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1.
Support Care Cancer ; 30(10): 7913-7922, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35732748

ABSTRACT

PURPOSE: We evaluated the incidence of febrile neutropenia (FN) and related clinical outcomes among patients treated with myelosuppressive chemotherapy for nonmyeloid malignancies who received pegfilgrastim on-body injector (OBI) or other options (Other) for FN prophylaxis. METHODS: In this prospective observational study, adult patients with breast, prostate, or lung cancer, or non-Hodgkin lymphoma at risk for FN were stratified into subgroups based on FN prophylaxis used in the first chemotherapy cycle: pegfilgrastim OBI vs Other (pegfilgrastim or biosimilar pegfilgrastim prefilled syringe, daily filgrastim, or no granulocyte colony-stimulating factor [G-CSF]) for up to 4 planned chemotherapy cycles. RESULTS: This US study enrolled 2575 eligible patients (OBI, 1624; Other, 951). FN incidence was lower in the OBI group (6.4% [95% CI, 5.2-7.6%]) than in the Other group (9.4% [7.5-11.2%]), with a relative risk (RR) of 0.66 (0.47-0.91; p = .006). A decreased risk of dose delays among patients receiving pegfilgrastim OBI vs Other was observed (RR for ≥ 5 days: 0.64 [0.42-0.96], p = .023; RR for ≥ 7 days: 0.62 [0.40-0.91], p = .016). Adherence, defined as G-CSF support for all chemotherapy cycles, was 94.0% (92.9-95.2%) in the OBI group compared with 58.4% (55.2-61.5%) in the Other group. Compliance with pegfilgrastim, defined as administration the day after chemotherapy, was 88.3% in the OBI group and 48.8% in the prefilled syringe group. CONCLUSION: Patients receiving pegfilgrastim OBI had a lower incidence of FN compared with those receiving alternatives. The OBI was associated with improved adherence to and compliance with clinically recommended G-CSF prophylaxis.


Subject(s)
Biosimilar Pharmaceuticals , Febrile Neutropenia , Lung Neoplasms , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Febrile Neutropenia/chemically induced , Febrile Neutropenia/epidemiology , Febrile Neutropenia/prevention & control , Filgrastim , Granulocyte Colony-Stimulating Factor , Humans , Incidence , Lung Neoplasms/drug therapy , Male , Polyethylene Glycols/therapeutic use , Prospective Studies , Recombinant Proteins/therapeutic use
2.
Support Care Cancer ; 30(7): 6135-6144, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35426046

ABSTRACT

BACKGROUND: Breast cancer chemotherapy often carries a high risk of febrile neutropenia (FN); guidelines recommend prophylaxis with granulocyte colony-stimulating factor (G-CSF), such as pegfilgrastim. Neulasta® Onpro® on-body injector (OBI) is a delivery device administering pegfilgrastim approximately 27 h after application. METHODS: This prospective study examined patients with breast cancer who received chemotherapy with a high risk of FN, receiving OBI ("OBI") or other options (other G-CSF or none; "other"). The primary endpoint was FN incidence; secondary endpoints included chemotherapy delivery, adherence (G-CSF in all cycles), compliance (G-CSF day after chemotherapy), and FN incidence in patients receiving curative or palliative treatment. RESULTS: A total of 1776 patients with breast cancer were enrolled (OBI, n = 1196; other, n = 580). Across all cycles, FN incidence was lower for OBI (4.4% [95% CI, 3.3-5.6%]) than other (7.4% [5.3-9.6%]). For curative treatment, the FN incidence across all cycles was lower for OBI (4.6% [3.4-5.8%]) than for other (7.1% [5.0-9.3%]). For palliative treatment (OBI, n = 33; other, n = 20), 3 patients (15%) in the other and none in the OBI group had FN. After adjusting for baseline covariates, FN incidence remained lower for OBI (4.6% [3.5-6.1%]) versus other (7.8% [5.7-10.5%]). Adherence was higher for OBI (93.8%) than for other G-CSF (69.8%), as was compliance (90.5 and 53.2%, respectively). Chemotherapy dose delays/reductions were similar for OBI (4.7%/32.3%, respectively) and other (4.7%/30.0%) groups. CONCLUSION: Pegfilgrastim OBI was associated with a lower FN incidence in patients with breast cancer compared to other options for FN prophylaxis. TRIAL REGISTRATION: www. CLINICALTRIALS: gov , NCT02178475, registered 30 June, 2014.


Subject(s)
Breast Neoplasms , Febrile Neutropenia , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/drug therapy , Breast Neoplasms/etiology , Febrile Neutropenia/drug therapy , Female , Filgrastim/therapeutic use , Granulocyte Colony-Stimulating Factor/therapeutic use , Humans , Incidence , Polyethylene Glycols/therapeutic use , Prospective Studies , Recombinant Proteins
3.
J Patient Rep Outcomes ; 5(1): 10, 2021 Jan 18.
Article in English | MEDLINE | ID: mdl-33459887

ABSTRACT

BACKGROUND: Several options for granulocyte colony-stimulating factor (G-CSF) prophylaxis of chemotherapy-induced febrile neutropenia are available to patients worldwide. We have developed a novel patient-reported outcome measure, the Satisfaction and Experience Questionnaire for G-CSF (SEQ-G-CSF), to help understand patients' perspectives of and satisfaction with different G-CSF options. RESULTS: Three oncology nurses and 40 adult oncology patients in the United States were enrolled and participated in focus group discussions to develop and refine the SEQ-G-CSF. Nurses had ≥ 5 years of experience treating oncology patients and were currently involved in the management of oncology patients receiving G-CSF prophylaxis. The patients had breast cancer, lung cancer, non-Hodgkin lymphoma, or prostate cancer (10 patients in each group) and were receiving G-CSF prophylaxis via injection or the on-body injector (OBI) device. The preliminary SEQ-G-CSF contained an item relevance questionnaire and three SEQ modules (sociodemographic, medical history, and G-CSF-related healthcare characteristics questionnaires). Twenty-one patients (53% of total sample size) discussed their experience and satisfaction with G-CSF. Their most common experiences were G-CSF effectiveness, convenience and benefits of the OBI, and relationships with healthcare providers. Side effects and having to undergo additional treatment were also reported. Satisfaction with aspects of G-CSF included the OBI and effectiveness of G-CSF treatment; dissatisfaction included inconvenience (having to return to the clinic the next day and administration of the injection) and the insurance approval process. The SEQ-G-CSF was finalized after three rounds of cognitive interviews and includes five domains related to general satisfaction (one item), treatment burden (four items), travel burden (two items), time burden (four items), and treatment compliance (two items). CONCLUSIONS: The SEQ-G-CSF is a novel instrument that quantifies a patient's experience and satisfaction with different G-CSF options using 13 easy-to-understand items. This study provides evidence for the content validity of SEQ-G-CSF. Although further psychometric testing is required, the SEQ-G-CSF may be a useful addition to clinical trials, observational studies, and clinical practice.

4.
Leuk Lymphoma ; 62(2): 377-386, 2021 02.
Article in English | MEDLINE | ID: mdl-33026271

ABSTRACT

Multiple myeloma treatment has evolved with approvals of new immunomodulatory imide drugs (IMiDs), monoclonal antibodies (MoABs), and proteasome inhibitors (PIs). We characterized U.S. treatment trends and survival from 2011 to 2019 using Flatiron data from multiple myeloma patients followed from treatment index until death/end of data. Patients (n = 10,553) were primarily (88%) treated in community centers. Frontline PI-IMiD-dexamethasone use increased over time, while IMiD-dexamethasone and PI-dexamethasone use decreased. MoAB-IMiD-dexamethasone use increased in relapsed/refractory disease. In all lines, use of doublets decreased and triplets increased, with triplets becoming the most prescribed combination by 2018-2019, especially in first line (62%). Monotherapy use decreased in first line (19% to 10%) but remained steady in relapsed/refractory disease (∼20%). With each increasing line of therapy, median overall survival decreased (60, 48, 36, 29, 23 months). Survival increased with more recent diagnosis. Our results indicate that the multiple myeloma landscape has evolved significantly in the last decade.


Subject(s)
Multiple Myeloma , Antibodies, Monoclonal/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Electronic Health Records , Humans , Multiple Myeloma/drug therapy , Multiple Myeloma/epidemiology , Proteasome Inhibitors/therapeutic use
5.
Blood Cancer J ; 10(6): 73, 2020 06 30.
Article in English | MEDLINE | ID: mdl-32606424

ABSTRACT

B-cell maturation antigen (BCMA) plays a critical role in regulating B-cell proliferation and survival. There is evidence for BCMA expression in various hematologic malignancies, suggesting that BCMA may play an important role as a biomarker or therapeutic target in these diseases. Given advances in understanding the role of BCMA in B-cell development and the promise of BCMA as a therapeutic target, a systematic review is needed to rigorously assess the evidence for BCMA expression and identify areas of consensus and future research. The objective of this review was to summarize the evidence on BCMA protein and mRNA expression across hematologic malignancies. Using a PubMed database search up to 28 August 2019, a systematic literature review of publications reporting BCMA expression in patients with hematologic malignancies was conducted. Data from published congress abstracts presented at the American Society of Clinical Oncology and the American Society of Hematology were also searched. Studies that assessed BCMA expression (protein or mRNA) in patients of any age with hematologic malignancies were included. A total of 21 studies met inclusion criteria and were included in the review. BCMA was expressed in several hematologic malignancies, including multiple myeloma (MM), chronic lymphocytic leukemia, acute B-lymphoblastic leukemia, non-Hodgkin lymphoma (NHL), and Hodgkin lymphoma. BCMA was expressed at uniformly high levels across all 13 MM studies and at low to moderate levels in acute myeloid leukemia and acute lymphoblastic leukemia. These results suggest that BCMA is a relevant target in MM as well as in a subset of B-cell leukemia. BCMA expression in Hodgkin lymphoma and NHL varied across studies, and further research is needed to determine the utility of BCMA as an antibody target and biomarker in these diseases. Differences in sample type, timing of sample collection, and laboratory technique used may have affected the reporting of BCMA levels.


Subject(s)
B-Cell Maturation Antigen/genetics , Gene Expression Regulation, Neoplastic , Hematologic Neoplasms/genetics , B-Cell Maturation Antigen/analysis , Hematologic Neoplasms/pathology , Hodgkin Disease/genetics , Hodgkin Disease/pathology , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Lymphoma, Non-Hodgkin/genetics , Lymphoma, Non-Hodgkin/pathology , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , RNA, Messenger/genetics
6.
J Geriatr Oncol ; 11(8): 1309-1315, 2020 11.
Article in English | MEDLINE | ID: mdl-32624415

ABSTRACT

PURPOSE: Evaluate the relationship between duration of primary prophylactic short-acting granulocyte colony-stimulating factor (PP-sG-CSF) and risk of neutropenia-related hospitalization (NRH) in older patients receiving myelosuppressive chemotherapy. METHODS: Using the Medicare claims database, we conducted a nested case-control study in a cohort of patients aged ≥66 years with breast, colorectal, lung, ovarian, or prostate cancer, or non-Hodgkin lymphoma who initiated a first cycle of any myelosuppressive chemotherapy January 1, 2008-September 30, 2016, and received PP-sG-CSF. We matched up to four controls to each NRH case by age, cancer type, regimen febrile neutropenia (FN) risk category, and year using incidence density sampling. We used conditional logistic regression adjusted for race, sex, and modified Charlson comorbidity index (CCI) to estimate relative risk of NRH related to duration of PP-sG-CSF categorized as <5 and ≥ 5 days. RESULTS: Of 2148 patients receiving PP-sG-CSF, 108 (5%) experienced NRH in the first cycle. We matched 333 controls to 96 cases. Cases were similar to controls in mean age, tumor type, and intermediate/high-risk regimen, but were more likely to have CCI ≥5 and less likely to use PP-sG-CSF ≥5 days (31% vs. 39%). Adjusted ORs (95% CI) for NRH were 0.69 (0.40-1.19) for ≥5 vs. <5 days of PP-sG-CSF among patients receiving any myelosuppressive chemotherapy, 0.43 (0.21-0.89) for intermediate/high-risk regimen, and 0.42 (0.19-0.89) for any myelosuppressive chemotherapy with all agents given on cycle day one only. CONCLUSIONS: Among older patients with cancer who are receiving PP-sG-CSF, ≥5 days of use was associated with substantial reduction in NRH risk.


Subject(s)
Neoplasms , Neutropenia , Aged , Antineoplastic Combined Chemotherapy Protocols , Case-Control Studies , Female , Granulocyte Colony-Stimulating Factor/therapeutic use , Hospitalization , Humans , Male , Medicare , Neoplasms/drug therapy , Neutropenia/chemically induced , Neutropenia/epidemiology , Neutropenia/prevention & control , Retrospective Studies , United States/epidemiology
7.
Support Care Cancer ; 28(9): 4413-4424, 2020 Sep.
Article in English | MEDLINE | ID: mdl-31919669

ABSTRACT

PURPOSE: To evaluate patterns of primary prophylactic (PP) granulocyte colony-stimulating factor (G-CSF) use following chemotherapy by cancer type and febrile neutropenia (FN) risk. METHODS: Using a commercial administrative database, we identified adult patients diagnosed with breast, colorectal, lung, ovarian cancer, or non-Hodgkin lymphoma (NHL) who initiated chemotherapy with high risk (HR) or intermediate risk (IR) for FN between January 1, 2013, and August 31, 2017. We describe use of PP-G-CSF, proportion completing all their cycles with pegfilgrastim, timing of pegfilgrastim, and duration of short-acting G-CSF. RESULTS: Among 22,868 patients (breast 11,513; colorectal 3765; lung 4273; ovarian 1287; and NHL 2030), 36.8% received HR and 63.2% received IR (64.4% of whom had ≥ 1 risk factor [RF] for FN). Proportions of patients receiving PP-G-CSF in the first cycle were 76.1%, 28.2%, and 26.4% among patients receiving HR, IR, and IR plus ≥ 1 RF, respectively. Among breast cancer patients receiving HR regimens and initiating PP-pegfilgrastim, 60.4% (95% confidence interval [CI] 57.2-63.6%) initiating via on-body injector (OBI) and 51.9% (95% CI 48.0-55.8%) initiating via prefilled syringe (PFS) completed all their cycles with OBI and PFS, respectively. Among all cycles with PP-PFS, 8.5% received PFS on the same day as chemotherapy completion. Mean administrations/cycle were 3.2 (standard deviation [SD] 2.3) for filgrastim, 3.0 (SD 1.6) for filgrastim-sndz, and 4.3 (SD 2.5) for tbo-filgrastim. CONCLUSIONS: There is under- and mistimed use of PP-G-CSF among patients at HR for FN. Novel pegfilgrastim delivery devices could help breast cancer patients at HR for FN complete all their cycles with timely prophylaxis.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Granulocyte Colony-Stimulating Factor/therapeutic use , Neoplasms/drug therapy , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Female , Granulocyte Colony-Stimulating Factor/pharmacology , Humans , Male , Middle Aged , Retrospective Studies
8.
J Cancer Educ ; 35(1): 178-186, 2020 02.
Article in English | MEDLINE | ID: mdl-31656028

ABSTRACT

The purpose of the study is to describe oncologists' perceptions and opinions about patient eligibility, guidelines, and barriers for use of granulocyte colony-stimulating factor (G-CSF), overall and stratified by their affiliation with the Oncology Care Model (OCM). In May 2018, we invited and recruited practicing US oncologists from a national database for an online survey. Level of agreement was identified using a seven-point scale, ranging from strongly disagree to strongly agree. Of 200 participating oncologists, 70 were OCM-affiliated. Overall, 65% of oncologists agreed or strongly agreed that all patients at high risk of febrile neutropenia (FN) should receive prophylactic G-CSF, and half agreed or strongly agreed that benefits of G-CSF outweigh the potential adverse effects. The most common barriers to G-CSF use for patients at high risk of FN included patient refusal (37.1% of OCM-affiliated oncologists vs. 21.5% of non-OCM-affiliated oncologists), not on protocol/not supported by guidelines (32.9% vs. 23.1%), lack of reimbursement to practice (30.0% vs. 15.4%), and concerns about insurance coverage (22.9% vs. 26.9%). More OCM-affiliated oncologists reported that their practices offer and strongly encourage adherence to a specific protocol for G-CSF use (49.2%) versus non-OCM oncologists (31.3%). Despite recommendations from national guidelines and strong evidence from randomized, controlled clinical trials, only two thirds of oncologists agree or strongly agree that all patients at high risk of FN should receive primary G-CSF prophylaxis. Decisions about G-CSF prophylaxis may be affected by factors other than risk of FN, such as patient choice, practice protocols/guidelines, lack of reimbursement, and insurance coverage.


Subject(s)
Drug Utilization/statistics & numerical data , Febrile Neutropenia/prevention & control , Granulocyte Colony-Stimulating Factor/therapeutic use , Neoplasms/drug therapy , Oncologists/psychology , Practice Patterns, Physicians'/statistics & numerical data , Humans , Neoplasms/pathology , Surveys and Questionnaires
9.
BMC Cancer ; 19(1): 792, 2019 Aug 09.
Article in English | MEDLINE | ID: mdl-31399079

ABSTRACT

BACKGROUND: Febrile neutropenia (FN) is a serious complication of myelosuppressive chemotherapy. Clinical practice guidelines recommend routine prophylactic coverage with granulocyte colony-stimulating factor (G-CSF)-such as pegfilgrastim-for most patients receiving chemotherapy with an intermediate to high risk for FN. Patterns of pegfilgrastim prophylaxis during the chemotherapy course and associated FN risks in US clinical practice have not been well characterized. METHODS: A retrospective cohort design and data from two commercial healthcare claims repositories (01/2010-03/2016) and Medicare Claims Research Identifiable Files (01/2007-09/2015) were employed. Study population included patients who had non-metastatic breast cancer or non-Hodgkin's lymphoma and received intermediate/high-risk regimens. Pegfilgrastim prophylaxis use and FN incidence were ascertained in each chemotherapy cycle, and all cycles were pooled for analyses. Adjusted odds ratios for FN were estimated for patients who did versus did not receive pegfilgrastim prophylaxis in that cycle. RESULTS: Study population included 50,778 commercial patients who received 190,622 cycles of chemotherapy and 71,037 Medicare patients who received 271,944 cycles. In cycle 1, 33% of commercial patients and 28% of Medicare patients did not receive pegfilgrastim prophylaxis, and adjusted odds of FN were 2.6 (95% CI 2.3-2.8) and 1.6 (1.5-1.7), respectively, versus those who received pegfilgrastim prophylaxis. In cycle 2, 28% (commercial) and 26% (Medicare) did not receive pegfilgrastim prophylaxis; corresponding adjusted FN odds were comparably elevated (1.9 [1.6-2.2] and 1.6 [1.5-1.8]). Results in subsequent cycles were similar. Across all cycles, 15% of commercial patients and 23% of Medicare patients did not receive pegfilgrastim prophylaxis despite having FN in a prior cycle, and prior FN increased odds of subsequent FN by 2.1-2.4 times. CONCLUSIONS: Notwithstanding clinical practice guidelines, a large minority of patients did not receive G-CSF prophylaxis, and FN incidence was substantially higher among this subset of the population. Appropriate use of pegfilgrastim prophylaxis may reduce patient exposure to this potentially fatal but largely preventable complication of myelosuppressive chemotherapy.


Subject(s)
Chemoprevention , Chemotherapy-Induced Febrile Neutropenia/prevention & control , Filgrastim/therapeutic use , Hematologic Agents/therapeutic use , Polyethylene Glycols/therapeutic use , Practice Patterns, Physicians' , Aged , Chemoprevention/methods , Chemotherapy-Induced Febrile Neutropenia/epidemiology , Chemotherapy-Induced Febrile Neutropenia/etiology , Disease Management , Female , Filgrastim/administration & dosage , Filgrastim/adverse effects , Hematologic Agents/administration & dosage , Hematologic Agents/adverse effects , Humans , Incidence , Male , Middle Aged , Polyethylene Glycols/administration & dosage , Polyethylene Glycols/adverse effects , Retrospective Studies , Risk , United States/epidemiology
11.
Proc Natl Acad Sci U S A ; 115(35): E8228-E8235, 2018 08 28.
Article in English | MEDLINE | ID: mdl-30104364

ABSTRACT

New mechanisms behind blood cell formation continue to be uncovered, with therapeutic approaches for hematological diseases being of great interest. Here we report an enzyme in protein synthesis, known for cell-based activities beyond translation, is a factor inducing megakaryocyte-biased hematopoiesis, most likely under stress conditions. We show an activated form of tyrosyl-tRNA synthetase (YRSACT), prepared either by rationally designed mutagenesis or alternative splicing, induces expansion of a previously unrecognized high-ploidy Sca-1+ megakaryocyte population capable of accelerating platelet replenishment after depletion. Moreover, YRSACT targets monocytic cells to induce secretion of transacting cytokines that enhance megakaryocyte expansion stimulating the Toll-like receptor/MyD88 pathway. Platelet replenishment by YRSACT is independent of thrombopoietin (TPO), as evidenced by expansion of the megakaryocytes from induced pluripotent stem cell-derived hematopoietic stem cells from a patient deficient in TPO signaling. We suggest megakaryocyte-biased hematopoiesis induced by YRSACT offers new approaches for treating thrombocytopenia, boosting yields from cell-culture production of platelet concentrates for transfusion, and bridging therapy for hematopoietic stem cell transplantation.


Subject(s)
Blood Platelets/metabolism , Hematopoiesis , Megakaryocytes/metabolism , Polyploidy , Thrombocytopenia/metabolism , Tyrosine-tRNA Ligase/metabolism , Blood Platelets/pathology , Cell Culture Techniques , Cells, Cultured , Female , Hematopoietic Stem Cells/metabolism , Hematopoietic Stem Cells/pathology , Humans , Induced Pluripotent Stem Cells/metabolism , Induced Pluripotent Stem Cells/pathology , Male , Megakaryocytes/pathology , Signal Transduction , Thrombocytopenia/pathology , Thrombopoietin/metabolism
12.
Case Rep Oncol Med ; 2012: 819546, 2012.
Article in English | MEDLINE | ID: mdl-23243534

ABSTRACT

Background. The posterior reversible encephalopathy syndrome (PRES) is a syndrome characterized by hypertension, headache, seizures, and visual disturbances. Causes of PRES include preeclampsia/eclampsia, hypertension, and recently bevacizumab, a monoclonal antibody vascular endothelial growth factor (VEGF) inhibitor. There is no information to date about PRES recurrence in patients taking bevacizumab or descriptions of deep vein thrombosis (DVT) in the setting of PRES. We reviewed data on a patient receiving bevacizumab who presented with a DVT and PRES and later developed recurrent PRES. Case. A 72-year-old man with metastatic pulmonary adenocarcinoma received maintenance bevacizumab following six cycles of carboplatin and paclitaxel. Following his eighth dose of bevacizumab, he developed a DVT as well as PRES. He made a rapid recovery and was discharged from the hospital but went on to develop PRES recurrence nine days following his original episode. Conclusion. Several mechanisms exist whereby exposure to bevacizumab could be related to the development of both DVT and PRES by inducing global endothelial dysfunction. Recurrent PRES may result from bevacizumab's prolonged half-life (11-50 days) and suboptimal blood pressure control. In the setting of bevacizumab, PRES surveillance may play a similar role in preeclampsia screening as both diseases share similar antiangiogenic signaling pathways.

13.
Nat Struct Mol Biol ; 17(1): 57-61, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20010843

ABSTRACT

Protein multifunctionality is an emerging explanation for the complexity of higher organisms. In this regard, aminoacyl tRNA synthetases catalyze amino acid activation for protein synthesis, but some also act in pathways for inflammation, angiogenesis and apoptosis. It is unclear how these multiple functions evolved and how they relate to the active site. Here structural modeling analysis, mutagenesis and cell-based functional studies show that the potent angiostatic, natural fragment of human tryptophanyl-tRNA synthetase (TrpRS) associates via tryptophan side chains that protrude from its cognate cellular receptor vascular endothelial cadherin (VE-cadherin). VE-cadherin's tryptophan side chains fit into the tryptophan-specific active site of the synthetase. Thus, specific side chains of the receptor mimic amino acid substrates and expand the functionality of the active site of the synthetase. We propose that orthogonal use of the same active site may be a general way to develop multifunctionality of human tRNA synthetases and other proteins.


Subject(s)
Amino Acyl-tRNA Synthetases/metabolism , Antigens, CD/metabolism , Cadherins/metabolism , Catalytic Domain , Models, Molecular , Tryptophan/metabolism , Amino Acyl-tRNA Synthetases/genetics , Blotting, Western , Humans , Immunoprecipitation , Mutagenesis , Structure-Activity Relationship
14.
Thromb Res ; 122(5): 604-9, 2008.
Article in English | MEDLINE | ID: mdl-18262600

ABSTRACT

BACKGROUND: Cancer patients have an increased risk of thrombosis. Tissue factor (TF) antigen and TF activity associated with microparticles in plasma are elevated in patients with various types of cancer. Of these two measurements, TF activity is considered superior to TF antigen levels because the activity more closely reflects the ability of TF to initiate coagulation. Recent studies showed that platelets also express TF. OBJECTIVE: To determine the level of TF activity associated with a combined platelet and microparticle sample from cancer patients (n = 20) and healthy individuals (n = 23). METHODS: TF activity was measured using a two step chromogenic assay and soluble P-selectin was measured by ELISA in healthy controls and metastatic cancer patients. RESULTS: We determined the composition of a combined platelet and microparticle sample. The sample consisted of platelets, large microparticles (30-200 nm) and membrane debris. We compared the TF activity of a combined platelet and microparticle sample from cancer patients with that from healthy individuals. We found that TF activity in a combined platelet and microparticle sample from cancer patients was higher than in samples from healthy individuals (21.5+/-12.3 pM (n = 20) versus 8.6+/-6.8 pM (n = 23), mean+/-SD, p < 0.001). Cancer patients also had a higher level of soluble P-selectin compared with controls (18.9+/-5.5 ng/mL versus 13.2+/-2.3 ng/mL, p < 0.001). CONCLUSION: This study indicates that measurement of TF activity in a combined platelet and microparticle sample can be used as a simple assay to determine the level of circulating TF.


Subject(s)
Blood Platelets/metabolism , Cell-Derived Microparticles/metabolism , Neoplasms/blood , Thromboplastin/metabolism , Adult , Aged , Aged, 80 and over , Blood Platelets/ultrastructure , Case-Control Studies , Cell-Derived Microparticles/ultrastructure , Female , Humans , Male , Microscopy, Electron, Transmission , Middle Aged , Neoplasms/complications , Risk Factors , Thrombosis/blood , Thrombosis/etiology
15.
J Biol Chem ; 283(4): 2070-7, 2008 Jan 25.
Article in English | MEDLINE | ID: mdl-17999956

ABSTRACT

In mammalian cells, specific aminoacyl-transfer RNA (tRNA) synthetases have cytokine functions that require interactions with partners outside of the translation apparatus. Little is known about these interactions and how they facilitate expanded functions that link protein translation to other cellular pathways. For example, an alternative splice fragment of tryptophanyl-tRNA synthetase (TrpRS) and a similar natural proteolytic fragment are potent angiostatic factors that act through the vascular endothelial-cadherin receptor and Akt signaling pathway. Here we demonstrate mobilization of TrpRS for exocytosis from endothelial cells and the potential for plasmin to activate the cytokine function of the extracellular synthetase. Direct physical evidence showed that the annexin II-S100A10 complex, which regulates exocytosis, forms a ternary complex with TrpRS. Functional studies demonstrate that both annexin II and S100A10 regulate trafficking of TrpRS. Thus, complexes of mammalian tRNA synthetases with seemingly disparate proteins may in general be relevant to understanding how their expanded functions are implemented.


Subject(s)
Angiostatic Proteins/metabolism , Annexin A2/metabolism , Cytokines/metabolism , Endothelial Cells/metabolism , Fibrinolysin/metabolism , S100 Proteins/metabolism , Tryptophan-tRNA Ligase/metabolism , Alternative Splicing/physiology , Angiostatic Proteins/genetics , Annexin A2/genetics , Cells, Cultured , Cytokines/genetics , Endothelial Cells/cytology , Exocytosis/physiology , Fibrinolysin/genetics , Humans , Multiprotein Complexes/genetics , Multiprotein Complexes/metabolism , Protein Biosynthesis/physiology , Protein Transport/physiology , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , S100 Proteins/genetics , Signal Transduction/physiology , Tryptophan-tRNA Ligase/genetics
16.
Hematol Oncol Clin North Am ; 20(5): 1109-23, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16990111

ABSTRACT

Cladribine results in prolonged complete remissions in most patients wo have HCL. Several studies have indicated that patients who are in complete remission have survivals that are comparable to those of normal age-matched controls. HCL-related mortality is distinctly uncommon. Nevertheless, it is unlikely that cladribine treatment of HCL is curative because MRD is common in the bone marrows of complete responders. Response criteria for HCL include clinical, hematologic, and morphologic criteria, but do not include flow cytometry, immunohistochemical analysis, or molecular studies. More sensitive techniques have been used by Filleul and colleagues to detect MRD. The used clonoegenic probes from the hypervariable regions of the immunoglobulin heavy-chain gene and performed polymerase chain reactions (PCRs) on bone marrow biopsy specimens, All seven patients who were in morphologic complete remission after a single cladribine infusion were PCR positive. These data indicate that cladribine induces protracted remissions but is not necessarily curative. MRD can be detected in most patients when sensitive techniques are used. Persistence of immunohistochemical MRD may predict detected MRD remains to be studied in a large number of patients. Investigators from the University of Pisa in Italy have used a combination of cladribine and rituximab to eradicate MRD in patients who have HCL. Ten patients received treatment with a standard infusion of cladribine. Two patients achieved a complete remission, 6 patients achieved a partial remission, and 2 patients failed to respond. All were PCR positive for the immunoglobulin heavy-chain (IgH) gene product at the completion of cladribine treatment. All 10 patients had achieved a complete hematologic response 2 months after the completion of ritximab therapy. The curative nature of this treatment will require long-term follow-up. Cladribine represents a major therapeutic advance in the treatment of HCL. The prognosis of patients who have HCL has improved greatly with cladribine therapy. Future strategies should address combination therapy with purine analogs and monclonal antibodies. These strategies should address eradication of MRD in an attempt to develop a potentially curative combination treatment program.


Subject(s)
Cladribine/therapeutic use , Leukemia, Hairy Cell/drug therapy , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Murine-Derived , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Combined Modality Therapy/methods , Disease-Free Survival , Genes, Immunoglobulin Heavy Chain/genetics , Humans , Italy , Leukemia, Hairy Cell/diagnosis , Leukemia, Hairy Cell/genetics , Leukemia, Hairy Cell/mortality , Leukemia, Hairy Cell/pathology , Neoplasm, Residual , Polymerase Chain Reaction/methods , Recurrence , Remission Induction/methods , Rituximab , Treatment Outcome
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