The Experts below are selected from a list of 8160 Experts worldwide ranked by ideXlab platform
Davide Sciuscio - One of the best experts on this subject based on the ideXlab platform.
-
toward refinement of the colony forming unit granulocyte macrophage Clonogenic Assay inclusion of a metabolic system
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Davide SciuscioAbstract:This work represents a first attempt to refine the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic Assay by incorporating liver microsomes and co-factors as a metabolic system into the in vitro test system in response to an ECVAM recommendation. From the comparison of results obtained with the CFU-GM Clonogenic Assay currently used and with the new experimental protocol, different toxicity on granulocyte/macrophage precursors was demonstrated, when drugs with a known metabolism in vivo were tested.
-
a new experimental protocol as an alternative to the colony forming unit granulocyte macrophage cfu gm Clonogenic Assay to assess the haematotoxic potential of new drugs
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Paolo Repeto, Davide SciuscioAbstract:Abstract In this work, a first attempt to set-up a new in vitro experimental protocol with culture in liquid medium and flow cytometry analysis of bone marrow progenitors is described. This protocol is proposed as an alternative to the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic in vitro Assay currently used to assess the toxic potential of new drugs in the bone marrow. This new experimental approach should enable to speed up the procedure of the in vitro haematotoxic potential assessment, to reduce inter-experimental variability and to enhance result accuracy. Preliminary results obtained demonstrated that the progenitor cell count by flow cytometry replacing the light microscopy granulocyte/macrophage colony count represents a tremendous improvement in terms of accuracy and standardisation. Moreover, differential counts of cell sub-populations can be performed by using specific monoclonal antibodies. Furthermore, this method demonstrated to be time-saving, since 4 day cell incubation period is required instead of 7–14 day incubation in the CFU-GM Clonogenic Assay. On the basis of results obtained so far, the new experimental protocol proposed looks a promising alternative to the CFU-GM Clonogenic Assay currently used.
Gianni Dal Negro - One of the best experts on this subject based on the ideXlab platform.
-
toward refinement of the colony forming unit granulocyte macrophage Clonogenic Assay inclusion of a metabolic system
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Davide SciuscioAbstract:This work represents a first attempt to refine the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic Assay by incorporating liver microsomes and co-factors as a metabolic system into the in vitro test system in response to an ECVAM recommendation. From the comparison of results obtained with the CFU-GM Clonogenic Assay currently used and with the new experimental protocol, different toxicity on granulocyte/macrophage precursors was demonstrated, when drugs with a known metabolism in vivo were tested.
-
a new experimental protocol as an alternative to the colony forming unit granulocyte macrophage cfu gm Clonogenic Assay to assess the haematotoxic potential of new drugs
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Paolo Repeto, Davide SciuscioAbstract:Abstract In this work, a first attempt to set-up a new in vitro experimental protocol with culture in liquid medium and flow cytometry analysis of bone marrow progenitors is described. This protocol is proposed as an alternative to the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic in vitro Assay currently used to assess the toxic potential of new drugs in the bone marrow. This new experimental approach should enable to speed up the procedure of the in vitro haematotoxic potential assessment, to reduce inter-experimental variability and to enhance result accuracy. Preliminary results obtained demonstrated that the progenitor cell count by flow cytometry replacing the light microscopy granulocyte/macrophage colony count represents a tremendous improvement in terms of accuracy and standardisation. Moreover, differential counts of cell sub-populations can be performed by using specific monoclonal antibodies. Furthermore, this method demonstrated to be time-saving, since 4 day cell incubation period is required instead of 7–14 day incubation in the CFU-GM Clonogenic Assay. On the basis of results obtained so far, the new experimental protocol proposed looks a promising alternative to the CFU-GM Clonogenic Assay currently used.
Luca Vandin - One of the best experts on this subject based on the ideXlab platform.
-
toward refinement of the colony forming unit granulocyte macrophage Clonogenic Assay inclusion of a metabolic system
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Davide SciuscioAbstract:This work represents a first attempt to refine the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic Assay by incorporating liver microsomes and co-factors as a metabolic system into the in vitro test system in response to an ECVAM recommendation. From the comparison of results obtained with the CFU-GM Clonogenic Assay currently used and with the new experimental protocol, different toxicity on granulocyte/macrophage precursors was demonstrated, when drugs with a known metabolism in vivo were tested.
-
a new experimental protocol as an alternative to the colony forming unit granulocyte macrophage cfu gm Clonogenic Assay to assess the haematotoxic potential of new drugs
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Paolo Repeto, Davide SciuscioAbstract:Abstract In this work, a first attempt to set-up a new in vitro experimental protocol with culture in liquid medium and flow cytometry analysis of bone marrow progenitors is described. This protocol is proposed as an alternative to the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic in vitro Assay currently used to assess the toxic potential of new drugs in the bone marrow. This new experimental approach should enable to speed up the procedure of the in vitro haematotoxic potential assessment, to reduce inter-experimental variability and to enhance result accuracy. Preliminary results obtained demonstrated that the progenitor cell count by flow cytometry replacing the light microscopy granulocyte/macrophage colony count represents a tremendous improvement in terms of accuracy and standardisation. Moreover, differential counts of cell sub-populations can be performed by using specific monoclonal antibodies. Furthermore, this method demonstrated to be time-saving, since 4 day cell incubation period is required instead of 7–14 day incubation in the CFU-GM Clonogenic Assay. On the basis of results obtained so far, the new experimental protocol proposed looks a promising alternative to the CFU-GM Clonogenic Assay currently used.
Monica Bonato - One of the best experts on this subject based on the ideXlab platform.
-
toward refinement of the colony forming unit granulocyte macrophage Clonogenic Assay inclusion of a metabolic system
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Davide SciuscioAbstract:This work represents a first attempt to refine the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic Assay by incorporating liver microsomes and co-factors as a metabolic system into the in vitro test system in response to an ECVAM recommendation. From the comparison of results obtained with the CFU-GM Clonogenic Assay currently used and with the new experimental protocol, different toxicity on granulocyte/macrophage precursors was demonstrated, when drugs with a known metabolism in vivo were tested.
-
a new experimental protocol as an alternative to the colony forming unit granulocyte macrophage cfu gm Clonogenic Assay to assess the haematotoxic potential of new drugs
Toxicology in Vitro, 2006Co-Authors: Gianni Dal Negro, Luca Vandin, Monica Bonato, Paolo Repeto, Davide SciuscioAbstract:Abstract In this work, a first attempt to set-up a new in vitro experimental protocol with culture in liquid medium and flow cytometry analysis of bone marrow progenitors is described. This protocol is proposed as an alternative to the colony-forming unit-granulocyte/macrophage (CFU-GM) Clonogenic in vitro Assay currently used to assess the toxic potential of new drugs in the bone marrow. This new experimental approach should enable to speed up the procedure of the in vitro haematotoxic potential assessment, to reduce inter-experimental variability and to enhance result accuracy. Preliminary results obtained demonstrated that the progenitor cell count by flow cytometry replacing the light microscopy granulocyte/macrophage colony count represents a tremendous improvement in terms of accuracy and standardisation. Moreover, differential counts of cell sub-populations can be performed by using specific monoclonal antibodies. Furthermore, this method demonstrated to be time-saving, since 4 day cell incubation period is required instead of 7–14 day incubation in the CFU-GM Clonogenic Assay. On the basis of results obtained so far, the new experimental protocol proposed looks a promising alternative to the CFU-GM Clonogenic Assay currently used.
Heinz-herbert Fiebig - One of the best experts on this subject based on the ideXlab platform.
-
abstract 3528 in vitro profiling of kinase inhibitors and targeted anticancer agents in panels of patient derived xenografts using a Clonogenic Assay
Cancer Research, 2011Co-Authors: Armin Maier, Thomas Metz, Rebekka Krumbach, Thomas Beckers, Heinz-herbert FiebigAbstract:Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Novel cancer therapeutics target proteins with key functions in cell survival and migration, protein turnover, mitosis regulation, or angiogenesis. These targets include receptor tyrosine (Y) kinases (e.g. BCR/ABL, EGF-R, FLT-3, Her-2, PDGF-R, KDR, c-KIT, Src, VEGF-R), serine-threonine (S/T) specific kinases (e.g. Aurora A/B (ARK), B-raf), and the chaperone Hsp90. At Oncotest, a unique profiling screen for anticancer agents is routinely done, using a Clonogenic Assay in a panel of 48 proprietary solid tumor xenografts. The xenograft models were in general established directly from patient tumors, representing all major tumor histotypes (non-small cell lung cancer/NSCLC, pancreatic, prostate, colon, gastric, breast, ovarian and renal cancer, melanoma and sarcoma) as well as niche tumors (pleuramesothelioma, bladder and head and neck cancer). After an initial profiling screen in the 48 tumor panel, follow-up testing in defined tumor histotypes are of high value for hypothesis generation and selection of a clinical development strategy. Here, activity profiles for inhibitors targeting multiple S/T and Y kinases (Dasatinib, Pazopanib, Sunitinib, Sorafenib), EGF-R (Erlotinib, Gefitinib), Her-2 (Lapatinib), Aurora A/B (VX-680), and Hsp90 (17-DMAG) are presented. Erlotinib and Gefitinib displayed a diverse pattern of activity with mean IC50 values of 36.5µM and 20.7µM, respectively. Selectivity was studied in an extended panel of NSCLC with tumors showing an activated EGF-R pathway being most sensitive. The Hsp90 inhibitor 17-DMAG was highly potent with a mean IC50 value of 19nM. As an example, tumor xenograft models selected based on Clonogenic Assay data responded very well in in vivo efficacy tests against 17-DMAG. The spectrum-kinase inhibitors Sunitinib and Sorafenib displayed a rather weak selectivity with mean IC50 values of 6.3µM and 10.5µM, respectively. In contrast the BCR/ABL and Src inhibitor Dasatinib was active with a mean IC50 of 5.4µM, and showed a highly differential activity against xenografts of solid tumors. Extended tests against 105 tumors of 16 different histotypes identified pancreatic, breast, small cell lung, and colon cancer to be the most sensitive ones. This implements that the use of this compound might not be limited to the treatment of chronic myelogenous leukaemia and gastrointestinal stromal tumors. In conclusion, the presented panel screen using a Clonogenic Assay, by retaining important characteristics of the original patient tumor, is of high value for profiling of traditional cytotoxic as well as new targeted cancer agents. By revealing diverse activity and resistance patterns, molecular characterization data including gene and protein expression are guiding the selection of tumor entities and patients likely to respond to therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3528. doi:10.1158/1538-7445.AM2011-3528
-
Clonogenic Assay with established human tumour xenografts correlation of in vitro to in vivo activity as a basis for anticancer drug discovery
European Journal of Cancer, 2004Co-Authors: Heinz-herbert Fiebig, A Maier, Angelika M BurgerAbstract:Pluripotent cells can be grown in Clonogenic Assays. The tumour stem-cell fraction, which accounts for <0.4% of the total cells, and which is considered the most relevant cell type in the development of metastases and recurrences, is able to divide and to form colonies in a semisolid matrix (agar or methylcellulose). Major applications of the tumour Clonogenic Assay (TCA) are chemosensitivity testing of tumours and xenografts, and for assessments within drug discovery programmes. Of critical relevance for the usefulness of the TCA is whether it can predict sensitivity or resistance towards clinically used agents. When we compared the response of human tumours established as xenografts in nude mice in the TCA in vitro to that of the clinical response, 62% of the comparisons for drug sensitivity, and 92% of the comparisons for drug resistance were correct. The same percentage of true/false observations was found when tumours were tested after serial passage in nude mice in the TCA in vitro and their response compared to in vivo activity in corresponding xenografts (60% and 90%, respectively). The highest correct predictive values were, however, found when the clinical response of tumours was compared to their explants established in the nude mouse and treated in vivo. Of 80 comparisons performed, we observed a correct prediction for tumour resistance in 97% and for tumour sensitivity in 90%. In our opinion, the TCA with established human tumour xenografts has an important role in current drug discovery strategies. We therefore included the TCA as secondary Assay in our approach to anticancer drug discovery and found that a number of novel agents were active; these are now in advanced preclinical development or clinical trials. Thus, the tumour Clonogenic Assay has proven predictive value in the chemosensitivity testing of standard and experimental anticancer drugs.