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1.
Biomed Opt Express ; 15(4): 2187-2201, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38633074

RESUMO

Slide-free imaging techniques have shown great promise in improving the histological workflow. For example, computational high-throughput autofluorescence microscopy by pattern illumination (CHAMP) has achieved high resolution with a long depth of field, which, however, requires a costly ultraviolet laser. Here, simply using a low-cost light-emitting diode (LED), we propose a deep learning-assisted framework of enhanced widefield microscopy, termed EW-LED, to generate results similar to CHAMP (the learning target). Comparing EW-LED and CHAMP, EW-LED reduces the cost by 85×, shortening the image acquisition time and computation time by 36× and 17×, respectively. This framework can be applied to other imaging modalities, enhancing widefield images for better virtual histology.

2.
PNAS Nexus ; 3(4): pgae133, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38601859

RESUMO

Deep learning algorithms have been widely used in microscopic image translation. The corresponding data-driven models can be trained by supervised or unsupervised learning depending on the availability of paired data. However, general cases are where the data are only roughly paired such that supervised learning could be invalid due to data unalignment, and unsupervised learning would be less ideal as the roughly paired information is not utilized. In this work, we propose a unified framework (U-Frame) that unifies supervised and unsupervised learning by introducing a tolerance size that can be adjusted automatically according to the degree of data misalignment. Together with the implementation of a global sampling rule, we demonstrate that U-Frame consistently outperforms both supervised and unsupervised learning in all levels of data misalignments (even for perfectly aligned image pairs) in a myriad of image translation applications, including pseudo-optical sectioning, virtual histological staining (with clinical evaluations for cancer diagnosis), improvement of signal-to-noise ratio or resolution, and prediction of fluorescent labels, potentially serving as new standard for image translation.

3.
Mod Pathol ; 37(6): 100487, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38588884

RESUMO

Lung adenocarcinoma (LUAD) is the most common primary lung cancer and accounts for 40% of all lung cancer cases. The current gold standard for lung cancer analysis is based on the pathologists' interpretation of hematoxylin and eosin (H&E)-stained tissue slices viewed under a brightfield microscope or a digital slide scanner. Computational pathology using deep learning has been proposed to detect lung cancer on histology images. However, the histological staining workflow to acquire the H&E-stained images and the subsequent cancer diagnosis procedures are labor-intensive and time-consuming with tedious sample preparation steps and repetitive manual interpretation, respectively. In this work, we propose a weakly supervised learning method for LUAD classification on label-free tissue slices with virtual histological staining. The autofluorescence images of label-free tissue with histopathological information can be converted into virtual H&E-stained images by a weakly supervised deep generative model. For the downstream LUAD classification task, we trained the attention-based multiple-instance learning model with different settings on the open-source LUAD H&E-stained whole-slide images (WSIs) dataset from the Cancer Genome Atlas (TCGA). The model was validated on the 150 H&E-stained WSIs collected from patients in Queen Mary Hospital and Prince of Wales Hospital with an average area under the curve (AUC) of 0.961. The model also achieved an average AUC of 0.973 on 58 virtual H&E-stained WSIs, comparable to the results on 58 standard H&E-stained WSIs with an average AUC of 0.977. The attention heatmaps of virtual H&E-stained WSIs and ground-truth H&E-stained WSIs can indicate tumor regions of LUAD tissue slices. In conclusion, the proposed diagnostic workflow on virtual H&E-stained WSIs of label-free tissue is a rapid, cost effective, and interpretable approach to assist clinicians in postoperative pathological examinations. The method could serve as a blueprint for other label-free imaging modalities and disease contexts.

4.
bioRxiv ; 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38405779

RESUMO

Extrachromosomal DNA (ecDNA) is a central mechanism for focal oncogene amplification in cancer, occurring in approximately 15% of early stage cancers and 30% of late-stage cancers. EcDNAs drive tumor formation, evolution, and drug resistance by dynamically modulating oncogene copy-number and rewiring gene-regulatory networks. Elucidating the genomic architecture of ecDNA amplifications is critical for understanding tumor pathology and developing more effective therapies. Paired-end short-read (Illumina) sequencing and mapping have been utilized to represent ecDNA amplifications using a breakpoint graph, where the inferred architecture of ecDNA is encoded as a cycle in the graph. Traversals of breakpoint graph have been used to successfully predict ecDNA presence in cancer samples. However, short-read technologies are intrinsically limited in the identification of breakpoints, phasing together of complex rearrangements and internal duplications, and deconvolution of cell-to-cell heterogeneity of ecDNA structures. Long-read technologies, such as from Oxford Nanopore Technologies, have the potential to improve inference as the longer reads are better at mapping structural variants and are more likely to span rearranged or duplicated regions. Here, we propose CoRAL (Complete Reconstruction of Amplifications with Long reads), for reconstructing ecDNA architectures using long-read data. CoRAL reconstructs likely cyclic architectures using quadratic programming that simultaneously optimizes parsimony of reconstruction, explained copy number, and consistency of long-read mapping. CoRAL substantially improves reconstructions in extensive simulations and 9 datasets from previously-characterized cell-lines as compared to previous short-read-based tools. As long-read usage becomes wide-spread, we anticipate that CoRAL will be a valuable tool for profiling the landscape and evolution of focal amplifications in tumors.

5.
J Clin Invest ; 134(3)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38299587

RESUMO

Synaptic plasticity is obstructed by pathogenic tau in the brain, representing a key mechanism that underlies memory loss in Alzheimer's disease (AD) and related tauopathies. Here, we found that reduced levels of the memory-associated protein KIdney/BRAin (KIBRA) in the brain and increased KIBRA protein levels in cerebrospinal fluid are associated with cognitive impairment and pathological tau levels in disease. We next defined a mechanism for plasticity repair in vulnerable neurons using the C-terminus of the KIBRA protein (CT-KIBRA). We showed that CT-KIBRA restored plasticity and memory in transgenic mice expressing pathogenic human tau; however, CT-KIBRA did not alter tau levels or prevent tau-induced synapse loss. Instead, we found that CT-KIBRA stabilized the protein kinase Mζ (PKMζ) to maintain synaptic plasticity and memory despite tau-mediated pathogenesis. Thus, our results distinguished KIBRA both as a biomarker of synapse dysfunction and as the foundation for a synapse repair mechanism to reverse cognitive impairment in tauopathy.


Assuntos
Doença de Alzheimer , Resiliência Psicológica , Tauopatias , Camundongos , Animais , Humanos , Proteínas tau/genética , Proteínas tau/metabolismo , Tauopatias/genética , Tauopatias/metabolismo , Tauopatias/patologia , Encéfalo/metabolismo , Doença de Alzheimer/patologia , Transtornos da Memória/genética , Transtornos da Memória/metabolismo , Plasticidade Neuronal , Camundongos Transgênicos , Rim/metabolismo , Modelos Animais de Doenças
6.
Nat Genet ; 55(12): 2189-2199, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37945900

RESUMO

Circular extrachromosomal DNA (ecDNA) in patient tumors is an important driver of oncogenic gene expression, evolution of drug resistance and poor patient outcomes. Applying computational methods for the detection and reconstruction of ecDNA across a retrospective cohort of 481 medulloblastoma tumors from 465 patients, we identify circular ecDNA in 82 patients (18%). Patients with ecDNA-positive medulloblastoma were more than twice as likely to relapse and three times as likely to die within 5 years of diagnosis. A subset of tumors harbored multiple ecDNA lineages, each containing distinct amplified oncogenes. Multimodal sequencing, imaging and CRISPR inhibition experiments in medulloblastoma models reveal intratumoral heterogeneity of ecDNA copy number per cell and frequent putative 'enhancer rewiring' events on ecDNA. This study reveals the frequency and diversity of ecDNA in medulloblastoma, stratified into molecular subgroups, and suggests copy number heterogeneity and enhancer rewiring as oncogenic features of ecDNA.


Assuntos
Neoplasias Cerebelares , Meduloblastoma , Neoplasias , Humanos , DNA Circular , Meduloblastoma/genética , Estudos Retrospectivos , Neoplasias/genética , Oncogenes , Neoplasias Cerebelares/genética
7.
bioRxiv ; 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37961138

RESUMO

Oncogene amplification on extrachromosomal DNA (ecDNA) is a pervasive driver event in cancer, yet our understanding of how ecDNA forms is limited. Here, we couple a CRISPR-based method for induction of ecDNA with extensive characterization of newly formed ecDNA to examine ecDNA biogenesis. We find that DNA circularization is efficient, irrespective of 3D genome context, with formation of a 1 Mb and 1.8 Mb ecDNA both reaching 15%. We show non-homologous end joining and microhomology mediated end joining both contribute to ecDNA formation, while inhibition of DNA-PKcs and ATM have opposing impacts on ecDNA formation. EcDNA and the corresponding chromosomal excision scar form at significantly different rates and respond differently to DNA-PKcs and ATM inhibition. Taken together, our results support a model of ecDNA formation in which double strand break ends dissociate from their legitimate ligation partners prior to joining of illegitimate ends to form the ecDNA and excision scar.

8.
bioRxiv ; 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37398236

RESUMO

Synaptic plasticity is obstructed by pathogenic tau in the brain, representing a key mechanism that underlies memory loss in Alzheimer's disease (AD) and related tauopathies. Here, we define a mechanism for plasticity repair in vulnerable neurons using the C-terminus of the KIdney/BRAin (KIBRA) protein (CT-KIBRA). We show that CT-KIBRA restores plasticity and memory in transgenic mice expressing pathogenic human tau; however, CT-KIBRA did not alter tau levels or prevent tau-induced synapse loss. Instead, we find that CT-KIBRA binds to and stabilizes protein kinase Mζ (PKMζ) to maintain synaptic plasticity and memory despite tau-mediated pathogenesis. In humans we find that reduced KIBRA in brain and increased KIBRA in cerebrospinal fluid are associated with cognitive impairment and pathological tau levels in disease. Thus, our results distinguish KIBRA both as a novel biomarker of synapse dysfunction in AD and as the foundation for a synapse repair mechanism to reverse cognitive impairment in tauopathy.

9.
bioRxiv ; 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37503111

RESUMO

The chromosomal theory of inheritance has dominated human genetics, including cancer genetics. Genes on the same chromosome segregate together while genes on different chromosomes assort independently, providing a fundamental tenet of Mendelian inheritance. Extrachromosomal DNA (ecDNA) is a frequent event in cancer that drives oncogene amplification, dysregulated gene expression and intratumoral heterogeneity, including through random segregation during cell division. Distinct ecDNA sequences, herein termed ecDNA species, can co-exist to facilitate intermolecular cooperation in cancer cells. However, how multiple ecDNA species within a tumor cell are assorted and maintained across somatic cell generations to drive cancer cell evolution is not known. Here we show that cooperative ecDNA species can be coordinately inherited through mitotic co-segregation. Imaging and single-cell analyses show that multiple ecDNAs encoding distinct oncogenes co-occur and are correlated in copy number in human cancer cells. EcDNA species are coordinately segregated asymmetrically during mitosis, resulting in daughter cells with simultaneous copy number gains in multiple ecDNA species prior to any selection. Computational modeling reveals the quantitative principles of ecDNA co-segregation and co-selection, predicting their observed distributions in cancer cells. Finally, we show that coordinated inheritance of ecDNAs enables co-amplification of specialized ecDNAs containing only enhancer elements and guides therapeutic strategies to jointly deplete cooperating ecDNA oncogenes. Coordinated inheritance of ecDNAs confers stability to oncogene cooperation and novel gene regulatory circuits, allowing winning combinations of epigenetic states to be transmitted across cell generations.

10.
Can Fam Physician ; 69(4): e86-e93, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37072203

RESUMO

OBJECTIVE: To understand the impact of virtual visits on primary care physician (PCP) work flows. DESIGN: Qualitative semistructured interviews. SETTING: Primary care practices within 5 regions in southern Ontario. PARTICIPANTS: Physicians representing primary care practices of various sizes and remuneration models (eg, capitation and fee-for-service models). METHODS: Interviews were conducted with PCPs involved in a large-scale pilot project implementing virtual visits (via a Web-based application) into clinical practices. Convenience and purposive sampling were used to recruit PCPs between January 2018 and March 2019. To obtain a representative sample, participants were sought from a variety of practice types and geographic regions. High and low users of virtual visits were included. Interviews were audiorecorded and transcribed. An inductive thematic analysis was used to identify prominent themes and subthemes. MAIN FINDINGS: Twenty-six physicians were interviewed (n=15 using convenience sampling and n=11 through purposive sampling). Four themes were identified: PCPs employ diverse approaches to integrate virtual care into their work flow; PCPs recognize that implementing virtual visits requires upfront time and effort but have variable perceptions regarding long-term impact of virtual care on processes; asynchronous messaging is preferable to synchronous audio or video visits; and strategies were identified to improve the integration of virtual visits. CONCLUSION: The potential of virtual care to improve work flow is dependent on the way these visits are implemented and used. Dedicated time for implementation, emphasis on using asynchronous secure messaging, and access to clinical champions and structured change management support were associated with more seamless integration of virtual visits.


Assuntos
Médicos de Atenção Primária , Humanos , Fluxo de Trabalho , Projetos Piloto , Planos de Pagamento por Serviço Prestado , Ontário
11.
Can Fam Physician ; 69(4): e78-e85, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37072204

RESUMO

OBJECTIVE: To explore primary care physician (PCP) perspectives on the clinical utility of virtual visits. DESIGN: Qualitative design involving semistructured interviews. SETTING: Primary care practices within 5 regions in southern Ontario. PARTICIPANTS: Primary care physicians representing different practice sizes and remuneration models. METHODS: Interviews were conducted with PCPs who were involved in a large-scale pilot implementation of virtual visits (patient-provider asynchronous messaging, or synchronous audio or video communication). The first phase involved a convenience sample of users in the first 2 regions where the pilot was initiated; after implementation in all 5 regions, purposive sampling was used to ensure diversity within the sample (eg, physicians representing different use frequencies of virtual visits, regions, and remuneration models). Interviews were audiorecorded and transcribed. An inductive thematic analysis was used to identify prominent themes and subthemes. MAIN FINDINGS: Twenty-six physicians were interviewed. Fifteen were recruited using convenience sampling and 11 through purposive sampling. Four themes regarding the clinical utility of virtual visits were identified: virtual visits can effectively resolve many patient concerns, with some variation in PCP comfort using virtual visits for specific conditions; virtual visits are beneficial for a range of patients but some patients might overuse or inappropriately use them; PCPs prefer to use asynchronous messaging (eg, text or online messaging) because of its convenience and flexibility; and virtual visits can provide value at the patient, provider, and health system levels. CONCLUSION: While participants believed that virtual visits can be appropriately used to resolve a variety of clinical concerns, they found in practice that virtual visits are fundamentally different from face-to-face encounters. Professional guidelines on appropriate use cases should be established to develop a standard framework for virtual care.


Assuntos
Médicos , Atenção Primária à Saúde , Humanos , Ontário , Projetos de Pesquisa , Pesquisa Qualitativa
12.
J Med Internet Res ; 25: e37867, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36630160

RESUMO

BACKGROUND: Vision loss from diabetic-related retinopathy (DR) is preventable through regular screening. OBJECTIVE: The purpose of this study was to test different patient engagement approaches to expand a teleophthalmology program at a primary care clinic in the city of Toronto, Canada. METHODS: A teleophthalmology program was set up in a large, urban, academic, team-based primary care practice. Patients older than 18 years with type 1 or type 2 diabetes were randomized to one of the following 4 engagement strategies: phone call, mail, mail plus phone call, or usual care. Outreach was conducted by administrative staff within the clinic. The primary outcome was booking an appointment for DR screening. RESULTS: A total of 23 patients in the phone, 28 in the mail, 32 in the mail plus phone call, and 27 in the control (usual care) group were included in the analysis. After the intervention and after excluding patients who said they were screened, 88% (15/17) of patients in the phone, 11% (2/18) in the mail, and 100% (21/21) in the mail and phone group booked an appointment with the teleophthalmology program compared to 0% (0/12) in the control group. Phoning patients positively predicted patients booking a teleophthalmology appointment (P<.001), whereas mailing a letter had no effect. CONCLUSIONS: Patient engagement to book DR screening via teleophthalmology in an urban, academic, team-based primary care practice using telephone calls was much more effective than patient engagement using letters or usual care. Practices that have access to a local DR screening program and have resources for such engagement strategies should consider using them as a means to improve their DR screening rates. TRIAL REGISTRATION: ClinicalTrials.gov NCT03927859; https://clinicaltrials.gov/ct2/show/NCT03927859.


Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Oftalmologia , Telemedicina , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Estudos Prospectivos , Retinopatia Diabética/diagnóstico , Telefone , Programas de Rastreamento , Atenção Primária à Saúde
13.
bioRxiv ; 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38168210

RESUMO

Oncogene amplification is a major driver of cancer pathogenesis. Breakage fusion bridge (BFB) cycles, like extrachromosomal DNA (ecDNA), can lead to high copy numbers of oncogenes, but their impact on intratumoral heterogeneity, treatment response, and patient survival are not well understood due to difficulty in detecting them by DNA sequencing. We describe a novel algorithm that detects and reconstructs BFB amplifications using optical genome maps (OGMs), called OM2BFB. OM2BFB showed high precision (>93%) and recall (92%) in detecting BFB amplifications in cancer cell lines, PDX models and primary tumors. OM-based comparisons demonstrated that short-read BFB detection using our AmpliconSuite (AS) toolkit also achieved high precision, albeit with reduced sensitivity. We detected 371 BFB events using whole genome sequences from 2,557 primary tumors and cancer lines. BFB amplifications were preferentially found in cervical, head and neck, lung, and esophageal cancers, but rarely in brain cancers. BFB amplified genes show lower variance of gene expression, with fewer options for regulatory rewiring relative to ecDNA amplified genes. BFB positive (BFB (+)) tumors showed reduced heterogeneity of amplicon structures, and delayed onset of resistance, relative to ecDNA(+) tumors. EcDNA and BFB amplifications represent contrasting mechanisms to increase the copy numbers of oncogene with markedly different characteristics that suggest different routes for intervention.

14.
Elife ; 112022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36331195

RESUMO

Rapid multicolor three-dimensional (3D) imaging for centimeter-scale specimens with subcellular resolution remains a challenging but captivating scientific pursuit. Here, we present a fast, cost-effective, and robust multicolor whole-organ 3D imaging method assisted with ultraviolet (UV) surface excitation and vibratomy-assisted sectioning, termed translational rapid ultraviolet-excited sectioning tomography (TRUST). With an inexpensive UV light-emitting diode (UV-LED) and a color camera, TRUST achieves widefield exogenous molecular-specific fluorescence and endogenous content-rich autofluorescence imaging simultaneously while preserving low system complexity and system cost. Formalin-fixed specimens are stained layer by layer along with serial mechanical sectioning to achieve automated 3D imaging with high staining uniformity and time efficiency. 3D models of all vital organs in wild-type C57BL/6 mice with the 3D structure of their internal components (e.g., vessel network, glomeruli, and nerve tracts) can be reconstructed after imaging with TRUST to demonstrate its fast, robust, and high-content multicolor 3D imaging capability. Moreover, its potential for developmental biology has also been validated by imaging entire mouse embryos (~2 days for the embryo at the embryonic day of 15). TRUST offers a fast and cost-effective approach for high-resolution whole-organ multicolor 3D imaging while relieving researchers from the heavy sample preparation workload.


Assuntos
Técnicas Histológicas , Imageamento Tridimensional , Animais , Camundongos , Camundongos Endogâmicos C57BL , Imageamento Tridimensional/métodos , Tomografia Computadorizada por Raios X , Coloração e Rotulagem
15.
Nat Genet ; 54(11): 1746-1754, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36253572

RESUMO

Extrachromosomal DNA (ecDNA) is a common mode of oncogene amplification but is challenging to analyze. Here, we adapt CRISPR-CATCH, in vitro CRISPR-Cas9 treatment and pulsed field gel electrophoresis of agarose-entrapped genomic DNA, previously developed for bacterial chromosome segments, to isolate megabase-sized human ecDNAs. We demonstrate strong enrichment of ecDNA molecules containing EGFR, FGFR2 and MYC from human cancer cells and NRAS ecDNA from human metastatic melanoma with acquired therapeutic resistance. Targeted enrichment of ecDNA versus chromosomal DNA enabled phasing of genetic variants, identified the presence of an EGFRvIII mutation exclusively on ecDNAs and supported an excision model of ecDNA genesis in a glioblastoma model. CRISPR-CATCH followed by nanopore sequencing enabled single-molecule ecDNA methylation profiling and revealed hypomethylation of the EGFR promoter on ecDNAs. We distinguished heterogeneous ecDNA species within the same sample by size and sequence with base-pair resolution and discovered functionally specialized ecDNAs that amplify select enhancers or oncogene-coding sequences.


Assuntos
Glioblastoma , Neoplasias , Humanos , Oncogenes , DNA/genética , Neoplasias/genética , Neoplasias/patologia , Glioblastoma/genética , Receptores ErbB/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-36141927

RESUMO

BACKGROUND: The link between nocturia and aging male symptoms (AMS) has not been scientifically established. This study aimed to measure the degree of severity of AMS that impacts health-related quality of life (HRQoL) in adult males living with nocturia and to determine the predictive values of nocturnal factors on AMS. METHODS: This is an extended analysis of new data collected by using the Hong Kong Traditional AMS (HK-AMS) scale and the Cantonese version of the Pittsburgh Sleep Quality Index (PSQI) in a recently published cross-sectional population-based survey. RESULTS: Of the 781 respondents that completed the set of questionnaires, 68% and 61% of men living with nocturia reported clinically significant (at moderate-to-severe levels) somato-vegetative and sexual AMS; the prevalence and severity were increased with advancing nighttime voiding frequency. Age, the Global PSQI score, certain metabolic diseases, the nocturia-specific QoL (NQoL) score and bedtime voiding frequency were found to be significant predictive factors for composite somato-vegetative and sexual AMS. CONCLUSIONS: The current findings suggested the inclusion of nocturia when measuring male-specific HRQoL related to aging.


Assuntos
Noctúria , Adulto , Envelhecimento , Estudos Transversais , Humanos , Masculino , Noctúria/epidemiologia , Qualidade de Vida , Inquéritos e Questionários
17.
Can J Diabetes ; 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35985924

RESUMO

OBJECTIVES: Teleophthalmology has improved diabetic retinopathy screening, and should be expanded in urban areas, where most unscreened individuals reside. In this study we explored facilitators and barriers of teleophthalmology in primary care settings in Toronto, Canada. METHODS: Semistructured interviews were conducted with 7 health-care providers and 7 individuals with diabetes to explore their perspectives of teleophthalmology in urban primary care settings. Interview data were analyzed using interpretive thematic analysis to generate themes. RESULTS: Six themes were identified. Facilitators included patient-centred implementation, access to teleophthalmology at primary care sites and patients' trust in their providers' recommendations. Barriers included patients' lack of understanding of diabetic retinopathy and the health-care system, providers' lack of interest and the need to streamline administrative processes. CONCLUSIONS: Although teleophthalmology was well-received by patients, there was limited interest from primary care providers. Strategies for increasing uptake include increasing primary care providers' awareness of teleophthalmology's value in urban centres, improving administrative processes and centralizing patient recruitment.

18.
Adv Sci (Weinh) ; 9(2): e2102358, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34747142

RESUMO

Rapid and high-resolution histological imaging with minimal tissue preparation has long been a challenging and yet captivating medical pursuit. Here, the authors propose a promising and transformative histological imaging method, termed computational high-throughput autofluorescence microscopy by pattern illumination (CHAMP). With the assistance of computational microscopy, CHAMP enables high-throughput and label-free imaging of thick and unprocessed tissues with large surface irregularity at an acquisition speed of 10 mm2 /10 s with 1.1-µm lateral resolution. Moreover, the CHAMP image can be transformed into a virtually stained histological image (Deep-CHAMP) through unsupervised learning within 15 s, where significant cellular features are quantitatively extracted with high accuracy. The versatility of CHAMP is experimentally demonstrated using mouse brain/kidney and human lung tissues prepared with various clinical protocols, which enables a rapid and accurate intraoperative/postoperative pathological examination without tissue processing or staining, demonstrating its great potential as an assistive imaging platform for surgeons and pathologists to provide optimal adjuvant treatment.


Assuntos
Encéfalo/citologia , Técnicas Histológicas/métodos , Rim/citologia , Pulmão/citologia , Microscopia/métodos , Aprendizado de Máquina não Supervisionado , Animais , Humanos , Camundongos , Modelos Animais
19.
Photoacoustics ; 25: 100313, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34804794

RESUMO

Ultraviolet photoacoustic microscopy (UV-PAM) has been investigated to provide label-free and registration-free volumetric histological images for whole organs, offering new insights into complex biological organs. However, because of the high UV absorption of lipids and pigments in tissue, UV-PAM suffers from low image contrast and shallow image depth, hindering its capability for revealing various microstructures in organs. To improve the UV-PAM imaging contrast and imaging depth, here we propose to implement a state-of-the-art optical clearing technique, CUBIC (clear, unobstructed brain/body imaging cocktails and computational analysis), to wash out the lipids and pigments from tissues. Our results show that the UV-PAM imaging contrast and quality can be significantly improved after tissue clearing. With the cleared tissue, multilayers of cell nuclei can also be extracted from time-resolved PA signals. Tissue clearing-enhanced UV-PAM can provide fine details for organ imaging.

20.
Nature ; 600(7890): 731-736, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34819668

RESUMO

Extrachromosomal DNA (ecDNA) is prevalent in human cancers and mediates high expression of oncogenes through gene amplification and altered gene regulation1. Gene induction typically involves cis-regulatory elements that contact and activate genes on the same chromosome2,3. Here we show that ecDNA hubs-clusters of around 10-100 ecDNAs within the nucleus-enable intermolecular enhancer-gene interactions to promote oncogene overexpression. ecDNAs that encode multiple distinct oncogenes form hubs in diverse cancer cell types and primary tumours. Each ecDNA is more likely to transcribe the oncogene when spatially clustered with additional ecDNAs. ecDNA hubs are tethered by the bromodomain and extraterminal domain (BET) protein BRD4 in a MYC-amplified colorectal cancer cell line. The BET inhibitor JQ1 disperses ecDNA hubs and preferentially inhibits ecDNA-derived-oncogene transcription. The BRD4-bound PVT1 promoter is ectopically fused to MYC and duplicated in ecDNA, receiving promiscuous enhancer input to drive potent expression of MYC. Furthermore, the PVT1 promoter on an exogenous episome suffices to mediate gene activation in trans by ecDNA hubs in a JQ1-sensitive manner. Systematic silencing of ecDNA enhancers by CRISPR interference reveals intermolecular enhancer-gene activation among multiple oncogene loci that are amplified on distinct ecDNAs. Thus, protein-tethered ecDNA hubs enable intermolecular transcriptional regulation and may serve as units of oncogene function and cooperative evolution and as potential targets for cancer therapy.


Assuntos
Neoplasias , Proteínas Nucleares , Azepinas/farmacologia , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias/genética , Proteínas Nucleares/genética , Oncogenes/genética , Fatores de Transcrição/genética
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