Chromosomal aberrations induced by 5-azacytidine combined with VP-16 (etoposide) in CHO-K1 and XRS-5 cell lines

2003 ◽  
Vol 23 (S1) ◽  
pp. 171-186 ◽  
Author(s):  
A.P.A. Guimar�es ◽  
F.L. Dias ◽  
R.S. Cardoso ◽  
S.N. Kronka ◽  
E.T. Sakamoto-Hojo
1988 ◽  
Vol 43 (11-12) ◽  
pp. 948-954 ◽  
Author(s):  
Friedrich J. Otto

Abstract A preparation, staining and measuring protocol for high resolution flow cytometry of chromosomes was developed. This method allows us to identify all chromosome types and is suited for characterization of permanent cell lines and cell clones by establishing their flow karyotypes. In cell clones this procedure can be used for the detection of chromosomal aberrations which appear spontaneously or are induced by mutagen treatment and persist in the cell population.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2856-2856 ◽  
Author(s):  
Dirk Hose ◽  
Anja Seckinger ◽  
Hartmut Goldschmidt ◽  
Tobias Meiβner ◽  
Blanka Rebacz ◽  
...  

Abstract Abstract 2856 Poster Board II-832 BACKGROUND. Molecular profiling of multiple myeloma allows the identification of novel targets, including HIF1A, and evaluation of their expression within large cohorts of patients. We report here the expression of HIF1A in myeloma and for the first time the preclinical testing of 4 members of a novel class of sulfonanilide HIF1A signaling inhibitors. PATIENTS AND METHODS. Expression of HIF1A was assessed using Affymetrix DNA-microarrays in 329 samples of CD138-purified myeloma cells from previously untreated patients. Chromosomal aberrations were assessed by comprehensive iFISH using a set of probes for the chromosomal regions 1q21, 6q21, 8p21, 9q34, 11q23, 11q13, 13q14.3, 14q32, 15q22, 17p13, 19q13, 22q11, as well as the translocations t(4;14)(p16.3;q32.3) and t(11;14)(q13;q32.3). Proliferation of primary myeloma cells (n=67) was determined by propidium iodine staining. The effect of the novel HIF1A signaling inhibitors ELR510490, ELR510454, ELR510444 and ELR105813 on the proliferation of 12 human myeloma cell lines and the first three on the survival of 5 primary myeloma cell-samples cultured within their microenvironment was tested, and their ability to inhibit HIF1A signaling was examined using a cell-based reporter assay. Studies were also conducted to determine in vitro stability (in plasma and microsomes), as well as single-dose PK (SDPK) parameters and maximum tolerated dose (MTD) levels after dosing in mice. RESULTS. We found (i) HIF1A to be expressed by 95.4% of CD138-purified primary myeloma cell samples from previously untreated patients. (ii) HIF1A expression shows a weak but significant correlation (r=0.3, p<0.001) with a gene expression based proliferation index. (iii) Of the chromosomal aberrations tested, myeloma cells of patients with presence of a translocation t(4,14) show a significantly higher expression of HIF1A (p<0.001) vs. patients without. Myeloma cells of hyperdiploid patients show a significantly lower expression of HIF1A (p=0.02) vs. non hyperdiploid patients. (iii) HIF1A expression does not show a correlation with event-free or overall survival. (iv) The sulfonanilides ELR510490, ELR510444, ELR510454 and ELR105813 completely inhibit proliferation of all tested myeloma cell lines at nM concentrations. (v) The compounds tested, i.e. ELR510490, ELR510444, ELR510454, are active on all primary myeloma cell-samples tested. (vi) The compounds show a pronounced effect on the HIF1A signaling pathway at EC50s of 1-25nM. (vii) Pre-clinical pharmacology data for the compounds ELR510444 and ELR510490 in mice indicate favorable absorption, distribution, metabolism, and excretion (ADME) profiles as well as exposure levels upon dosing at well-tolerated levels that are significantly above the in vitro EC50 in all the cell lines tested. CONCLUSION. HIF1A is expressed in almost all primary myeloma cells. The novel HIF1A signaling inhibitors tested are very active on myeloma cell lines as well as primary myeloma cells and show favorable in vivo profiles with exposure levels in mice significantly higher than the concentrations required for the inhibition of cell proliferation or apoptosis induction in vitro. This class of compounds thus represents a promising weapon in the therapeutic arsenal against multiple myeloma. Disclosures: Rebacz: ELARA Pharmaceuticals: Employment. Lewis:ELARA Pharmaceuticals: Employment. Schultes:ELARA Pharmaceuticals: Employment.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 248-248
Author(s):  
Dirk Hose ◽  
Thierry Rème ◽  
Tobias Meißner ◽  
Jérôme Moreaux ◽  
Anja Seckinger ◽  
...  

Abstract BACKGROUND. At the time of diagnosis, myeloma cells are characterized by a low proliferation rate that increases in relapse. Presence of proliferation correlates with adverse prognosis. At the same time, myeloma cells harbor a high median number of chromosomal aberrations, often associated with genetic instability. Cellular proliferation and genetic instability in turn have been associated with Aurora-kinase expression in several cancer entities, including multiple myeloma. PATIENTS AND METHODS. Expression of Aurora-A, -B and -C was assessed using Affymetrix DNA-microarrays in 784 samples including two independent sets of 233 and 345 CD138-purified myeloma cells from previously untreated patients. Chromosomal aberrations were assessed by comprehensive iFISH using a set of probes for the chromosomal regions 1q21, 6q21, 8p21, 9q34, 11q23, 11q13, 13q14.3, 14q32, 15q22, 17p13, 19q13, 22q11, as well as the translocations t(4;14)(p16.3;q32.3) and t(11;14) (q13;q32.3). Proliferation of primary myeloma cells (n=67) was determined by propidium iodine staining. The effect of the clinical Aurora-kinase inhibitor VX680 on proliferation of 20 human myeloma cell lines and survival of 5 primary myeloma cell-samples was tested. RESULTS. We found Aurora-A and -B to be expressed at varying frequencies in primary myeloma cells of different patient-cohorts, including 23% for Aurora A in our first cohort of patients treated with high dose therapy (see figure shown below). Aurora-C expression was found in testis-samples only. Myeloma cell-samples with detectable Aurora-A expression show a significantly higher proliferation rate, whereas the number of chromosomal aberrations (aneuploidy) is not higher compared to myeloma-cells with absent Aurora-A expression. The same holds true for subclonal aberrations (i.e. genetic instability). The Aurora-kinase inhibitor VX680 induces apoptosis in all myeloma cell lines and primary myeloma cell-samples tested. Presence of Aurora-A expression delineates significantly inferior event-free and overall survival in two independent cohorts of patients undergoing high-dose chemotherapy and autologous stem cell transplantation. This observation is independent of conventional prognostic factors, i.e. serum-ß2-microglobulin or ISS-stage. CONCLUSION. Aurora-kinase inhibitors (including VX680 tested here) are very active on myeloma cell lines as well as primary myeloma cells and represent a promising weapon in the therapeutic arsenal against multiple myeloma. Gene expression profiling allows the assessment of Aurora-kinase expression and thus in turn a tailoring of treatment to patients expressing Aurora-A associated with adverse prognosis. Figure Figure


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10023-10023
Author(s):  
B. Yan ◽  
H. Wang ◽  
J. S. Bedford ◽  
M. W. Dewhirst ◽  
C. Li

10023 Background: DNA fragmentation is a hallmark of apoptosis. However, the biological function of apoptotic DNA fragmentation remains unclear. Genes encoding the nuclease responsible for DNA fragmentation, DFF40/CAD and DFF45/ICAD, are deleted, mutated, or aberrantly expressed in many human tumor types. Abnormalities in this gene are associated with aggressive tumors and poor prognosis in cancer patients. Tumor-specific DFF45 gene mutations were identified in human tumors, indicating the involvement of this gene in tumor development. Methods: We studied genetic instability, cellular transformation and tumorigenesis in cells and mice deficient in DNA fragmentation. We applied two methods to inhibit DNA fragmentation, overexpressing a modified ICAD which inhibits DNA fragmentation during apoptosis in stable cell lines and disrupting cad gene in transgenic mice. Genetic instability was studied by gene amplification assay, mutation assay and cytogenetic analysis including chromosomal aberrations and translocations. Cellular transformation was studied by soft agar assay using CAD-/- MEF cells. Tumorigenesis in DFF/CAD-knockout mice was studied by radiation carcinogenesis and two-stage skin chemical carcinogenesis. Results: (1) Human and mouse cancer cell lines with their CAD activity inhibited exhibited significantly more genetic instability under spontaneous or mutagen (ionizing radiation) induced conditions. These are reflected as elevated frequencies of chromosomal aberrations, gene amplifications, and gene mutations; (2) Mouse cells with targeted disruption of the cad gene exhibit a similar, increased level of genetic instability when the host animal is irradiated; (3) Mechanistically, CAD maintains genetic instability through the removal of cells with DNA damage, a role that is similar to genomic “gatekeepers” like p53; (4) CAD-null mouse embryo fibroblasts exhibited enhanced cellular transformation; (5) Significantly enhanced susceptibility to chemical and radiation-induced tumor development was observed in mice with targeted disruption of the CAD gene, indicating that it plays a role in suppressing tumor development. Conclusions: CAD plays an important role in maitaining genetic stability and suppressing tumor development. No significant financial relationships to disclose.


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