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1.
J Oncol Pharm Pract ; : 10781552241281936, 2024 Sep 04.
Article in English | MEDLINE | ID: mdl-39228222

ABSTRACT

INTRODUCTION: The goal of pharmacogenetic testing is to identify genetic variants with significant implications on drug safety and efficacy. Several professional organizations and institutions have demonstrated the value of pharmacist involvement in the implementation of pharmacogenomic services. Therefore, we aimed to establish a pharmacist-guided model for interpretation of pharmacogenetic results for all oncology patients seen at the Dartmouth Cancer Center (DCC) in Lebanon, NH. METHODS: A pilot of a pharmacist-guided pharmacogenomics dosing service was implemented at the DCC. Pharmacy services included review of results from a next generation sequencing panel for DPYD, TPMT, NUDT15, and UGT1A1 variants. The pharmacist wrote a note in the electronic health record (EHR) detailing actionable drug-gene interactions and drug-dosing guidance, which was then routed to the treating oncologist. Outcomes collected included highlighting actionable mutations and defining pharmacist interventions. In addition, time spent formulating and documenting patient-specific drug-dosing recommendations was collected. RESULTS: From February 2024 through May 2024, a total of 71 patients with pharmacogenetic results, provided by the clinical molecular laboratory at Dartmouth Health, were reviewed by the pharmacist. The majority of patients tested were diagnosed with a malignancy of gastrointestinal origin. Twenty-one patients were found to have actionable variants in at least one of the four genes evaluated, and five of the 21 identified patients had active treatment plans for which dose changes were then implemented. CONCLUSIONS: Implementation of a pharmacist-guided pharmacogenomics based dosing service aided in optimizing drug therapy and has positioned Dartmouth Health for further expansion of pharmacogenomics and personalized patient care.

3.
Int J Surg Pathol ; 31(8): 1473-1484, 2023 Dec.
Article in English | MEDLINE | ID: mdl-36911994

ABSTRACT

Introduction: Molecular analysis plays a growing role in the diagnosis of mesenchymal neoplasms. The aim of this study was to retrospectively apply broad, multiplex molecular assays (a solid tumor targeted next-generation sequencing [NGS]) assay and single nucleotide polymorphism [SNP] microarray) to selected tumors, exploring the current utility and limitations. Methods: We searched our database (2010-2020) for diagnostically challenging mesenchymal neoplasms. After histologic review of available slides, tissue blocks were selected for NGS, SNP microarray, or both. DNA and RNA were extracted using the AllPrep DNA/RNA FFPE Kit Protocol on the QIAcube instrument. The NGS platform used was the TruSight Tumor 170 (TST-170). For SNP array, copy number variant (CNV) analysis was performed using the OncoScanTM CNV Plus Assay. Results: DNA/RNA was successfully extracted from 50% of tumors (n = 10/20). Specimens not successfully extracted included 6 core biopsies, 3 incisional biopsies, and 1 resection; 4 were decalcified (3 hydrochloric acid, 1 ethylenediaminetetraacetic acid). Higher tumor proportion and number of tumor cells were parameters positively associated with sufficient DNA/RNA extraction whereas necrosis and decalcification were negatively associated with sufficient extraction. Molecular testing helped reach a definitive diagnosis in 50% of tumors (n = 5/10). Conclusions: Although the overall utility of this approach is limited, these molecular panels can be helpful in detecting a specific "driver" alteration.


Subject(s)
Neoplasms, Connective and Soft Tissue , Neoplasms , Humans , Retrospective Studies , Neoplasms/diagnosis , Biopsy , DNA , RNA
4.
J Neurooncol ; 148(3): 473-480, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32583303

ABSTRACT

INTRODUCTION: Recent molecular characterization of gliomas has uncovered somatic gene variation and DNA methylation changes that are associated with etiology, prognosis, and therapeutic response. Here we describe genomic profiling of gliomas assessed for associations between genetic mutations and patient outcomes, including overall survival (OS) and recurrence-free survival (RFS). METHODS: Mutations in a 50-gene cancer panel, 1p19q co-deletion, and MGMT promoter methylation (MGMT methylation) status were obtained from tumor tissue of 293 glioma patients. Multivariable regression models for overall survival (OS) and recurrence-free survival (RFS) were constructed for MGMT methylation, 1p19q co-deletion, and gene mutations controlling for age, treatment status, and WHO grade. RESULTS: Mutational profiles of gliomas significantly differed based on WHO Grade, such as high prevalence of BRAF V600E, IDH1, and PTEN mutations in WHO Grade I, II/III, and IV tumors, respectively. In multivariate regression analysis, MGMT methylation and IDH1 mutations were significantly associated with improved OS (HR = 0.44, p = 0.0004 and HR = 0.21, p = 0.007, respectively), while FLT3 and TP53 mutations were significantly associated with poorer OS (HR = 19.46, p < 0.0001 and HR = 1.67, p = 0.014, respectively). MGMT methylation and IDH1 mutations were the only significant alterations associated with improved RFS in the model (HR = 0.42, p < 0.0001 and HR = 0.37, p = 0.002, respectively). These factors were then included in a combined model, which significantly exceeded the predictive value of the base model alone (age, surgery, radiation, chemo, grade) (likelihood ratio test OS p = 1.64 × 10-8 and RFS p = 3.80 × 10-7). CONCLUSIONS: This study highlights the genomic landscape of gliomas in a single-institution cohort and identifies a novel association between FLT3 mutation and OS in gliomas.


Subject(s)
Biomarkers, Tumor/genetics , Brain Neoplasms/mortality , DNA Methylation , Glioma/mortality , Mutation , fms-Like Tyrosine Kinase 3/genetics , Aged , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Brain Neoplasms/therapy , Cohort Studies , Combined Modality Therapy , Follow-Up Studies , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Glioma/genetics , Glioma/pathology , Glioma/therapy , Humans , Middle Aged , Prognosis , Survival Rate
5.
Pract Lab Med ; 20: e00156, 2020 May.
Article in English | MEDLINE | ID: mdl-32181314

ABSTRACT

INTRODUCTION: Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene in non-small cell lung cancer (NSCLC) patients predicts response to EGFR tyrosine kinase inhibitors (TKIs). The Idylla™ system (Biocartis, Mechelen, Belgium) is a fully integrated, cartridge-based platform that provides automated sample processing and real-time PCR-based mutation detection in a single-use cartridge. This study evaluated the Idylla™ EGFR Mutation Assay cartridges against next-generation sequencing (NGS) using formalin fixed, paraffin embedded (FFPE) lung cancer tissue samples. METHODS: Thirty-four FFPE lung adenocarcinoma tissue samples were tested on the Idylla™ system. 21 had at least one mutation in EGFR and 13 had no EGFR mutation as determined by NGS analysis using the Ion AmpliSeq 50-gene Cancer Hotspot Panel v2 (Thermo Fisher Scientific). One 10 â€‹µm FFPE tissue section was used for each Idylla™ test and all cases met the Idylla™ minimum tumor content requirement (≥10%). RESULTS: Idylla™ results were in complete agreement with those obtained by NGS for EGFR mutations targeted by the Idylla™. NGS identified two additional EGFR mutations that are not targeted by the Idylla™ in two samples (E709V and V774M). No EGFR mutations were detected by the Idylla™ in samples determined by NGS as having wild-type EGFR. CONCLUSION: The fully automated Idylla™ system offers rapid and reliable testing for clinically actionable mutations in EGFR directly from FFPE tissue sections. Its simplicity and ease of use compared to other available molecular techniques make it suitable for routine clinical use in a variety of settings.

6.
J Cutan Pathol ; 47(6): 541-547, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31943331

ABSTRACT

Undifferentiated melanoma should be considered in the differential diagnosis of sarcomatoid cutaneous malignancies to ensure that patients receive the correct treatment. Dermatopathologists should recognize the pitfalls of relying too heavily on immunohistochemistry to establish this diagnosis and consider ancillary tests, including single-nucleotide polymorphism (SNP) copy number arrays and targeted next-generation sequencing (NGS), when a definitive diagnosis cannot be rendered on a primary or metastatic tumor. This technology can also help to exclude a collision of melanoma and sarcoma when both differentiated and undifferentiated components are juxtaposed. We describe an exceedingly rare, illustrative example of undifferentiated sarcomatoid melanoma presenting as a pedunculated nodule. The clinical context and presence of a small differentiated component helped to establish the diagnosis; however, the transition from differentiated to undifferentiated melanoma was accompanied by an abrupt loss of S100, Sox10, MITF, MelanA, and HMB45 with gain of CD10 and p63 staining. SNP copy number array and NGS revealed shared chromosomal copy number changes and overlapping mutations with additional aberrances detected exclusively in the sarcomatoid component, thereby excluding a collision tumor and confirming our putative impression of melanoma with progression to an undifferentiated sarcomatoid phenotype.


Subject(s)
Melanoma/genetics , Membrane Proteins/metabolism , Neprilysin/metabolism , Sarcoma/genetics , Aftercare , Aged , Antibodies, Monoclonal, Humanized/therapeutic use , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Diagnosis, Differential , Humans , Lymphadenopathy/pathology , MART-1 Antigen/metabolism , Male , Melanoma/pathology , Melanoma/ultrastructure , Melanoma-Specific Antigens/metabolism , Microphthalmia-Associated Transcription Factor/metabolism , Mutation , Polymorphism, Single Nucleotide/genetics , SOXE Transcription Factors/metabolism , Sarcoma/pathology , Sarcoma/secondary , Skin Neoplasms/pathology , Soft Tissue Neoplasms/pathology , Treatment Outcome , gp100 Melanoma Antigen
7.
Int J Surg Pathol ; 28(4): 427-435, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31813296

ABSTRACT

Adenomyoepithelioma is an extremely rare primary cutaneous neoplasm. Although there is ample evidence on the existence of malignant adenomyoepithelioma in the breast, a malignant counterpart in the skin has not been documented. We report a primary cutaneous adenomyoepithelioma (pcAME) with malignant features arising from a spiradenoma in a 39-year-old female patient. The tumor was solid-cystic in appearance and entirely located in the subcutaneous tissue. Histologically, the tumor displayed foci of adenomatous changes and adenomyoepitheliomatous hyperplasia adjacent to a minute spiradenoma. Gradual increase of architectural complexity, cytologic atypia, mitotic activity, and infiltrative growth were observed in a significant portion of the neoplasm, indicative of transformation to adenomyoepithelioma and subsequently low- to high-grade salivary-type epithelial-myoepithelial carcinoma (EMCA). The intimate dual populations of ductal and myoepithelial cells were highlighted by a panel of immunohistochemical stains in all different components of the tumor. Molecular studies revealed a PIKCA3 mutation, a genetic aberration that has been documented in EMCA, particularly of breast origin. The current case documents for the first time a pcAME with malignant features arising from a spiradenoma and suggests adenomyoepithelioma ex spiradenoma as a possible tumorigenesis pathway of this rare cutaneous tumor.


Subject(s)
Acrospiroma/diagnosis , Adenomyoepithelioma/diagnosis , Biomarkers, Tumor/analysis , Carcinoma/diagnosis , Sweat Gland Neoplasms/diagnosis , Sweat Glands/pathology , Acrospiroma/pathology , Adenomyoepithelioma/pathology , Adult , Biomarkers, Tumor/metabolism , Carcinoma/pathology , Female , Humans , Immunohistochemistry , Sweat Gland Neoplasms/pathology
8.
Leuk Lymphoma ; 60(10): 2415-2422, 2019 10.
Article in English | MEDLINE | ID: mdl-30997856

ABSTRACT

Next generation sequencing (NGS) has introduced new types of data, such as variant allele frequencies (VAFs), into the workup of acute myeloid leukemias (AML). There is interest in using NGS to prognosticate disease behavior and monitor residual disease, but the attribution of sequencing data entirely to the leukemic clone may be confounded by VAF contribution from background non-leukemic populations and undetected copy number aberrations. Sixty-eight patients with AML were evaluated by a clinically validated gene sequencing panel at our institution from 2015 to 2018. No correlation was found with a direct comparison of blast counts and VAFs in both primary- and secondary-AML (R2 = 0.0584 and 0.0235, respectively). Only moderate correlations were attained when evaluating against mutant NPM1 allele fraction alone (R2 = 0.5303) or when variants with allelic frequencies >55% of the blast burden were excluded (R2 = 0.4608). VAFs from regular clinical-use gene sequencing panels show poor unrestricted correlation with leukemic blast proportions in AML.


Subject(s)
Alleles , Bone Marrow/pathology , Gene Frequency , Genetic Variation , Granulocyte Precursor Cells/pathology , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Biomarkers, Tumor , High-Throughput Nucleotide Sequencing , Humans , Mutation , Neoplasms, Second Primary/diagnosis , Neoplasms, Second Primary/etiology , Nucleophosmin
9.
J Glob Oncol ; 4: 1-8, 2018 09.
Article in English | MEDLINE | ID: mdl-30241169

ABSTRACT

PURPOSE: Cervical cancer is a leading cause of cancer-related mortality in low- and middle-income countries (LMICs) and screening in LMICs is extremely limited. We aimed to implement on-site high-risk human papillomavirus (hrHPV) DNA testing in cohorts of women from an urban factory and from a rural village. METHODS: A total of 802 women were recruited for this study in partnership with La Liga Contra el Cancer through the establishment of women's health resource fairs at two locations in Honduras: a textile factory (n = 401) in the city of San Pedro Sula and the rural village of El Rosario (n = 401) in Yoro. Participants received a routine cervical examination during which three sterile cytobrushes were used to collect cervical samples for testing. hrHPV genotyping was performed using a hrHPV genotyping assay and a real-time polymerase chain reaction instrument. RESULTS: hrHPV status across all participants at both sites was 13% hrHPV positive and 67% hrHPV negative. When hrHPV status was compared across all three testing sites, hrHPV-positive rates were approximately equal among the factory (13%), village (12%), and confirmatory testing at Dartmouth-Hitchcock Medical Center (Lebanon, NH; 14%). hrHPV genotype was compared across sites, with HPV16 showing the highest infection rate (15%), followed by HPV59 (12%), and HPV68 (11%). There was a low prevalence of HPV18 observed in both populations compared with the hrHPV-positive population in the United States. CONCLUSION: In collaboration with oncologists and pathologists from La Liga Contra el Cancer, we were able to provide a continuum of care once health-fair testing was performed. We established a method and implementation plan for hrHPV testing that is sustainable in LMICs.


Subject(s)
Papillomavirus Infections/diagnosis , Uterine Cervical Neoplasms/diagnosis , Adult , DNA, Viral , Developing Countries , Early Detection of Cancer , Female , Genotype , Humans , Middle Aged , Papillomaviridae/genetics , Papillomavirus Infections/virology , Patient Education as Topic , Pilot Projects , Polymerase Chain Reaction , Uterine Cervical Neoplasms/virology
10.
Methods Inf Med ; 57(1): 63-73, 2018 02.
Article in English | MEDLINE | ID: mdl-29621832

ABSTRACT

OBJECTIVE: We aim to build an informatics methodology capable of identifying statistically significant associations between the clinical findings of non-small cell lung cancer (NSCLC) recorded in patient pathology reports and the various clinically actionable genetic mutations identified from next-generation sequencing (NGS) of patient tumor samples. METHODS: We built an information extraction and analysis pipeline to identify the associations between clinical findings in the pathology reports of patients and corresponding genetic mutations. Our pipeline leverages natural language processing (NLP) techniques, large biomedical terminologies, semantic similarity measures, and clustering methods to extract clinical concepts in freetext from patient pathology reports and group them as salient findings. RESULTS: In this study, we developed and applied our methodology to lobectomy surgical pathology reports of 142 NSCLC patients who underwent NGS testing and who had mutations in 4 oncogenes with clinical ramifications for NSCLC treatment (EGFR, KRAS, BRAF, and PIK3CA). Our approach identified 732 distinct positive clinical concepts in these reports and highlighted multiple findings with strong associations (P-value ≤ 0.05) to mutations in specific genes. Our assessment showed that these associations are consistent with the published literature. CONCLUSIONS: This study provides an automatic pipeline to find statistically significant associations between clinical findings in unstructured text of patient pathology reports and genetic mutations. This approach is generalizable to other types of pathology and clinical reports in various disorders and can provide the first steps toward understanding the role of genetic mutations in the development and treatment of different types of cancer.


Subject(s)
Genetic Association Studies , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Mutation/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cohort Studies , Humans , Natural Language Processing , Unified Medical Language System
11.
J Appl Lab Med ; 2(2): 138-149, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-32630970

ABSTRACT

BACKGROUND: Next-generation sequencing (NGS) assays are highly complex tests that can vary substantially in both their design and intended application. Despite their innumerous advantages, NGS assays present some unique challenges associated with the preanalytical process, library preparation, data analysis, and reporting. According to a number of professional laboratory organization, control materials should be included both during the analytical validation phase and in routine clinical use to guarantee highly accurate results. The SeraseqTM Solid Tumor Mutation Mix AF10 and AF20 control materials consist of 26 biosynthetic DNA constructs in a genomic DNA background, each containing a specific variant or mutation of interest and an internal quality marker at 2 distinct allelic frequencies of 10% and 20%, respectively. The goal of this interlaboratory study was to evaluate the Seraseq AF10 and AF20 control materials by verifying their performance as control materials and by evaluating their ability to measure quality metrics essential to a clinical test. METHODS: Performance characteristics were assessed within and between 6 CLIA-accredited laboratories and 1 research laboratory. RESULTS: Most laboratories detected all 26 mutations of interest; however, some discrepancies involving the internal quality markers were observed. CONCLUSION: This interlaboratory study showed that the Seraseq AF10 and AF20 control materials have high quality, stability, and genomic complexity in variant types that are well suited for assisting in NGS assay analytical validation and monitoring routine clinical applications.

12.
J Immunol ; 197(10): 3970-3981, 2016 11 15.
Article in English | MEDLINE | ID: mdl-27742829

ABSTRACT

Plasmalemma vesicle-associated protein (Plvap) is an endothelial protein with roles in endothelial diaphragm formation and maintenance of basal vascular permeability. At the same time, Plvap has roles in immunity by facilitating leukocyte diapedesis at inflammatory sites and controlling peripheral lymph node morphogenesis and the entry of soluble Ags into lymph node conduits. Based on its postulated role in diapedesis, we have investigated the role of Plvap in hematopoiesis and show that deletion of Plvap results in a dramatic decrease of IgM+IgDlo B cells in both the spleen and the peritoneal cavity. Tissue-specific deletion of Plvap demonstrates that the defect is B cell extrinsic, because B cell and pan-hematopoietic Plvap deletion has no effect on IgM+IgDlo B cell numbers. Endothelial-specific deletion of Plvap in the embryo or at adult stage recapitulates the full Plvap knockout phenotype, whereas endothelial-specific reconstitution of Plvap under the Chd5 promoter rescues the IgM+IgDlo B cell phenotype. Taken together, these results show that Plvap expression in endothelial cells is important in the maintenance of IgM+ B cells in the spleen and peritoneal cavity.


Subject(s)
B-Lymphocytes/metabolism , Carrier Proteins/metabolism , Homeostasis , Membrane Proteins/metabolism , Precursor Cells, B-Lymphoid/metabolism , Spleen/cytology , Animals , B-Lymphocytes/pathology , Capillary Permeability , Carrier Proteins/genetics , DNA Helicases/genetics , Endothelial Cells/chemistry , Endothelial Cells/metabolism , Gene Expression Regulation , Immunoglobulin D/genetics , Immunoglobulin D/metabolism , Immunoglobulin M/genetics , Immunoglobulin M/metabolism , Membrane Proteins/deficiency , Membrane Proteins/genetics , Mice , Peritoneal Cavity/cytology , Phenotype , Spleen/immunology , Transendothelial and Transepithelial Migration/immunology
13.
Cell Mol Gastroenterol Hepatol ; 1(4): 381-394.e7, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26207260

ABSTRACT

BACKGROUND & AIMS METHODS: Severe intestinal diseases observed in very young children are often the result of monogenic defects. We used whole exome sequencing (WES) to examine the genetic cause in a patient with a distinct severe form of protein losing enteropathy (PLE) characterized by hypoproteinemia, hypoalbuminemia, and hypertriglyceridemia. METHODS: WES was performed at the Centre for Applied Genomics, Hospital for Sick Children, Toronto, Canada. Exome library preparation was performed using the Ion Torrent AmpliSeq RDY Exome Kit. Functional studies were carried out based on the identified mutation. RESULTS: Using whole exome sequencing we identified a homozygous nonsense mutation (1072C>T; p.Arg358*) in the PLVAP (plasmalemma vesicle associated protein) gene in an infant from consanguineous parents who died at five months of age of severe protein losing enteropathy. Functional studies determined that the mutated PLVAP mRNA and protein were not expressed in the patient biopsy tissues, presumably secondary to nonsense-mediated mRNA decay. Pathological analysis showed that the loss of PLVAP resulted in disruption of endothelial fenestrated diaphragms. CONCLUSIONS: PLVAP p.Arg358* mutation resulted in loss of PLVAP expression with subsequent deletion of the diaphragms of endothelial fenestrae leading to plasma protein extravasation, protein-losing enteropathy and ultimately death.

14.
Mol Imaging Biol ; 16(3): 372-82, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24217944

ABSTRACT

PURPOSE: Cancer-specific endothelial markers available for intravascular binding are promising targets for new molecular therapies. In this study, a molecular imaging approach of quantifying endothelial marker concentrations (EMCI) is developed and tested in highly light-absorbing melanomas. The approach involves injection of targeted imaging tracer in conjunction with an untargeted tracer, which is used to account for nonspecific uptake and tissue optical property effects on measured targeted tracer concentrations. PROCEDURES: Theoretical simulations and a mouse melanoma model experiment were used to test out the EMCI approach. The tracers used in the melanoma experiments were fluorescently labeled anti-Plvap/PV1 antibody (plasmalemma vesicle associated protein Plvap/PV1 is a transmembrane protein marker exposed on the luminal surface of endothelial cells in tumor vasculature) and a fluorescent isotype control antibody, the uptakes of which were measured on a planar fluorescence imaging system. RESULTS: The EMCI model was found to be robust to experimental noise under reversible and irreversible binding conditions and was capable of predicting expected overexpression of PV1 in melanomas compared to healthy skin despite a 5-time higher measured fluorescence in healthy skin compared to melanoma: attributable to substantial light attenuation from melanin in the tumors. CONCLUSIONS: This study demonstrates the potential of EMCI to quantify endothelial marker concentrations in vivo, an accomplishment that is currently unavailable through any other methods, either in vivo or ex vivo.


Subject(s)
Biomarkers, Tumor/metabolism , Fluorescent Dyes/metabolism , Melanoma/metabolism , Animals , Fluorescent Dyes/pharmacokinetics , Mice
15.
Proc Natl Acad Sci U S A ; 110(22): 9025-30, 2013 May 28.
Article in English | MEDLINE | ID: mdl-23671066

ABSTRACT

The up-regulation of cell surface receptors has become a central focus in personalized cancer treatment; however, because of the complex nature of contrast agent pharmacokinetics in tumor tissue, methods to quantify receptor binding in vivo remain elusive. Here, we present a dual-tracer optical technique for noninvasive estimation of specific receptor binding in cancer. A multispectral MRI-coupled fluorescence molecular tomography system was used to image the uptake kinetics of two fluorescent tracers injected simultaneously, one tracer targeted to the receptor of interest and the other tracer a nontargeted reference. These dynamic tracer data were then fit to a dual-tracer compartmental model to estimate the density of receptors available for binding in the tissue. Applying this approach to mice with deep-seated gliomas that overexpress the EGF receptor produced an estimate of available receptor density of 2.3 ± 0.5 nM (n = 5), consistent with values estimated in comparative invasive imaging and ex vivo studies.


Subject(s)
Fluorescence , Glioma/metabolism , Magnetic Resonance Imaging/methods , Molecular Imaging/methods , Receptors, Cell Surface/metabolism , Tomography, Optical/methods , Animals , ErbB Receptors/metabolism , Kinetics , Mice , Protein Binding
16.
Dev Cell ; 23(6): 1203-18, 2012 Dec 11.
Article in English | MEDLINE | ID: mdl-23237953

ABSTRACT

Fenestral and stomatal diaphragms are endothelial subcellular structures of unknown function that form on organelles implicated in vascular permeability: fenestrae, transendothelial channels, and caveolae. PV1 protein is required for diaphragm formation in vitro. Here, we report that deletion of the PV1-encoding Plvap gene in mice results in the absence of diaphragms and decreased survival. Loss of diaphragms did not affect the fenestrae and transendothelial channels formation but disrupted the barrier function of fenestrated capillaries, causing a major leak of plasma proteins. This disruption results in early death of animals due to severe noninflammatory protein-losing enteropathy. Deletion of PV1 in endothelium, but not in the hematopoietic compartment, recapitulates the phenotype of global PV1 deletion, whereas endothelial reconstitution of PV1 rescues the phenotype. Taken together, these data provide genetic evidence for the critical role of the diaphragms in fenestrated capillaries in the maintenance of blood composition.


Subject(s)
Blood Proteins/metabolism , Capillaries/physiology , Capillaries/ultrastructure , Capillary Permeability , Carrier Proteins/metabolism , Endothelium, Vascular/physiology , Endothelium, Vascular/ultrastructure , Membrane Proteins/metabolism , Animals , Carrier Proteins/genetics , Caveolae/physiology , Cell Membrane/metabolism , Endothelium, Vascular/cytology , Membrane Proteins/genetics , Mice , Mice, Transgenic , Protein-Losing Enteropathies/physiopathology
17.
J Cell Mol Med ; 16(11): 2690-700, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22568538

ABSTRACT

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two different human pancreatic adenocarcinoma cell lines (AsPC-1 and BxPC-3). The effect observed is because of down-regulation of PV1 in the tumour endothelial cells of host origin, PV1 being specifically expressed in tumour vascular endothelial cells and not in cancer or other stromal cells. There are no differences in vascular density of tumours treated or not with PV1 shRNA, and gain and loss of function of PV1 in endothelial cells does not modify either their proliferation or migration, suggesting that tumour angiogenesis is not impaired. Together, our data argue that down-regulation of PV1 in tumour endothelial cells results in the inhibition of tumour growth via a mechanism different from inhibiting angiogenesis.


Subject(s)
Adenocarcinoma/genetics , Adenocarcinoma/pathology , Carrier Proteins/genetics , Membrane Proteins/genetics , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Adenocarcinoma/blood supply , Animals , Base Sequence , Carrier Proteins/metabolism , Cell Line, Tumor , Cell Movement/genetics , Down-Regulation , Drug Screening Assays, Antitumor , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Lentivirus/genetics , Membrane Proteins/metabolism , Mice , Mice, Knockout , Mice, Nude , Molecular Sequence Data , Neovascularization, Pathologic/genetics , Pancreatic Neoplasms/blood supply , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , RNA, Small Interfering/pharmacology , Stromal Cells/metabolism , Stromal Cells/pathology
18.
PLoS One ; 7(3): e32655, 2012.
Article in English | MEDLINE | ID: mdl-22403691

ABSTRACT

PV1 protein is an essential component of stomatal and fenestral diaphragms, which are formed at the plasma membrane of endothelial cells (ECs), on structures such as caveolae, fenestrae and transendothelial channels. Knockout of PV1 in mice results in in utero and perinatal mortality. To be able to interpret the complex PV1 knockout phenotype, it is critical to determine whether the formation of diaphragms is the only cellular role of PV1. We addressed this question by measuring the effect of complete and partial removal of structures capable of forming diaphragms on PV1 protein level. Removal of caveolae in mice by knocking out caveolin-1 or cavin-1 resulted in a dramatic reduction of PV1 protein level in lungs but not kidneys. The magnitude of PV1 reduction correlated with the abundance of structures capable of forming diaphragms in the microvasculature of these organs. The absence of caveolae in the lung ECs did not affect the transcription or translation of PV1, but it caused a sharp increase in PV1 protein internalization rate via a clathrin- and dynamin-independent pathway followed by degradation in lysosomes. Thus, PV1 is retained on the cell surface of ECs by structures capable of forming diaphragms, but undergoes rapid internalization and degradation in the absence of these structures, suggesting that formation of diaphragms is the only role of PV1.


Subject(s)
Carrier Proteins/metabolism , Caveolae/metabolism , Endothelial Cells/cytology , Endothelial Cells/metabolism , Membrane Proteins/metabolism , Animals , Carrier Proteins/biosynthesis , Carrier Proteins/genetics , Diaphragm/cytology , Lung/cytology , Membrane Proteins/biosynthesis , Membrane Proteins/genetics , Mice , Mice, Inbred C57BL , Protein Transport , Transcription, Genetic
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