Effect of Erythropoietin Treatment on Lipid Signalling Pathways in Low-Risk MDS Patients.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2384-2384
Author(s):  
Matilde Y Follo ◽  
Sara Mongiorgi ◽  
Cristina Clissa ◽  
Francesca Chiarini ◽  
Stefania Paolini ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Signal Transduction ◽  
Rapid Evolution ◽  
Low Risk ◽  
Signalling Pathways ◽  
Signal Transduction Pathways ◽  
Akt Activation ◽  
Lipid Signalling ◽  
Gene And Protein Expression ◽  
Allelic Deletion

Abstract Abstract 2384 Poster Board II-361 Introduction: Phosphoinositide-phospholipase (PI-PLC) C beta1, PI-PLCgamma1 and Akt are key enzymes in nuclear signal transduction pathways, affecting both cell cycle and differentiation in normal physiology and neoplastic transformation. Our group previously showed not only that the Akt/mTOR axis is activated in patients with high-risk MDS (Follo MY et al, Cancer Res 2007), but also that there is an inverse correlation between PI-PLCbeta1 expression and Akt activation (Follo MY et al, Leukemia 2008). Moreover, we recently demonstrated that patients belonging to all of the IPSS risk groups can display a PI-PLCbeta1 mono-allelic deletion, and that this cytogenetic alteration is associated with a higher risk of evolution into Acute Myeloid Leukemia (AML) (Follo MY et al, J Clin Oncol 2009). Erythropoietin (EPO) is an effective treatment of anemia in 40-60% of low-risk MDS, often inducing a prolonged response. Interestingly, the activation of the EPO receptor has been correlated to the PI3K/Akt axis, which in turn is linked to either PI-PLCbeta1 or PI-PLCgamma1 signalling, so that EPO could affect cell proliferation and apoptosis. The aim of this study was therefore to clarify the relationship between EPO treatment and lipid signalling pathways, to investigate their role as molecular targets or predictive factors during EPO therapy. In fact, in patients who are refractory or lose response to EPO there could be a specific activation or inhibition of pathways involved in both cell cycle and differentiation. Patients and Methods: In this study we examined the effect of EPO treatment on lipid signal transduction pathways in MDS patients. The study included 16 patients (IPSS risk: low or intermediate-1), with a favourable response to EPO in 8/16 (50%) of the cases. For each patient we had the opportunity to analyze the expression of PI-PLCbeta1, PI-PLCgamma1, p-Akt and PIP2, which is involved in both PI-PLCbeta1 and PI3K/Akt activation processes, before and during EPO treatment, in order to detect every change in both clinical and biological features. By FISH analysis, we firstly assessed the presence of PI-PLCbeta1 mono-allelic deletion. Then, we quantified PI-PLCbeta1 and PI-PLCgamma1 gene and protein expression, as well as PIP2 and the degree of Akt activation; mRNA levels were quantified by real-time PCR, whereas the protein amount was detected by both a immunocytochemical and a flow cytometric detection approach. Results: The PI-PLCbeta1 mono-allelic deletion was found in 5/16 (31%) low-risk MDS patients: 2 of them showed a rapid evolution into AML, whilst the remaining 3 cases did not respond to EPO treatment. The molecular analyses showed a specific increase in Akt/PI-PLCgamma1 pathway for responder patients, whereas most of the patients refactory to EPO displayed a slight decrease in p-Akt levels and an activation of PI-PLCbeta1 signalling during EPO administration, so that these patients seem to counteract the lack of one PI-PLCbeta1 allele by increasing PI-PLCbeta1 gene and protein expression. Conclusions: Our results, although obtained in a small number of cases, confirm the possible involvement of PI-PLCbeta1 pathways in the EPO signalling. Moreover, our data suggest that the presence of the PI-PLCbeta1 mono-allelic deletion is associated with a worse clinical outcome and with a lack of response to EPO treatment, even in low-risk MDS patients who apparently have a good response profile for EPO (recent diagnosis, absence of long-term transfusion dependence, low or intermediate-1 IPSS risk, serum EPO levels<500 U/L). In fact, in our series, patients with the PI-PLCbeta1 mono-allelic deletion showed an unfavourable outcome (either a rapid evolution into AML or refractoriness to EPO treatment). Moreover, our findings indicate that not only PI-PLCbeta1, but also Akt/PI-PLCgamma1 pathways are critical for cell survival and proliferation in MDS patients treated with EPO. Therefore, these signal transduction pathways could become in the future an important target for the development of innovative strategies for MDS. Disclosures: Finelli: Celgene: Consultancy.

scholarly journals Iodide- and Glucose-Handling Gene Expression Regulated by Sorafenib or Cabozantinib in Papillary Thyroid Cancer

2015 ◽  
Vol 100 (5) ◽  
pp. 1771-1779 ◽  
Author(s):  
Maomei Ruan ◽  
Min Liu ◽  
Qianggang Dong ◽  
Libo Chen
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Signal Transduction ◽  
Cell Proliferation ◽  
Thyroid Cancer ◽  
Western Blot ◽  
Glucose Transporter ◽  
Signal Transduction Pathways ◽  
Papillary Thyroid ◽  
Cycle Arrest

Abstract Context: The aberrant silencing of iodide-handling genes accompanied by up-regulation of glucose metabolism presents a major challenge for radioiodine treatment of papillary thyroid cancer (PTC). Objective: This study aimed to evaluate the effect of tyrosine kinase inhibitors on iodide-handling and glucose-handling gene expression in BHP 2-7 cells harboring RET/PTC1 rearrangement. Main Outcome Measures: In this in vitro study, the effects of sorafenib or cabozantinib on cell growth, cycles, and apoptosis were investigated by cell proliferation assay, cell cycle analysis, and Annexin V-FITC apoptosis assay, respectively. The effect of both agents on signal transduction pathways was evaluated using the Western blot. Quantitative real-time PCR, Western blot, immunofluorescence, and radioisotope uptake assays were used to assess iodide-handling and glucose-handling gene expression. Results: Both compounds inhibited cell proliferation in a time-dependent and dose-dependent manner and caused cell cycle arrest in the G0/G1 phase. Sorafenib blocked RET, AKT, and ERK1/2 phosphorylation, whereas cabozantinib blocked RET and AKT phosphorylation. The restoration of iodide-handling gene expression and inhibition of glucose transporter 1 and 3 expression could be induced by either drug. The robust expression of sodium/iodide symporter induced by either agent was confirmed, and 125I uptake was correspondingly enhanced. 18F-fluorodeoxyglucose accumulation was significantly decreased after treatment by either sorafenib or cabozantinib. Conclusions: Sorafenib and cabozantinib had marked effects on cell proliferation, cell cycle arrest, and signal transduction pathways in PTC cells harboring RET/PTC1 rearrangement. Both agents could be potentially used to enhance the expression of iodide-handling genes and inhibit the expression of glucose transporter genes.

Investigating lipid signalling: it's all about finding the right PI

2008 ◽  
Vol 413 (1) ◽  
pp. e5-e6 ◽  
Author(s):  
Erik Nielsen
Keyword(s):  
Signal Transduction ◽  
Signal Transduction Pathways ◽  
Lipid Kinase ◽  
Phosphatase Activities ◽  
Cellular Signal Transduction ◽  
Lipid Signalling ◽  
Lipid Phosphatase ◽  
Biochemical Journal ◽  
Cellular Signal ◽  
The Right

Phosphoinositides are well-known components of cellular signal transduction pathways and, more recently, have been shown to play important roles in organelle identity and targeting determinants for various cytosolic proteins. Conversion of PtdIns into its various phosphorylated derivatives, such as PtdIns4P and PtdIns(4,5)P2, is accomplished by a series of distinct lipid kinase and lipid phosphatase activities that are localized to specific subcellular membranes. As a result, production of distinct PtdIns forms is thought to be largely dependent on the access of these enzymes to their PtdIns or PtdInsP substrates. Interestingly, an investigation of two different PIS (PtdIns synthase) isoforms by Lofke et al. in this issue of the Biochemical Journal now indicates that the ability of PtdIns to be converted into downstream PtdInsPs may depend upon the PIS isoform from which it was synthesized.

Effect of Lenalidomide Treatment on Lipid Signalling Pathways in Low-Risk MDS Patients

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4635-4635
Author(s):  
Matilde Y Follo ◽  
Cristina Clissa ◽  
Sara Mongiorgi ◽  
Francesca Chiarini ◽  
Michele Baccarani ◽  
...  
Keyword(s):  
Supportive Care ◽  
Molecular Mechanisms ◽  
Conflicts Of Interest ◽  
Best Supportive Care ◽  
Low Risk ◽  
Cyclin D3 ◽  
Signalling Pathways ◽  
Globin Genes ◽  
Downstream Target ◽  
Lipid Signalling

Abstract Abstract 4635 Nuclear inositide signalling pathways are involved in the MDS progression to AML. Indeed, in the last few years our group demonstrated not only that MDS cells can show alterations on PI-PLCbeta1 and Akt pathways, but also that Akt is inversely correlated with PI-PLCbeta1, therefore affecting MDS cell survival and differentiation. Lenalidomide has proven effectiveness in 70–80% low-risk MDS cases with del(5q), resulting in transfusion-independence with a rise in hemoglobin levels, suppression of the 5q clone, and improvement of bone marrow morphologic features. In particular, in del(5q) MDS, Lenalidomide probably acts by directly suppressing the dysplastic clone, while in non-del(5q) it might enhance an effective erythropoiesis, possibly via activation of the EPO signalling, which in turn is associated with PI-PLCgamma1 pathways. However, the exact molecular mechanisms underlying the effect of Lenalidomide in MDS cells are still not completely clarified. Interestingly, Lenalidomide might inhibit the phosphatase PP2A, whose gene is located in the common deleted region and which usually targets Akt. Indeed, Akt-dependent pathways are critical in low-risk MDS cells, which display a marked apoptosis and a low proliferation rate. In this study we examined four MDS patients treated with Lenalidomide, and compared them with four low-risk MDS patients (IPSS: Low or Int-1) who only received best supportive care. In our study, all of the patients treated with Lenalidomide were affected by del(5q) low-risk MDS (IPSS: Low or Int-1), with transfusion-dependent anemia, and had only received supportive care before undergoing Lenalidomide treatment. Clinically, all of the patients responded to Lenalidomide: one patient reached Complete Remission, whilst the other three patients showed erythroid Hematologic Improvement. In contrast, all of the patients who were treated only with best supportive care maintained a Stable Disease. As for the molecular effects of Lenalidomide on lipid signalling pathways, we analyzed the expression of critical molecules involved in both cell proliferation and differentiation, that is PI-PLCbeta1 and its downstream target Cyclin D3, as well as PI-PLCgamma1, which is linked with EPO signalling. Ongoing analyses are also trying to examine the effect of Lenalidomide on Akt phosphorylation and Globin genes, which are specifically associated with erythropoiesis. So far, our results indicate that, in our responder patients, both PI-PLCbeta1 and Cyclin D3 are not significantly affected by Lenalidomide, whereas PI-PLCgamma1 is specifically induced, as compared with both healthy subjects and low-risk MDS patients treated with supportive care. Overall, these findings hint at a specific activation of PI-PLCgamma1 signalling following Lenalidomide treatment, and possibly pave the way to larger investigations aiming to better understand the role of these pathways in the mechanism of action of Lenalidomide in del(5q) MDS. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Targeting mediators of Wnt signalling pathways by GnRH in gonadotropes

2010 ◽  
Vol 44 (4) ◽  
pp. 195-201 ◽  
Author(s):  
Samantha Gardner ◽  
Emmanouil Stavrou ◽  
Patricia E Rischitor ◽  
Elena Faccenda ◽  
Adam J Pawson
Keyword(s):  
Signal Transduction ◽  
Gnrh Receptor ◽  
Wnt Signalling ◽  
Signalling Pathway ◽  
Signalling Pathways ◽  
Signal Transduction Pathways ◽  
Cellular Processes ◽  
Key Players ◽  
Canonical Wnt ◽  
Recent Demonstration

The binding of GnRH to its receptor on pituitary gonadotropes leads to the targeting of a diverse array of signalling mediators. These mediators drive multiple signal transduction pathways, which in turn regulate a variety of cellular processes, including the biosynthesis and secretion of the gonadotropins LH and FSH. Advances in our understanding of the mechanisms and signalling pathways that are recruited to regulate gonadotrope function are continually being made. This review will focus on the recent demonstration that key mediators of the canonical Wnt signalling pathway are targeted by GnRH in gonadotropes, and that these may play essential roles in regulating the expression of many of the key players in gonadotrope biology, including the GnRH receptor and the gonadotropins.

scholarly journals Two distinct, calcium-mediated, signal transduction pathways can trigger deflagellation in Chlamydomonas reinhardtii

1994 ◽  
Vol 124 (5) ◽  
pp. 807-815 ◽  
Author(s):  
LM Quarmby ◽  
HC Hartzell
Keyword(s):  
Signal Transduction ◽  
Chlamydomonas Reinhardtii ◽  
Living Cells ◽  
Signalling Pathways ◽  
Signal Transduction Pathways ◽  
Channel Blockers ◽  
Wasp Venom ◽  
Intracellular Pool ◽  
Cell Biol ◽  
Molecular Machinery

The molecular machinery of deflagellation can be activated in detergent permeabilized Chlamydomonas reinhardtii by the addition of Ca2+ (Sanders, M. A., and J. L. Salisbury, 1989. J. Cell Biol. 108:1751-1760). This suggests that stimuli which induce deflagellation in living cells cause an increase in the intracellular concentration of Ca2+, but this has never been demonstrated. In this paper we report that the wasp venom peptide, mastoparan, and the permeant organic acid, benzoate, activate two different signalling pathways to trigger deflagellation. We have characterized each pathway with respect to: (a) the requirement for extracellular Ca2+; (b) sensitivity to Ca2+ channel blockers; and (c) 45Ca influx. We also report that a new mutant strain of C. reinhardtii, adf-1, is specifically defective in the acid-activated signalling pathway. Both signalling pathways appear normal in another mutant, fa-1, that is defective in the machinery of deflagellation (Lewin, R. and C. Burrascano. 1983. Experientia. 39:1397-1398; Sanders, M. A., and J. L. Salisbury. 1989. J. Cell Biol. 108:1751-1760). We conclude that mastoparan induces the release of an intracellular pool of Ca2+ whereas acid induces an influx of extracellular Ca2+ to activate the machinery of deflagellation.

Prevalence and Clinical Implications of N-RAS Mutations in Childhood AML – A Report From the Children's Oncology Group.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3115-3115
Author(s):  
Jason N. Berman ◽  
Robert B. Gerbing ◽  
Lillian Sung ◽  
Kristen Miller ◽  
Jessica A. Pollard ◽  
...  
Keyword(s):  
Signal Transduction ◽  
High Risk ◽  
Prognostic Significance ◽  
Low Risk ◽  
Signal Transduction Pathways ◽  
Free Survival ◽  
Ras Mutations ◽  
Significant Difference ◽  
Pediatric Aml ◽  
The Impact

Abstract Abstract 3115 Poster Board III-52 Mutations in the RAS proto-oncogenes are frequent in acute myeloid leukemia (AML) and serve as prototypic Class I lesions, initiating key downstream hyper-proliferative signal transduction pathways. N-RAS mutations (N-RASmut) are common in AML, occurring in 10-20% of adult and pediatric AML patients; however their prognostic significance in both adults and children remains disputed. Due to a frequent association with a normal karyotype, delineating the impact of these mutations on outcome may enable appropriate risk-adapted therapeutic approaches. Here, we report on the incidence and prognostic significance of N-RASmut in a cohort of 825 pediatric AML patients treated on 2 recent co-operative group studies, CCG-2961 and COG AAML03P1. In total, of the 825 children with de novo AML who underwent N-RAS mutational analysis, 86 (10%) were positive. Gender, age, race, presence of hepatosplenomegaly and FAB subtype were comparable between patients with and without N-RASmut. There was no statistically significant difference between those with and without N-RASmut with respect to specific chromosome class. FLT3/Internal tandem duplications (FLT3/ITD) were less common in those with N-RASmut (2% vs. 9%, p=0.03). In contrast, nucleophosmin (NPM) mutations were more common in those with N-RASmut (13% vs. 5%, p=0.02). Overall, N-RASmut showed a significant correlation with low risk AML (CBF, CEBPαa, or NPM, p=0.04) and an inverse relationship with high risk disease (-5/5q- or -7, FLT3/ITD/high allelic ratio, p=0.007). Patients with N-RASmut had similar complete remission (CR) rates following two courses of induction chemotherapy compared with non-mutated patients (79% vs. 79%, p=0.92). Those in CR had a similar relapse rate regardless of the presence of N-RASmut (RR 39% vs. 36%, p=0.97). Five year event free survival (EFS) and overall survival (OS) from study entry were also comparable, however N-RASmut patients demonstrated a marked increase in overall treatment related mortality (TRM) (21% vs. 14%, p=0.03), which was maintained when high and low risk patients were excluded (22% vs. 11%, p=0.05). Evaluation of TRM in CCG-2961 compared with COG AAML03P1 demonstrated that increased TRM in N-RASmut was only seen in patients treated on CCG-2961 and TRM was primarily due to invasive fungal and gram negative infections. Interestingly, for patients treated on CCG-2961, who received interval compressed intensive induction therapy, this increase in TRM correlated with a decrease in both OS and disease free survival from CR. Remission specimens from patients with N-RASmut were negative for the mutation, demonstrating that an increased infectious risk could not be attributed to a host polymorphism. We found N-RASmut did not contribute to increased disease recurrence in pediatric AML. Our findings indicate that N-RAS mutations do not identify a high risk population, however, as such mutations lead to downstream activation of signal transduction pathways, they may identify a target for directed therapy. Disclosures No relevant conflicts of interest to declare.

Synergistic Killing of Leukemic Cells by Small Molecule Inhibitors of the Pim Protein Kinases and Inactivators of Additional Signal Transduction Pathways.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 409-409
Author(s):  
Yingwei Lin ◽  
Zanna M Beharry ◽  
Elizabeth G Hill ◽  
Jin H. Song ◽  
Wenxue Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Signal Transduction ◽  
Cell Growth ◽  
Small Molecule ◽  
Single Agent ◽  
Signal Transduction Pathways ◽  
Pim Kinases ◽  
Cycle Arrest ◽  
Mtorc1 Pathway ◽  
P70 S6k

Abstract Abstract 409 The serine/threonine Pim kinases are up regulated in specific hematologic neoplasms, and play an important role in key signal transduction pathways, including those regulated by c-Myc, N-Myc, FLT3-ITD, BCR-ABL, HOXA9, and EWS fusions. Pim protein kinases were first identified as a proviral integration site in c-Myc overexpressor mice and function to greatly enhance lymphoma development. Here we demonstrate that SMI-4a, a novel benzylidene-thiazolidine-2, 4-dione small molecule inhibitor of the Pim kinases supplied by Vortex Biotechnology (Mt. Pleasant, SC), kills a wide range of both myeloid and lymphoid cell lines with precursor T-cell lymphoblastic leukemia/lymphoma (pre T-LBL/T-ALL) being the most sensitive. Incubation of pre T-LBL cells with SMI-4a induced G1 phase cell cycle arrest secondary to a dose dependent induction of p27Kip1, apoptosis through the mitochondrial pathway, inhibition of mTORC1 pathway based on decreases in phosphorylation of p70 S6K and 4E-BP1, two substrates of this enzyme, and down regulation of c-myc. We demonstrate that treatment with 60 mg/kg twice daily by oral gavage of SMI-4a inhibits subcutaneous growth of pre T-LBL tumors by an average of 47.9% (p< .05) in immuno-deficient animals without notable toxicity to weight, blood counts, cell morphology, or blood chemistries. To enhance the killing effect of SMI-4a we have examined a number of potential combination therapies. First, because we find in animals and cell culture that single agent SMI-4a treatment up regulates the ERK pathway and in the spleen and thymus of Pim1/2/3 knock out mice there is increased phosphorylation of ERK1/2, we combined SMI-4a and a MEK1/2 inhibitor, U0126 or PD184352. Our results demonstrate that this combination is highly synergistic in killing pre T-LBL cells in culture. Secondly, because SMI-4a shares a number of important properties with γ-secretase inhibitors (GSI), Notch1 pathway inhibitor, including inhibition of pre T-LBL cell growth, cell cycle arrest, induction of p27Kip1, mTORC1 inhibition, and c-Myc down regulation, we tested the possibility that these agents could be synergistic. We find that single agent treatment with SMI-4a at 5 μM or treatment with the GSI Z-IL-CHO at 10 μM kills less than 20% of pre T-LBL cells, whereas in combination these drugs kill 78% of these cells, suggesting a high degree of synergy. Finally, because SMI-4a inhibits the mTORC1 pathway decreasing the phosphorylation of two mTOR substrates, p70 S6K and 4E-BP1, and because Pim plays an essential role in the FLT3/ITD signaling pathway, we examined the activity of SMI-4a with or without rapamycin in myeloid leukemic MV4-11 carrying both MLL-AF4 and FLT3-ITD and the RS4-11 cell line containing only MLL-AF4. We find that these two agents are highly synergistic in culture. SMI-4a alone inhibited growth 18% and rapamycin 40% but when combined 76% of the cell growth was blocked. SMI-4a had no effect on RS 4-11 cells. Our results demonstrate that unique combinations of a potent Pim inhibitor, SMI-4a, and small molecule blockade of either the mTORC1, ERK or Notch pathways has promise as a novel combination strategies for the treatment of human leukemia. Disclosures: No relevant conflicts of interest to declare.

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