Abstract 3289: Microenvironment modulation and enhancement of cytotoxic therapy by the heparanase inhibitor Roneparstat against human B-non Hodgkin lymphomas

Abstract Background: The standard chemotherapy treatment for Non-Hodgkin lymphoma (NHL) consists in the combination of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP). Because of the relevant treatment-related toxicity and the minor therapeutic effectiveness of CHOP therapy variants, the development of novel therapeutic approaches represents an urgent clinical need. Despite treatment with the anti-CD20 monoclonal antibody Rituximab and CHOP has led to favourable results for CD20+ lymphoma, many patients experienced drug resistance. Based on studies indicating that the malignant behaviour of tumors depends on the interactions between tumor and its microenvironment, we tested…

Abstract A18: miR-9 and miR-200 regulate PDGFRβ-mediated endothelial differentiation of neoplastic cells in triple-negative breast cancer

Abstract Tumor vascularization is a fundamental step in solid tumor progression and is orchestrated by different pathways of vasculogenesis. In malignant tumors, neoplastic cells can differentiate into endothelial-like cells acquiring the expression of endothelial markers (i.e. CD31 and CD34) and participating in the formation of vascular-like structures that functionally deliver oxygen and nutrients to the tumor site. We recently identified PDGFRβ as an important player of this process in triple negative breast cancer (TNBC). Interestingly, increasing evidence supported a connection between PDGFRβ and epithelial to mesenchymal transition (EMT), important step for the endothelial trans-diff…

miR-9 and miR-200 regulate PDGFRβ-mediated endothelial differentiation of tumor cells in triple-negative breast cancer

Abstract Organization of cancer cells into endothelial-like cell-lined structures to support neovascularization and to fuel solid tumors is a hallmark of progression and poor outcome. In triple-negative breast cancer (TNBC), PDGFRβ has been identified as a key player of this process and is considered a promising target for breast cancer therapy. Thus, we aimed at investigating the role of miRNAs as a therapeutic approach to inhibit PDGFRβ-mediated vasculogenic properties of TNBC, focusing on miR-9 and miR-200. In MDA-MB-231 and MDA-MB-157 TNBC cell lines, miR-9 and miR-200 promoted and inhibited, respectively, the formation of vascular-like structures in vitro. Induction of endogenous miR-9…

OX40 expression in tumor-associated Tregs as a potential prognostic biomarker and immunotherapeutic target in ovarian cancer.

e16576 Background: Treatment of ovarian cancer (OC) remains very challenging, with 80-85% of the cases still dying after relapse to standard chemotherapy, and novel treatments are urgently needed. Expansion of regulatory T cells (Tregs) is considered the major factor limiting immune responses to OC. Agonist antibodies against the co-stimulatory receptor OX40 have recently demonstrated to abrogate Treg functions and are under clinical evaluation. We thus studied whether OX40 constituted a valid target of OC-associated Tregs. Methods: Treg immunophenotypic analyses were performed by flow cytometry in ascites and OC specimens and studied in association with patients’ outcome Results: CD4+CD25+…

Microenvironment modulation and enhancement of antilymphoma therapy by the heparanase inhibitor roneparstat

Surveillance of spontaneous breast cancer metastasis by TRAIL-expressing CD34⁺ cells in a xenograft model

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), delivered as a membrane-bound molecule expressed on the surface of adenovirus-transduced CD34+ cells (CD34-TRAIL+), was analyzed for its apoptotic activity in vitro on 12 breast cancer cell lines representing estrogen receptor-positive, HER2+ and triple-negative (TN) subtypes and for its effect on tumor growth, vascularization, necrosis, and lung metastasis incidence in NOD/SCID mice xenografted with the TN breast cancer line MDA-MB-231. Mesenchymal TN cell lines, which are the richest in putative tumor stem cells among the different breast cancer cell subtypes, were the most susceptible to apoptosis induced by CD34-TRAIL+ cel…