Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 38
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Proc Natl Acad Sci U S A ; 120(31): e2216127120, 2023 08.
Article in English | MEDLINE | ID: mdl-37487091

ABSTRACT

Retroviruses and their host have coevolved in a delicate balance between viral replication and survival of the infected cell. In this equilibrium, restriction factors expressed by infected cells control different steps of retroviral replication such as entry, uncoating, nuclear import, expression, or budding. Here, we describe a mechanism of restriction against human T cell leukemia virus type 1 (HTLV-1) by the helicase-like transcription factor (HLTF). We show that RNA and protein levels of HLTF are reduced in primary T cells of HTLV-1-infected subjects, suggesting a clinical relevance. We further demonstrate that the viral oncogene Tax represses HLTF transcription via the Enhancer of zeste homolog 2 methyltransferase of the Polycomb repressive complex 2. The Tax protein also directly interacts with HLTF and induces its proteasomal degradation. RNA interference and gene transduction in HTLV-1-infected T cells derived from patients indicate that HLTF is a restriction factor. Restoring the normal levels of HLTF expression induces the dispersal of the Golgi apparatus and overproduction of secretory granules. By synergizing with Tax-mediated NF-κB activation, physiologically relevant levels of HLTF intensify the autophagic flux. Increased vesicular trafficking leads to an enlargement of the lysosomes and the production of large vacuoles containing viral particles. HLTF induction in HTLV-1-infected cells significantly increases the percentage of defective virions. In conclusion, HLTF-mediated activation of the autophagic flux blunts the infectious replication cycle of HTLV-1, revealing an original mode of viral restriction.


Subject(s)
Human T-lymphotropic virus 1 , Leukemia, T-Cell , Humans , Human T-lymphotropic virus 1/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Gene Products, tax/genetics , Gene Products, tax/metabolism , T-Lymphocytes/metabolism , NF-kappa B/metabolism , DNA-Binding Proteins
2.
Proc Natl Acad Sci U S A ; 119(49): e2210766119, 2022 12 06.
Article in English | MEDLINE | ID: mdl-36442093

ABSTRACT

Transient soluble oligomers of amyloid-ß (Aß) are toxic and accumulate early prior to insoluble plaque formation and cognitive impairment in Alzheimer's disease (AD). Synthetic cyclic D,L-α-peptides (e.g., 1) self-assemble into cross ß-sheet nanotubes, react with early Aß species (1-3 mers), and inhibit Aß aggregation and toxicity in stoichiometric concentrations, in vitro. Employing a semicarbazide as an aza-glycine residue with an extra hydrogen-bond donor to tune nanotube assembly and amyloid engagement, [azaGly6]-1 inhibited Aß aggregation and toxicity at substoichiometric concentrations. High-resolution NMR studies revealed dynamic interactions between [azaGly6]-1 and Aß42 residues F19 and F20, which are pivotal for early dimerization and aggregation. In an AD mouse model, brain positron emission tomography (PET) imaging using stable 64Cu-labeled (aza)peptide tracers gave unprecedented early amyloid detection in 44-d presymptomatic animals. No tracer accumulation was detected in the cortex and hippocampus of 44-d-old 5xFAD mice; instead, intense PET signal was observed in the thalamus, from where Aß oligomers may spread to other brain parts with disease progression. Compared with standard 11C-labeled Pittsburgh compound-B (11C-PIB), which binds specifically fibrillar Aß plaques, 64Cu-labeled (aza)peptide gave superior contrast and uptake in young mouse brain correlating with Aß oligomer levels. Effectively crossing the blood-brain barrier (BBB), peptide 1 and [azaGly6]-1 reduced Aß oligomer levels, prolonged lifespan of AD transgenic Caenorhabditis elegans, and abated memory and behavioral deficits in nematode and murine AD models. Cyclic (aza)peptides offer novel promise for early AD diagnosis and therapy.


Subject(s)
Alzheimer Disease , Amyloidosis , Animals , Mice , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/drug therapy , Early Diagnosis , Amyloid beta-Peptides , Plaque, Amyloid , Amyloidogenic Proteins
3.
Bioinformatics ; 39(8)2023 08 01.
Article in English | MEDLINE | ID: mdl-37549060

ABSTRACT

MOTIVATION: Detection of genomic alterations in circulating tumor DNA (ctDNA) is currently used for active clinical monitoring of cancer progression and treatment response. While methods for analysis of small mutations are more developed, strategies for detecting structural variants (SVs) in ctDNA are limited. Additionally, reproducibly calling small-scale mutations, copy number alterations, and SVs in ctDNA is challenging due to the lack to unified tools for these different classes of variants. RESULTS: We developed a unified pipeline for the analysis of ctDNA [Pipeline for the Analysis of ctDNA (PACT)] that accurately detects SVs and consistently outperformed similar tools when applied to simulated, cell line, and clinical data. We provide PACT in the form of a Common Workflow Language pipeline which can be run by popular workflow management systems in high-performance computing environments. AVAILABILITY AND IMPLEMENTATION: PACT is freely available at https://github.com/ChrisMaherLab/PACT.


Subject(s)
Circulating Tumor DNA , Neoplasms , Humans , Circulating Tumor DNA/genetics , Mutation , Neoplasms/genetics , Genomics , Cell Line , Biomarkers, Tumor/genetics
4.
Proc Natl Acad Sci U S A ; 117(12): 6831-6835, 2020 03 24.
Article in English | MEDLINE | ID: mdl-32152102

ABSTRACT

Glutamate is the major excitatory neurotransmitter in the brain, and photochemical release of glutamate (or uncaging) is a chemical technique widely used by biologists to interrogate its physiology. A basic prerequisite of these optical probes is bio-inertness before photolysis. However, all caged glutamates are known to have strong antagonism toward receptors of γ-aminobutyric acid, the major inhibitory transmitter. We have developed a caged glutamate probe that is inert toward these receptors at concentrations that are effective for photolysis with violet light. Pharmacological tests in vitro revealed that attachment of a fifth-generation (G5) dendrimer (i.e., cloaking) to the widely used 4-methoxy-7-nitro-indolinyl(MNI)-Glu probe prevented such off-target effects while not changing the photochemical properties of MNI-Glu significantly. G5-MNI-Glu was used with optofluidic delivery to stimulate dopamine neurons of the ventral tegmental area of freely moving mice in a conditioned place-preference protocol so as to mediate Pavlovian conditioning.


Subject(s)
Glutamates/pharmacology , Indoles/pharmacology , Learning/physiology , Microfluidics , Neurons/physiology , Neurotransmitter Agents/pharmacology , Animals , Learning/drug effects , Mice , Mice, Inbred C57BL , Neurochemistry , Neurons/drug effects , Photochemistry , Photolysis , Receptors, GABA/metabolism , Receptors, N-Methyl-D-Aspartate/metabolism
5.
PLoS Med ; 18(8): e1003732, 2021 08.
Article in English | MEDLINE | ID: mdl-34464379

ABSTRACT

BACKGROUND: The standard of care treatment for muscle-invasive bladder cancer (MIBC) is radical cystectomy, which is typically preceded by neoadjuvant chemotherapy. However, the inability to assess minimal residual disease (MRD) noninvasively limits our ability to offer bladder-sparing treatment. Here, we sought to develop a liquid biopsy solution via urine tumor DNA (utDNA) analysis. METHODS AND FINDINGS: We applied urine Cancer Personalized Profiling by Deep Sequencing (uCAPP-Seq), a targeted next-generation sequencing (NGS) method for detecting utDNA, to urine cell-free DNA (cfDNA) samples acquired between April 2019 and November 2020 on the day of curative-intent radical cystectomy from 42 patients with localized bladder cancer. The average age of patients was 69 years (range: 50 to 86), of whom 76% (32/42) were male, 64% (27/42) were smokers, and 76% (32/42) had a confirmed diagnosis of MIBC. Among MIBC patients, 59% (19/32) received neoadjuvant chemotherapy. utDNA variant calling was performed noninvasively without prior sequencing of tumor tissue. The overall utDNA level for each patient was represented by the non-silent mutation with the highest variant allele fraction after removing germline variants. Urine was similarly analyzed from 15 healthy adults. utDNA analysis revealed a median utDNA level of 0% in healthy adults and 2.4% in bladder cancer patients. When patients were classified as those who had residual disease detected in their surgical sample (n = 16) compared to those who achieved a pathologic complete response (pCR; n = 26), median utDNA levels were 4.3% vs. 0%, respectively (p = 0.002). Using an optimal utDNA threshold to define MRD detection, positive utDNA MRD detection was highly correlated with the absence of pCR (p < 0.001) with a sensitivity of 81% and specificity of 81%. Leave-one-out cross-validation applied to the prediction of pathologic response based on utDNA MRD detection in our cohort yielded a highly significant accuracy of 81% (p = 0.007). Moreover, utDNA MRD-positive patients exhibited significantly worse progression-free survival (PFS; HR = 7.4; 95% CI: 1.4-38.9; p = 0.02) compared to utDNA MRD-negative patients. Concordance between urine- and tumor-derived mutations, determined in 5 MIBC patients, was 85%. Tumor mutational burden (TMB) in utDNA MRD-positive patients was inferred from the number of non-silent mutations detected in urine cfDNA by applying a linear relationship derived from The Cancer Genome Atlas (TCGA) whole exome sequencing of 409 MIBC tumors. We suggest that about 58% of these patients with high inferred TMB might have been candidates for treatment with early immune checkpoint blockade. Study limitations included an analysis restricted only to single-nucleotide variants (SNVs), survival differences diminished by surgery, and a low number of DNA damage response (DRR) mutations detected after neoadjuvant chemotherapy at the MRD time point. CONCLUSIONS: utDNA MRD detection prior to curative-intent radical cystectomy for bladder cancer correlated significantly with pathologic response, which may help select patients for bladder-sparing treatment. utDNA MRD detection also correlated significantly with PFS. Furthermore, utDNA can be used to noninvasively infer TMB, which could facilitate personalized immunotherapy for bladder cancer in the future.


Subject(s)
Biomarkers, Tumor/analysis , Cystectomy/statistics & numerical data , DNA, Neoplasm/analysis , Neoplasm, Residual/diagnosis , Urinary Bladder Neoplasms/diagnosis , Urine/chemistry , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Male , Middle Aged , Missouri , Neoplasm Invasiveness/pathology , Neoplasm, Residual/etiology , Progression-Free Survival , Urinary Bladder Neoplasms/etiology
7.
Biochemistry ; 55(17): 2427-40, 2016 May 03.
Article in English | MEDLINE | ID: mdl-27050631

ABSTRACT

Described herein are the synthesis and photophysical characterization of a library of aryl-substituted oxazole- and thiazole-based dipeptidomimetic analogues, and their incorporation into position 66 of green fluorescent protein (GFP) in lieu of the natural fluorophore. These fluorescent analogues resemble the fluorophore formed naturally by GFP. As anticipated, the photophysical properties of the analogues varied as a function of the substituents at the para position of the phenyl ring. The fluorescence emission wavelength maxima of compounds in the library varied from ∼365 nm (near-UV region) to ∼490 nm (visible region). The compounds also exhibited a large range of quantum yields (0.01-0.92). The analogues were used to activate a suppressor tRNACUA and were incorporated into position 66 of GFP using an in vitro protein biosynthesizing system that employed engineered ribosomes selected for their ability to incorporate dipeptides. Four analogues with interesting photophysical properties and reasonable suppression yields were chosen, and the fluorescent proteins (FPs) containing these fluorophores were prepared on a larger scale for more detailed study. When the FPs were compared with the respective aminoacyl-tRNAs and the actual dipeptide analogues, the FPs exhibited significantly enhanced fluorescence intensities at the same concentrations. Part of this was shown to be due to the presence of the fluorophores as an intrinsic element of the protein backbone. There were also characteristic shifts in the emission maxima, indicating the environmental sensitivity of these probes. Acridon-2-ylalanine and oxazole 1a were incorporated into positions 39 and 66 of GFP, respectively, and were shown to form an efficient Förster resonance energy transfer (FRET) pair, demonstrating that the analogues can be used as FRET probes.


Subject(s)
Dipeptides/metabolism , Escherichia coli/metabolism , Fluorescence , Peptidomimetics/chemical synthesis , Peptidomimetics/metabolism , RNA, Transfer/metabolism , Ribosomes/metabolism , Dipeptides/chemical synthesis , Fluorescence Resonance Energy Transfer , Fluorescent Dyes , Green Fluorescent Proteins , Humans , Models, Molecular , Molecular Structure , Protein Biosynthesis
8.
Tumour Biol ; 36(4): 3061-73, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25514873

ABSTRACT

High incidence of nasopharyngeal carcinoma (NPC) has been reported from China, Southeast Asia and Northeast (NE) region of India. Populations at geographic regions having higher incidence of NPC display human leukocyte antigen (HLA) distribution patterns different from areas having low incidence. The current study has investigated the contribution of environmental risk factors and ethnic variation of microsatellite markers in HLA region for the high incidence of NPC in NE India. Genotyping of HLA region using 33 microsatellite markers by fragment length analysis was done in 220 study subjects (120 NPC patients and 100 healthy controls). Association analysis showed two adjacent microsatellite markers HL003 (allele 121) and D6S2704 (allele 218) in the HLA class I region having association with high risk of NPC while allele 127 of HL003 and allele 255 of D6S2678 conferred a protective effect. The environmental factors mainly use of firewood (odds ratio (OR) = 3.797385, confidence interval (CI) = 1.97-7.30, P < 0), living in mud house (OR = 3.46, CI = 1.19-10.08, P = 0.022) and consumption of alcohol (OR = 2.11, CI = 1.02-4.37, P = 0.043) were found as major risk factors for NPC. Higher-order interaction showed combination of smoked food consumption and firewood use for cooking in multifactor dimensionality reduction (MDR) analysis and interaction of non-firewood users, non-ventilated houses and residence in mud houses in classification and regression tree (CART) analysis as the significant risk factors for NPC. Expression of Epstein-Barr virus (EBV) RNA was found in 92% (23/25) of NPC cases suggesting its significant role in NPC aetiopathogenesis. This study identified association of NPC with a susceptibility locus in the HLA class I region which has complex interaction with viral DNA and environmental factors.


Subject(s)
Genetic Association Studies , HLA Antigens/genetics , Microsatellite Repeats/genetics , Nasopharyngeal Neoplasms/genetics , Adult , Aged , Alleles , Female , Genetic Predisposition to Disease , Genotype , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/pathogenicity , Humans , India , Male , Middle Aged , Nasopharyngeal Neoplasms/pathology , Nasopharyngeal Neoplasms/virology , Risk Factors
9.
Tumour Biol ; 35(1): 723-37, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23982874

ABSTRACT

Targeting breast cancer stem cells (BCSCs) offers a promising strategy for breast cancer treatment. We examined the plant alkaloid ellipticine for its efficacy to inhibit the expression of aldehyde dehydrogenase 1 class A1 (ALDH1A1)-positive BCSCs by in vitro and in silico methods. At 3 mM concentration, ellipticine decreased the expression of ALDH1A1-positive BCSCs by 62% (p = 0.073) in the MCF7 cell line and by 53% (p = 0.024) in the SUM159 cell line compared to vehicle-treated cultures. Ellipticine significantly reduced the formation of mammospheres, whereas paclitaxel enhanced mammosphere formation in both the treated cell lines. Interestingly, when treated with a combination of ellipticine and paclitaxel, the percentage of ALDH1A1-positive BCSCs dropped by several fold in vitro. A homology model of Homo sapiens ALDH1A1 was built using the crystal structure of NAD-bound sheep liver class I aldehyde dehydrogenase [PDB ID: 1BXS] as a template. Molecular simulation and docking studies revealed that the amino acids Asn-117 and Asn-121, Glu-249, Cys-302, and Gln-350, present in the active site of human ALDH1A1, played a vital role in interacting with the drug. The present study suggests that ellipticine reduces the proliferation and self-renewal ability of ALDH1A1-positive BCSCs and can be used in combination with a cytotoxic drug like paclitaxel for potential targeting of BCSCs.


Subject(s)
Aldehyde Dehydrogenase/metabolism , Antineoplastic Agents/pharmacology , Breast Neoplasms/metabolism , Ellipticines/pharmacology , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Aldehyde Dehydrogenase/chemistry , Aldehyde Dehydrogenase/genetics , Aldehyde Dehydrogenase 1 Family , Amino Acid Sequence , Antineoplastic Agents/chemistry , Breast Neoplasms/genetics , Catalytic Domain , Cell Line, Tumor , Cell Proliferation/drug effects , Ellipticines/chemistry , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , MCF-7 Cells , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Sequence Data , Paclitaxel/pharmacology , Protein Binding , Protein Conformation , Retinal Dehydrogenase , Spheroids, Cellular , Tumor Cells, Cultured
10.
Tumour Biol ; 35(6): 5885-94, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24604328

ABSTRACT

Polymorphisms in DNA repair and cell cycle genes contribute to increased breast cancer (BC) risk. Their association and interaction in relation to betel quid and tobacco chewing habits need exhaustive multi-analytical investigation to explain BC predisposition due to DNA damage. Polymorphism in TP53-72Arg>Pro, RAD51-135G>C, BRCA2, and CCND1-G870A were examined in 204 BC cases and 217 controls from Northeast Indian population. Multifaceted analytic approaches were used to explore relationships between polymorphisms, tobacco history, and BC susceptibility. Betel quid chewing was identified as the predominant risk factor. CCND-AA and dominant model showed protection towards BC in betel quid chewer (BQC) [(0.28 (0.10-0.77), 0.01 and 0.32 (0.12-0.81), 0.01)] and non-betel quid chewers (NBQC) [(0.26 (0.09-0.78), 0.01 and 0.37 (0.16-0.87), 0.02)]. TP53-Pro/Pro genotype showed protection towards BC in NBQC (0.29 (0.10-0.81), p=0.01) and (0.51 (0.32-0.80), p=0.003, respectively). RAD51-C allele was associated with BC risk (2.03 (1.26-3.30) 0.002) in BQC. Two BQC cases had BRCA2 8415G>T:K2729N mutation in Exon18. MDR analysis showed best four locus model with TBA 0.6765 (0.005) and CVC of 10/10 in NBQC. Interaction diagram concurred the interactions between TP53 and RAD51 (1.32 %) with independent effect (1.89 %) of CCND1in NBQC. In CART analysis, BQC with CCND1 GG genotype were at risk (OR=33.0; 95 % CI=6.08-179.07), p<0.001) followed by combination of BQC, CCND1, No-Smk, and Alc (OR=42.00; 95 % CI=5.11-345.11, p<0.001). Risk was also observed in BQC, CCND1, No-Smk, Non-Alc, and TP53 combination (OR=14.84; 95 % CI=3.13-70.34, p<0.001) and BQC, CCND1, No-Smk, Non-Alc, TP53 (OR=9.40; 95 % CI=1.99-44.34, p<0.001). NBQC group showed risk with combination of NBQC and TP53 (OR=5.54; 95 % CI=1.11-27.42, p=0.03). Genetic variants in DNA repair and cell cycle genes contribute to BC risk through gene-gene and gene-environmental interactions.


Subject(s)
Breast Neoplasms/genetics , Cell Cycle/genetics , DNA Repair/genetics , Genetic Predisposition to Disease , Adult , Aged , Areca/adverse effects , Breast Neoplasms/etiology , Cyclin D1/genetics , Entropy , Female , Genes, BRCA2 , Genes, p53 , Genetic Variation , Humans , Middle Aged , Polymorphism, Single Nucleotide , Rad51 Recombinase/genetics , Risk
11.
J Org Chem ; 79(13): 6389-93, 2014 Jul 03.
Article in English | MEDLINE | ID: mdl-24927230

ABSTRACT

Readily available methyl 3-formylindol-2-ylacetate and N-tosyl-4-chloro-3-piperidone oxime have been used to construct the tetracyclic skeleton of the apparicine class of monoterpene indole alkaloids in only four steps in 80% overall yield. Key transformations in this convergent approach involve use of an intermolecular ester enolate/nitrosoalkene conjugate addition to form the C-15/16 bond, followed by a reductive cyclization to construct the C-ring of the tetracycle.


Subject(s)
Alkaloids/chemical synthesis , Indole Alkaloids/chemical synthesis , Nitroso Compounds/chemistry , Oximes/chemistry , Piperidones/chemistry , Alkaloids/chemistry , Cyclization , Indole Alkaloids/chemistry , Molecular Structure , Stereoisomerism
12.
Indian J Med Res ; 139(5): 720-9, 2014 May.
Article in English | MEDLINE | ID: mdl-25027082

ABSTRACT

BACKGROUND & OBJECTIVES: Genetic polymorphisms in glutathione-S-transferase genes ( GSTM1 and GSTT1 ) have been studied intensively for their potential role in lung cancer susceptibility. However, most of the studies on association between the polymorphisms and lung cancer do not distinguish between genotypes with one or two copies of the genes. The present study investigates the gene dosage effects of GSTT1 and GSTM1 copy number and their environmental interactions to examine the association of lung cancer risk with trimodular genotypes of the GSTs in a high-risk population from north-east India. METHODS: A total of 154 lung cancer cases and 154 age and sex matched controls from the high risk region of north-east India were analyzed by multiplex real-time PCR to determine the trimodal genotypes (+/+, +/- and -/-) in both the genes ( GSTM1 and GSTT1 ). RESULTS: No significant association and gene dosage effect of GSTM1 gene copy number with lung cancer risk ( P trend =0.13) were found. However, absence of GSTT1 conferred 68 per cent (OR=0.32;95%CI=0.15-0.71;P=0.005) reduced risk compared to the two copy number of the gene. t0 here was evidence of gene dosage effect of GSTT1 gene ( P trend =0.006). Tobacco smoking was a major environmental risk factor to lung cancer (OR=3.03;95%CI=1.73-5.31;P<0.001). However, its interaction with null genotype of GSTT1 conferred significant reduced risk to lung cancer (OR=0.30;95%CI=0.10-0.91;P=0.03). Further in only tobacco smokers, null genotype was associated with increased reduced risk [0.03(0.001-0.78)0.03; P trend =0.006]. No effect modification of GSTM1 was observed with lung cancer risk by environmental risk factors. INTERPRETATION & CONCLUSIONS: The results suggest that absence of GSTT1 null genotype may be associated with a reduced risk of lung cancer and the effect remains unchanged after interaction with smoking.


Subject(s)
DNA Copy Number Variations , Glutathione Transferase/genetics , Lung Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Case-Control Studies , Female , Genetic Association Studies , Genetic Predisposition to Disease , Glutathione/metabolism , Humans , India , Lung Neoplasms/pathology , Male , Middle Aged , Risk Factors , Smoking/genetics
13.
Clin Cancer Res ; 2024 Aug 23.
Article in English | MEDLINE | ID: mdl-39177583

ABSTRACT

PURPOSE: Metastatic castration-resistant prostate cancer (mCRPC) resistant to androgen receptor signaling inhibitors (ARSIs) is often lethal. Liquid biopsy biomarkers for this deadly form of disease remain under investigation, and underpinning mechanisms remain ill-understood. EXPERIMENTAL DESIGN: We applied targeted cell-free DNA sequencing to 126 mCRPC patients from three academic cancer centers, and separately performed genome-wide cell-free DNA methylation sequencing on 43 plasma samples collected prior to the initiation of first-line ARSI treatment. To analyze the genome-wide sequencing data, we performed nucleosome-positioning and differential methylated region analysis. We additionally analyzed single-cell and bulk RNA sequencing data from 14 and 80 mCRPC patients, respectively, to develop and validate a stem-like signature, which we inferred from cell-free DNA. RESULTS: Targeted cell-free DNA sequencing detected AR/enhancer alterations prior to first-line ARSIs which correlated with significantly worse PFS (p = 0.01; HR = 2.12) and OS (p = 0.02; HR = 2.48). Plasma methylome analysis revealed that AR/enhancer lethal mCRPC patients have significantly higher promoter-level hypomethylation than AR/enhancer wild-type mCRPC patients (p < 0.0001). Moreover, gene ontology and CytoTRACE analysis of nucleosomally more accessible transcription factors in cell-free DNA revealed enrichment for stemness-associated transcription factors in lethal mCRPC patients. The resulting stemness signature was then validated in a completely held-out cohort of 80 mCRPC patients profiled by tumor RNA sequencing. CONCLUSIONS: We analyzed a total of 220 mCRPC patients, validated the importance of cell-free AR/enhancer alterations as a prognostic biomarker in lethal mCRPC and showed that the underlying mechanism for lethality involves reprogramming developmental states toward increased stemness.

14.
Semin Radiat Oncol ; 33(3): 262-278, 2023 07.
Article in English | MEDLINE | ID: mdl-37331781

ABSTRACT

Recent breakthroughs in circulating tumor DNA (ctDNA) technologies present a compelling opportunity to combine this emerging liquid biopsy approach with the field of radiogenomics, the study of how tumor genomics correlate with radiotherapy response and radiotoxicity. Canonically, ctDNA levels reflect metastatic tumor burden, although newer ultrasensitive technologies can be used after curative-intent radiotherapy of localized disease to assess ctDNA for minimal residual disease (MRD) detection or for post-treatment surveillance. Furthermore, several studies have demonstrated the potential utility of ctDNA analysis across various cancer types managed with radiotherapy or chemoradiotherapy, including sarcoma and cancers of the head and neck, lung, colon, rectum, bladder, and prostate . Additionally, because peripheral blood mononuclear cells are routinely collected alongside ctDNA to filter out mutations associated with clonal hematopoiesis, these cells are also available for single nucleotide polymorphism analysis and could potentially be used to detect patients at high risk for radiotoxicity. Lastly, future ctDNA assays will be utilized to better assess locoregional MRD in order to more precisely guide adjuvant radiotherapy after surgery in cases of localized disease, and guide ablative radiotherapy in cases of oligometastatic disease.


Subject(s)
Circulating Tumor DNA , Neoplasms , Radiation Oncology , Male , Humans , Circulating Tumor DNA/genetics , Leukocytes, Mononuclear , Neoplasms/genetics , Neoplasms/radiotherapy , Liquid Biopsy , Biomarkers, Tumor/genetics , Neoplasm, Residual/radiotherapy
15.
J Immunother Cancer ; 11(6)2023 06.
Article in English | MEDLINE | ID: mdl-37349125

ABSTRACT

Liquid biopsies using cell-free circulating tumor DNA (ctDNA) are being used frequently in both research and clinical settings. ctDNA can be used to identify actionable mutations to personalize systemic therapy, detect post-treatment minimal residual disease (MRD), and predict responses to immunotherapy. ctDNA can also be isolated from a range of different biofluids, with the possibility of detecting locoregional MRD with increased sensitivity if sampling more proximally than blood plasma. However, ctDNA detection remains challenging in early-stage and post-treatment MRD settings where ctDNA levels are minuscule giving a high risk for false negative results, which is balanced with the risk of false positive results from clonal hematopoiesis. To address these challenges, researchers have developed ever-more elegant approaches to lower the limit of detection (LOD) of ctDNA assays toward the part-per-million range and boost assay sensitivity and specificity by reducing sources of low-level technical and biological noise, and by harnessing specific genomic and epigenomic features of ctDNA. In this review, we highlight a range of modern assays for ctDNA analysis, including advancements made to improve the signal-to-noise ratio. We further highlight the challenge of detecting ultra-rare tumor-associated variants, overcoming which will improve the sensitivity of post-treatment MRD detection and open a new frontier of personalized adjuvant treatment decision-making.


Subject(s)
Circulating Tumor DNA , Humans , Circulating Tumor DNA/genetics , Neoplasm, Residual/diagnosis , Neoplasm, Residual/genetics , Genomics
16.
Transl Oncol ; 37: 101763, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37657155

ABSTRACT

Up to 430,000 cases of bladder cancer are diagnosed each year worldwide. A proposed method for non-invasive monitoring has been to utilize a "liquid biopsy." Liquid biopsy has been proposed as a non-invasive method of testing biomarkers in bodily fluids in order to detect and survey cancer. The liquid biopsy could be utilized to obtain information regarding circulating tumor cells, circulating cell-free tumor DNA, circulating cell-free tumor RNA, and more. It is currently being investigated to help guide adjuvant therapy and improve oncological outcomes. We highlight an array of exciting past and ongoing clinical trials regarding ctDNA and adjuvant therapy in regard to urothelial carcinoma which we believe to be amongst the leaders in the field.

17.
J Med Chem ; 66(4): 3058-3072, 2023 02 23.
Article in English | MEDLINE | ID: mdl-36763536

ABSTRACT

Transient soluble oligomers of amyloid-ß (Aß) are considered among the most toxic species in Alzheimer's disease (AD). Soluble Aß oligomers accumulate early prior to insoluble plaque formation and cognitive impairment. The cyclic d,l-α-peptide CP-2 (1) self-assembles into nanotubes and demonstrates promising anti-amyloidogenic activity likely by a mechanism involving engagement of soluble oligomers. Systematic replacement of the residues in peptide 1 with aza-amino acid counterparts was performed to explore the effects of hydrogen bonding on propensity to mitigate Aß aggregation and toxicity. Certain azapeptides exhibited improved ability to engage, alter the secondary structure, and inhibit aggregation of Aß. Moreover, certain azapeptides disassembled preformed Aß fibrils and protected cells from Aß-mediated toxicity. Substitution of the l-norleucine3 and d-serine6 residues in peptide 1 with aza-norleucine and aza-homoserine provided, respectively, nontoxic [azaNle3]-1 (4) and [azaHse6]-1 (7), that significantly abated symptoms in a transgenic Caenorhabditis elegans AD model by decreasing Aß oligomer levels.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Nanotubes, Peptide , Humans , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Amyloid beta-Peptides/antagonists & inhibitors , Amyloid beta-Peptides/chemistry , Peptide Fragments/chemistry , Protein Structure, Secondary , Caenorhabditis elegans , Disease Models, Animal
18.
ACS Appl Mater Interfaces ; 15(15): 18598-18607, 2023 Apr 19.
Article in English | MEDLINE | ID: mdl-37015072

ABSTRACT

Traditional cold chain systems of collection, transportation, and storage of biofluid specimens for eventual analysis pose a huge financial and environmental burden. These systems are impractical in pre-hospital and resource-limited settings, where refrigeration and electricity are not reliable or even available. Here, we develop an innovative technology using metal-organic frameworks (MOFs), a novel class of organic-inorganic hybrids with high thermal stability, as encapsulates for preserving the integrity of protein biomarkers in biofluids under ambient or non-refrigerated storage conditions. We encapsulate prostate-specific antigen (PSA) in whole patient plasma using hydrophilic zeolitic imidazolate framework-90 (ZIF-90) for preservation at 40 °C for 4 weeks and eventual on-demand reconstitution for antibody-based assays with recovery above 95% compared to storage at -20 °C. Without ZIF-90 encapsulation, only 10-30% of the PSA immunoactivity remained. Furthermore, we demonstrate encapsulation of multiple cancer biomarker proteins in whole patient plasma using ZIF-8 or ZIF-90 encapsulants for eventual on-demand reconstitution and analysis after 1 week at 40 °C. Overall, MOF encapsulation of patient biofluids is important as climate change may be affecting the stability and increase costs of maintaining biospecimen cold chain custody for the collection, transportation, and storage of biospecimens prior to analysis or for biobanking regardless of any countries' affluence.


Subject(s)
Metal-Organic Frameworks , Humans , Male , Prostate-Specific Antigen , Biological Specimen Banks
19.
medRxiv ; 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38077092

ABSTRACT

Metastatic castration-resistant prostate cancer (mCRPC) resistant to androgen receptor (AR)-targeted agents is often lethal. Unfortunately, biomarkers for this deadly disease remain under investigation, and underpinning mechanisms are ill-understood. Here, we applied deep sequencing to ∼100 mCRPC patients prior to the initiation of first-line AR-targeted therapy, which detected AR /enhancer alterations in over a third of patients, which correlated with lethality. To delve into the mechanism underlying why these patients with cell-free AR /enhancer alterations developed more lethal prostate cancer, we next performed genome-wide cell-free DNA epigenomics. Strikingly, we found that binding sites for transcription factors associated with developmental stemness were nucleosomally more accessible. These results were corroborated using cell-free DNA methylation data, as well as tumor RNA sequencing from a held-out cohort of mCRPC patients. Thus, we validated the importance of AR /enhancer alterations as a prognostic biomarker in lethal mCRPC, and showed that the underlying mechanism for lethality involves reprogramming developmental states toward increased stemness.

20.
NPJ Precis Oncol ; 7(1): 6, 2023 Jan 19.
Article in English | MEDLINE | ID: mdl-36658307

ABSTRACT

Circulating tumor DNA (ctDNA) sensitivity remains subpar for molecular residual disease (MRD) detection in bladder cancer patients. To remedy this problem, we focused on the biofluid most proximal to the disease, urine, and analyzed urine tumor DNA in 74 localized bladder cancer patients. We integrated ultra-low-pass whole genome sequencing (ULP-WGS) with urine cancer personalized profiling by deep sequencing (uCAPP-Seq) to achieve sensitive MRD detection and predict overall survival. Variant allele frequency, inferred tumor mutational burden, and copy number-derived tumor fraction levels in urine cell-free DNA (cfDNA) significantly predicted pathologic complete response status, far better than plasma ctDNA was able to. A random forest model incorporating these urine cfDNA-derived factors with leave-one-out cross-validation was 87% sensitive for predicting residual disease in reference to gold-standard surgical pathology. Both progression-free survival (HR = 3.00, p = 0.01) and overall survival (HR = 4.81, p = 0.009) were dramatically worse by Kaplan-Meier analysis for patients predicted by the model to have MRD, which was corroborated by Cox regression analysis. Additional survival analyses performed on muscle-invasive, neoadjuvant chemotherapy, and held-out validation subgroups corroborated these findings. In summary, we profiled urine samples from 74 patients with localized bladder cancer and used urine cfDNA multi-omics to detect MRD sensitively and predict survival accurately.

SELECTION OF CITATIONS
SEARCH DETAIL