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Essential role for cyclic-AMP responsive element binding protein 1 (CREB) in the survival of acute lymphoblastic leukemia.

van der Sligte NE, Kampen KR, ter Elst A, Scherpen FJ, Meeuwsen-de Boer TG, Guryev V, van Leeuwen FN, Kornblau SM, de Bont ES - Oncotarget (2015)

Bottom Line: In this study, we determined CREB phosphorylation and mRNA levels showing that CREB expression was significantly higher in ALL compared to normal bone marrow (phosphorylation: P < 0.0001, mRNA: P = 0.004).Similar to CREB knockdown, the CREB inhibitor KG-501 decreased leukemic cell viability and induced apoptosis in ALL cell lines, as well as primary T-ALL samples, with cases showing high phospho-CREB levels being more sensitive than those with lower phospho-CREB levels.Together, these in vitro findings support an important role for CREB in the survival of ALL cells and identify this transcription factor as a potential target for treatment.

View Article: PubMed Central - PubMed

Affiliation: Division of Pediatric Oncology/Hematology, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

ABSTRACT
Acute lymphoblastic leukemia (ALL) relapse remains a leading cause of cancer related death in children, therefore, new therapeutic options are needed. Recently, we showed that a peptide derived from Cyclic-AMP Responsive Element Binding Protein (CREB) was highly phosphorylated in pediatric leukemias. In this study, we determined CREB phosphorylation and mRNA levels showing that CREB expression was significantly higher in ALL compared to normal bone marrow (phosphorylation: P < 0.0001, mRNA: P = 0.004). High CREB and phospho-CREB expression was correlated with a lower median overall survival in a cohort of 140 adult ALL patients. ShRNA mediated knockdown of CREB in ALL cell lines blocked leukemic cell growth by inducing cell cycle arrest and apoptosis. Gene expression array analysis showed downregulation of CREB target genes regulating cell proliferation and glucose metabolism and upregulation of apoptosis inducing genes. Similar to CREB knockdown, the CREB inhibitor KG-501 decreased leukemic cell viability and induced apoptosis in ALL cell lines, as well as primary T-ALL samples, with cases showing high phospho-CREB levels being more sensitive than those with lower phospho-CREB levels. Together, these in vitro findings support an important role for CREB in the survival of ALL cells and identify this transcription factor as a potential target for treatment.

No MeSH data available.


Related in: MedlinePlus

CREB downregulation induces cell cycle arrest and apoptosisCell cycle analysis shows a reduction in the percentage of cells in S and G2/M phases with a concomitant increase of cells in sub-G0 and G0/G1 phases in comparison with shControl A. Annexin-V staining shows an increase in apoptotic cell numbers for CREB downregulated cells as compared to control transduced cells B. The results are shown as mean ± standard deviation. Asteriks (*) indicate significant differences (P < 0.05) by Student t-test.
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Figure 5: CREB downregulation induces cell cycle arrest and apoptosisCell cycle analysis shows a reduction in the percentage of cells in S and G2/M phases with a concomitant increase of cells in sub-G0 and G0/G1 phases in comparison with shControl A. Annexin-V staining shows an increase in apoptotic cell numbers for CREB downregulated cells as compared to control transduced cells B. The results are shown as mean ± standard deviation. Asteriks (*) indicate significant differences (P < 0.05) by Student t-test.

Mentions: To explain the dramatic effect of CREB knockdown on cell growth, we studied the consequences of CREB knockdown on cell cycle progression and apoptosis. Cell cycle analysis for Jurkat, Nalm6, and RS4;11 revealed that CREB knockdown decreased the percentage of cells in S and G2/M phases with a concomitant increase of cells in the apoptotic sub-G0/G1 and / or G0/G1 phases, consistent with a cell cycle arrest (Figure 5A). No cell cycle analysis was performed on Molt4 transduced cells since this is an aneuploid cell line. Complementary to the increase of cells in the apoptotic sub-G0/G1 phase, Annexin-V staining showed an increase in apoptotic cell numbers for the shCREB transduced cells at the 144 hour time point as compared to the 0 hour time point, which was not observed in cells transduced with a scrambled shRNA control (Figure 5B).


Essential role for cyclic-AMP responsive element binding protein 1 (CREB) in the survival of acute lymphoblastic leukemia.

van der Sligte NE, Kampen KR, ter Elst A, Scherpen FJ, Meeuwsen-de Boer TG, Guryev V, van Leeuwen FN, Kornblau SM, de Bont ES - Oncotarget (2015)

CREB downregulation induces cell cycle arrest and apoptosisCell cycle analysis shows a reduction in the percentage of cells in S and G2/M phases with a concomitant increase of cells in sub-G0 and G0/G1 phases in comparison with shControl A. Annexin-V staining shows an increase in apoptotic cell numbers for CREB downregulated cells as compared to control transduced cells B. The results are shown as mean ± standard deviation. Asteriks (*) indicate significant differences (P < 0.05) by Student t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4558129&req=5

Figure 5: CREB downregulation induces cell cycle arrest and apoptosisCell cycle analysis shows a reduction in the percentage of cells in S and G2/M phases with a concomitant increase of cells in sub-G0 and G0/G1 phases in comparison with shControl A. Annexin-V staining shows an increase in apoptotic cell numbers for CREB downregulated cells as compared to control transduced cells B. The results are shown as mean ± standard deviation. Asteriks (*) indicate significant differences (P < 0.05) by Student t-test.
Mentions: To explain the dramatic effect of CREB knockdown on cell growth, we studied the consequences of CREB knockdown on cell cycle progression and apoptosis. Cell cycle analysis for Jurkat, Nalm6, and RS4;11 revealed that CREB knockdown decreased the percentage of cells in S and G2/M phases with a concomitant increase of cells in the apoptotic sub-G0/G1 and / or G0/G1 phases, consistent with a cell cycle arrest (Figure 5A). No cell cycle analysis was performed on Molt4 transduced cells since this is an aneuploid cell line. Complementary to the increase of cells in the apoptotic sub-G0/G1 phase, Annexin-V staining showed an increase in apoptotic cell numbers for the shCREB transduced cells at the 144 hour time point as compared to the 0 hour time point, which was not observed in cells transduced with a scrambled shRNA control (Figure 5B).

Bottom Line: In this study, we determined CREB phosphorylation and mRNA levels showing that CREB expression was significantly higher in ALL compared to normal bone marrow (phosphorylation: P < 0.0001, mRNA: P = 0.004).Similar to CREB knockdown, the CREB inhibitor KG-501 decreased leukemic cell viability and induced apoptosis in ALL cell lines, as well as primary T-ALL samples, with cases showing high phospho-CREB levels being more sensitive than those with lower phospho-CREB levels.Together, these in vitro findings support an important role for CREB in the survival of ALL cells and identify this transcription factor as a potential target for treatment.

View Article: PubMed Central - PubMed

Affiliation: Division of Pediatric Oncology/Hematology, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

ABSTRACT
Acute lymphoblastic leukemia (ALL) relapse remains a leading cause of cancer related death in children, therefore, new therapeutic options are needed. Recently, we showed that a peptide derived from Cyclic-AMP Responsive Element Binding Protein (CREB) was highly phosphorylated in pediatric leukemias. In this study, we determined CREB phosphorylation and mRNA levels showing that CREB expression was significantly higher in ALL compared to normal bone marrow (phosphorylation: P < 0.0001, mRNA: P = 0.004). High CREB and phospho-CREB expression was correlated with a lower median overall survival in a cohort of 140 adult ALL patients. ShRNA mediated knockdown of CREB in ALL cell lines blocked leukemic cell growth by inducing cell cycle arrest and apoptosis. Gene expression array analysis showed downregulation of CREB target genes regulating cell proliferation and glucose metabolism and upregulation of apoptosis inducing genes. Similar to CREB knockdown, the CREB inhibitor KG-501 decreased leukemic cell viability and induced apoptosis in ALL cell lines, as well as primary T-ALL samples, with cases showing high phospho-CREB levels being more sensitive than those with lower phospho-CREB levels. Together, these in vitro findings support an important role for CREB in the survival of ALL cells and identify this transcription factor as a potential target for treatment.

No MeSH data available.


Related in: MedlinePlus