Elongation Factor 1 alpha interacts with phospho-Akt in breast cancer cells and regulates their proliferation, survival and motility

BACKGROUND: Akt/PKB is a serine/threonine kinase that has attracted much attention because of its central role in regulating cell proliferation, survival, motility and angiogenesis. Activation of Akt in breast cancer portends aggressive tumour behaviour, resistance to hormone-, chemo-, and radiotherapy-induced apoptosis and it is correlated with decreased overall survival. Recent studies have identified novel tumor-specific substrates of Akt that may provide new diagnostic and prognostic markers and serve as therapeutic targets. This study was undertaken to identify pAkt-interacting proteins and to assess their biological roles in breast cancer cells. RESULTS: We confirmed that one of the pAkt interacting proteins is the Elongation Factor EF1alpha. EF1alpha contains a putative Akt phosphorylation site, but is not phosphorylated by pAkt1 or pAkt2, suggesting that it may function as a modulator of pAkt activity. Indeed, downregulation of EF1alpha expression by siRNAs led to markedly decreased expression of pAkt1 and to less extent of pAkt2 and was associated with reduced proliferation, survival and invasion of HCC1937 cells. Proliferation and survival was further reduced by combining EF1alpha siRNAs with specific pAkt inhibitors whereas EF1alpha downregulation slightly attenuated the decreased invasion induced by Akt inhibitors. CONCLUSION: We show here that EF1alpha is a pAkt-interacting protein which regulates pAkt levels. Since EF1alpha is often overexpressed in breast cancer, the consequences of EF1alpha increased levels for proliferation, survival and invasion will likely depend on the relative concentration of Akt1 and Akt2

Understanding Tumor-Stroma Interplays for Targeted Therapies by Armed Mesenchymal Stromal Progenitors: The Mesenkillers.

Tumor represents a complex structure containing malignant cells strictly coupled with a large variety of surroundingcells constituting the tumor stroma (TS). In recent years, the importance of TS for cancer initiation, development,local invasion and metastases became increasingly clear allowing the identification of TS as one of the possibleways to indirectly target tumors. Inside the heterogeneous stromal cell population, tumor associated fibroblasts(TAF) play a crucial role providing both functional and supportive environments. During both tumor and stroma development,several findings suggest that TAF could be recruited from different sources such as locally derived host fibroblasts,via epithelial/endothelial mesenchymal transitions or from circulating pools of fibroblasts deriving form mesenchymalprogenitors, namely mesenchymal stem/stromal cells (MSC). These insights prompted scientists to identifymultimodal approaches to target TS by biomolecules, monoclonal antibodies and, more recently, via cell basedstrategies. These latter appear extremely promising, although associated with still debated and unclear findings. Thisreview discusses on crosstalk between cancers and their stroma, dissecting specific tumor types, such as sarcoma,pancreatic and breast carcinoma where stroma plays distinct paradigmatic roles. The recognition of these distinctstromal functions may help in planning effective and safer approaches aimed either to eradicate or to substitute TSby novel compounds and/or MSC having specific killing activitie

The Future of Cities

This report is an initiative of the Joint Research Centre (JRC), the science and knowledge service of the European Commission (EC), and supported by the Commission's Directorate-General for Regional and Urban Policy (DG REGIO). It highlights drivers shaping the urban future, identifying both the key challenges cities will have to address and the strengths they can capitalise on to proactively build their desired futures. The main aim of this report is to raise open questions and steer discussions on what the future of cities can, and should be, both within the science and policymaker communities. While addressing mainly European cities, examples from other world regions are also given since many challenges and solutions have a global relevance. The report is particularly novel in two ways. First, it was developed in an inclusive manner – close collaboration with the EC’s Community of Practice on Cities (CoP-CITIES) provided insights from the broader research community and city networks, including individual municipalities, as well as Commission services and international organisations. It was also extensively reviewed by an Editorial Board. Secondly, the report is supported by an online ‘living’ platform which will host future updates, including additional analyses, discussions, case studies, comments and interactive maps that go beyond the scope of the current version of the report. Steered by the JRC, the platform will offer a permanent virtual space to the research, practice and policymaking community for sharing and accumulating knowledge on the future of cities. This report is produced in the framework of the EC Knowledge Centre for Territorial Policies and is part of a wider series of flagship Science for Policy reports by the JRC, investigating future perspectives concerning Artificial Intelligence, the Future of Road Transport, Resilience, Cybersecurity and Fairness Interactive online platform : https://urban.jrc.ec.europa.eu/thefutureofcitiesJRC.B.3-Territorial Developmen

METHOD FOR PRODUCTION OF ANTI-TUMOR TRAIL PROTEIN

The method for production of anti-tumor TRAIL comprises: inserting a TRAIL molecule, encoded by a viral vector irreversibly derived from a cell line, into a carrier cell, thereby obtaining a stably TRAIL-producing carrier cell, said TRAIL molecule comprising a soluble molecule

A degradation-resistant c-Myb mutant cooperates with Bcl-2 in enhancing proliferative potential and survival of hematopoietic cells

The c-myb gene is preferentially expressed in primitive hematopoietic cell and plays a central role in the control of cell proliferation, differentiation and survival by regulating the transcription of several genes implicated in these processes including the antiapoptotic Bcl-2. We show here that, compared to wild-type c-Myb, overexpression of a degradation resistant c-Myb mutant [Delta(358-452) c-Myb] enhances the clonogenic potential of hematopoietic progenitors as indicated by increased cytokine-dependent primary and secondary colony formation of Lin(-) Sca-1(+) Kit(+) mouse marrow cells. Moreover, proliferation assays of IL-3 dependent myeloid precursor 32Dcl3 cells co-expressing Bcl-2 and c-Myb indicate that these cells continue to proliferate in the absence of IL-3 and this effect is more apparent in cells expressing the degradation resistant Delta(358-452) c-Myb. Interestingly, overexpression of Delta(358-452) c-Myb is by itself sufficient to protect 32Dcl3 cells from apoptosis induced by IL-3 deprivation; moreover, these cells are also increased in number which most likely reflects the enhanced proliferative potential conferred by Delta(358-452) c-Myb to apoptosis-resistant cell

Human multipotent mesenchymal stromal cells use galectin-1 to inhibit immune effector cells

Human multipotent mesenchymal stromal cells (MSC) suppress proliferation and alloreactivity of T cells. Several signalling molecules and enzymes contribute to this effect. We focused on carbohydrate-protein interactions and investigated if lectins are involved in immune modulation by MSC. Gene expression profiling of MSC revealed that one of the most important lectins in this setting, galectin-1, was highly expressed. Galectin-1 protein was detected intracellularly and on the cell surface of MSC. In addition, galectin-1 was released into the cell culture supernatant by MSC. In order to analyze the functional role of galectin-1, a stable knockdown of galectin-1 in MSC using a retroviral transfection system was established. Galectin-1 knockdown in MSC resulted in a significant loss of their immunomodulatory properties, when compared to MSC infected with non-targeting control sequences. The galectin-1 knockdown partially restored the proliferation of CD4(+) and CD8(+) T cells. By contrast, the effect of MSC on non-alloreactive NK cells was unaffected by downregulation of galectin-1 expression. Furthermore, MSC-derived galectin-1 significantly modulated the release of cytokines involved in GvHD and autoimmunity, e. g. TNFalpha, IFNgamma, IL-2 and IL-10. These results identify galectin-1 as the first lectin mediating the immunomodulatory effect of MSC on allogeneic T cells

Enhanced proliferative potential of hematopoietic cells expressing degradation-resistant c-Myb mutants

The c-myb gene encodes a transcription factor required for proliferation, differentiation, and survival of hematopoietic cells. Expression of c-Myb is often increased in hematological malignancies, but the underlying mechanisms are poorly understood. We show here that c-Myb has a longer half-life ( at least 2-fold) in BCR/ABL-expressing than in normal hematopoietic cells. Such enhanced stability was dependent on a phosphatidylinositol 3-kinase ( PI-3K)/Akt/GSKIII beta pathway( s) as indicated by the suppression of c-Myb expression upon treatment with PI-3K inhibitors or co-expression with dominant negative Akt or constitutively active GSKIII beta. Moreover, inhibition of GSKIII beta by LiCl enhanced cMyb expression in parental 32Dcl3 cells. Compared with wild type c-Myb, three mutants ( Delta( 358 - 452), Delta( 389 - 418), and L389A/L396A c-Myb) of the leucine zipper domain had increased stability. However, only expression of Delta( 358 - 452) was not affected by inhibition of the PI-3K/Akt pathway and was not enhanced by a proteasome inhibitor, suggesting that leucine zipper-dependent and - independent mechanisms are involved in the regulation of c-Myb stability. Indeed, Delta( 389 - 418) carrying four lysine-to-alanine substitutions ( Delta( 389 - 418) K387A/K428A/ K442A/K445A) was as stable as Delta( 358 - 452) c-Myb. Compared with full-length c-Myb, constitutive expression of Delta( 358 - 452) and Delta( 389 - 418) c-Myb in Lin-Sca-1(+) mouse marrow cells increased cytokine-dependent primary and secondary colony formation. In K562 cells, expression of Delta( 358 - 452), Delta( 389 - 418), and L389A/L396A c-Myb led to enhanced proliferation after STI571 treatment. Thus, enhanced stability of c-Myb by activation of PI-3K-dependent pathway( s) might contribute to the higher proliferative potential of BCR/ABL-expressing and, perhaps, other leukemic cells

Isolation and functional assessment of common, polymorphic variants of the B-MYB proto-oncogene associated with a reduced cancer risk.

The B-MYB proto-oncogene is a transcription factor belonging to the MYB family that is frequently overexpressed or amplified in different types of human malignancies. While it is suspected that B-MYB plays a role in human cancer, there is still no direct evidence of its causative role. Looking for mutations of the B-MYB gene in human cell lines and primary cancer samples, we frequently isolated two nonsynonymous B-MYB polymorphic variants (rs2070235 and rs11556379). Compared to the wild-type protein, the B-MYB isoforms display altered conformation, impaired regulation of target genes and decreased antiapoptotic activity, suggesting that they are hypomorphic variants of the major allele. Importantly, the B-MYB polymorphisms are common; rs2070235 and rs11556379 are found, depending on the ethnic background, in 10-50% of human subjects. We postulated that, if B-MYB activity is important for transformation, the presence of common, hypomorphic variants might modify cancer risk. Indeed, the B-MYB polymorphisms are underrepresented in 419 cancer patients compared to 230 controls (odds ratio 0.53; (95%) confidence interval 0.385-0.755; P=0.001). This data imply that a large fraction of the human population is carrier of B-MYB alleles that might be associated with a reduced risk of developing neoplastic disease

Cytokine-Induced Osteopoietic Differentiation of Transplanted Marrow Cells

Transplantation of whole bone marrow (BMT) leads to engraftment of both osteoprogenitor cells and hematopoietic cells; however, the robust osteopoietic chimerism seen early after BMT decreases with time. Using our established murine model, we demonstrate that a post-BMT regimen of either granulocyte-colony stimulating factor, growth hormone, parathyroid hormone, or stem cell factor each stimulates greater donor osteoblast chimerism at 4 months posttransplantation than saline-treated controls and approximates the robust osteopoietic chimerism seen early after BMT; however, only growth hormone led to significantly more donor-derived osteocytes than controls. Importantly, there were no adverse hematologic consequences of the different treatments. Our data demonstrate that these cytokines can stimulate the differentiation of transplanted donor marrow cells into the osteopoietic lineage after BMT. Post-BMT cytokine therapy may generate durable osteopoietic engraftment, which should lead to sustained clinical benefit and render BMT more applicable to bone disorders