Oral Communications 7
15.2 - Mesenchymal Stromal Cells (MSCs) primed with Paclitaxel as tool for carrying and delivering the drug in cancer therapy
Presenter: Valentina, Cocce, Milan, Italy
Authors: Valentina Coccè1,2,3,4,5, Arianna Bonomi1,2,3,4,5, Loredana Cavicchini1,2,3,4,5, Francesca Sisto1,2,3,4,5, Maura Ferrari1,2,3,4,5, Luisa Pascucci1,2,3,4,5, Giulio Alessandri1,2,3,4,5, Eugenio Parati1,2,3,4,5, Enrico Lucarelli1,2,3,4,5, Augusto Pessina1,2,3,4,5
Mesenchymal Stromal Cells (MSCs) primed with Paclitaxel as tool for carrying and delivering the drug in cancer therapy
Valentina Coccè1,2,3,4,5, Arianna Bonomi1,2,3,4,5, Loredana Cavicchini1,2,3,4,5, Francesca Sisto1,2,3,4,5, Maura Ferrari1,2,3,4,5, Luisa Pascucci1,2,3,4,5, Giulio Alessandri1,2,3,4,5, Eugenio Parati1,2,3,4,5, Enrico Lucarelli1,2,3,4,5, Augusto Pessina1,2,3,4,5
1Department of Biomedical, Surgical, and Dental Sciences, University of Milan, Milan, Italy; 2Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Brescia, Italy; 3Department of Biopathological Sciences and Hygiene of Animal and Food Productions, University of Perugia, Perugia, Italy; 4Department of Cerebrovascular Disease, Fondazione IRCCS Neurological Institute C. Besta , Milan, Italy; 5Istituti Ortopedici Rizzoli, IOR, Bologna, Italy
Mesenchymal stromal cells (MSCs) can be easily isolated from bone marrow and adipose tissue and cultured and expanded in vitro. Their migratory capacity and tropism to solid tumors (both primary and metastatic) have increased the interest in their use as a "carrier" to transport molecules for cancer therapy. Many methodologies have been described to create "engineered" MSCs capable of secreting therapeutic cytokines, pro-drugs or inhibitory factors.
As previously demonstrated, MSCs derived from human bone marrow, if exposed to high doses of Doxorobicin, are able to inhibit, without any manipulation, the proliferation of hematopoietic stem cells (HSCs). We therefore assessed whether human mesenchymal stromal cells (hMSCs) in vitro loaded with Paclitaxel (PTX), were able to release the drug in sufficient quantity to inhibit the proliferation of tumor cells. The incorporation of the drug into hMSCs was analyzed by FACS and confocal microscopy, using PTX FITC-labeled probe, and the release of PTX in the cellular culture medium (CM) has been demonstrated by liquid chromatography HPLC. The hMSCs loaded with PTX (hMSCsPTX) show some degree of chemo-apoptosis, but 80% of the hMSCsPTX are inhibited to proliferate maintaining their viability and capacity to release PTX in the CM in a time-dependent manner. The ultrastructural analysis of hMSCsPTX with transmission electron microscope (TEM) showed that the treatment with PTX does not induce morphological alterations. Leukemic cells are attracted and bound by MSCs as demonstrated by the formation of "rosettes" (aggregates of hMSCs surrounded by a "crown" of leukemia cells MOLT-4) in in vitro co-cultures. The morphology of rosettes analyzed with TEM and SEM (scanning electron microscopy) revealed the presence of cytoplasmic and nuclear damage in MOLT-4 adherent to hMSCsPTX.
The anti-tumor effects of hMCSsPTX were demonstrated by in vitro experiments: CM obtained from hMSCsPTX inhibit the proliferation of MOLT-4 and other human tumor lines (DU-145 prostate cancer, glioblastoma T98G). Furthermore, in vivo experiments in nude mice have demonstrated that hMSCsPTX co-injected subcutaneously with tumor cells (MOLT-4, DU145 and U87MG glioblastoma), inhibit the early stages of tumor proliferation; if hMSCsPTX were injected into preformed tumoral nodules, they reduced the capacity of engraftment and tumor vasculature. We demonstrated that also mature stromal cells, as human skin derived fibroblasts (hSDFs), had the same properties of hMSCs. In vitro experiments showed that hSDFs loaded with PTX (hSDFsPTX) released the drug in a time-dependent manner and their CM inhibited tumor growth in vitro.
Our data demonstrate that hMSCs, without the need of any genetic manipulation, can be used as "drug carrier" opening their application for new complementary anticancer therapeutic approach.