Limitations of Anti-Angiogenic Treatment of Tumors

Clinical trials using anti-vascular endothelial growth factor /(VEGF) molecules induce a modest improvement in overall survival, measurable in weeks to just a few months, and tumors respond differently to these agents. In this review article, we have exposed some tumor characteristics and processes that may impair the effectiveness of anti-angiogenic approaches, including genotypic changes on endothelial cells, the vascular normalization phenomenon, and the vasculogenic mimicry. The usage of anti-angiogenic molecules leads to hypoxic tumor microenvironment which enhances tumor invasiveness. The role of tumor-infiltrating cells, including tumor associated macrophages and fibroblasts (TAMs and TAFs) in the therapeutic response to anti-angiogenic settings was also highlighted. Finally, among the new therapeutic approaches to target tumor vasculature, anti-PD-1 or anti-PD-L1 therapy sensitizing and prolonging the efficacy of anti-angiogenic therapy, have been discussed

New insights in Diffuse Large B Cell Lymphoma Pathobiology

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL), accounting for about 40% of all cases of NHL. Analysis of the tumor microenvironment is an important aspect of the assessment of the progression of DLBCL. In this review article, we analyzed the role of different cellular components of the tumor microenvironment, including mast cells, macrophages, and lymphocytes, in the tumor progression of DLBCL. We examined several approaches to confront the available pieces of evidence, whereby three key points emerged. DLBCL is a disease of malignant B cells spreading and accumulating both at nodal and at extranodal sites. In patients with both nodal and extranodal lesions, the subsequent induction of a cancer-friendly environment appears pivotal. The DLBCL cell interaction with mature stromal cells and vessels confers tumor protection and inhibition of immune response while delivering nutrients and oxygen supply. Single cells may also reside and survive in protected niches in the nodal and extranodal sites as a source for residual disease and relapse. This review aims to molecularly and functionally recapitulate the DLBCL-milieu crosstalk, to relate niche and pathological angiogenic constitution and interaction factors to DLBCL progression

Inflammatory Cells in Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL), known as the most common non-Hodgkin lymphoma (NHL) subtype, is characterized by high clinical and biological heterogeneity. The tumor microenvironment (TME), in which the tumor cells reside, is crucial in the regulation of tumor initiation, progression, and metastasis, but it also has profound effects on therapeutic efficacy. The role of immune cells during DLBCL development is complex and involves reciprocal interactions between tumor cells, adaptive and innate immune cells, their soluble mediators and structural components present in the tumor microenvironment. Different immune cells are recruited into the tumor microenvironment and exert distinct effects on tumor progression and therapeutic outcomes. In this review, we focused on the role of macrophages, Neutrophils, T cells, natural killer cells and dendritic cells in the DLBCL microenvironment and their implication as target for DLBCL treatment. These new therapies, carried out by the induction of adaptive immunity through vaccination or passive of immunologic effectors delivery, enhance the ability of the immune system to react against the tumor antigens inducing the destruction of tumor cells

Role of erythropoietin in the angiogenic activity of bone marrow endothelial cells of MGUS and multiple myeloma patients

Increasing evidences suggest several biological roles for erythropoietin and its receptor (Epo and EpoR), unrelated to erythropoiesis, including angiogenesis. Here, we detected the expression of EpoR in bone marrow-derived endothelial cells from monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) patients (MGECs and MMECs, respectively) and assessed whether Epo plays a role in MGECs- and MMECs-mediated angiogenesis. We show that EpoR is expressed by both MGECs and MMECs even though at a higher level in the first ones. Both EC types respond to rHuEpo in terms of cell proliferation, whereas other responses, including activation of JAK2/STAT5 and PI3K/Akt pathways, cell migration and capillarogenesis are enhanced by Epo in MGECs, but not in MMECs. In addition, the conditioned media of both Epo-treated cells induce a strong angiogenic response in vivo in the chorioallantoic membrane assay, comparable to that of vascular endothelial growth factor (VEGF). Overall, these data highlight the effect of Epo on MGECs- and MMECs-mediated angiogenesis: MGECs are more responsive to Epo treatment than MMECs, probably because over-angiogenic phenotype of MMECs is already activated by their autocrine/paracrine loops occurring in the "angiogenic switch" from MGUS

Effect of resveratrol on mitochondrial function: Implications in parkin-associated familiar Parkinson's disease

Mitochondrial dysfunction and oxidative stress occur in Parkinson's disease (PD), but the molecular mechanisms controlling these events are not completely understood. Peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a transcriptional coactivator known as master regulator of mitochondrial functions and oxidative metabolism. Recent studies, including one from our group, have highlighted altered PGC-1α activity and transcriptional deregulation of its target genes in PD pathogenesis suggesting it as a new potential therapeutic target. Resveratrol, a natural polyphenolic compound proved to improve mitochondrial activity through the activation of several metabolic sensors resulting in PGC-1α activation. Here we have tested in vitro the effect of resveratrol treatment on primary fibroblast cultures from two patients with early-onset PD linked to different Park2 mutations. We show that resveratrol regulates energy homeostasis through activation of AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) and raise of mRNA expression of a number of PGC-1α's target genes resulting in enhanced mitochondrial oxidative function, likely related to a decrease of oxidative stress and to an increase of mitochondrial biogenesis. The functional impact of resveratrol treatment encompassed an increase of complex I and citrate synthase activities, basal oxygen consumption, and mitochondrial ATP production and a decrease in lactate content, thus supporting a switch from glycolytic to oxidative metabolism. Moreover, resveratrol treatment caused an enhanced macro-autophagic flux through activation of an LC3-independent pathway. Our results, obtained in early-onset PD fibroblasts, suggest that resveratrol may have potential clinical application in selected cases of PD-affected patients

Prednisolone restores blood brain barrier damages in dystrophic MDX mouse

Although the glucocorticoids delay the progression of Duchenne muscular dystrophy (DMD) their mechanism of action is unknown. In our previous studies we demonstrated that in the mdx mice, an animal model of DMD, besides the muscle degeneration, serious damages of the blood-brain barrier (BBB) occur taking to enhanced vessels permeability and brain edema (1). Moreover, we observed that the mdx mice after α–methyl-prednisolone (PDN) treatment ameloriated the histopathological profiles and the excitation-contraction of the myofibers (2). In this study, we evaluated the effects of the PDN on the BBB of the mdx mice, by estimating the immunocytochemical and biochemical expression of endothelial ZO-1 and occludin, pericyte desmin, and glial GFAP and short dystrophin isoform Dp 71 proteins, used as BBB markers. In addition, we analyzed the expression of dystrophin associate proteins (DAPs) aquaporin-4 (AQP4) and α-β dystroglycan in parallel in both brain and muscles of PDN treated mdx as well as in control mice. Results showed in mdx PDN treated mice a significant increase of the mRNA and protein content of all the glial, pericyte and endothelial proteins as compared to untreated mdx. Moreover, by immunoprecipitation we demonstrated that the BBB alteration in the mdx mice were coupled with enhanced occludin and AQP4 phosphorylation degree which, instead, was reduced after PDN treatment. Finally we observed that AQP4 and α-β dystroglycan complex increases its mRNA and protein content in both PDN mdx brain and muscle fibers, compared with mdx mice where the perivascular glial membranes and the myofibers showed a light staining after immunofluorescence analysis . These data indicate that the PDN restores the BBB damages in the mdx mice by inducing in the glial cell the expression of GFAP, AQP4 and Dp71 proteins and in the pericytes and endothelial cells, of the desmin and ZO-1 proteins, which are deficient in the distrophic mice. Moreover, the reduction in the AQP4 and occludin phosphorylation degree coupled with their ankoring to glial and endothelial membranes in the PDN mdx mice suggests that the glial and endothelial cells may be a cellular target of the drug. Finally, the enhanced expression of DAPs AQP4 and α-β dystroglycan in both brain and myofibers of PDN treated mdx mice compared to untreated mdx ones suggest the PDN might ameliorate the brain vessels and muscles functions of the dystrophic mice by a restoring a correct links between DAPs proteins and the extracellular matrix. 1. Nico B et al. Glia, 42: 235-251. (2003). 2. Cozzoli A. et al., Neuropathol. Appl. Neurobiol. 37, 243-256 (2011)

Generation of Induced Pluripotent Stem Cells from Patients with Duchenne Muscular Dystrophy and their induction to Neurons

Duchenne muscular dystrophy (DMD) is an X-linked recessive disease characterized by deficient expression of the cytoskeletal protein dystrophin. DMD has been associated with intellectual disability and mental retardation (MR) and is present in about a third of all patients. Loss of Dp71, the major dystrophin-gene product in brain, and the dystrophin associated proteins (DAPs) are thought to contribute to severity of MR, but the specific function of the neural dystrophin proteins are poorly understood for a limited access to DMD patients brain tissue (1). Differentiation of induced Pluripotent Stem Cells (iPSCs) provides an opportunity to generate an unlimited supply of living neurons genetically identical to those present in patients. In this study we obtained DMD-iPSCs from peripheral blood mononuclear cells of DMD patients with cognitive impairment and we performed morphological (fluorescence and electron microscopy), molecular (Western Blot and Real Time PCR) and functional (electrophysiology) characterization both of iPSC-derived Neural Stem Cells (NSCs) and the differentiated neurons. Preliminary data showed a reduction of Dp71 and DAPs proteins, including the AQP4, potassium channel Kir4.1, α- and β-dystroglycan (α/βDG) and α-syntrophin (αSyn), both at transcriptional and traductional level, coupled with membrane dys-arrangment in DMD-iPSCs compared with healthy iPSCs. Moreover, we demonstrated that the neurons obtained from the differentiation of iPSCs derived from DMD patient showed after confocal analysis, altered cytoskeleton and reduction in Dp71expression, and by single-cell imaging experiments and electrophysiology, altered intracellular calcium homeostasis, in analogy with what shown in the dystrophic mdx mouse neurons (2). Overall these results showed that the Dp71 and DAPs alterations affect also the neural precursor as well as the differentiated neurons in DMD patients, so suggesting a key role in the pathogenesis of neurocognitive deficits in DMD disease

Epha3 acts as proangiogenic factor in multiple myeloma

This study investigates the role of ephrin receptor A3 (EphA3) in the angiogenesis of Multiple Myeloma (MM) and the effects of a selective target of EphA3 by a specific monoclonal antibody on primary bone marrow endothelial cells (ECs) of MM patients.EphA3 mRNA and protein were evaluated in ECs of MM patients (MMECs), in ECs of patients with monoclonal gammopathies of undetermined significance (MGECs) and in ECs of healthy subjects (control ECs). The effects of EphA3 targeting by mRNA silencing (siRNA) or by the anti EphA3 antibody on the angiogenesis were evaluated. We found that EphA3 is highly expressed in MMECs compared to the other EC types. Loss of function of EphA3 by siRNA significantly inhibited the ability of MMECs to adhere to fibronectin, to migrate and to form tube like structures in vitro, without affecting cell proliferation or viability. In addition, gene expression profiling showed that knockdown of EphA3 down modulated some molecules that regulate adhesion, migration and invasion processes. Interestingly, EphA3 targeting by an anti EphA3 antibody reduced all the MMEC angiogenesis-related functions in vitro. In conclusion, our findings suggest that EphA3 plays an important role in MM angiogenesis