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1.
Mol Biol Cell ; 35(2): ar14, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38019611

RESUMEN

Myosin 10 (Myo10) couples microtubules and integrin-based adhesions to movement along actin filaments via its microtubule-binding MyTH4 domain and integrin-binding FERM domain, respectively. Here we show that Myo10-depleted HeLa cells and mouse embryo fibroblasts (MEFs) both exhibit a pronounced increase in the frequency of multipolar spindles. Staining of unsynchronized metaphase cells showed that the primary driver of spindle multipolarity in Myo10-depleted MEFs and in Myo10-depleted HeLa cells lacking supernumerary centrosomes is pericentriolar material (PCM) fragmentation, which creates y-tubulin-positive acentriolar foci that serve as extra spindle poles. For HeLa cells possessing supernumerary centrosomes, Myo10 depletion further accentuates spindle multipolarity by impairing the clustering of the extra spindle poles. Complementation experiments show that Myo10 must interact with both microtubules and integrins to promote PCM/pole integrity. Conversely, Myo10 only needs interact with integrins to promote supernumerary centrosome clustering. Importantly, images of metaphase Halo-Myo10 knockin cells show that the myosin localizes exclusively to the spindle and the tips of adhesive retraction fibers. We conclude that Myo10 promotes PCM/pole integrity in part by interacting with spindle microtubules, and that it promotes supernumerary centrosome clustering by supporting retraction fiber-based cell adhesion, which likely serves to anchor the microtubule-based forces driving pole focusing.


Asunto(s)
Centrosoma , Huso Acromático , Ratones , Humanos , Animales , Células HeLa , Huso Acromático/metabolismo , Centrosoma/metabolismo , Microtúbulos/metabolismo , Miosinas/metabolismo , Integrinas/metabolismo , Mitosis
2.
bioRxiv ; 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37645762

RESUMEN

The extracellular matrix (ECM) supports blood vessel architecture and functionality and undergoes active remodelling during vascular repair and atherogenesis. Vascular smooth muscle cells (VSMCs) are essential for vessel repair and, via their secretome, are able to invade from the vessel media into the intima to mediate ECM remodelling. Accumulation of fibronectin (FN) is a hallmark of early vascular repair and atherosclerosis and here we show that FN stimulates VSMCs to secrete small extracellular vesicles (sEVs) by activating the ß1 integrin/FAK/Src pathway as well as Arp2/3-dependent branching of the actin cytoskeleton. Spatially, sEV were secreted via filopodia-like cellular protrusions at the leading edge of migrating cells. We found that sEVs are trapped by the ECM in vitro and colocalise with FN in symptomatic atherosclerotic plaques in vivo. Functionally, ECM-trapped sEVs induced the formation of focal adhesions (FA) with enhanced pulling forces at the cellular periphery. Proteomic and GO pathway analysis revealed that VSMC-derived sEVs display a cell adhesion signature and are specifically enriched with collagen VI. In vitro assays identified collagen VI as playing the key role in cell adhesion and invasion. Taken together our data suggests that the accumulation of FN is a key early event in vessel repair acting to promote secretion of collage VI enriched sEVs by VSMCs. These sEVs stimulate migration and invasion by triggering peripheral focal adhesion formation and actomyosin contraction to exert sufficient traction forces to enable VSMC movement within the complex vascular ECM network.

3.
bioRxiv ; 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37398378

RESUMEN

Myosin 10 (Myo10) has the ability to link actin filaments to integrin-based adhesions and to microtubules by virtue of its integrin-binding FERM domain and microtubule-binding MyTH4 domain, respectively. Here we used Myo10 knockout cells to define Myo10's contribution to the maintenance of spindle bipolarity, and complementation to quantitate the relative contributions of its MyTH4 and FERM domains. Myo10 knockout HeLa cells and mouse embryo fibroblasts (MEFs) both exhibit a pronounced increase in the frequency of multipolar spindles. Staining of unsynchronized metaphase cells showed that the primary driver of spindle multipolarity in knockout MEFs and knockout HeLa cells lacking supernumerary centrosomes is pericentriolar material (PCM) fragmentation, which creates γ-tubulin-positive acentriolar foci that serve as additional spindle poles. For HeLa cells possessing supernumerary centrosomes, Myo10 depletion further accentuates spindle multipolarity by impairing the clustering of the extra spindle poles. Complementation experiments show that Myo10 must interact with both integrins and microtubules to promote PCM/pole integrity. Conversely, Myo10's ability to promote the clustering of supernumerary centrosomes only requires that it interact with integrins. Importantly, images of Halo-Myo10 knock-in cells show that the myosin localizes exclusively within adhesive retraction fibers during mitosis. Based on these and other results, we conclude that Myo10 promotes PCM/pole integrity at a distance, and that it facilitates supernumerary centrosome clustering by promoting retraction fiber-based cell adhesion, which likely provides an anchor for the microtubule-based forces driving pole focusing.

4.
Biophys J ; 122(18): 3549-3550, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37311456

Asunto(s)
Actinas , Seudópodos
5.
Biophys J ; 122(18): 3656-3677, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37207658

RESUMEN

To facilitate rapid changes in morphology without endangering cell integrity, each cell possesses a substantial amount of cell surface excess (CSE) that can be promptly deployed to cover cell extensions. CSE can be stored in different types of small surface projections such as filopodia, microvilli, and ridges, with rounded bleb-like projections being the most common and rapidly achieved form of storage. We demonstrate that, similar to rounded cells in 2D culture, rounded cells in 3D collagen contain large amounts of CSE and use it to cover developing protrusions. Upon retraction of a protrusion, the CSE this produces is stored over the cell body similar to the CSE produced by cell rounding. We present high-resolution imaging of F-actin and microtubules (MTs) for different cell lines in a 3D environment and demonstrate the correlated changes between CSE and protrusion dynamics. To coordinate CSE storage and release with protrusion formation and motility, we expect cells to have specific mechanisms for regulating CSE, and we hypothesize that MTs play a substantial role in this mechanism by reducing cell surface dynamics and stabilizing CSE. We also suggest that different effects of MT depolymerization on cell motility, such as inhibiting mesenchymal motility and enhancing amoeboid, can be explained by this role of MTs in CSE regulation.


Asunto(s)
Actinas , Colágeno , Actinas/metabolismo , Membrana Celular/metabolismo , Colágeno/metabolismo , Microtúbulos/metabolismo , Seudópodos/metabolismo , Movimiento Celular/fisiología , Extensiones de la Superficie Celular
6.
Aust J Rural Health ; 30(5): 582-592, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35749467

RESUMEN

OBJECTIVE: To evaluate the acceptability and effectiveness of a small community-based hospice on the end-of-life experiences of patients and families. METHODS: Mixed-methods study. DESIGN: Patient admission data were used to assess utilisation of the hospice. Open-ended interviews with hospice patients and their families/carers were used to understand the emotional effects of the service. SETTING: A small palliative end-of-life hospice in a rural town in NSW, Australia, during a 12-month trial period that began in March 2019. Data were collected in October-November 2019. PARTICIPANTS: Patients, families and carers who used the hospice during the trial period, as well as staff working at the hospice. MAIN OUTCOME MEASURE(S): Quantitative measures included the number of patients admitted to the hospice, the average length of stay and the overall occupancy rate of the hospice. Quantitative interviews were used to explore the experiences of patients and families who used the hospice, and whether the hospice met their end-of-life needs. RESULTS: During the trial, 58 patients were admitted to the hospice. The majority of admissions were less than 7 days. Two patients and nine family members were interviewed about their experiences, and six staff completed interviews. Experiences were consistently positive, with the community setting of the hospice contributing to a peaceful and home-like end-of-life experience. Interviewees described meaningful relationships with staff, a pleasant physical environment and the comprehensive care provided were key elements of this experience. CONCLUSION: This model, embedding end-of-life care within a residential aged care facility, facilitated a positive end-of-life experience for residents of this regional community. The development of local models to meet local needs is essential to enabling people nearing the end of life to remain in their location of choice, and ensure that their needs are met at this vulnerable time.


Asunto(s)
Cuidados Paliativos al Final de la Vida , Cuidado Terminal , Anciano , Servicios de Salud Comunitaria , Muerte , Humanos , Cuidados Paliativos
7.
Sci Adv ; 7(38): eabg6908, 2021 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-34524844

RESUMEN

Genomic instability is a hallmark of human cancer; yet the underlying mechanisms remain poorly understood. Here, we report that the cytoplasmic unconventional Myosin X (MYO10) regulates genome stability, through which it mediates inflammation in cancer. MYO10 is an unstable protein that undergoes ubiquitin-conjugating enzyme H7 (UbcH7)/ß-transducin repeat containing protein 1 (ß-TrCP1)­dependent degradation. MYO10 is upregulated in both human and mouse tumors and its expression level predisposes tumor progression and response to immune therapy. Overexpressing MYO10 increased genomic instability, elevated the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING)­dependent inflammatory response, and accelerated tumor growth in mice. Conversely, depletion of MYO10 ameliorated genomic instability and reduced the inflammation signaling. Further, inhibiting inflammation or disrupting Myo10 significantly suppressed the growth of both human and mouse breast tumors in mice. Our data suggest that MYO10 promotes tumor progression through inducing genomic instability, which, in turn, creates an immunogenic environment for immune checkpoint blockades.

8.
Elife ; 102021 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-34519272

RESUMEN

Skeletal muscle fibers are multinucleated cellular giants formed by the fusion of mononuclear myoblasts. Several molecules involved in myoblast fusion have been discovered, and finger-like projections coincident with myoblast fusion have also been implicated in the fusion process. The role of these cellular projections in muscle cell fusion was investigated herein. We demonstrate that these projections are filopodia generated by class X myosin (Myo10), an unconventional myosin motor protein specialized for filopodia. We further show that Myo10 is highly expressed by differentiating myoblasts, and Myo10 ablation inhibits both filopodia formation and myoblast fusion in vitro. In vivo, Myo10 labels regenerating muscle fibers associated with Duchenne muscular dystrophy and acute muscle injury. In mice, conditional loss of Myo10 from muscle-resident stem cells, known as satellite cells, severely impairs postnatal muscle regeneration. Furthermore, the muscle fusion proteins Myomaker and Myomixer are detected in myoblast filopodia. These data demonstrate that Myo10-driven filopodia facilitate multinucleated mammalian muscle formation.


Asunto(s)
Fibras Musculares Esqueléticas/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Mioblastos Esqueléticos/metabolismo , Miosinas/metabolismo , Seudópodos/metabolismo , Animales , Diferenciación Celular , Fusión Celular , Línea Celular , Proliferación Celular , Modelos Animales de Enfermedad , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Ratones Noqueados , Desarrollo de Músculos , Fibras Musculares Esqueléticas/patología , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patología , Mioblastos Esqueléticos/patología , Miosinas/genética , Seudópodos/genética , Regeneración , Células Satélite del Músculo Esquelético/metabolismo , Células Satélite del Músculo Esquelético/patología , Factores de Tiempo
9.
J Thorac Oncol ; 16(6): 990-1002, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33647504

RESUMEN

INTRODUCTION: KRAS mutations, the most frequent gain-of-function alterations in NSCLC, are currently emerging as potential predictive therapeutic targets. The role of KRAS-G12C (Kr_G12C) is of special interest after the recent discovery and preclinical analyses of two different Kr_G12C covalent inhibitors (AMG-510, MRTX849). METHODS: KRAS mutations were evaluated in formalin-fixed, paraffin-embedded tissue sections by a microfluidic-based multiplex polymerase chain reaction platform as a component of the previously published European Thoracic Oncology Platform Lungscape 003 Multiplex Mutation study, of clinically annotated, resected, stage I to III NSCLC. In this study, -Kr_G12C mutation prevalence and its association with clinicopathologic characteristics, molecular profiles, and postoperative patient outcome (overall survival, relapse-free survival, time-to-relapse) were explored. RESULTS: KRAS gene was tested in 2055 Lungscape cases (adenocarcinomas: 1014 [49%]) with I or II or III stage respective distribution of 53% or 24% or 22% and median follow-up of 57 months. KRAS mutation prevalence in the adenocarcinoma cohort was 38.0% (95% confidence interval (CI): 35.0% to 41.0%), with Kr_G12C mutation representing 17.0% (95% CI: 14.7% to 19.4%). In the "histologic-subtype" cohort, Kr_G12C prevalence was 10.5% (95% CI: 9.2% to 11.9%). When adjusting for clinicopathologic characteristics, a significant negative prognostic effect of Kr_G12C presence versus other KRAS mutations or nonexistence of KRAS mutation was identified in the adenocarcinoma cohort alone and in the "histologic-subtype" cohort. For overall survival in adenocarcinomas, hazard ratio (HR)G12C versus other KRAS is equal to 1.39 (95% CI: 1.03 to 1.89, p = 0.031) and HRG12C versus no KRAS is equal to 1.32 (95% CI: 1.03 to 1.69, p = 0.028) (both also significant in the "histologic-subtype" cohort). For time-to-relapse, HRG12C versus other KRAS is equal to 1.41 (95% CI: 1.03 to 1.92, p = 0.030). In addition, among all patients, for relapse-free survival, HRG12C versus no KRAS is equal to 1.27 (95% CI: 1.04 to 1.54, p = 0.017). CONCLUSIONS: In this large, clinically annotated stage I to III NSCLC cohort, the specific Kr_G12C mutation is significantly associated with poorer prognosis (adjusting for clinicopathologic characteristics) among adenocarcinomas and in unselected NSCLCs.


Asunto(s)
Neoplasias Pulmonares , Proteínas Proto-Oncogénicas p21(ras) , Humanos , Neoplasias Pulmonares/genética , Mutación , Recurrencia Local de Neoplasia , Piperazinas , Pronóstico , Proteínas Proto-Oncogénicas p21(ras)/genética , Piridinas , Pirimidinas
10.
Elife ; 102021 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-33570491

RESUMEN

Morphogens function in concentration-dependent manners to instruct cell fate during tissue patterning. The cytoneme morphogen transport model posits that specialized filopodia extend between morphogen-sending and responding cells to ensure that appropriate signaling thresholds are achieved. How morphogens are transported along and deployed from cytonemes, how quickly a cytoneme-delivered, receptor-dependent signal is initiated, and whether these processes are conserved across phyla are not known. Herein, we reveal that the actin motor Myosin 10 promotes vesicular transport of Sonic Hedgehog (SHH) morphogen in mouse cell cytonemes, and that SHH morphogen gradient organization is altered in neural tubes of Myo10-/- mice. We demonstrate that cytoneme-mediated deposition of SHH onto receiving cells induces a rapid, receptor-dependent signal response that occurs within seconds of ligand delivery. This activity is dependent upon a novel Dispatched (DISP)-BOC/CDON co-receptor complex that functions in ligand-producing cells to promote cytoneme occurrence and facilitate ligand delivery for signal activation.


During development, cells must work together and talk to each other to build the organs and tissues of the growing embryo. To communicate precisely with long-distance targets, cells can project a series of thin finger-like structures known as cytonemes. Cells use these miniature highways to exchange cargo and signals, such as the protein sonic hedgehog (SHH for short). Alterations to the way SHH is exchanged during development predispose to cancer and lead to disorders of the nervous system. Yet, the mechanisms by which cytonemes work in mammals remain to be fully elucidated. In particular, it is still unclear how the structures start to form, and how the proteins are loaded and transported from one end to another. A 'molecular motor' called myosin 10, which can carry cargo along the internal skeleton of cells, may be involved in these processes. To find out, Hall et al. used fluorescent probes to track both myosin 10 and SHH in mouse cells, showing that myosin 10 carries SHH from the core of the signal-producing cell to the tips of cytonemes. There, the protein is passed to the target cell upon contact, triggering a quick response. SHH also appeared to be more than just passive cargo, interacting with another group of proteins in the signal-emitting cell before reaching its target. This mechanism then encourages the signalling cells to produce more cytonemes towards their neighbours. SHH is crucial during development, but also after birth: in fact, changes to SHH transport in adulthood can also disrupt tissue balance and hinder healing. Understanding how healthy tissues send this signal may reveal why and how disease emerges.


Asunto(s)
Moléculas de Adhesión Celular/genética , Proteínas Hedgehog/genética , Inmunoglobulina G/genética , Proteínas de la Membrana/genética , Miosinas/genética , Receptores de Superficie Celular/genética , Animales , Transporte Biológico , Moléculas de Adhesión Celular/metabolismo , Proteínas Hedgehog/metabolismo , Inmunoglobulina G/metabolismo , Ligandos , Proteínas de la Membrana/metabolismo , Ratones , Ratones Transgénicos , Miosinas/metabolismo , Receptores de Superficie Celular/metabolismo
11.
J Pediatr Hematol Oncol ; 43(4): e525-e528, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32516200

RESUMEN

Sclerosing lipogranuloma (SLG) in children is a rare, benign disease of unknown etiology suspected to be due to abnormal fatty tissue reaction. A 13-year-old girl presented with progressively worsening back pain. Cross-sectional imaging identified a retroperitoneal mass compressing the left ureter as well as infrarenal inferior vena cava atresia with extensive venous collaterals and chronic partially occlusive thromboses of the iliac veins. Surgical biopsy was consistent with SLG and it resolved spontaneously. SLG is typically a disease of adulthood but may be seen in children. The association between inferior vena cava atresia with venous thrombosis and development of SLG has not been reported previously.


Asunto(s)
Lipidosis/patología , Grasa Subcutánea/patología , Adolescente , Femenino , Humanos , Inflamación/complicaciones , Inflamación/patología , Lipidosis/complicaciones , Fibrosis Retroperitoneal/complicaciones , Fibrosis Retroperitoneal/patología , Vena Cava Inferior/patología , Trombosis de la Vena/complicaciones , Trombosis de la Vena/patología
12.
iScience ; 23(12): 101802, 2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33299973

RESUMEN

Invasion and proliferation are defining phenotypes of cancer, and in glioblastoma blocking one stimulates the other, implying that effective therapy must inhibit both, ideally through a single target that is also dispensable for normal tissue function. The molecular motor myosin 10 meets these criteria. Myosin 10 knockout mice can survive to adulthood, implying that normal cells can compensate for its loss; its deletion impairs invasion, slows proliferation, and prolongs survival in murine models of glioblastoma. Myosin 10 deletion also enhances tumor dependency on the DNA damage and the metabolic stress responses and induces synthetic lethality when combined with inhibitors of these processes. Our results thus demonstrate that targeting myosin 10 is active against glioblastoma by itself, synergizes with other clinically available therapeutics, may have acceptable side effects in normal tissues, and has potential as a heretofore unexplored therapeutic approach for this disease.

13.
Genetics ; 216(4): 905-930, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33067325

RESUMEN

The laboratory mouse is the most widely used animal model for biomedical research, due in part to its well-annotated genome, wealth of genetic resources, and the ability to precisely manipulate its genome. Despite the importance of genetics for mouse research, genetic quality control (QC) is not standardized, in part due to the lack of cost-effective, informative, and robust platforms. Genotyping arrays are standard tools for mouse research and remain an attractive alternative even in the era of high-throughput whole-genome sequencing. Here, we describe the content and performance of a new iteration of the Mouse Universal Genotyping Array (MUGA), MiniMUGA, an array-based genetic QC platform with over 11,000 probes. In addition to robust discrimination between most classical and wild-derived laboratory strains, MiniMUGA was designed to contain features not available in other platforms: (1) chromosomal sex determination, (2) discrimination between substrains from multiple commercial vendors, (3) diagnostic SNPs for popular laboratory strains, (4) detection of constructs used in genetically engineered mice, and (5) an easy-to-interpret report summarizing these results. In-depth annotation of all probes should facilitate custom analyses by individual researchers. To determine the performance of MiniMUGA, we genotyped 6899 samples from a wide variety of genetic backgrounds. The performance of MiniMUGA compares favorably with three previous iterations of the MUGA family of arrays, both in discrimination capabilities and robustness. We have generated publicly available consensus genotypes for 241 inbred strains including classical, wild-derived, and recombinant inbred lines. Here, we also report the detection of a substantial number of XO and XXY individuals across a variety of sample types, new markers that expand the utility of reduced complexity crosses to genetic backgrounds other than C57BL/6, and the robust detection of 17 genetic constructs. We provide preliminary evidence that the array can be used to identify both partial sex chromosome duplication and mosaicism, and that diagnostic SNPs can be used to determine how long inbred mice have been bred independently from the relevant main stock. We conclude that MiniMUGA is a valuable platform for genetic QC, and an important new tool to increase the rigor and reproducibility of mouse research.


Asunto(s)
Estudio de Asociación del Genoma Completo/métodos , Técnicas de Genotipaje/métodos , Ratones/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Animales , Femenino , Estudio de Asociación del Genoma Completo/normas , Genotipo , Técnicas de Genotipaje/normas , Masculino , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos/normas , Polimorfismo Genético , Reproducibilidad de los Resultados , Procesos de Determinación del Sexo
14.
Aust J Rural Health ; 28(5): 490-499, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32985045

RESUMEN

OBJECTIVE: To explore the patterns of and investigate the factors associated with rises in emergency department presentations in rural and metropolitan New South Wales from 2012 to 2018. DESIGN: A retrospective descriptive study of de-identified data from the New South Wales Emergency Department Data Collection. SETTING: New South Wales, Australia. PARTICIPANTS: All individuals presenting to 99 New South Wales emergency departments, which continuously reported to the Emergency Department Data Collection between 2012 and 2018. A total of 2 166 449 presentations recorded throughout New South Wales in 2012 (rural 786 278; metropolitan 1 380 171) and 2 477 192 in 2018 (rural 861 761; metropolitan 1 615 431). MAIN OUTCOME MEASURES: Total emergency department presentations, plus Poisson regression modelled annual changes in emergency department presentations over the period 2012-2018. RESULTS: Growth in emergency department presentations outpaced population growth in both rural and metropolitan New South Wales between 2012 and 2018. The patterns of age-standardised rates of presentations were broadly similar between rural and metropolitan areas, with highest rates observed in the youngest (0-4 years) and oldest (85+ years) cohorts. The rural sample also displayed a distinct third peak in ages 15-39 years, and rates were higher across all age groups. Rural New South Wales displayed disproportionately higher emergency department presentations in the two most deprived socio-economic status quintiles. While rural New South Wales displayed significant reductions in triage category 5 (non-urgent cases) over time, the relative proportion remained approximately double that of metropolitan sites. CONCLUSIONS: There are differences between rural and metropolitan emergency department presentations relating to demographic factors, triage levels, acuity and admissions. Detailed local investigations are required to determine specific contextual issues that impact on emergency department demand.


Asunto(s)
Servicio de Urgencia en Hospital , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Servicio de Urgencia en Hospital/estadística & datos numéricos , Humanos , Lactante , Recién Nacido , Persona de Mediana Edad , Nueva Gales del Sur/epidemiología , Estudios Retrospectivos , Población Rural , Triaje , Población Urbana , Adulto Joven
15.
J Biol Chem ; 295(28): 9297-9298, 2020 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-32651283

RESUMEN

Recent research has revealed that an adhesion complex based on cadherins and the motor protein myosin-7b (MYO7B) links the tips of intestinal microvilli. Choi et al. now report that a largely uncharacterized protein known as calmodulin-like protein 4 (CALML4) is a component of this adhesion complex and functions as a light chain for myosin-7b. Because the intermicrovillar adhesion complex is homologous to the myosin-7a (MYO7A)-based Usher syndrome complex and Choi et al. also report that CALML4 can bind to myosin-7a, this work also has important implications for research on myosin-7a and hereditary deaf-blindness.


Asunto(s)
Miosina VIIa , Síndromes de Usher , Cadherinas/metabolismo , Dineínas , Humanos , Cadenas Ligeras de Miosina
16.
Mod Pathol ; 33(5): 792-801, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31740722

RESUMEN

PD-L1, as assessed by immunohistochemistry, is a predictive biomarker for immuno-oncology treatment in lung cancer. Different scoring methods have been used to assess its status, resulting in a wide range of positivity rates. We use the European Thoracic Oncology Platform Lungscape non-small cell lung carcinoma cohort to explore this issue. PD-L1 expression was assessed via immunohistochemistry on tissue microarrays (up to four cores per case), using the DAKO 28-8 immunohistochemistry assay, following a two-round external quality assessment procedure. All samples were analyzed under the same protocol. Cross-validation of scoring between tissue microarray and whole sections was performed in 10% randomly selected samples. Cutoff points considered: ≥1, 50 (primarily), and 25%. At the two external quality assessment rounds, tissue microarray scoring agreement rates between pathologists were: 73% and 81%. There were 2008 cases with valid immunohistochemistry tissue microarray results (50% all cores evaluable). Concordant cases at 1, 25, and 50% were: 85, 91, and 93%. Tissue microarray core results were identical for 70% of cases. Sensitivity of the tissue microarray method for 1, 25, and 50% was: 80, 78, and 79% (specificity: 90, 95, 98%). Complete agreement between tissue microarrays and whole sections was achieved for 60% of the cases. Highest sensitivity rates for 1% and 50% cutoffs were detected for higher number of cores. Underestimation of PD-L1 expression on small samples is more common than overestimation. We demonstrated that classification of PD-L1 on small biopsy samples does not represent the overall expression of PD-L1 in all non-small cell cancer carcinoma cases, although the majority of cases are 'correctly' classified. In future studies, sampling more and larger biopsies, recording the biopsy size and tumor load may permit further refinement, increasing predictive accuracy.


Asunto(s)
Antígeno B7-H1/análisis , Antígeno B7-H1/biosíntesis , Biomarcadores de Tumor/análisis , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Biopsia/métodos , Estudios de Cohortes , Humanos , Garantía de la Calidad de Atención de Salud , Estudios Retrospectivos , Análisis de Matrices Tisulares
17.
Anaerobe ; 59: 205-211, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31386902

RESUMEN

Regulation of bacterial motility to maximize nutrient acquisition or minimize exposure to harmful substances plays an important role in microbial proliferation and host colonization. The technical difficulties of performing high-resolution live microscopy on anaerobes have hindered mechanistic studies of motility in Clostridioides (formerly Clostridium) difficile. Here, we present a widely applicable protocol for live cell imaging of anaerobic bacteria that has allowed us to characterize C. difficile swimming at the single-cell level. This accessible method for anaerobic live cell microscopy enables inquiry into previously inaccessible aspects of C. difficile physiology and behavior. We present the first report that vegetative C. difficile are capable of regulated motility in the presence of different nutrients. We demonstrate that the epidemic C. difficile strain R20291 exhibits regulated motility in the presence of multiple nutrient sources by modulating its swimming velocity. This is a powerful illustration of the ability of single-cell studies to explain population-wide phenomena such as dispersal through the environment.


Asunto(s)
Clostridioides difficile/efectos de los fármacos , Clostridioides difficile/fisiología , Microscopía Intravital/métodos , Locomoción/efectos de los fármacos , Nutrientes/metabolismo
18.
Lung Cancer ; 131: 95-103, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31027705

RESUMEN

INTRODUCTION: The PD-L1 biomarker is an important factor in selecting patients with non-small cell lung cancer for immunotherapy. While several reports suggest that PD-L1 positivity is linked to a poor prognosis, others suggest that PD-L1 positive status portends a good prognosis. METHODS: PD-L1 positivity prevalence, assessed via immunohistochemistry (IHC) on tissue microarrays (TMAs), and its association with clinicopathological characteristics, molecular profiles and patient outcome- Relapse-free Survival (RFS), Time-to-Relapse (TTR) and Overall Survival (OS)- is explored in the ETOP Lungscape cohort of stage I-III non-small cell lung cancer (NSCLC). Tumors are considered positive if they have ≥1/5/25/50% neoplastic cell membrane staining. RESULTS: PD-L1 expression was assessed in 2182 NSCLC cases (2008 evaluable, median follow-up 4.8 years, 54.6% still alive), from 15 ETOP centers. Adenocarcinomas represent 50.9% of the cohort (squamous cell: 42.4%). Former smokers are 53.7% (current: 31.6%, never: 10.5%). PD-L1 positivity prevalence is present in more than one third of the Lungscape cohort (1%/5% cut-offs). It doesn't differ between adenocarcinomas and squamous cell histologies, but is more frequently detected in higher stages, never smokers, larger tumors (1/5/25% cut-offs). With ≥1% cut-off it is significantly associated with IHC MET overexpression, expression of PTEN, EGFR and KRAS mutation (only for adenocarcinoma). Results for 5%, 25% and 50% cut-offs were similar, with MET being significantly associated with PD-L1 positivity both for AC (p < 0.001, 5%/25%/50% cut-offs) and SCC (p < 0.001, 5% & 50% cut-offs and p = 0.0017 for 25%). When adjusting for clinicopathological characteristics, a significant prognostic effect was identified in adenocarcinomas (adjusted p-values: 0.024/0.064/0.063 for RFS/TTR/OS 1% cut-off, analogous for 5%/25%, but not for 50%). Similar results obtained for the model including all histologies, but no effect was found for the squamous cell carcinomas. CONCLUSION: PD-L1 positivity, when adjusted for clinicopathological characteristics, is associated with a better prognosis for non-metastatic adenocarcinoma patients.


Asunto(s)
Adenocarcinoma del Pulmón/metabolismo , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Inmunoterapia/métodos , Neoplasias Pulmonares/metabolismo , Adenocarcinoma del Pulmón/diagnóstico , Adenocarcinoma del Pulmón/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Estudios de Cohortes , Europa (Continente) , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Proteínas Proto-Oncogénicas c-met/metabolismo , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento , Adulto Joven
19.
J Thorac Oncol ; 13(12): 1851-1863, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30240851

RESUMEN

INTRODUCTION: Phosphatase and tensin homolog (PTEN) loss is frequently observed in NSCLC and associated with both phosphoinositide 3-kinase activation and tumoral immunosuppression. PTEN immunohistochemistry is a valuable readout, but lacks standardized staining protocol and cutoff value. METHODS: After an external quality assessment using SP218, 138G6 and 6H2.1 anti-PTEN antibodies, scored on webbook and tissue microarray, the European Thoracic Oncology Platform cohort samples (n = 2245 NSCLC patients, 8980 tissue microarray cores) were stained with SP218. All cores were H-scored by pathologists and by computerized pixel-based intensity measurements calibrated by pathologists. RESULTS: All three antibodies differentiated six PTEN+ versus six PTEN- cases on external quality assessment. For 138G6 and SP218, high sensitivity and specificity was found for all H-score threshold values including prospectively defined 0, calculated 8 (pathologists), and calculated 5 (computer). High concordance among pathologists in setting computer-based intensities and between pathologists and computer in H-scoring was observed. Because of over-integration of the human eye, pixel-based computer H-scores were overall 54% lower. For all cutoff values, PTEN- was associated with smoking history, squamous cell histology, and higher tumor stage (p < 0.001). In adenocarcinomas, PTEN- was associated with poor survival. CONCLUSION: Calibration of immunoreactivity intensities by pathologists following computerized H-score measurements has the potential to improve reproducibility and homogeneity of biomarker detection regarding epitope validation in multicenter studies.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/patología , Diagnóstico por Computador/métodos , Inmunohistoquímica/métodos , Neoplasias Pulmonares/patología , Fosfohidrolasa PTEN/metabolismo , Patólogos/estadística & datos numéricos , Adenocarcinoma del Pulmón/metabolismo , Adenocarcinoma del Pulmón/patología , Adenocarcinoma del Pulmón/cirugía , Anciano , Biomarcadores de Tumor , Carcinoma de Células Grandes/metabolismo , Carcinoma de Células Grandes/patología , Carcinoma de Células Grandes/cirugía , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/cirugía , Masculino , Persona de Mediana Edad , Pronóstico , Tasa de Supervivencia , Análisis de Matrices Tisulares
20.
Am J Clin Pathol ; 150(5): 393-405, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30052721

RESUMEN

OBJECTIVES: To assess bone marrow (BM) sampling in academic medical centers. METHODS: Data from 6,374 BM samples obtained in 32 centers in 2001 and 2011, including core length (CL), were analyzed. RESULTS: BM included a biopsy (BMB; 93%) specimen, aspirate (BMA; 92%) specimen, or both (83%). The median (SD) CL was 12 (8.5) mm, and evaluable marrow was 9 (7.6) mm. Tissue contraction due to processing was 15%. BMB specimens were longer in adults younger than 60 years, men, and bilateral, staging, and baseline samples. Only 4% of BMB and 2% of BMB/BMA samples were deemed inadequate for diagnosis. BM for plasma cell dyscrasias, nonphysician operators, and ancillary studies usage increased, while bilateral sampling decreased over the decade. BM-related quality assurance programs are infrequent. CONCLUSIONS: CL is shorter than recommended and varies with patient age and sex, clinical circumstances, and center experience. While pathologists render diagnoses on most cases irrespective of CL, BMB yield improvement is desirable.


Asunto(s)
Enfermedades de la Médula Ósea/patología , Médula Ósea/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja Gruesa , Enfermedades de la Médula Ósea/diagnóstico , Examen de la Médula Ósea/normas , Canadá , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Estados Unidos , Adulto Joven
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