15 results on '"Kraveka J"'
Search Results
2. A phase I trial of TPI-287 as a single agent and its combination with temozolomide in relapsed neuroblastoma or medulloblastoma.
- Author
-
Saulnier Sholler, G. L., primary, Bergendahl, G., additional, Lenox, S., additional, Zage, P. E., additional, Roberts, W., additional, Kraveka, J. M., additional, Eslin, D., additional, Kaplan, J., additional, Higgins, T., additional, and Ferguson, W., additional
- Published
- 2010
- Full Text
- View/download PDF
3. Bioactive Sphingolipids: An Overview on Ceramide, Ceramide 1-Phosphate Dihydroceramide, Sphingosine, Sphingosine 1-Phosphate.
- Author
-
Kraveka, J. M. and Hannun, Y. A.
- Abstract
Bioactive sphingolipids such as ceramide, ceramide 1-phosphate, dihydroceramide, sphingosine, and sphingosine 1-phosphate have key roles in cell proliferation, differentiation, senescence, apoptosis, migration, carcinogenesis, inflammation, and angiogenesis. There has been much progress made in understanding the complex pathways of sphingolipid metabolism and identifying the enzymes involved in sphingolipid production. This chapter reviews the structure, metabolism and functions of these bioactive sphingolipids. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
4. Role of ceramide in mediating the inhibition of telomerase activity in A549 human lung adenocarcinoma cells.
- Author
-
Ogretmen, B, Schady, D, Usta, J, Wood, R, Kraveka, J M, Luberto, C, Birbes, H, Hannun, Y A, and Obeid, L M
- Abstract
This study was designed to analyze whether ceramide, a bioeffector of growth suppression, plays a role in the regulation of telomerase activity in A549 cells. Telomerase activity was inhibited significantly by exogenous C(6)-ceramide, but not by the biologically inactive analog dihydro-C(6)-ceramide, in a time- and dose-dependent manner, with 85% inhibition produced by 20 microm C(6)-ceramide at 24 h. Moreover, analysis of phosphatidylserine translocation from the inner to the outer plasma membrane by flow cytometry and of poly(ADP-ribose) polymerase degradation by Western blotting showed that ceramide treatment (20 microm for 24 h) had no apoptotic effects. Trypan blue exclusion, [(3)H]thymidine incorporation, and cell cycle analyses, coupled with clonogenic cell survival assay on soft agar, showed that ceramide treatment with a 20 microm concentration at 24 h resulted in the cell cycle arrest of the majority of the cell population at G(0)/G(1) with no detectable cell death. These results suggest that the inhibition of telomerase by ceramide is not a consequence of cell death but is correlated with growth arrest. Next, to determine the role of endogenous ceramide in telomerase modulation, A549 cells were transiently transfected with an expression vector containing the full-length bacterial sphingomyelinase cDNA (b-SMase). The overexpression of b-SMase, but not exogenously applied purified b-SMase enzyme, resulted in significantly decreased telomerase activity compared with controls, showing that the increased endogenous ceramide is sufficient for telomerase inhibition. Moreover, treatment of A549 cells with daunorubicin at 1 microm for 6 h resulted in the inhibition of telomerase, which correlated with the elevation of endogenous ceramide levels and growth arrest. Finally, stable overexpression of human glucosylceramide synthase, which attenuates ceramide levels by converting ceramide to glucosylceramide, prevented the inhibitory effects of C(6)-ceramide and daunorubicin on telomerase. Therefore, these results provide novel data showing for the first time that ceramide is a candidate upstream regulator of telomerase.
- Published
- 2001
- Full Text
- View/download PDF
5. Skin fibroblasts from individuals hemizygous for the familial adenopolyposis susceptibility gene show delayed crisis in vitro.
- Author
-
Chen, S Z, Kazim, D, Kraveka, J, and Pollack, R E
- Abstract
Normal human fibroblast cells have not been reported to escape crisis--that is, they die after about 24 doublings in culture. We have been studying the growth properties of skin fibroblast cells from persons in families with familial adenopolyposis of the colon (FAP). An individual hemizygous at the FAP locus will develop hyperplasia of the colonic epithelium followed by colonic polyps, both at an early age. Polyps themselves still retain a single functional FAP allele. A mutation or deletion in this allele in a polyp is hypothesized to lead to further loss of growth control; thus, a tumor is formed. We found that the in vitro life-span of skin fibroblast cells from FAP individuals and from some asymptomatic children were markedly extended when compared with normal individuals.
- Published
- 1989
- Full Text
- View/download PDF
6. Telomerase activity and phenotypic characterization of bone marrow harvested after chemotherapy.
- Author
-
Petryk, A, Russo, DA, Kraveka, J, and August, CS
- Published
- 1996
- Full Text
- View/download PDF
7. Monoclonal antibodies to the cell surface of MCRI-39 mark this human lymphoid/myeloid cell line but not human peripheral blood mononuclear cells
- Author
-
Cusano, G, Russo, DA, Bash, JA, Kraveka, J, and August, CS
- Published
- 1996
- Full Text
- View/download PDF
8. Comprehensive genomic analysis reveals molecular heterogeneity in pediatric ALK-positive anaplastic large cell lymphoma.
- Author
-
Shaw TI, Pounds S, Cao X, Ma J, Palacios G, Mason J, Perkins S, Wu G, Fan Y, Wang J, Zhou X, Obermayer A, Kinney MC, Kraveka J, Gross T, Sandlund J, Zhang J, Mullighan C, Lim MS, and Leventaki V
- Abstract
Anaplastic large cell lymphoma (ALCL) is a mature T-cell lymphoma that accounts for 10-15% of childhood lymphomas. Despite the observation that more than 90% of pediatric cases harbor the anaplastic lymphoma kinase (ALK) rearrangement resulting in aberrant ALK kinase expression, there is significant clinical, morphologic, and biological heterogeneity. To gain insights into the genomic aberrations and molecular heterogeneity within ALK-positive ALCL (ALK+ ALCL), we analyzed 46 pediatric ALK+ ALCLs by whole-exome sequencing, RNA sequencing, and DNA methylation profiling. Whole-exome sequencing found on average 25 SNV/Indel events per sample with recurring genetic events in regulators of DNA damage (TP53, MDM4), transcription (JUNB), and epigenetic regulators (TET1, KMT2B, KMT2A, KMT2C, KMT2E). Gene expression and methylation profiling consistently subclassified ALK+ ALCLs into two groups characterized by differential ALK expression levels. The ALK-low group showed enrichment of pathways associated with immune response, cytokine signaling, and a hypermethylated predominant pattern compared to the ALK-high group, which had more frequent copy number changes and was enriched with pathways associated with cell growth, proliferation, and metabolism. Altogether, these findings suggest that there is molecular heterogeneity within pediatric ALK+ ALCL, predicting distinct biological mechanisms that may provide novel insights into disease pathogenesis and represent prognostic markers., Competing Interests: Competing interests: TIS reports a patent for EBD CAR pending. CGM reports personal fees from Illumina during the conduct of the study, as well as grants from Pfizer and AbbVie, and other support from Amgen outside the submitted work. No disclosures were reported by the other authors. Ethics approval and consent to participate: This study was conducted in accordance with the International Ethical Guidelines for Biomedical Research Involving Human Subjects. Informed written consent was obtained from all patients and/or their legal guardians before enrollment in the study. The St. Jude Children’s Research Hospital Institutional Review Board approved the use of excess diagnostic material and data for this study (XPD14-018). All methods were performed in accordance with the relevant guidelines and regulations., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2024
- Full Text
- View/download PDF
9. Molecular-guided therapy for the treatment of patients with relapsed and refractory childhood cancers: a Beat Childhood Cancer Research Consortium trial.
- Author
-
Sholler GLS, Bergendahl G, Lewis EC, Kraveka J, Ferguson W, Nagulapally AB, Dykema K, Brown VI, Isakoff MS, Junewick J, Mitchell D, Rawwas J, Roberts W, Eslin D, Oesterheld J, Wada RK, Pastakia D, Harrod V, Ginn K, Saab R, Bielamowicz K, Glover J, Chang E, Hanna GK, Enriquez D, Izatt T, Halperin RF, Moore A, Byron SA, Hendricks WPD, and Trent JM
- Subjects
- Child, Humans, Antineoplastic Combined Chemotherapy Protocols adverse effects, Neoplasm Recurrence, Local drug therapy, Neoplasm Recurrence, Local etiology, Neuroblastoma drug therapy, Neuroblastoma genetics
- Abstract
Background: Children with relapsed central nervous system (CNS tumors), neuroblastoma, sarcomas, and other rare solid tumors face poor outcomes. This prospective clinical trial examined the feasibility of combining genomic and transcriptomic profiling of tumor samples with a molecular tumor board (MTB) approach to make real‑time treatment decisions for children with relapsed/refractory solid tumors., Methods: Subjects were divided into three strata: stratum 1-relapsed/refractory neuroblastoma; stratum 2-relapsed/refractory CNS tumors; and stratum 3-relapsed/refractory rare solid tumors. Tumor samples were sent for tumor/normal whole-exome (WES) and tumor whole-transcriptome (WTS) sequencing, and the genomic data were used in a multi-institutional MTB to make real‑time treatment decisions. The MTB recommended plan allowed for a combination of up to 4 agents. Feasibility was measured by time to completion of genomic sequencing, MTB review and initiation of treatment. Response was assessed after every two cycles using Response Evaluation Criteria in Solid Tumors (RECIST). Patient clinical benefit was calculated by the sum of the CR, PR, SD, and NED subjects divided by the sum of complete response (CR), partial response (PR), stable disease (SD), no evidence of disease (NED), and progressive disease (PD) subjects. Grade 3 and higher related and unexpected adverse events (AEs) were tabulated for safety evaluation., Results: A total of 186 eligible patients were enrolled with 144 evaluable for safety and 124 evaluable for response. The average number of days from biopsy to initiation of the MTB-recommended combination therapy was 38 days. Patient benefit was exhibited in 65% of all subjects, 67% of neuroblastoma subjects, 73% of CNS tumor subjects, and 60% of rare tumor subjects. There was little associated toxicity above that expected for the MGT drugs used during this trial, suggestive of the safety of utilizing this method of selecting combination targeted therapy., Conclusions: This trial demonstrated the feasibility, safety, and efficacy of a comprehensive sequencing model to guide personalized therapy for patients with any relapsed/refractory solid malignancy. Personalized therapy was well tolerated, and the clinical benefit rate of 65% in these heavily pretreated populations suggests that this treatment strategy could be an effective option for relapsed and refractory pediatric cancers., Trial Registration: ClinicalTrials.gov, NCT02162732. Prospectively registered on June 11, 2014., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
10. A phase II trial of nifurtimox combined with topotecan and cyclophosphamide for refractory or relapsed neuroblastoma and medulloblastoma.
- Author
-
Eslin D, Zage PE, Bergendahl G, Lewis E, Roberts W, Kraveka J, Mitchell D, Isakoff MS, Rawwas J, Wada RK, Fluchel M, Brown VI, Ginn K, Higgins T, BeeravallyNagulapally A, Dykema K, Hanna G, Ferguson W, and Saulnier Sholler GL
- Subjects
- Child, Humans, Topotecan adverse effects, Nifurtimox therapeutic use, Neoplasm Recurrence, Local pathology, Cyclophosphamide, Antineoplastic Combined Chemotherapy Protocols adverse effects, Medulloblastoma drug therapy, Neuroblastoma drug therapy, Neuroblastoma etiology, Cerebellar Neoplasms
- Abstract
Children with relapsed/refractory (R/R) neuroblastoma (NB) and medulloblastoma (MB) have poor outcomes. We evaluated the efficacy of nifurtimox (Nfx) in a clinical trial for children with R/R NB and MB. Subjects were divided into three strata: first relapse NB, multiply R/R NB, and R/R MB. All patients received Nfx (30 mg/kg/day divided TID daily), Topotecan (0.75 mg/m
2 /dose, days 1-5) and Cyclophosphamide (250 mg/m2 /dose, days 1-5) every 3 weeks. Response was assessed after every two courses using International Neuroblastoma Response Criteria and Response Evaluation Criteria in Solid Tumors (RECIST) criteria. One hundred and twelve eligible patients were enrolled with 110 evaluable for safety and 76 evaluable for response. In stratum 1, there was a 53.9% response rate (CR + PR), and a 69.3% total benefit rate (CR + PR + SD), with an average time on therapy of 165.2 days. In stratum 2, there was a 16.3% response rate, and a 72.1% total benefit rate, and an average time on study of 158.4 days. In stratum 3, there was a 20% response rate and a 65% total benefit rate, an average time on therapy of 105.0 days. The most common side effects included bone marrow suppression and reversible neurologic complications. The combination of Nfx, topotecan and cyclophosphamide was tolerated, and the objective response rate plus SD of 69.8% in these heavily pretreated populations suggests that this combination is an effective option for patients with R/R NB and MB. Although few objective responses were observed, the high percentage of stabilization of disease and prolonged response rate in patients with multiply relapsed disease shows this combination therapy warrants further testing., (© 2023 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)- Published
- 2023
- Full Text
- View/download PDF
11. A Phase 1 Trial of TPI 287 as a Single Agent and in Combination With Temozolomide in Patients with Refractory or Recurrent Neuroblastoma or Medulloblastoma.
- Author
-
Mitchell D, Bergendahl G, Ferguson W, Roberts W, Higgins T, Ashikaga T, DeSarno M, Kaplan J, Kraveka J, Eslin D, Werff AV, Hanna GK, and Sholler GL
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Dacarbazine administration & dosage, Dacarbazine pharmacokinetics, Dacarbazine toxicity, Female, Humans, Infusions, Intravenous, Male, Maximum Tolerated Dose, Neoplasm Recurrence, Local, Taxoids pharmacokinetics, Taxoids toxicity, Temozolomide, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Dacarbazine analogs & derivatives, Medulloblastoma drug therapy, Neuroblastoma drug therapy, Taxoids administration & dosage, Taxoids therapeutic use
- Abstract
Background: The primary aim of this Phase I study was to determine the maximum tolerated dose (MTD) of TPI 287 and the safety and tolerability of TPI 287 alone and in combination with temozolomide (TMZ) in pediatric patients with refractory or recurrent neuroblastoma or medulloblastoma. The secondary aims were to evaluate the pharmacokinetics of TPI 287 and the treatment responses., Procedure: Eighteen patients were enrolled to a phase I dose escalation trial of weekly intravenous infusion of TPI 287 for two 28-day cycles with toxicity monitoring to determine the MTD, followed by two cycles of TPI 287 in combination with TMZ. Samples were collected to determine the pharmacokinetic parameters C(max), AUC(0-24), t(1/2), CL, and Vd on day 1 of cycles 1 (TPI 287 alone) and 3 (TPI 287 + TMZ) following TPI 287 infusion. Treatment response was evaluated by radiographic (CT or MRI) and radionuclide (MIBG) imaging for neuroblastoma., Results: We determined the MTD of TPI 287 alone and in combination with temozolomide to be 125 mg/m(2). The non-dose-limiting toxicities at this dose were mainly anorexia and pain. The dose-limiting toxicities (DLTs) of two patients at 135 mg/m(2) were grade 3 hemorrhagic cystitis and grade 3 sensory neuropathy., Conclusions: Overall, TPI 287 was well tolerated by pediatric patients with refractory and relapsed neuroblastoma and medulloblastoma at a dose of 125 mg/m(2) IV on days 1, 8, and 15 of a 28 day cycle., (© 2015 Wiley Periodicals, Inc.)
- Published
- 2016
- Full Text
- View/download PDF
12. Feasibility of implementing molecular-guided therapy for the treatment of patients with relapsed or refractory neuroblastoma.
- Author
-
Saulnier Sholler GL, Bond JP, Bergendahl G, Dutta A, Dragon J, Neville K, Ferguson W, Roberts W, Eslin D, Kraveka J, Kaplan J, Mitchell D, Parikh N, Merchant M, Ashikaga T, Hanna G, Lescault PJ, Siniard A, Corneveaux J, Huentelman M, and Trent J
- Subjects
- Adolescent, Antineoplastic Agents therapeutic use, Child, Child, Preschool, Chronic Disease, Feasibility Studies, Female, Gene Expression Profiling methods, Genome-Wide Association Study methods, Humans, Male, Molecular Targeted Therapy adverse effects, Patient Safety, Prospective Studies, RNA, Neoplasm genetics, Sequence Analysis, RNA methods, Time-to-Treatment, Treatment Outcome, Young Adult, Molecular Targeted Therapy methods, Neoplasm Recurrence, Local therapy, Neuroblastoma therapy
- Abstract
The primary objective of the study was to evaluate the feasibility and safety of a process which would utilize genome-wide expression data from tumor biopsies to support individualized treatment decisions. Current treatment options for recurrent neuroblastoma are limited and ineffective, with a survival rate of <10%. Molecular profiling may provide data which will enable the practitioner to select the most appropriate therapeutic option for individual patients, thus improving outcomes. Sixteen patients with neuroblastoma were enrolled of which fourteen were eligible for this study. Feasibility was defined as completion of tumor biopsy, pathological evaluation, RNA quality control, gene expression profiling, bioinformatics analysis, generation of a drug prediction report, molecular tumor board yielding a treatment plan, independent medical monitor review, and treatment initiation within a 21 day period. All eligible biopsies passed histopathology and RNA quality control. Expression profiling by microarray and RNA sequencing were mutually validated. The average time from biopsy to report generation was 5.9 days and from biopsy to initiation of treatment was 12.4 days. No serious adverse events were observed and all adverse events were expected. Clinical benefit was seen in 64% of patients as stabilization of disease for at least one cycle of therapy or partial response. The overall response rate was 7% and the progression free survival was 59 days. This study demonstrates the feasibility and safety of performing real-time genomic profiling to guide treatment decision making for pediatric neuroblastoma patients., (© 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)
- Published
- 2015
- Full Text
- View/download PDF
13. EFFECTS OF POLYMERIC NANOPARTICLE SURFACE PROPERTIES ON INTERACTION WITH BRAIN TUMOR ENVIRONMENT.
- Author
-
Mattix B, Moore T, Uvarov O, Pollard S, O'Donnell L, Park K, Horne D, Dhulekar J, Reese L, Nguyen D, Kraveka J, Burg K, and Alexis F
- Abstract
Current chemotherapy treatments are limited by poor drug solubility, rapid drug clearance and systemic side effects. Additionally, drug penetration into solid tumors is limited by physical diffusion barriers [e.g., extracellular matrix (ECM)]. Nanoparticle (NP) blood circulation half-life, biodistribution and ability to cross extracellular and cellular barriers will be dictated by NP composition, size, shape and surface functionality. Here, we investigated the effect of surface charge of poly(lactide)-poly(ethylene glycol) NPs on mediating cellular interaction. Polymeric NPs of equal sizes were used that had two different surface functionalities: negatively charged carboxyl (COOH) and neutral charged methoxy (OCH
3 ). Cellular uptake studies showed significantly higher uptake in human brain cancer cells compared to noncancerous human brain cells, and negatively charged COOH NPs were uptaken more than neutral OCH3 NPs in 2D culture. NPs were also able to load and control the release of paclitaxel (PTX) over 19 days. Toxicity studies in U-87 glioblastoma cells showed that PTX-loaded NPs were effective drug delivery vehicles. Effect of surface charge on NP interaction with the ECM was investigated using collagen in a 3D cellular uptake model, as collagen content varies with the type of cancer and the stage of the disease compared to normal tissues. Results demonstrated that NPs can effectively diffuse across an ECM barrier and into cells, but NP mobility is dictated by surface charge. In vivo biodistribution of OCH3 NPs in intracranial tumor xenografts showed that NPs more easily accumulated in tumors with less collagen. These results indicate that a robust understanding of NP interaction with various tumor environments can lead to more effective patient-tailored therapies.- Published
- 2013
- Full Text
- View/download PDF
14. Molecular mechanisms of ceramide-mediated telomerase inhibition in the A549 human lung adenocarcinoma cell line.
- Author
-
Ogretmen B, Kraveka JM, Schady D, Usta J, Hannun YA, and Obeid LM
- Subjects
- Adenocarcinoma, Cycloheximide pharmacology, DNA-Binding Proteins, Gene Expression Regulation, Enzymologic drug effects, Gene Expression Regulation, Neoplastic drug effects, Genes, Reporter, Genes, myc drug effects, Half-Life, Humans, Luciferases genetics, Lung Neoplasms, Proto-Oncogene Proteins c-myc metabolism, RNA, Messenger genetics, Reverse Transcriptase Polymerase Chain Reaction, Telomerase antagonists & inhibitors, Transfection, Tumor Cells, Cultured, Ubiquitins metabolism, Ceramides pharmacology, Promoter Regions, Genetic, Telomerase genetics, Telomerase metabolism, Transcription, Genetic drug effects
- Abstract
This study was aimed at identifying the molecular mechanisms by which ceramide inhibits telomerase activity in the A549 human lung adenocarcinoma cell line. C(6)-ceramide (20 microm) caused a significant reduction of telomerase activity at 24 h as detected using the telomeric repeat amplification protocol, and this inhibition correlated with decreased telomerase reverse transcriptase (hTERT) protein. Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot analyses showed that C(6)-ceramide significantly decreased hTERT mRNA in a time-dependent manner. Electrophoretic mobility shift and supershift assays demonstrated that the binding activity of c-Myc transcription factor to the E-box sequence on the hTERT promoter was inhibited in response to C(6)-ceramide at 24 h. These results were also confirmed by transient transfections of A549 cells with pGL3-Basic plasmid constructs containing the functional hTERT promoter and its E-box deleted sequences cloned upstream of a luciferase reporter gene. Further analysis using RT-PCR and Western blotting showed that c-Myc protein but not its mRNA levels were decreased in response to C(6)-ceramide at 24 h. The effects of ceramide on the c-Myc protein were shown to be due to a reduction in half-life via increased ubiquitination. Similar results were obtained by increased endogenous ceramide levels in response to nontoxic concentrations of daunorubicin, resulting in the inhibition of telomerase and c-Myc activities. Furthermore, the elevation of endogenous ceramide by overexpression of bacterial sphingomyelinase after transient transfections also induced the inhibition of telomerase activity with concomitant decreased hTERT and c-Myc protein levels. Taken together, these results show for the first time that both exogenous and endogenous ceramides mediate the modulation of telomerase activity via decreased hTERT promoter activity caused by rapid proteolysis of the ubiquitin-conjugated c-Myc transcription factor.
- Published
- 2001
- Full Text
- View/download PDF
15. Immunoprecipitation of human telomerase reverse transcriptase with telomerase activity.
- Author
-
Kraveka JM, Schady D, Obeid LM, and Ogretmen B
- Subjects
- Cholic Acids analysis, Cholic Acids immunology, DNA-Binding Proteins, Humans, Lung Neoplasms enzymology, Tumor Cells, Cultured enzymology, Antibodies immunology, Precipitin Tests methods, RNA, Telomerase analysis, Telomerase immunology, Telomerase metabolism
- Published
- 2001
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.