Loss of microRNA-135b Enhances Bone Metastasis in Prostate Cancer and Predicts Aggressiveness in Human Prostate Samples

About 70% of advanced-stage prostate cancer (PCa) patients will experience bone metastasis, which severely affects patients’ quality of life and progresses to lethal PCa in most cases. Hence, understanding the molecular heterogeneity of PCa cell populations and the signaling pathways associated with bone tropism is crucial. For this purpose, we generated an animal model with high penetrance to metastasize to bone using an intracardiac percutaneous injection of PC3 cells to identify PCa metastasis-promoting factors. Using genomic high-throughput analysis we identified a miRNA signature involved in bone metastasis that also presents potential as a biomarker of PCa progression in human samples. In particular, the downregulation of miR-135b favored the incidence of bone metastases by significantly increasing PCa cells’ migratory capacity. Moreover, the PLAG1, JAKMIP2, PDGFA, and VTI1b target genes were identified as potential mediators of miR-135b’s role in the dissemination to bone. In this study, we provide a genomic signature involved in PCa bone growth, contributing to a better understanding of the mechanisms responsible for this process. In the future, our results could ultimately translate into promising new therapeutic targets for the treatment of lethal PCa.

Comparative cytogenetic patterns in Carangidae fishes in association with their distribution range

Carangidae are an important and widespreaded family of pelagic predatory fishes that inhabit reef regions or open ocean areas, some species occupying a vast circumglobal distribution. Cytogenetic comparisons among representatives of its different tribes help to understand the process of karyotype divergence in marine ecosystems due to the variable migratory ability of species. In this sense, conventional cytogenetic investigations (Giemsa staining, Ag-NORs, and C-banding), GC base-specific fluorochrome staining and FISH mapping of ribosomal DNAs were performed. Four species, Elagatis bipinnulata (Quoy et Gaimard, 1825) and Seriola rivoliana (Valenciennes, 1883) (Naucratini), with circumtropical distributions, Gnathanodon speciosus (Forsskål, 1775) (Carangini), widely distributed in the tropical and subtropical waters of the Indian and Pacific oceans, and Trachinotus carolinus (Linnaeus, 1766) (Trachinotini), distributed along the western Atlantic Ocean, were analyzed, thus encompassing representatives of three out its four tribes. All species have diploid chromosome number 2n = 48, with karyotypes composed mainly by acrocentric chromosomes (NF = 50–56). The 18S rDNA/Ag-NORs/GC+ and 5S rDNA loci were located on chromosomes likely homeologs. Karyotypes showed a pattern considered basal for the family or with small variations in their structures, apparently due to pericentric inversions. The migratory capacity of large pelagic swimmers, in large distribution areas, likely restricts the fixation of chromosome changes in Carangidae responsible for a low level of karyotype diversification.

Enpp2 Expression by Dendritic Cells Is a Key Regulator in Migration

Enpp2 is an enzyme that catalyzes the conversion of lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), which exhibits a wide variety of biological functions. Here, we examined the biological effects of Enpp2 on dendritic cells (DCs), which are specialized antigen-presenting cells (APCs) characterized by their ability to migrate into secondary lymphoid organs and activate naïve T-cells. DCs were generated from bone marrow progenitors obtained from C57BL/6 mice. Enpp2 levels in DCs were regulated using small interfering (si)RNA or recombinant Enpp2. Expression of Enpp2 in LPS-stimulated mature (m)DCs was high, however, knocking down Enpp2 inhibited mDC function. In addition, the migratory capacity of mDCs increased after treatment with rmEnpp2; this phenomenon was mediated via the RhoA-mediated signaling pathway. Enpp2-treated mDCs showed a markedly increased capacity to migrate to lymph nodes in vivo. These findings strongly suggest that Enpp2 is necessary for mDC migration capacity, thereby increasing our understanding of DC biology. We postulate that regulating Enpp2 improves DC migration to lymph nodes, thus improving the effectiveness of cancer vaccines based on DC.

Characterisation of a New Clinical Presentation of Chronic Lymphocytic Leukemia with Symptomatic Nasopharyngeal Mucosa Involvement

Patients with chronic lymphocytic leukemia (CLL) are prone to infectious complications, including Ears, Nose and Throat (ENT) infections due to the humoral immunodepression and/or to the immunosuppression related to the therapy. However, specific CLL infiltration in non-lymphoid regions of the head and neck causing ENT symptoms but unrelated to an infection is not well described. Extra-nodal localizations of CLL cells, including involvement of the mucosa of the rhinopharynx is uncommon and poorly reported. Here, we retrospectively analyzed the clinical, histopathologic and molecular features of 25 CLL patients with specific head and neck involvement. To date, this is the largest cohort reporting this new entity of CLL also named Nasal Associated Lymphoid Tissue (NALT) CLL. All patients had proven CLL prior to symptoms. Median time between ENT manifestation and CLL was 3 years [1-11 years]. Symptoms included chronic coughing (44%), antero-posterior nasal discharge (44%), nasal congestion (33%) and pharyngitidis (33%). ENT examination evidenced cervical lymphadenopathies in 68 % of cases, a granular aspect of the mucosa of the pharynx in 56%, enlarged tonsil (37%) or adenoids (37%). All patients underwent a biopsy of the mucosa of the nose or the throat. Histology and immunochemistry analysis demonstrated an infiltration of small lymphocytes CD20+, CD5+ and CD23+, consistent with a phenotype of CLL. The infiltration was diffuse in 50% of biopsies and perivascular in 38%. Patients with NALT-CLL had a poor prognosis: the majority was IGHV unmutated (n=18/25, 72%). Furthermore, they all required a treatment according to IWCLL criteria few time after the first ENT symptoms (median time 2 years), indicating that NALT-CLL is associated with a more progressive disease. To characterize the genetic background of NALT-CLL, we analyzed the cytogenetic data and NGS sequencing of 13 CLL-associated mutations from peripheral CLL cells. The karyotype was normal in only 2/24 cases (8%) and complex (>3 abnormalities) in 5/24 cases (20%). Half of the patients had a trisomy 12(12/24; 50%), while 13q, 17p and 11q deletions were found in 29%, 8% and 4% respectively. Eleven patients harbored one mutation (44%) while 9 patients had 2 to 5. Mutation of the NOTCH1 pathway was found in half of the cases (11/25 NOTCH1 and 2/25 FBXW7 mutated cases). TP53 and SF3B1 mutations occurred respectively in 20% (5/25 cases) and in 12% (3/25 cases). To gain insight into the molecular mechanism associated with involvement of the rhinopahrynx, we studied the expression of 70 genes related to cell migration and cell adhesion pathways using a qPCR array in the peripheral CLL cells of patients with NALT (n=4) compare to no NALT-CLL (n=4). Genes significantly up regulated with a fold change >2 included the chemokine receptors CCR7 (p=0.05) and CCR5 (p=0.04), the receptor involved in leukocyte trafficking CXCR3 (p=0.01) or the chemoattractant chemokine-like factor CKLF. By targeted qPCR, we confirmed the up regulation of CCR7 (p=0.002), CXCR3 (p=0.04) and CCR5 (p=0.03) in the cohort NALT-CLL patient (n=25) as compared to 20 age-matched CLL patients without head and neck symptoms (77% with unmutated IGHV, 30% with NOTCH1 mutation and 30% with trisomy 12). Up regulation of those targets was independent of the presence of NOTCH1/trisomy12 aberration or of the IGHV mutation status. These results suggest an increased migratory capacity of the leukemic CLL cells into the rhynopharynx mucosa related to a higher expression of these receptors involved in cell trafficking and migration. In line with these results, immunohistochemistry analysis of 5 patients with nasal involvement showed a strong staining of the CCR7 marker on the membrane of CLL cells infiltrating the mucosa. Interestingly, the staining of CCL21, the cognate ligand of CCR7, was positive in the vessels of the mucosa, suggesting that the recruitment and the transendothelial migration of CLL cells into the mucosa occur through a local secretion of CCL21 by the vessels. In summary, we report here a new presentation of CLL associated with symptomatic and specific ENT localization. CLL cells are predominantly IGHV unmutated, harbor NOTCH1 mutation and/or trisomy12 and show a higher expression of the chemokine receptors CCR7, CCR5 and CXCR3. We are currently studying the expression of those receptors by flow cytometry and the enhanced migratory capacity toward CCL21 through an in vitro chemotaxis assay. Disclosures Letestu: AbbVie: Research Funding, Speakers Bureau; Roche: Speakers Bureau; Janssen: Research Funding, Speakers Bureau. Cymbalista: Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTRA ZENECA: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Lilly-LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Enhanced Migratory Capacity of T Lymphocytes in Severe Chagasic Patients Is Correlated With VLA-4 and TNF-α Expression

Trypanosoma cruzi infection in humans leads to progression to chronic chagasic myocarditis (CCM) in 30% of infected individuals, paralleling T cell inflammatory infiltrates in the heart tissue. T-cell trafficking into the hearts of CCM patients may be modulated by in situ expression of chemotactic or haptotactic molecules, as the chemokine CXCL12, the cytokine tumor necrosis factor-alpha (TNF-α), and extracellular matrix proteins (ECM), such as fibronectin. Herein we evaluated the expression of fibronectin, CXCL12, and TNF-α in the myocardial tissue of T. cruzi seropositive (asymptomatic or with CCM), as well as seronegative individuals as healthy controls. Hearts from CCM patients exhibited enhanced expression of these three molecules. CXCL12 and TNF-α serum levels were also increased in CCM individuals. We then evaluated T lymphocytes from chronic chagasic patients by cytofluorometry, in terms of membrane expression levels of molecules involved in cell activation and cell migration, respectively, HLA-DR and the VLA-4 (very late antigen-4, being one integrin-type fibronectin receptor). Indeed, the expression of HLA-DR and VLA-4 was enhanced on T lymphocytes from chagasic patients, especially in the CCM group. To further approach the dynamics of T cell migratory events, we performed fibronectin-, TNF-α-, and CXCL12-driven migration. Peripheral blood mononuclear cells (PBMCs) and T cells from CCM patients presented an ex vivo enhanced migratory capacity driven by fibronectin alone when this ECM protein was placed in the membrane of transwell migration chambers. When TNF-α was previously placed upon fibronectin, we observed a further and significant increase in the migratory response of both PBMCs and T lymphocytes. Overall, these data suggest the existence in patients with chronic Chagas disease of a cardiac inflammatory infiltrate vector that promotes the recruitment and accumulation of activated T cells, driven in part by enhanced tissue expression of fibronectin and TNF-α, as well as the respective corresponding VLA-4 and TNF receptors.

TAMI-42. THE ROLE OF HFE AND IRON IN CELL ADHESION AND MIGRATION IN GLIOBLASTOMA

Glioblastoma (GBM) remains one of the most difficult to treat malignancies facing modern medicine. The strong migratory and invasive capacity of GBM cells allows for diffuse invasion into neighboring healthy brain which presents a significant hurdle for complete surgical resection of these tumors. Unsurprisingly, even after receiving maximal surgical resection, radiation and chemotherapy, the majority of GBM patients end up with recurrent disease. Increased expression levels of the homeostatic iron regulator gene (HFE) in brain tumors such as GBM have been associated with poorer outcomes. In order to better understand how HFE expression impacts the adhesive and migratory capacity of GBM, we utilized syngeneic mouse glioma models (KR158, CT2A) that have been transfected to either over-express or under-express HFE. We observed that knocking down HFE in the KR158 model resulted in significantly decreased migratory capacity as well as decreased adhesion to fibronectin and artificial basement membrane. Likewise, overexpressing HFE in a CT2A model resulted in increased adhesion to fibronectin or artificial basement membrane. Since HFE is known to regulate iron uptake, we studied how modulating the iron status of GBM cells impacted their ability to migrate and adhere. We found that increasing the iron pool of these mouse glioma models by exposure to exogenous iron compounds decreased migratory capacity. To better understand mechanistically how HFE and iron status impacted migration and adhesion, we probed how expression of integrins and their downstream signaling molecules, the Rho GTPases were altered in response to iron. We found that exposure to iron decreased levels of the Rho GTPases Cdc42 and RhoA. Furthermore, cells that overexpressed HFE were found to have increased expression of integrin β1 and integrin α5 suggesting that HFE and iron may impact integrins and their downstream signaling pathways to alter migration of GBM cells.

Regulation of mitochondrial fission by GIPC-mediated Drp1 retrograde transport

Drp1 is a key regulator of mitochondrial fission, a large cytoplasmic GTPase recruited to the mitochondrial surface via transmembrane adaptors to initiate scission. While Brownian motion likely accounts for the local interactions between Drp1 and the mitochondrial adaptors, how this essential enzyme is targeted from more distal regions like the cell periphery remains unknown. Based on proteomic interactome screening and cell-based studies, we report that GIPC mediates the actin-based retrograde transport of Drp1 towards the perinuclear mitochondria to enhance fission. Drp1 interacts with GIPC through its atypical C-terminal PDZ-binding motif. Loss of this interaction abrogates Drp1 retrograde transport resulting in cytoplasmic mislocalization and reduced fission despite retaining normal intrinsic GTPase activity. Functionally, we demonstrate that GIPC potentiates the Drp1-driven proliferative and migratory capacity in cancer cells. Together, these findings establish a direct molecular link between altered GIPC expression and Drp1 function in cancer progression and metabolic disorders.

Mitochondrial Telomerase Reverse Transcriptase Protects from Myocardial Ischemia/reperfusion Injury by Improving Complex I Composition and Function

Background: The catalytic subunit of telomerase, Telomerase Reverse Transcriptase (TERT) has protective functions in the cardiovascular system. TERT is not only present in the nucleus, but also in mitochondria. However, it is unclear whether nuclear or mitochondrial TERT is responsible for the observed protection and appropriate tools are missing to dissect this. Methods: We generated new mouse models containing TERT exclusively in the mitochondria (mitoTERT mice) or the nucleus (nucTERT mice) to finally distinguish between the functions of nuclear and mitochondrial TERT. Outcome after ischemia/reperfusion, mitochondrial respiration in the heart as well as cellular functions of cardiomyocytes, fibroblasts, and endothelial cells were determined. Results: All mice were phenotypically normal. While respiration was reduced in cardiac mitochondria from TERT-deficient and nucTERT mice, it was increased in mitoTERT animals. The latter also had smaller infarcts than wildtype mice, whereas nucTERT animals had larger infarcts. The decrease in ejection fraction after one, two and four weeks of reperfusion was attenuated in mitoTERT mice. Scar size was also reduced and vascularization increased. Mitochondrial TERT protected a cardiomyocyte cell line from apoptosis. Myofibroblast differentiation, which depends on complex I activity, was abrogated in TERT-deficient and nucTERT cardiac fibroblasts and completely restored in mitoTERT cells. In endothelial cells, mitochondrial TERT enhanced migratory capacity and activation of endothelial NO synthase. Mechanistically, mitochondrial TERT improved the ratio between complex I matrix arm and membrane subunits explaining the enhanced complex I activity. In human right atrial appendages, TERT was localized in mitochondria and there increased by remote ischemic preconditioning. The Telomerase activator, TA-65 evoked a similar effect in endothelial cells, thereby increasing their migratory capacity, and enhanced myofibroblast differentiation. Conclusions: Mitochondrial, but not nuclear TERT, is critical for mitochondrial respiration and during ischemia/reperfusion injury. Mitochondrial TERT improves complex I subunit composition. TERT is present in human heart mitochondria, and remote ischemic preconditioning increases its level in those organelles. TA-65 has comparable effects ex vivo and improves migratory capacity of endothelial cells and myofibroblast differentiation. We conclude that mitochondrial TERT is responsible for cardioprotection and its increase could serve as a therapeutic strategy.

Understanding Interactions Histological, Cytological, and Molecular Among the fungus P. Striiformis Tritici and Wheat

Yellow rust is caused by the fungus Puccinia striiformis f.sp.tritici (Pst), which due to its great migratory capacity, adaptation to different environments, and high levels of mutation; is one of the most devastating wheat diseases worldwide. Due to this, several strategies have been implemented to control the disease, the best being genetic improvement. The key to develop resistant cultivars is understanding the interactions between wheat and Pst. Therefore, this work synthesizes the most important investigations carried out in the last 30 years regarding: cellular, histological, and molecular interactions between wheat and Pst. This will allow a deeper and more complete understanding of the interaction between resistance and virulence genes in the yellow rust disease. The results of this work revealed that the early stage of infection, in susceptible and resistant cultivars, is the same qualitatively, but not quantitatively. However, a clear difference at the histological and molecular level, in terms of the amount and type of genes expressed, begins 48 hours after infection. It was also found that the haustorium, in addition to absorbing nutrients from the host; can also manipulate its metabolism to benefit itself, and can make some nutrients on its own. Keywords: haustorio, Puccinia striiformis f.sp.tritici, histological, resistance genes, virulence genes. Resumen La roya amarilla es causada por el hongo Puccinia striiformis f.sp.tritici (Pst), el cual debido a su gran capacidad migratoria, adaptación a diferentes ambientes, y niveles altos de mutación; es la enfermedad más devastadoras del trigo a nivel mundial. Debido a esto, varias estrategias han sido implementadas para controlar la enfermedad, siendo la mejor, el mejoramiento genético. La clave para desarrollar cultivares resistentes, es el entendimiento de las interacciones entre el trigo y Pst. Por lo tanto, este trabajo sintetiza las investigaciones más importantes realizadas en los últimos 30 años, en cuanto a interacciones celulares, histológicas y moleculares entre el trigo y Pst. Esto permitirá un entendimiento más profundo y completo de la interacción entre los genes de resistencia y virulencia, en la enfermedad de la roya. Los resultados revelaron que la fase temprana de infección en cultivares susceptibles y resistentes, es igual cualitativamente, pero no cuantitativamente. Sin embargo, una diferencia clara a nivel histológico y molecular, en cuanto a la cantidad y al tipo de genes expresados, empieza 48 hr post infección. También, se halló que el haustorio además de absorber nutrientes del huésped, también manipula el metabolismo de éste para su beneficio y puede elaborar algunos nutrientes por sí mismo. Palabras Clave: haustorio, Puccinia striiformis f.sp.tritici, histológico, genes de resistencia, genes de virulencia.

Mimicking of Blood Flow Results in a Distinct Functional Phenotype in Human Non-Adherent Classical Monocytes

Ex vivo culture conditions during the manufacturing process impact the therapeutic effect of cell-based products. Mimicking blood flow during ex vivo culture of monocytes has beneficial effects by preserving their migratory ability. However, the effects of shear flow on the inflammatory response have not been studied so far. Hence, the present study investigates the effects of shear flow on both blood-derived naïve and activated monocytes. The activation of monocytes was experimentally induced by granulocyte-macrophage colony-stimulating factor (GM-CSF), which acts as a pro-survival and growth factor on monocytes with a potential role in inflammation. Monocytes were cultured under dynamic (=shear flow) or static conditions while preventing monocytes' adherence by using cell-repellent surfaces to avoid adhesion-induced differentiation. After cultivation (40 h), cell size, viability, and cytokine secretion were evaluated, and the cells were further applied to functional tests on their migratory capacity, adherence, and metabolic activity. Our results demonstrate that the application of shear flow resulted in a decreased pro-inflammatory signaling concurrent with increased secretion of the anti-inflammatory cytokine IL-10 and increased migratory capacity. These features may improve the efficacy of monocyte-based therapeutic products as both the unwanted inflammatory signaling in blood circulation and the loss of migratory ability will be prevented.