ACTIVATION OF IRS1/ BETA-CATENIN AXIS IN ACUTE LYMPHOBLASTIC LEUKEMIA
(Abstract release date: 05/19/16)
EHA Library. Fernandes J. 06/09/16; 134492; PB1592
Ms. Jaqueline Fernandes
Contributions
Contributions
Abstract
Abstract: PB1592
Type: Publication Only
Background
Acute lymphoblastic leukemia (ALL) is an aggressive cancer of immature progenitors that shows aberrant activation of signaling pathways. Insulin-like growth factor 1 (IGF1) and its receptor regulate normal cell growth and contribute to transformation and growth of malignant cells. In solid tumors, IGF1 has the ability to activate a cascade of downstream phosphorylation events including translocation of beta-catenin to the nuclei, and activation of the target gene MYC. In fibroblasts, IGF1 was found to induce nuclear IRS1 translocation, IRS1/beta-catenin association and MYC transcription. When highly expressed, MYC may acts as oncogene, contributing to the development of cancers, including hematopoietic neoplasm.
Aims
We herein aimed to investigate the IRS1/beta-catenin axis in ALL cells.
Methods
Bone marrow or peripheral blood samples were obtained from 58 patients with ALL and 13 healthy donors. T-ALL cell lines, Jurkat and MOLT-4, and B-ALL cell lines, Namalwa and Raji, were obtained from ATCC. Gene expression was measured by quantitative real-time PCR; relative expression was calculated using the expression of beta-actin as an endogenous control. The Mann-Whitney test was used to compare the median of gene expression among normal donors and patients with ALL. Protein expression, associations and cellular localization were evaluated by immunoprecipitation, immunoblotting and western blotting analysis, subcellular fractionation and confocal microscopy. To evaluate the effects of IGF1 upon IRS1 and beta-catenin cellular localization, cells were submitted to starvation in serum-free medium for 24 hours, followed by IGF1 stimulation (20 ng/mL) and/or IGF1R pharmacological inhibition (OSI-906; 20 µM), for 24 hours.
Results
IRS1, beta-catenin, and MYC relative gene expression were significantly higher in ALL patients compared to normal donors (IRS1, ALL: median=1.10 [minimum=0.01 - maximum=9.96] vs. normal donors: 0.34 [0.19 - 1.49], p=0.01); (beta-catenin, ALL: 1.12 [0.23 - 5.18] vs. normal donors: 0.56 [0.01 - 1.57], p=0.002); (MYC, ALL: 1.78 [0.06 - 28.37] vs. normal donors: 0.33 [0:13 - 1.13], p=0.0003). A positive correlation between beta-catenin and MYC mRNA expression (p=0.002, r=0.39) and between IRS1 and MYC expression (p=0.02, r=0.29) was found. In ALL cell lines (Jurkat, MOLT-4, Namalwa and Raji) high expression of IGF1R, IRS1, beta-catenin and MYC protein were observed. IRS1 and beta-catenin was found to be located in the nuclei and the cytoplasm of ALL cell lines by subcellular fractionation and western blotting analysis. The confocal microscopic analysis reveals elevated co-localization of IRS1/beta-catenin in both nuclei and cytoplasm of ALL cell lines (r≥0.69). In Jurkat cells, the constitutive protein interaction IRS1 and beta-catenin were observed; IGF1 stimulation increased nuclear translocation of IRS1 and beta-catenin. The IGF1R inhibitor OSI-906 decreased IGF1R tyrosine phosphorylation, decreased nuclear beta-catenin translocation and MYC protein expression in Jurkat cells.
Conclusion
IRS1, beta-catenin and MYC mRNA expression were elevated in ALL patients compared to normal controls. The IRS1/beta-catenin protein association observed in ALL cell lines, together with the data that IGF1 modulates IRS1 and beta-catenin nuclear translocation and MYC expression indicate that the IRS1/beta-catenin axis is activated in ALL cells, which may represent an important signaling pathway involved in the pathophysiology of the disease.
Session topic: E-poster
Type: Publication Only
Background
Acute lymphoblastic leukemia (ALL) is an aggressive cancer of immature progenitors that shows aberrant activation of signaling pathways. Insulin-like growth factor 1 (IGF1) and its receptor regulate normal cell growth and contribute to transformation and growth of malignant cells. In solid tumors, IGF1 has the ability to activate a cascade of downstream phosphorylation events including translocation of beta-catenin to the nuclei, and activation of the target gene MYC. In fibroblasts, IGF1 was found to induce nuclear IRS1 translocation, IRS1/beta-catenin association and MYC transcription. When highly expressed, MYC may acts as oncogene, contributing to the development of cancers, including hematopoietic neoplasm.
Aims
We herein aimed to investigate the IRS1/beta-catenin axis in ALL cells.
Methods
Bone marrow or peripheral blood samples were obtained from 58 patients with ALL and 13 healthy donors. T-ALL cell lines, Jurkat and MOLT-4, and B-ALL cell lines, Namalwa and Raji, were obtained from ATCC. Gene expression was measured by quantitative real-time PCR; relative expression was calculated using the expression of beta-actin as an endogenous control. The Mann-Whitney test was used to compare the median of gene expression among normal donors and patients with ALL. Protein expression, associations and cellular localization were evaluated by immunoprecipitation, immunoblotting and western blotting analysis, subcellular fractionation and confocal microscopy. To evaluate the effects of IGF1 upon IRS1 and beta-catenin cellular localization, cells were submitted to starvation in serum-free medium for 24 hours, followed by IGF1 stimulation (20 ng/mL) and/or IGF1R pharmacological inhibition (OSI-906; 20 µM), for 24 hours.
Results
IRS1, beta-catenin, and MYC relative gene expression were significantly higher in ALL patients compared to normal donors (IRS1, ALL: median=1.10 [minimum=0.01 - maximum=9.96] vs. normal donors: 0.34 [0.19 - 1.49], p=0.01); (beta-catenin, ALL: 1.12 [0.23 - 5.18] vs. normal donors: 0.56 [0.01 - 1.57], p=0.002); (MYC, ALL: 1.78 [0.06 - 28.37] vs. normal donors: 0.33 [0:13 - 1.13], p=0.0003). A positive correlation between beta-catenin and MYC mRNA expression (p=0.002, r=0.39) and between IRS1 and MYC expression (p=0.02, r=0.29) was found. In ALL cell lines (Jurkat, MOLT-4, Namalwa and Raji) high expression of IGF1R, IRS1, beta-catenin and MYC protein were observed. IRS1 and beta-catenin was found to be located in the nuclei and the cytoplasm of ALL cell lines by subcellular fractionation and western blotting analysis. The confocal microscopic analysis reveals elevated co-localization of IRS1/beta-catenin in both nuclei and cytoplasm of ALL cell lines (r≥0.69). In Jurkat cells, the constitutive protein interaction IRS1 and beta-catenin were observed; IGF1 stimulation increased nuclear translocation of IRS1 and beta-catenin. The IGF1R inhibitor OSI-906 decreased IGF1R tyrosine phosphorylation, decreased nuclear beta-catenin translocation and MYC protein expression in Jurkat cells.
Conclusion
IRS1, beta-catenin and MYC mRNA expression were elevated in ALL patients compared to normal controls. The IRS1/beta-catenin protein association observed in ALL cell lines, together with the data that IGF1 modulates IRS1 and beta-catenin nuclear translocation and MYC expression indicate that the IRS1/beta-catenin axis is activated in ALL cells, which may represent an important signaling pathway involved in the pathophysiology of the disease.
Session topic: E-poster
Abstract: PB1592
Type: Publication Only
Background
Acute lymphoblastic leukemia (ALL) is an aggressive cancer of immature progenitors that shows aberrant activation of signaling pathways. Insulin-like growth factor 1 (IGF1) and its receptor regulate normal cell growth and contribute to transformation and growth of malignant cells. In solid tumors, IGF1 has the ability to activate a cascade of downstream phosphorylation events including translocation of beta-catenin to the nuclei, and activation of the target gene MYC. In fibroblasts, IGF1 was found to induce nuclear IRS1 translocation, IRS1/beta-catenin association and MYC transcription. When highly expressed, MYC may acts as oncogene, contributing to the development of cancers, including hematopoietic neoplasm.
Aims
We herein aimed to investigate the IRS1/beta-catenin axis in ALL cells.
Methods
Bone marrow or peripheral blood samples were obtained from 58 patients with ALL and 13 healthy donors. T-ALL cell lines, Jurkat and MOLT-4, and B-ALL cell lines, Namalwa and Raji, were obtained from ATCC. Gene expression was measured by quantitative real-time PCR; relative expression was calculated using the expression of beta-actin as an endogenous control. The Mann-Whitney test was used to compare the median of gene expression among normal donors and patients with ALL. Protein expression, associations and cellular localization were evaluated by immunoprecipitation, immunoblotting and western blotting analysis, subcellular fractionation and confocal microscopy. To evaluate the effects of IGF1 upon IRS1 and beta-catenin cellular localization, cells were submitted to starvation in serum-free medium for 24 hours, followed by IGF1 stimulation (20 ng/mL) and/or IGF1R pharmacological inhibition (OSI-906; 20 µM), for 24 hours.
Results
IRS1, beta-catenin, and MYC relative gene expression were significantly higher in ALL patients compared to normal donors (IRS1, ALL: median=1.10 [minimum=0.01 - maximum=9.96] vs. normal donors: 0.34 [0.19 - 1.49], p=0.01); (beta-catenin, ALL: 1.12 [0.23 - 5.18] vs. normal donors: 0.56 [0.01 - 1.57], p=0.002); (MYC, ALL: 1.78 [0.06 - 28.37] vs. normal donors: 0.33 [0:13 - 1.13], p=0.0003). A positive correlation between beta-catenin and MYC mRNA expression (p=0.002, r=0.39) and between IRS1 and MYC expression (p=0.02, r=0.29) was found. In ALL cell lines (Jurkat, MOLT-4, Namalwa and Raji) high expression of IGF1R, IRS1, beta-catenin and MYC protein were observed. IRS1 and beta-catenin was found to be located in the nuclei and the cytoplasm of ALL cell lines by subcellular fractionation and western blotting analysis. The confocal microscopic analysis reveals elevated co-localization of IRS1/beta-catenin in both nuclei and cytoplasm of ALL cell lines (r≥0.69). In Jurkat cells, the constitutive protein interaction IRS1 and beta-catenin were observed; IGF1 stimulation increased nuclear translocation of IRS1 and beta-catenin. The IGF1R inhibitor OSI-906 decreased IGF1R tyrosine phosphorylation, decreased nuclear beta-catenin translocation and MYC protein expression in Jurkat cells.
Conclusion
IRS1, beta-catenin and MYC mRNA expression were elevated in ALL patients compared to normal controls. The IRS1/beta-catenin protein association observed in ALL cell lines, together with the data that IGF1 modulates IRS1 and beta-catenin nuclear translocation and MYC expression indicate that the IRS1/beta-catenin axis is activated in ALL cells, which may represent an important signaling pathway involved in the pathophysiology of the disease.
Session topic: E-poster
Type: Publication Only
Background
Acute lymphoblastic leukemia (ALL) is an aggressive cancer of immature progenitors that shows aberrant activation of signaling pathways. Insulin-like growth factor 1 (IGF1) and its receptor regulate normal cell growth and contribute to transformation and growth of malignant cells. In solid tumors, IGF1 has the ability to activate a cascade of downstream phosphorylation events including translocation of beta-catenin to the nuclei, and activation of the target gene MYC. In fibroblasts, IGF1 was found to induce nuclear IRS1 translocation, IRS1/beta-catenin association and MYC transcription. When highly expressed, MYC may acts as oncogene, contributing to the development of cancers, including hematopoietic neoplasm.
Aims
We herein aimed to investigate the IRS1/beta-catenin axis in ALL cells.
Methods
Bone marrow or peripheral blood samples were obtained from 58 patients with ALL and 13 healthy donors. T-ALL cell lines, Jurkat and MOLT-4, and B-ALL cell lines, Namalwa and Raji, were obtained from ATCC. Gene expression was measured by quantitative real-time PCR; relative expression was calculated using the expression of beta-actin as an endogenous control. The Mann-Whitney test was used to compare the median of gene expression among normal donors and patients with ALL. Protein expression, associations and cellular localization were evaluated by immunoprecipitation, immunoblotting and western blotting analysis, subcellular fractionation and confocal microscopy. To evaluate the effects of IGF1 upon IRS1 and beta-catenin cellular localization, cells were submitted to starvation in serum-free medium for 24 hours, followed by IGF1 stimulation (20 ng/mL) and/or IGF1R pharmacological inhibition (OSI-906; 20 µM), for 24 hours.
Results
IRS1, beta-catenin, and MYC relative gene expression were significantly higher in ALL patients compared to normal donors (IRS1, ALL: median=1.10 [minimum=0.01 - maximum=9.96] vs. normal donors: 0.34 [0.19 - 1.49], p=0.01); (beta-catenin, ALL: 1.12 [0.23 - 5.18] vs. normal donors: 0.56 [0.01 - 1.57], p=0.002); (MYC, ALL: 1.78 [0.06 - 28.37] vs. normal donors: 0.33 [0:13 - 1.13], p=0.0003). A positive correlation between beta-catenin and MYC mRNA expression (p=0.002, r=0.39) and between IRS1 and MYC expression (p=0.02, r=0.29) was found. In ALL cell lines (Jurkat, MOLT-4, Namalwa and Raji) high expression of IGF1R, IRS1, beta-catenin and MYC protein were observed. IRS1 and beta-catenin was found to be located in the nuclei and the cytoplasm of ALL cell lines by subcellular fractionation and western blotting analysis. The confocal microscopic analysis reveals elevated co-localization of IRS1/beta-catenin in both nuclei and cytoplasm of ALL cell lines (r≥0.69). In Jurkat cells, the constitutive protein interaction IRS1 and beta-catenin were observed; IGF1 stimulation increased nuclear translocation of IRS1 and beta-catenin. The IGF1R inhibitor OSI-906 decreased IGF1R tyrosine phosphorylation, decreased nuclear beta-catenin translocation and MYC protein expression in Jurkat cells.
Conclusion
IRS1, beta-catenin and MYC mRNA expression were elevated in ALL patients compared to normal controls. The IRS1/beta-catenin protein association observed in ALL cell lines, together with the data that IGF1 modulates IRS1 and beta-catenin nuclear translocation and MYC expression indicate that the IRS1/beta-catenin axis is activated in ALL cells, which may represent an important signaling pathway involved in the pathophysiology of the disease.
Session topic: E-poster
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