In Vitro Antitumor Effects of the Cold-Water Extracts of Mediterranean Species of Genus Pleurotus (Higher Basidiomycetes) on Human Colon Cancer Cells

The aim of the present study was to evaluate whether the cold-water extract of Pleurotus eryngii var. ferulae (CWE-Pef) and Pleurotus nebrodensis (CWE-Pn), two of the most prized wild and cultivated edible mushrooms can affect the tumour phenotype of human colon cancer HCT116 cells. Our results showed that treatment with CWE-Pef and CWE-Pn resulted in a significant inhibition of the viability of HCT116 cells and promoted apoptosis as also demonstrated by the increase of bax/bcl-2 mRNA ratio. Moreover, we observed that both extracts were able to inhibit cell migration and to affect homotypic and heterotypic cell-cell adhesion. It was also found that treatment with CWE-Pef and CWE-Pn negatively modulated the protein tyrosine phosphorylation as well as the phosphorylation levels of ERK1/2. In conclusion, the in vitro antitumor effects of CWE-Pef and CWE-Pn indicate that they can be considered as possible sources for new alternative therapeutic agents for cancer treatment

Role of exosomes released by chronic myelogenous leukemia cells in angiogenesis

The present study is designed to assess if exosomes released from Chronic Myelogenous Leukemia (CML) cells may modulate angiogenesis. We have isolated and characterized the exosomes generated from LAMA84 CML cells and demonstrated that addition of exosomes to human vascular endothelial cells (HUVEC) induces an increase of both ICAM-1 and VCAM-1 cell adhesion molecules and interleukin-8 expression. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of CML cells to a HUVEC monolayer. We further showed that the treatment with exosomes from CML cells caused an increase in endothelial cell motility accompanied by a loss of VE-cadherin and β-catenin from the endothelial cell surface. Functional characterization of exosomes isolated from CML patients confirmed the data obtained with exosomes derived from CML cell line. CML exosomes caused reorganization into tubes of HUVEC cells cultured on Matrigel. When added to Matrigel plugs in vivo, exosomes induced ingrowth of murine endothelial cells and vascularization of the Matrigel plugs. Our results suggest for the first time that exosomes released from CML cells directly affect endothelial cells modulating the process of neovascularization

Carboxyamidotriazole-orotate inhibits the growth of Imatinib resistantchronic myeloid leukemia cells and modulates exosomes stimulated Angiogenesis

Chronic myeloid leukemia (CML) is characterized by the expression of Bcr\u2013Abl oncoprotein with a constitutive tyrosine kinase that drives disease pathogenesis. Imatinib is the election therapy for CML, but some patients are resistant to this drug. Recently, attention is being focused on cell-cell communication that involves membrane vesicles called exosomes. A number of studies have described exosomes as new players in modulating the tumor microenvironment, promoting angiogenesis and tumor development; furthermore neovascularization is known to exert an important role in the progression of chronic myeloid leukaemia and may represent a valid alternative target for therapy. Little is known regarding the role of exosomes in CML biology. Our data indicate that LAMA84 R, an Imatinib resistant human CML cell line releases exosomes and that the addition of those microvesicles to human vascular endothelial cells affects in vitro and in vivo angiogenesis. Interestingly, in the last years some data have indicated that modulation of exosome release by pharmacological agents may affect malignant progression. We have tested the effects of the carboxyamidotriazole-orotate (CTO) on LAMA84 R, we observed the inhibitor effects of CTO on LAMA84 R cells proliferation and on CML tumor xenografts growth. CTO is able to decrease in vitro BCR/ABL level expression and its phosphorilation and consequently inhibition of the downstream signalling . Our data also show that treatment of endothelial cells with CTO may inhibit exosomes-dependent angiogenesis by interfering with signal transduction pathways activated in endothelial cells by interaction with the microvesicles

Role of S128R polymorphism of E-Selectin in colon metastasis formation.

Role of S128R polymorphism of E-Selectin in colon metastasis formation

Effects of carboxyamidotriazole on in vitro models of imatinib-resistant chronic myeloid leukemia

Although imatinib mesylate (IM) has revolutionized the treatment of chronic myeloid leukemia (CML), some patients develop resistance with progression of leukemia. Alternative or additional targeting of signaling pathways deregulated in bcr-abl-driven CML cells may provide a feasible option for improving clinical response and overcoming resistance. In this study, we show that carboxyamidotriazole (CAI), an orally bioavailable calcium influx and signal transduction inhibitor, is equally effective in inhibiting the proliferation and bcr-abl dependent- and independent-signaling pathways in imatinib-resistant CML cells. CAI inhibits phosphorylation of cellular proteins including STAT5 and CrkL at concentrations that induce apoptosis in IM-resistant CML cells. The combination of imatinib and CAI also down-regulated bcr-abl protein levels. Since CAI is already available for clinical use, these results suggest that it may be an effective addition to the armamentarium of drugs for the treatment of CM