Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 79
1.
Opt Express ; 32(7): 12508-12519, 2024 Mar 25.
Article En | MEDLINE | ID: mdl-38571071

Two-photon polymerization (TPP) is an advanced 3D fabrication technique capable of creating features with submicron precision. A primary challenge in TPP lies in the facile and accurate characterization of fabrication quality, particularly for structures possessing complex internal features. In this study, we introduce an automated brightfield layerwise evaluation technique that enables a simple-to-implement approach for in situ monitoring and quality assessment of TPP-fabricated structures. Our approach relies on sequentially acquired brightfield images during the TPP writing process and using background subtraction and image processing to extract layered spatial features. We experimentally validate our method by printing a fibrous tissue scaffold and successfully achieve an overall system-adjusted fidelity of 87.5% in situ. Our method is readily adaptable in most TPP systems and can potentially facilitate high-quality TPP manufacturing of sophisticated microstructures.

2.
J Cardiothorac Vasc Anesth ; 38(4): 957-963, 2024 Apr.
Article En | MEDLINE | ID: mdl-38310067

OBJECTIVES: Chronic alcohol use is associated with chronic pain and increased opioid consumption. The association between chronic alcohol use and acute postoperative pain has been studied minimally. The authors' objective was to explore the association among preoperative alcohol use, postoperative pain, and opioid consumption after coronary artery bypass grafting (CABG). DESIGN: A retrospective cohort study. SETTING: At a single academic medical center. PARTICIPANTS: Patients having isolated CABG. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographics, comorbidities, and baseline alcohol consumption were recorded. Primary outcomes were mean pain score and morphine milligram equivalent (MME) consumption on postoperative day 0. Among 1,338 patients, there were 764 (57.1%) who had no weekly preoperative alcohol use, 294 (22.0%) who drank ≤1 drink per week, 170 (12.7%) who drank 2-to-7 drinks per week, and 110 (8.2%) who drank 8 or more drinks per week. There was no significant difference in mean pain score on postoperative day 0 in patients who consumed different amounts of alcohol (no alcohol = 5.3 ± 2.2, ≤1 drink = 5.2 ± 2.1, 2 to 7 drinks = 5.3 ± 2.3, 8 or more drinks = 5.4 ± 1.9, p = 0.66). There was also no significant difference in median MME use on postoperative day 0 in patients who consumed different amounts of alcohol (no alcohol = 22.5 mg, ≤1 drink = 21.1 mg, 2-to-7 drinks = 24.8 mg, 8 or more drinks = 24.5 mg, p = 0.14). CONCLUSIONS: There is no apparent association among mild-to-moderate preoperative alcohol consumption and early postoperative pain and opioid use in patients who underwent CABG.


Analgesics, Opioid , Endrin/analogs & derivatives , Opioid-Related Disorders , Humans , Analgesics, Opioid/adverse effects , Retrospective Studies , Pain, Postoperative/diagnosis , Pain, Postoperative/drug therapy , Alcohol Drinking , Coronary Artery Bypass/adverse effects
3.
Lang Speech Hear Serv Sch ; 55(2): 394-408, 2024 04 11.
Article En | MEDLINE | ID: mdl-38227486

PURPOSE: The purpose of this clinical focus article is to discuss processes and procedures for building school-based programs to address the feeding and swallowing needs of students in the public-school setting. Interprofessional practice (IPP) team member roles and responsibilities, screening, eligibility, considerations for developing Individualized Education Programs that address the needs of students with pediatric feeding disorder (PFD) and dysphagia, as well as billing documentation requirements, are discussed. Additionally, coordination across the continuum of service delivery for students with PFD and dysphagia is investigated. Guidance on documentation, processes, and procedures that comply with the Individuals with Disabilities Education Act mandates will be provided. CONCLUSIONS: This clinical focus article will demonstrate that students with PFD and dysphagia continue to present to public schools and require skilled services and supports in order to meet their individualized needs. School-based speech-language pathologists have a legal requirement to provide these supports when deemed educationally relevant. Schools must employ processes and procedures that result in the timely and effective evaluation and identification of students with PFD and dysphagia. An IPP approach to the management of PFD and dysphagia is critical to ensure optimal outcomes for students found eligible for services.


Deglutition Disorders , Learning Disabilities , Speech-Language Pathology , Child , Humans , Deglutition Disorders/therapy , Schools , Social Behavior , School Health Services , Speech-Language Pathology/methods
4.
Sci Rep ; 13(1): 19232, 2023 11 06.
Article En | MEDLINE | ID: mdl-37932310

More than 75% of epithelial ovarian cancer (EOC) patients experience disease recurrence after initial treatment, highlighting our incomplete understanding of how chemoresistant populations evolve over the course of EOC progression post chemotherapy treatment. Here, we show how two paclitaxel (PTX) treatment methods- a single high dose and a weekly metronomic dose for four weeks, generate unique chemoresistant populations. Using mechanically relevant alginate microspheres and a combination of transcript profiling and heterogeneity analyses, we found that these PTX-treatment regimens produce distinct and resilient subpopulations that differ in metabolic reprogramming signatures, acquisition of resistance to PTX and anoikis, and the enrichment for cancer stem cells (CSCs) and polyploid giant cancer cells (PGCCs) with the ability to replenish bulk populations. We investigated the longevity of these metabolic reprogramming events using untargeted metabolomics and found that metabolites associated with stemness and therapy-induced senescence were uniquely abundant in populations enriched for CSCs and PGCCs. Predictive network analysis revealed that antioxidative mechanisms were likely to be differentially active dependent on both time and exposure to PTX. Our results illustrate how current standard chemotherapies contribute to the development of chemoresistant EOC subpopulations by either selecting for intrinsically resistant subpopulations or promoting the evolution of resistance mechanisms. Additionally, our work describes the unique phenotypic signatures in each of these distinct resistant subpopulations and thus highlights potential vulnerabilities that can be exploited for more effective treatment.


Ovarian Neoplasms , Paclitaxel , Female , Humans , Paclitaxel/pharmacology , Ovarian Neoplasms/metabolism , Drug Resistance, Neoplasm , Neoplasm Recurrence, Local , Carcinoma, Ovarian Epithelial , Cell Line, Tumor
5.
Cancers (Basel) ; 15(12)2023 Jun 14.
Article En | MEDLINE | ID: mdl-37370796

Metastatic progression of epithelial ovarian cancer (EOC) involves the partial epithelial-to-mesenchymal transition (EMT) of cancer cells in the primary tumor and dissemination into peritoneal fluid. In part to the high degree of heterogeneity in EOC cells, the identification of EMT in highly epithelial cells in response to differences in matrix mechanics, growth factor signaling, and tissue hypoxia is very difficult. We analyzed different degrees of EMT by tracking changes in cell and nuclear morphology, along with the organization of cytoskeletal proteins. In our analysis, we see a small percentage of individual cells that show dramatic response to TGF-ß1 and hypoxia treatment. We demonstrate that EOC cells are spatially aware of their surroundings, with a subpopulation of EOC cells at the periphery of a cell cluster in 2D environments exhibited a greater degree of EMT. These peripheral cancer cells underwent partial EMT, displaying a hybrid of mesenchymal and epithelial characteristics, which often included less cortical actin and more perinuclear cytokeratin expression. Collectively, these data show that tumor-promoting microenvironment conditions can mediate invasive cell behavior in a spatially regulated context in a small subpopulation of highly epithelial clustered cancer cells that maintain epithelial characteristics while also acquiring some mesenchymal traits through partial EMT.

6.
Aging (Albany NY) ; 15(5): 1237-1256, 2023 02 23.
Article En | MEDLINE | ID: mdl-36842089

Radiation-induced fibrosis is a common side effect of radiotherapy, which is the most common treatment for cancer. However, radiation also causes p53-mediated cell cycle arrest, prolonged expression of p21, and the development of senescence in normal cells that reside in irradiated tissues. Bone marrow-derived mesenchymal stem cells (MSCs) accumulate in primary tumor sites because of their natural tropism for inflammatory and fibrotic tissues. MSCs are extremely sensitive to low doses of ionizing radiation and acquire senescence as a result of bystander radiation effects. Senescent cells remain metabolically active but develop a potent senescence-associated secretory phenotype (SASP) that correlates to hyperactive secretion of cytokines, pro-fibrotic growth factors, and exosomes (EXOs). Integrative pathway analysis highlighted that radiation-induced senescence significantly enriched cell-cycle, extracellular matrix, transforming growth factor-ß (TGF-ß) signaling, and vesicle-mediated transport genes in MSCs. EXOs are cell-secreted nanovesicles (a subclass of small extracellular vesicles) that contain biomaterials-proteins, RNAs, microRNAs (miRNAs)-that are critical in cell-cell communication. miRNA content analysis of secreted EXOs further revealed that radiation-induced senescence uniquely altered miRNA profiles. In fact, several of the standout miRNAs directly targeted TGF-ß or downstream genes. To examine bystander effects of radiation-induced senescence, we further treated normal MSCs with senescence-associated EXOs (SA-EXOs). These modulated genes related to TGF-ß pathway and elevated both alpha smooth muscle actin (protein increased in senescent, activated cells) and Ki-67 (proliferative marker) expression in SA-EXO treated MSCs compared to untreated MSCs. We revealed SA-EXOs possess unique miRNA content that influence myofibroblast phenotypes via TGF-ß pathway activation. This highlights that SA-EXOs are potent SASP factors that play a large role in cancer-related fibrosis.


Exosomes , Extracellular Vesicles , MicroRNAs , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Exosomes/metabolism , Extracellular Vesicles/metabolism , Fibrosis , Transforming Growth Factor beta/metabolism
7.
Front Med (Lausanne) ; 9: 889998, 2022.
Article En | MEDLINE | ID: mdl-35801209

Objective: In 2019, dengue was among the "top-ten threats to global health," with 3.1 million cases reported from the Americas, the highest ever. Simultaneously, Jamaica reported its largest dengue outbreak in 40 years, following Chikungunya and Zika virus epidemics, in 2014 and 2016-2017, respectively. We describe dengue in children admitted to five hospitals in Jamaica during August 2018 through September 2019. Methods: Hospitalized children and adolescents aged 0 to 15 years with dengue were managed using PAHO/WHO criteria. Data were extracted from questionnaires, entered into a dataset on Microsoft Excel version 2016, exported to SPSS version 20 and analyzed. Groups were compared using Student's t-test for normally distributed parametric data. Chi-square analysis, or Fisher's exact test was used for categorical variables. A p-value < 0.05 was considered statistically significant. Results: There were 339 children, 245 (72.3%) aged 1-10 years, males:females 1:1. Classification was "dengue without warning signs" 53 (15.3%), "dengue with warning signs" 218 (64.3%) and "severe dengue" 68 (20%). Co-morbidities were reported in 88 (26%). Hemoglobin SC disease was associated with severe dengue with hemorrhage (p = 0.005). Organ-system involvement occurred in 334 (98.5%) including gastrointestinal 317 (93.5%), hematologic 311 (91.7%) and musculoskeletal 180 (53.1%). Thirty-nine (11.5%) had 5-7 organ-systems involved. Metabolomics emphasized increased hepatic transaminases 245 (72.3%), lactate dehydrogenase 164 (48.4%) and creatine phosphokinase 84 (24.8%) approaching the high thousands (121,560 u/L), both were markers for severe disease (p < 0.002). Thirteen (3.8%) received intensive care. Dengue was laboratory-confirmed in 220 (78.9%): NS1 antigen-positive (218); RT-PCR-positive (23), with an overlap of NS1 antigen and RT-PCR positive (21); DENV-3 serotype (20). Seventeen (5%) died, 16 (94.1%) had severe dengue and 11 (64.7%) succumbed within 24 to 48 h of admission despite resuscitation and transfusion of blood products. Conclusion: Severe dengue with increased attributable mortality occurred in hospitalized children after Jamaica's maiden Zika epidemic.

8.
Cancers (Basel) ; 14(6)2022 Mar 10.
Article En | MEDLINE | ID: mdl-35326569

High-grade serous ovarian cancer (HGSOC) constitutes the majority of all ovarian cancer cases and has staggering rates of both refractory and recurrent disease. While most patients respond to the initial treatment with paclitaxel and platinum-based drugs, up to 25% do not, and of the remaining that do, 75% experience disease recurrence within the subsequent two years. Intrinsic resistance in refractory cases is driven by environmental stressors like tumor hypoxia which alter the tumor microenvironment to promote cancer progression and resistance to anticancer drugs. Recurrent disease describes the acquisition of chemoresistance whereby cancer cells survive the initial exposure to chemotherapy and develop adaptations to enhance their chances of surviving subsequent treatments. Of the environmental stressors cancer cells endure, exposure to hypoxia has been identified as a potent trigger and priming agent for the development of chemoresistance. Both in the presence of the stress of hypoxia or the therapeutic stress of chemotherapy, cancer cells manage to cope and develop adaptations which prime populations to survive in future stress. One adaptation is the modification in the secretome. Chemoresistance is associated with translational reprogramming for increased protein synthesis, ribosome biogenesis, and vesicle trafficking. This leads to increased production of soluble proteins and extracellular vesicles (EVs) involved in autocrine and paracrine signaling processes. Numerous studies have demonstrated that these factors are largely altered between the secretomes of chemosensitive and chemoresistant patients. Such factors include cytokines, growth factors, EVs, and EV-encapsulated microRNAs (miRNAs), which serve to induce invasive molecular, biophysical, and chemoresistant phenotypes in neighboring normal and cancer cells. This review examines the modifications in the secretome of distinct chemoresistant ovarian cancer cell populations and specific secreted factors, which may serve as candidate biomarkers for aggressive and chemoresistant cancers.

9.
Autism ; 26(7): 1833-1848, 2022 10.
Article En | MEDLINE | ID: mdl-35168392

LAY ABSTRACT: Autistic people are believed to have emotions that are too negative and not positive enough, starting early in life. Their facial expressions are also persistently judged to be unusual, as reflected in criteria used to identify autism. But it is possible that common autistic facial expressions are poorly understood by observers, as suggested by a range of findings from research. Another issue is that autistic emotions have always been assessed in contexts suited to non-autistics. In our study, the facial expressions of young autistic and typical children were rated as positive, negative, neutral, or "unknown"-a category we created for emotions that observers notice but do not understand. These emotions were assessed using a context suited to autistic children, including objects of potential interest to them. We found that in this context, autistic and typical children did not differ in positive, negative, or neutral facial emotions. They did differ in unknown emotions, which were found only in autistic children. We also found that repetitive behaviors in autistic children co-occurred with positive, neutral, and unknown emotions, but not with negative emotions. In a context which suits their characteristics, autistic children do not show emotions that are too negative or not positive enough. They do show emotions perceived as unknown, which means we need to improve our understanding of their full emotional repertoire.


Autism Spectrum Disorder , Autistic Disorder , Autism Spectrum Disorder/psychology , Autistic Disorder/psychology , Child , Emotions , Face , Facial Expression , Humans
10.
J Exp Psychol Gen ; 151(3): 578-596, 2022 Mar.
Article En | MEDLINE | ID: mdl-34582232

Autism is diagnosed according to atypical social-communication and repetitive behaviors. However, autistic individuals are also distinctive in the high variability of specific abilities such as learning. Having been characterized as experiencing great difficulty with learning, autistics have also been reported to learn spontaneously in exceptional ways. These contrasting accounts suggest that some situations may be better than others for learning in autism. We tested this possibility using a probabilistic category learning task with four learning situations differing either in feedback intensity or information presentation. Two learning situations compared high- versus low-intensity feedback, while two other learning situations without external feedback compared isolated sequentially presented information versus arrays of simultaneously presented information. We assessed the categorization and generalization performance of 54 autistic and 52 age-matched typical school-age children after they learned in different situations. We found that children in both groups were able to learn and generalize novel probabilistic categories in all four learning situations. However, across and within groups, autistic children were advantaged by simultaneously presented information while typical children were advantaged by high-intensity feedback when learning. These findings question some common aspects of autism interventions (e.g., frequent intense feedback, minimized simplified information), and underline the importance of improving our current understanding of how and when autistics learn optimally. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Autism Spectrum Disorder , Autistic Disorder , Child , Cognition , Generalization, Psychological , Humans , Learning
12.
Semin Cancer Biol ; 81: 64-72, 2022 06.
Article En | MEDLINE | ID: mdl-33992783

Polyploid giant cancer cells (PGCCs) are a commonly observed histological feature of human tumors and are particularly prominent in late stage and drug resistant cancers. The chromosomal duplication conferred by their aneuploidy gives rise to DNA damage resistance and complex tumor cell karyotypes, a driving factor in chemotherapy resistance and disease relapse. Furthermore, PGCCs also exhibit key cytoskeletal features that give rise to a distinct biophysical phenotype, including increased density of polymerized actin and vimentin intermediate filaments, nuclear and cytoskeletal stiffening, increased traction force, and migratory persistence. Despite recent research highlighting the role PGCCs play in cancer progression, this population of tumor cells remains poorly characterized in terms of their biophysical properties. In this review, we will discuss the various aspects of their biomolecular phenotype, such as increased stemness as well as a mixed EMT signature. These features have been extensively associated with tumorigenesis and recurrence, and aggressive cancers. Additionally, we will also examine the distinct PGCC cytoskeletal features of actin and filamentous vimentin. Specifically, how the differential organization of these networks serve to support their increased size and drive migratory persistence. These findings could shed light on potential therapeutic strategies that allow for specific elimination or mitigation of the invasive potential of these polyploid cancer cells. Lastly, we will examine how the biophysical and molecular phenotype of PGCCs combine to tip the scale in favor of promoting cancer progression, presenting an important target in the clinical treatment of cancer.


Actins , Neoplasms , Cell Line, Tumor , Humans , Neoplasms/genetics , Phenotype , Polyploidy , Vimentin
13.
Int Rev Cell Mol Biol ; 360: 1-31, 2021.
Article En | MEDLINE | ID: mdl-33962748

The tumor microenvironment is a complex milieu that dictates the growth, invasion, and metastasis of cancer cells. Both cancer and stromal cells in the tumor tissue encounter and adapt to a variety of extracellular factors, and subsequently contribute and drive the progression of the disease to more advanced stages. As the disease progresses, a small population of cancer cells becomes more invasive through a complex process known as epithelial-mesenchymal transition, and nearby stromal cells assume a carcinoma associated fibroblast phenotype characterized by enhanced migration, cell contractility, and matrix secretion with the ability to reorganize extracellular matrices. As cells transition into more malignant phenotypes their biophysical properties, controlled by the organization of cytoskeletal proteins, are altered. Actin and its associated proteins are essential modulators and facilitators of these changes. As the cells respond to the cues in the microenvironment, actin driven mechanical forces inside and outside the cells also evolve. Recent advances in biophysical techniques have enabled us to probe these actin driven changes in cancer and stromal cells and demarcate their role in driving changes in the microenvironment. Understanding the underlying biophysical mechanisms that drive cancer progression could provide critical insight on novel therapeutic approaches in the fight against cancer.


Actins/metabolism , Cytoskeleton/metabolism , Neoplasms/pathology , Tumor Microenvironment , Animals , Biomechanical Phenomena , Epithelial-Mesenchymal Transition , Humans , Stromal Cells
14.
West J Emerg Med ; 22(2): 177-185, 2021 Jan 12.
Article En | MEDLINE | ID: mdl-33856298

INTRODUCTION: Patients with spontaneous intracranial hemorrhage (sICH) have high mortality and morbidity, which are associated with blood pressure variability. Additionally, blood pressure variability is associated with acute kidney injury (AKI) in critically ill patients, but its association with sICH patients in emergency departments (ED) is unclear. Our study investigated the association between blood pressure variability in the ED and the risk of developing AKI during sICH patients' hospital stay. METHODS: We retrospectively analyzed patients with sICH, including those with subarachnoid and intraparenchymal hemorrhage, who were admitted from any ED and who received an external ventricular drain at our academic center. Patients were identified by the International Classification of Diseases, Ninth Revision (ICD-9). Outcomes were the development of AKI, mortality, and being discharged home. We performed multivariable logistic regressions to measure the association of clinical factors and interventions with outcomes. RESULTS: We analyzed the records of 259 patients: 71 (27%) patients developed AKI, and 59 (23%) patients died. Mean age (± standard deviation [SD]) was 58 (14) years, and 150 (58%) were female. Patients with AKI had significantly higher blood pressure variability than patients without AKI. Each millimeter of mercury increment in one component of blood pressure variability, SD in systolic blood pressure (SBPSD), was significantly associated with 2% increased likelihood of developing AKI (odds ratio [OR] 1.02, 95% confidence interval [CI], 1.005-1.03, p = 0.007). Initiating nicardipine infusion in the ED (OR 0.35, 95% CI, 0.15-0.77, p = 0.01) was associated with lower odds of in-hospital mortality. No ED interventions or blood pressure variability components were associated with patients' likelihood to be discharged home. CONCLUSION: Our study suggests that greater SBPSD during patients' ED stay is associated with higher likelihood of AKI, while starting nicardipine infusion is associated with lower odds of in-hospital mortality. Further studies about interventions and outcomes of patients with sICH in the ED are needed to confirm our observations.


Blood Pressure/physiology , Emergency Service, Hospital/statistics & numerical data , Intracranial Hemorrhages/mortality , Length of Stay/statistics & numerical data , Acute Kidney Injury/epidemiology , Adult , Aged , Critical Illness , Female , Hospital Mortality , Hospitalization , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors
15.
J Child Psychol Psychiatry ; 62(1): 16-18, 2021 01.
Article En | MEDLINE | ID: mdl-32845011

Bottema-Beutel, Crowley, Sandbank, and Woynaroski (Journal of Child Psychology and Psychiatry, 2020) have performed a Herculean and invaluable task in their investigation of conflicts of interest (COIs) in nonpharmacological early autism intervention research. Drawing on a meta-analysis of 150 articles reporting group designs, they found COIs in 105 (70%), only 6 (5.7%) of which had fully accurate COI statements. Most reports had no COI statements, but among the 48 (32%) which did, the majority of those declaring no COIs had detectable COIs (23 of 30; 77%). Thus, COI reporting in the literature examined is routinely missing, misleading, and/or incomplete; accurate reporting is the exception rather than the rule. That 120 of the 150 reports were published in 2010 or later, compared to 6 pre-2000, tells us this is not about practices confined to decades past. Instead, it reflects and is a telling indictment of established standards in autism intervention research.


Autistic Disorder , Conflict of Interest , Child , Disclosure , Humans
16.
Proc Natl Acad Sci U S A ; 117(43): 26756-26765, 2020 10 27.
Article En | MEDLINE | ID: mdl-33046658

Polyploidal giant cancer cells (PGCCs) are multinucleated chemoresistant cancer cells found in heterogeneous solid tumors. Due in part to their apparent dormancy, the effect of PGCCs on cancer progression has remained largely unstudied. Recent studies have highlighted the critical role of PGCCs as aggressive and chemoresistant cancer cells, as well as their ability to undergo amitotic budding to escape dormancy. Our recent study demonstrated the unique biophysical properties of PGCCs, as well as their unusual migratory persistence. Here we unveil the critical function of vimentin intermediate filaments (VIFs) in maintaining the structural integrity of PGCCs and enhancing their migratory persistence. We performed in-depth single-cell analysis to examine the distribution of VIFs and their role in migratory persistence. We found that PGCCs rely heavily on their uniquely distributed and polarized VIF network to enhance their transition from a jammed to an unjammed state to allow for directional migration. Both the inhibition of VIFs with acrylamide and small interfering RNA knockdown of vimentin significantly decreased PGCC migration and resulted in a loss of PGCC volume. Because PGCCs rely on their VIF network to direct migration and to maintain their enlarged morphology, targeting vimentin or vimentin cross-linking proteins could provide a therapeutic approach to mitigate the impact of these chemoresistant cells in cancer progression and to improve patient outcomes with chemotherapy.


Cell Movement/drug effects , Giant Cells/drug effects , Neoplastic Processes , Polyploidy , Vimentin/pharmacology , Breast Neoplasms/metabolism , Cell Line, Tumor , Drug Resistance, Neoplasm , Epithelial-Mesenchymal Transition/drug effects , Female , Humans , Intermediate Filaments , Single-Cell Analysis
18.
Sci Rep ; 10(1): 8686, 2020 05 26.
Article En | MEDLINE | ID: mdl-32457479

Exosomes are cell-secreted microvesicles that play important roles in epithelial ovarian cancer (EOC) progression, as they are constantly secreted into ascites fluids. While cells spontaneously release exosomes, alterations in intracellular calcium or extracellular pH can release additional exosomes. Yet, little is known about how these exosomes compare to those that are continuously released without stimulation and how they mediate cellular activities important in cancer progression. Here, we demonstrate that chelation of extracellular calcium leads to release of chelation-induced exosomes (CI-exosomes) from OVCAR-3 EOC cells. CI-exosomes display a unique miRNA profile compared to naturally secreted exosomes (SEC-exosomes). Furthermore, treatment with CI- and SEC-exosomes leads to differential biophysical and functional changes including, adhesion and migration in EOC-derived fibroblasts that suggest the development of a malignant tumor microenvironment. This result highlights how tumor environmental factors contribute to heterogeneity in exosome populations and how different exosome populations mediate diversity in stromal cell behavior.


Cancer-Associated Fibroblasts/metabolism , Exosomes/metabolism , Actins/metabolism , Calcium/chemistry , Cancer-Associated Fibroblasts/cytology , Cancer-Associated Fibroblasts/drug effects , Cell Adhesion , Cell Line, Tumor , Cell Movement , Chelating Agents/chemistry , Chelating Agents/pharmacology , Disease Progression , Exosomes/chemistry , Female , Humans , MicroRNAs/metabolism , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Principal Component Analysis , Vinculin/metabolism
19.
J Cell Sci ; 133(2)2020 01 23.
Article En | MEDLINE | ID: mdl-31932504

Mesenchymal stem cells (MSCs) are essential for the regenerative process; however, biological aging and environmental stress can induce senescence - an irreversible state of growth arrest - that not only affects the behavior of cells but also disrupts their ability to restore tissue integrity. While abnormal tissue properties, including increased extracellular matrix stiffness, are linked with the risk of developing breast cancer, the role and contribution of senescent MSCs to the disease progression to malignancy are not well understood. Here, we investigated senescence-associated biophysical changes in MSCs and how this influences cancer cell behavior in a 3D matrix interface model. Although senescent MSCs were far less motile than pre-senescent MSCs, they induced an invasive breast cancer phenotype, characterized by increased spheroid growth and cell invasion in collagen gels. Further analysis of collagen gels using second-harmonic generation showed increased collagen density when senescent MSCs were present, suggesting that senescent MSCs actively remodel the surrounding matrix. This study provides direct evidence of the pro-malignant effects of senescent MSCs in tumors.


Breast Neoplasms/genetics , Extracellular Matrix/metabolism , Mesenchymal Stem Cells/metabolism , Cell Proliferation , Female , Humans , Phenotype , Tumor Microenvironment
20.
Sci Rep ; 9(1): 11478, 2019 08 07.
Article En | MEDLINE | ID: mdl-31391540

Recent studies suggest that glypican-1 (GPC-1) is a biomarker for prostate cancer, but there are few studies elucidating the role of GPC-1 in prostate cancer progression. We observed high expression of GPC-1 in more aggressive prostate cancer cell lines such as PC-3 and DU-145. While inhibition of GPC-1 expression in PC-3 cells decreased cell growth and migration in vitro, it surprisingly increased cell proliferation and migration in DU-145 cells, suggesting that the role of GPC-1 is cell type-dependent. Further, GPC-1 inhibition increased PC-3 tumor size in NCr nude mice xenografts. We hypothesized that the discrepancy between the in vitro and in vivo data is mediated by stromal cells in the tumor microenvironment. Thus, we tested the effect of tumor conditioned media (TCM) on gene expression in human mesenchymal stem cells and fibroblasts. Treatment of stromal cells with TCM from PC-3 cells transfected with GPC-1 shRNA increased the expression of migration markers, endocrine/paracrine biomolecules, and extracellular matrix components. Additionally, the decreased cell growth in GPC-1 knockdown PC-3 cells was rescued by coculturing with stromal cells. These data demonstrate the paradoxical role that GPC-1 plays in prostate cancer cell growth by interacting with stromal cells and through ECM remodeling and endocrine/paracrine signaling.


Antineoplastic Agents/pharmacology , Extracellular Matrix/pathology , Glypicans/metabolism , Prostatic Neoplasms/pathology , Stromal Cells/pathology , Animals , Antineoplastic Agents/therapeutic use , Cell Culture Techniques , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Coculture Techniques , Culture Media, Conditioned , Extracellular Matrix/drug effects , Fibroblasts , Gene Knockdown Techniques , Glypicans/antagonists & inhibitors , Glypicans/genetics , Humans , Male , Mesenchymal Stem Cells , Mice , Paracrine Communication/drug effects , Prostate/cytology , Prostate/pathology , Prostatic Neoplasms/drug therapy , Stromal Cells/drug effects , Tumor Burden/drug effects , Tumor Microenvironment/drug effects , Xenograft Model Antitumor Assays
...