Zebrafish liver transcriptome in response to chronic treatment with environmentally relevant concentrations of imatinib mesylate
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ABSTRACT: Imatinib mesylate (IM) a protein kinase inhibitor drug that selectively inhibits certain oncogenic mutant protein tyrosine kinases. After application, IM is via hospital and municipal waste water effluents released into the aquatic environment, where it can harm non-target organisms. The aim of this study was to evaluate changes in gene transcription in liver of adult F1 zebrafish (Danio rerio) continuously exposed to IM at environmentaly relevant concentrations of 0.01 µg/L and 1 µg/L.
Project description:The fluoropyrimidine 5-fluorouracil (5-FU) is an antimetabolite that exerts its anticancer effects through inhibition of DNA synthesis and replication by inhibiting thymidylate synthase, and by incorporation of its metabolites into RNA and DNA. 5-FU is used in most of the currently applied regimens for the treatment of patients with cancers of the gastrointestinal tract, breast, head, neck, and belongs to the most consumed cytostatic drugs. After application, 5-FU is via hospital and municipal waste water effluents released into the aquatic environment, where it can harm non-target organisms. The aim of this study was to evaluate changes in gene transcription in liver of adult F1 zebrafish (Danio rerio) continuously exposed to 5-FU at environmentaly relevant concentrations of 0.01 µg/L and 1 µg/L.
Project description:The fluoropyrimidine 5-fluorouracil (5-FU) is an antimetabolite that exerts its anticancer effects through inhibition of DNA synthesis and replication by inhibiting thymidylate synthase, and by incorporation of its metabolites into RNA and DNA. 5-FU is used in most of the currently applied regimens for the treatment of patients with cancers of the gastrointestinal tract, breast, head, neck, and belongs to the most consumed cytostatic drugs. After application, 5-FU is via hospital and municipal waste water effluents released into the aquatic environment, where it can harm non-target organisms. The aim of this study was to evaluate changes in gene transcription in liver of adult F1 zebrafish (Danio rerio) continuously exposed to 5-FU at environmentaly relevant concentrations of 0.01 µg/L and 1 µg/L. One color design, control and treatment in two concentrations; 6 pools of 3 individuals per treatment
Project description:Gene expression profiling using oligonucleotide microarrays performed on tumor samples obtained before and after imatinib mesylate (IM) therapy. Rapid responding (to IM) samples were compared to non-responding/stable disease samples as measured by CT scan measurements to identify a gene signature that can predict rapid response to IM.
Project description:Gene expression profiling using oligonucleotide microarrays performed on tumor samples obtained before and after imatinib mesylate (IM) therapy. Rapid responding (to IM) samples were compared to non-responding/stable disease samples as measured by CT scan measurements to identify a gene signature that can predict rapid response to IM. Experiment Overall Design: 54 samples, 29 pre-treatment biopsy samples, 25 post-treatment/post-surgery tumor samples from Gastrointestinal Stromal Tumors
Project description:Activation-induced cytidine deaminase (AID) is essential for class switch recombination (CSR) and somatic hypermutation (SHM). Its deregulated expression acts as a genomic mutator that can contribute to the development of various malignancies. During treatment with imatinib mesylate (IM), patients with chronic myeloid leukemia (CML) often develop hypogammaglobulinemia, the mechanism of which has not yet been clarified. Here, we provide evidence that CSR upon B cell activation is apparently inhibited by IM through downregulation of AID. Furthermore, expression of E2A, a key transcription factor for AID induction, was markedly suppressed by IM. These results elucidate not only the underlying mechanism of IM-induced hypogammaglobulinemia but also its potential efficacy as an AID suppressor.
Project description:The outcome of treating chronic myeloid leukemia (CML) with imatinib mesylate (IM) is inferior when therapy is commenced in late chronic or accelerated phase as compared to early chronic phase. This may be attributed to additional genomic alterations that accumulate during disease progression. We sought to identify such lesions in patients showing suboptimal response to IM by performing array-CGH analysis on 39 sequential samples from 15 CML patients. Seventy-four cumulative copy number alterations (CNAs) consisting of 35 losses and 39 gains were identified. Alterations flanking the ABL1 and BCR genes on chromosomes 9 and 22, respectively, were the most common identified lesions with 5 patients losing variable portions of 9q34.11 proximal to ABL1. Losses involving 1p36, 5q31, 17q25, Y and gains of 3q21, 8q24, 22q11, Xp11 were among other recurrent lesions identified. Aberrations were also observed in individual patients, involving regions containing known leukemia-associated genes; CDKN2A/2B, IKZF1, RB1, TLX1, AFF4. CML patients in late stages of their disease, harbor pre-existing and evolving sub-microscopic CNAs that may influence disease progression and IM response.
Project description:Activation-induced cytidine deaminase (AID) is essential for class switch recombination (CSR) and somatic hypermutation (SHM). Its deregulated expression acts as a genomic mutator that can contribute to the development of various malignancies. During treatment with imatinib mesylate (IM), patients with chronic myeloid leukemia (CML) often develop hypogammaglobulinemia, the mechanism of which has not yet been clarified. Here, we provide evidence that CSR upon B cell activation is apparently inhibited by IM through downregulation of AID. Furthermore, expression of E2A, a key transcription factor for AID induction, was markedly suppressed by IM. These results elucidate not only the underlying mechanism of IM-induced hypogammaglobulinemia but also its potential efficacy as an AID suppressor. We investigated that class switch recombination(CSR) upon B cell activation is apparently inhibited by imatinib mesylate(IM) through downregulation of activation-induced cytidine deaminase(AID). Furthermore, expression of E2A was markedly suppressed by IM. To elucidate the more detailed pathway, we performed the microarray analysis. Microarray analysis was performed on splenocytes cultured for 72 h in the presence or absence of 10 µM Imatinib. The mouse splenocytes were cultured for 72 h with or without 10 µM Imatinib (IM) in conditioning medium containing IL-4 and LPS. RNA from 1X10^6 splenocytes used for microarray analysis was isolated using the RNeasy Mini Kit (50) (Qiagen, Hilden, Germany). Gene expression microarray analysis was performed using one-color microarray-based gene-expression analysis (Agilent Technologies, Santa Clara, CA, USA) according to the manufacturer’s instructions. After scanning, expression values for the genes were determined using GeneSpringGX software.
Project description:We investigated the ability of HDAC inhibitors (HDACi) to target CML stem cells. Treatment with HDACi combined with IM effectively induced apoptosis in quiescent CML progenitors resistant to elimination by IM alone, and eliminated CML stem cells capable of engrafting immunodeficient mice. In vivo administration of HDACi with IM markedly diminished LSC in a transgenic mouse model of CML. The interaction of IM and HDACi inhibited genes regulating hematopoietic stem cell maintenance and survival. HDACi treatment represents a novel and effective strategy to target LSC in CML patients receiving tyrosine kinase inhibitors.
Project description:The outcome of treating chronic myeloid leukemia (CML) with imatinib mesylate (IM) is inferior when therapy is commenced in late chronic or accelerated phase as compared to early chronic phase. This may be attributed to additional genomic alterations that accumulate during disease progression. We sought to identify such lesions in patients showing suboptimal response to IM by performing array-CGH analysis on 39 sequential samples from 15 CML patients. Seventy-four cumulative copy number alterations (CNAs) consisting of 35 losses and 39 gains were identified. Alterations flanking the ABL1 and BCR genes on chromosomes 9 and 22, respectively, were the most common identified lesions with 5 patients losing variable portions of 9q34.11 proximal to ABL1. Losses involving 1p36, 5q31, 17q25, Y and gains of 3q21, 8q24, 22q11, Xp11 were among other recurrent lesions identified. Aberrations were also observed in individual patients, involving regions containing known leukemia-associated genes; CDKN2A/2B, IKZF1, RB1, TLX1, AFF4. CML patients in late stages of their disease, harbor pre-existing and evolving sub-microscopic CNAs that may influence disease progression and IM response. Fifteen patients with confirmed CML, on IM for a minimum period of 18-months and showing suboptimal response to IM, as evidenced by failure to achieve major molecular remission (MMolR) at 18 months were identified from a series of patients treated in our centre. Patients received their medication under the auspices of the Glivec International Patient Assistance Program (GIPAP) and were started on an initial dose of 400mg with dose escalations or reductions made according to the patientM-bM-^@M-^Ys response and tolerance. Archived sequential peripheral blood lysates from the patients were retrieved and DNA/RNA extracted. Thirty-nine DNA samples of sufficient quality and quantity from the 15 patients were subjected to array-CGH analysis to identify recurrent genomic aberrations that occur through the course of disease.