopies incompletely differentiated myoblasts or activated satellite (muscle stem) cells. Interestingly, embryonal RMS (ERMS) has been observed to undergo terminal myogenic differentiation in response to stress induced by chemotherapy and radiation therapy4, 9, 24. Given the propensity of rhabdomyosarcoma to differentiation, in this report we explore the use of differentiation therapy combining MEK inhibitor (MEKi) cobimetinib and chemotherapy as a strategy to halt RMS growth. We evaluated a representative panel of RMS cell lines with cobimetinib and chemotherapy in two dosing schedules that mimic clinical use followed by cell growth evaluation and high content analysis (differentiation) assays. We uncovered that cobimetinib does not have significant additive or synergistic effects on cell differentiation or cell growth with chemotherapy in RMS and can have unanticipated antagonistic effects; specifically, pre-exposure of cobimetinib to cells can decrease the effectiveness of chemotherapy-mediated cell growth inhibition in vitro. Although differentiation-therapy is still a potential viable strategy in RMS, our data do not support MEKi/chemotherapy co-treatment in this context.

cancer biology↗

Structural variation targets neurodevelopmental genes and identifies SHANK2 as a tumor suppressor in neuroblastoma

Neuroblastoma is a malignancy of the developing sympathetic nervous system that accounts for 12% of childhood cancer deaths. Like many childhood cancers, neuroblastoma exhibits a relative paucity of somatic single nucleotide variants (SNVs) and small insertions and deletions (indels) compared to adult cancers. Here, we assessed the contribution of somatic structural variation (SV) in neuroblastoma using a combination of whole genome sequencing (WGS; n=135) and single nucleotide polymorphism (SNP) genotyping (n=914) of matched tumor-normal pairs. Our study design allowed for orthogonal validation and replication across platforms. SV frequency, type, and localization varied significantly among high-risk tumors. MYCN non-amplified high-risk tumors harbored an increased SV burden overall, including a substantial excess of tandem-duplication events across the genome. Genes disrupted by SV breakpoints were enriched in neuronal lineages and autism spectrum disorder (ASD). The postsynaptic adapter protein-coding gene SHANK2, located on chromosome 11q13, was disrupted by SVs in 14% of MYCN non-amplified high-risk tumors based on WGS and 10% in the SNP array cohort. Expression of SHANK2 was low across human-derived neuroblastoma cell lines and high-risk neuroblastoma tumors. Forced expression of SHANK2 in neuroblastoma cell models resulted in significant growth inhibition (P=2.62x10-2 to 3.4x10-5) and accelerated neuronal differentiation following treatment with all-trans retinoic acid (P=3.08x10-13 to 2.38x10-30). These data further define the complex landscape of structural variation in neuroblastoma and suggest that events leading to deregulation of neurodevelopmental processes, such as inactivation of SHANK2, are key mediators of tumorigenesis in this childhood cancer.

cancer biology↗

Transcriptome analysis of the human tibial nerve identifies sexually dimorphic expression of genes involved in pain, inflammation and neuro-immunity

Sex differences in gene expression are important contributors to normal physiology and mechanisms of disease. This is increasingly apparent in understanding and potentially treating chronic pain where molecular mechanisms driving sex differences in neuronal plasticity are giving new insight into why certain chronic pain disorders preferentially affect women versus men. Large transcriptomic resources are increasingly available and can be used to mine for sex differences and molecular insight using donor cohorts. We analyzed more than 250 human tibial nerve (hTN) transcriptomes from the GTex Consortium project to gain insight into sex-dependent gene expression in the peripheral nervous system (PNS). We discover 149 genes with sex differential expression. Many of the genes upregulated in men are associated with inflammation, and appear to be primarily expressed by glia or immune cells. In women, we find the differentially upregulated transcription factor SP4 that drives a regulatory program, and may impact sex differences in PNS physiology. Many of these 149 DE genes have some previous association with chronic pain but few of them have been explored thoroughly. Additionally, using clinical data in the GTex database, we identify a subset of differentially expressed (DE) genes in diseases associated with chronic pain, arthritis and type II diabetes. Our work identifies sexually dimorphic gene expression in the human PNS with implications for discovery of sex-specific pain mechanisms.

neuroscience↗

Integrated proteogenomic analysis of metastatic thoracic tumors identifies APOBEC mutagenesis and copy number alterations as drivers of proteogenomic tumor evolution and heterogeneity

Elucidation of the proteogenomic evolution of metastatic tumors may offer insight into the poor prognosis of patients harboring metastatic disease. We performed whole-exome and transcriptome sequencing, copy number alterations (CNA) and mass spectrometry-based quantitative proteomics of 37 lung adenocarcinoma (LUAD) and thymic carcinoma (TC) metastases obtained by rapid autopsy and found evidence of patient-specific, multi-dimensional heterogeneity. Extreme mutational heterogeneity was evident in a subset of patients whose tumors showed increased APOBEC-signature mutations and expression of APOBEC3 region transcripts compared to patients with lesser mutational heterogeneity. TP53 mutation status was associated with APOBEC hypermutators in our cohort and in three independent LUAD datasets. In a thymic carcinoma patient, extreme heterogeneity and increased APOBEC3AB expression was associated with a high-risk germline APOBEC3AB variant allele. Patients with CNA occurring late in tumor evolution had corresponding changes in gene expression and protein abundance indicating genomic instability as a mechanism of downstream transcriptomic and proteomic heterogeneity between metastases. Across all tumors, proteomic heterogeneity was greater than copy number and transcriptomic heterogeneity. Enrichment of interferon pathways was evident both in the transcriptome and proteome of the tumors enriched for APOBEC mutagenesis despite a heterogeneous immune microenvironment across metastases suggesting a role for the immune microenvironment in the expression of APOBEC transcripts and generation of mutational heterogeneity. The evolving, heterogeneous nature of LUAD and TC, through APOBEC-mutagenesis and CNA illustrate the challenges facing treatment outcomes.

cancer biology↗