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GSE33075
Homo sapiens
25 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Background: Chronic myeloid leukemia (CML) is a malignant clonal disorder of the hematopoietic system caused by the expression of the BCR/ABL fusion oncogene. It is well known that CML cells are genetically unstable. However, the mechanisms by which these cells acquire genetic alterations are poorly understood. Imatinib mesylate (IM) is the standard therapy for newly diagnosed CML patients. IM targets the oncogenic kinase activity of BCR-ABL. Objective: To study the gene expression profile of BM hematopoietic cells in the same patients with CML before and one month after imatinib therapy. Methods: Samples from patients with CML were analyzed using Affymetrix GeneChip Expression Arrays. Results: A total of 594 differentially expressed genes, most of which (393 genes) were downregulated, as a result of imatinib therapy were observed. Conclusions: The blockade of oncoprotein Bcr-abl by imatinib could cause a decrease in the expression of key DNA repair genes, and cells try to restore the normal gene expression levels required for cell proliferation and chromosomal integrity.
Publication Title
Imatinib therapy of chronic myeloid leukemia restores the expression levels of key genes for DNA damage and cell-cycle progression.
Sample Metadata Fields
Age, Specimen part
View Samples- Homo sapiens
- 30 Downloadable Samples
- Affymetrix Human Transcriptome Array 2.0 (hta20)
Description
The iron chelator deferasirox is widely used in patients with iron overload. Patients with low-grade myelodysplastic syndromes (MDS) get transfusion dependency and need to be treated with deferasirox to avoid iron overload. Moreover, in some patients an increase in both erythroid and platelets have been observed after deferasirox therapy. However, the mechanisms involved in these clinical findings are poorly understood. The aim of this work was to analyze, in patients treated with deferasirox, the changes in the gene expression profile after receiving the treatment. A total of fifteen patients with the diagnosis of low-grade MDS were studied. Microarrays were carried out in RNA from peripheral blood before and after 14 weeks of deferasirox therapy. Changes in 1,457 genes and 54 miRNAs were observed: deferasirox induced the downregulation of genes related to the Nf kB pathway leading of an overall inactivation of this pathway. In addition, the iron chelator also downregulated gamma interferon. Altogether these changes could be related to the improvement of erythroid response observed in these patients after therapy. Moreover, the inhibition of NFE2L2/ NRF2, which was predicted in silico, could be playing a critical role in the reduction of reactive oxygen species (ROS). Of note, miR-125b, overexpressed after deferasirox treatment, could be involved in the reduced inflammation and increased hematopoiesis observed in the patients after treatment. In summary this study shows, for the first time, the mechanisms that could be governing deferasirox impact in vivo.
Publication Title
Genome-wide transcriptomics leads to the identification of deregulated genes after deferasirox therapy in low-risk MDS patients.
Sample Metadata Fields
Specimen part, Disease, Treatment, Subject
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