Project description:Chronic myelogenous leukemia (CML) is a malignant stem cell disease characterized by a reciprocal translocation between chromosome 9 and 22. The selective bcr-abl tyrosine-kinase inhibitor Imatinib has become the therapy of choice for patients with newly diagnosed CML including those previously considered candidates for allogeneic haematopoietic stem cell transplantation. The tyrosine-kinase inhibitor Nilotinib is a derivate of Imatinib with higher potency. To examine the molecular and functional effects of Nilotinib and Imatinib in chronic myelogenous leukemia, we performed gene expression and functional analyses in K562 cells following treatment with the two tyrosine kinase inhibitors.
Project description:Chronic myelogenous leukemia (CML) is a malignant stem cell disease characterized by a reciprocal translocation between chromosome 9 and 22. The selective bcr-abl tyrosine-kinase inhibitor Imatinib has become the therapy of choice for patients with newly diagnosed CML including those previously considered candidates for allogeneic haematopoietic stem cell transplantation. The tyrosine-kinase inhibitor Nilotinib is a derivate of Imatinib with higher potency. To examine the molecular and functional effects of Nilotinib and Imatinib in chronic myelogenous leukemia, we performed gene expression and functional analyses in K562 cells following treatment with the two tyrosine kinase inhibitors. Experiment Overall Design: Affymetrix U133A 2.0 microarrays were used to examine the gene expression profile of K562 cells after in vitro treatment with Imatinib (0.5 µM) or Nilotinib (0.05 µM) for 24 hours. Gene expression data of the treated cells were compared with data of untreated cells.
Project description:Imatinib has become the current standard therapy for patients with chronic myelogenous leukaemia (CML). For a better understanding of the Imatinib-related molecular effects in vivo, we assessed gene expression profiles of Philadelphia Chromosome positive (Ph+) CD34+ cells from peripheral blood of 6 patients with de novo CML in chronic phase. After 7 days of treatment with Imatinib the Ph+ CD34+ cells were reassessed to look for changes in the transcriptome. The expression level of 303 genes was significantly different comparing the transcriptome of the Ph+ CD34+ cells before and after 7 days of Imatinib therapy (183 down-regulated, 120 up-regulated, lower bound â¥1.2-fold). For a substantial number of genes governing cell cycle and DNA replication, the level of expression significantly decreased (CDC2, RRM2, PCNA, MCM4). On the other hand, therapy with Imatinib was associated with an increase of genes related to adhesive interactions, such as L-selectin or CD44. A group of 8 genes with differential expression levels were confirmed using a gene specific quantitative real-time PCR. Thus, during the first week of treatment, Imatinib is preferentially counteracting the bcr-abl induced effects related to a disturbed cell cycle and defective adhesion of leukemic Ph+ CD34+ cells. Experiment Overall Design: In total 6 patients with new diagnosis CML (Chronic Myelogenous Leukemia) in chronic phase are inculded in the study. The gene expression profiles of the CD34+ hematopoietic stem and progenitor cells from the patients before first treatment with Glivec (Imatinib) are compared to the gene expression profiles of the CD34+ hematopoietic stem and progenitor cells of the same patients after 7 days of treatment with 400 mg Glivec / day.
Project description:Imatinib has become the current standard therapy for patients with chronic myelogenous leukaemia (CML). For a better understanding of the Imatinib-related molecular effects in vivo, we assessed gene expression profiles of Philadelphia Chromosome positive (Ph+) CD34+ cells from peripheral blood of 6 patients with de novo CML in chronic phase. After 7 days of treatment with Imatinib the Ph+ CD34+ cells were reassessed to look for changes in the transcriptome. The expression level of 303 genes was significantly different comparing the transcriptome of the Ph+ CD34+ cells before and after 7 days of Imatinib therapy (183 down-regulated, 120 up-regulated, lower bound ≥1.2-fold). For a substantial number of genes governing cell cycle and DNA replication, the level of expression significantly decreased (CDC2, RRM2, PCNA, MCM4). On the other hand, therapy with Imatinib was associated with an increase of genes related to adhesive interactions, such as L-selectin or CD44. A group of 8 genes with differential expression levels were confirmed using a gene specific quantitative real-time PCR. Thus, during the first week of treatment, Imatinib is preferentially counteracting the bcr-abl induced effects related to a disturbed cell cycle and defective adhesion of leukemic Ph+ CD34+ cells.
Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which is present in almost every patient with chronic myeloid leukemia. In this study, the tyrosine kinase inhibitor Imatinib was used for pharmacological inhibition of BCR-ABL1. Gene expression profiles of CML cell lines were analyzed in response to Imatinib treatment.
Project description:The two major isoforms of the oncogenic Bcr-Abl tyrosine kinase, p210 and p185, are expressed upon the Philadelphia chromosome translocation. p210 is the hallmark of chronic myelogenous leukemia, whereas p185 occurs in the majority of B-cell acute lymphoblastic leukemia. Differences in protein-protein interactions and activated signaling pathways that may be associated with the different diseases driven by p210 and p185 are unknown. We have performed a quantitative comparative proteomics study of p210 and p185 and found strong differences in the interactome and phosphoproteome. Whereas the AP2 endocytosis complex interacts preferentially with p185, the phosphatase Sts1 is enriched with p210. Stronger activation of STAT5 and ERK1/2 is observed with p210, whereas Lyn is activated by p185. These results were validated in human p210 and p185-positive cell lines. Our findings contribute to a more coherent understanding of Bcr-Abl signaling, mechanisms of oncogenic transformation, resulting disease pathobiology and responses to kinase inhibitors.
Project description:Expression profile of 14 Chronic Myeloid Leukemia Philadelphia chromossome negative patients after allo haematopoietc stem cell transplantation and Chronic Myeloid Leukemia treated with imatinib mesylate. We tested 754 microRNAs by reverse transcription quantitative polymerase chain reaction (RT-qPCR) array for each patient.
Project description:Precursor B-lineage acute lymphoblastic leukemia (pre-B ALL) can be subdivided into different categories based on genetic abnormalities. One type of pre-B ALL is characterized by the presence of the Philadelphia (Ph) chromosome, the derivative chromosome 22 that is one product of a reciprocal translocation between chromosomes 22 and 9. The 22/9 translocation fuses the 5’ part of the BCR gene to the 3’ end of the c-ABL gene. The resulting BCR/ABL fusion encodes a Bcr/Abl protein with deregulated Abl kinase activity. Two major fusion proteins are found in Ph-positive leukemias which differ in molecular weight and the size of the Bcr moiety. The P190 Bcr/Abl protein is common in Ph-positive ALL. Targeted tyrosine kinase inhibitors such as nilotinib are used therapeutically to treat this type of leukemia. The 22/9 translocation fuses the 5’ part of the BCR gene to the 3’ end of the c-ABL gene. The resulting BCR/ABL fusion encodes a Bcr/Abl protein with deregulated Abl kinase activity. Two major fusion proteins are found in Ph-positive leukemias which differ in molecular weight and the size of the Bcr moiety. The P190 Bcr/Abl protein is common in Ph-positive ALL. Targeted tyrosine kinase inhibitors such as nilotinib are used therapeutically to treat this type of leukemia.