Tumor Immunotherapy Using Gene-Modified Human Mesenchymal Stem Cells Loaded into Synthetic Extracellular Matrix Scaffolds

Mesenchymal stem cells (MSCs) are appealing as gene therapy cell vehicles given their ease of expansion and transduction. However, MSCs exhibit immunomodulatory and proangiogenic properties that may pose a risk in their use in anticancer therapy. For this reason, we looked for a strategy to confine MSCs to a determined location, compatible with a clinical application. Human MSCs genetically modified to express luciferase (MSCluc), seeded in a synthetic extracellular matrix (sECM) scaffold (sentinel scaffold) and injected subcutaneously in immunodeficient mice, persisted for more than 40 days, as assessed by bioluminescence imaging in vivo. MSCs modified to express a bispecific α-carcinoembryonic antigen (αCEA)/αCD3 diabody (MSCdAb) and seeded in an sECM scaffold (therapeutic scaffolds) supported the release of functional diabody into the bloodstream at detectable levels for at least 6 weeks after implantation. Furthermore, when therapeutic scaffolds were implanted into CEA-positive human colon cancer xenograft-bearing mice and human T lymphocytes were subsequently transferred, circulating αCEA/αCD3 diabody activated T cells and promoted tumor cell lysis. Reduction of tumor growth in MSCdAb-treated mice was statistically significant compared with animals that only received MSCluc. In summary, we report here for the first time that human MSCs genetically engineered to secrete a bispecific diabody, seeded in an sECM scaffold and implanted in a location distant from the primary tumor, induce an effective antitumor response and tumor regression

Mesenchymal Stromal Cells Primed with Paclitaxel Provide a New Approach for Cancer Therapy

BACKGROUND: Mesenchymal stromal cells may represent an ideal candidate to deliver anti-cancer drugs. In a previous study, we demonstrated that exposure of mouse bone marrow derived stromal cells to Doxorubicin led them to acquire anti-proliferative potential towards co-cultured haematopoietic stem cells (HSCs). We thus hypothesized whether freshly isolated human bone marrow Mesenchymal stem cells (hMSCs) and mature murine stromal cells (SR4987 line) primed in vitro with anti-cancer drugs and then localized near cancer cells, could inhibit proliferation. METHODS AND PRINCIPAL FINDINGS: Paclitaxel (PTX) was used to prime culture of hMSCs and SR4987. Incorporation of PTX into hMSCs was studied by using FICT-labelled-PTX and analyzed by FACS and confocal microscopy. Release of PTX in culture medium by PTX primed hMSCs (hMSCsPTX) was investigated by HPLC. Culture of Endothelial cells (ECs) and aorta ring assay were used to test the anti-angiogenic activity of hMSCsPTX and PTX primed SR4987(SR4987PTX), while anti-tumor activity was tested in vitro on the proliferation of different tumor cell lines and in vivo by co-transplanting hMSCsPTX and SR4987PTX with cancer cells in mice. Nevertheless, despite a loss of cells due to chemo-induced apoptosis, both hMSCs and SR4987 were able to rapidly incorporate PTX and could slowly release PTX in the culture medium in a time dependent manner. PTX primed cells acquired a potent anti-tumor and anti-angiogenic activity in vitro that was dose dependent, and demonstrable by using their conditioned medium or by co-culture assay. Finally, hMSCsPTX and SR4987PTX co-injected with human cancer cells (DU145 and U87MG) and mouse melanoma cells (B16) in immunodeficient and in syngenic mice significantly delayed tumor takes and reduced tumor growth. CONCLUSIONS: These data demonstrate, for the first time, that without any genetic manipulation, mesenchymal stromal cells can uptake and subsequently slowly release PTX. This may lead to potential new tools to increase efficacy of cancer therapy

Nitric Oxide: Perspectives and Emerging Studies of a Well Known Cytotoxin

The free radical nitric oxide (NO•) is known to play a dual role in human physiology and pathophysiology. At low levels, NO• can protect cells; however, at higher levels, NO• is a known cytotoxin, having been implicated in tumor angiogenesis and progression. While the majority of research devoted to understanding the role of NO• in cancer has to date been tissue-specific, we herein review underlying commonalities of NO• which may well exist among tumors arising from a variety of different sites. We also discuss the role of NO• in human physiology and pathophysiology, including the very important relationship between NO• and the glutathione-transferases, a class of protective enzymes involved in cellular protection. The emerging role of NO• in three main areas of epigenetics—DNA methylation, microRNAs, and histone modifications—is then discussed. Finally, we describe the recent development of a model cell line system in which human tumor cell lines were adapted to high NO• (HNO) levels. We anticipate that these HNO cell lines will serve as a useful tool in the ongoing efforts to better understand the role of NO• in cancer

Maladie du Morbihan : une revue de la littérature/thèse présentée pour le diplôme d'État de docteur en médecine, diplôme d'État, mention DES de dermatologie et vénéréologie

Médecine (dermatologie et vénéréologie)La maladie du Morbihan est une entité décrite pour la première fois par Degos en 1957. Nous avons réalisé une revue de la littérature afin de préciser ses caractéristiques démographiques, cliniques et histologiques, d’exposer les traitements et hypothèses physiopathologiques ainsi que le cadre nosologique. Il s’agissait de 117 cas, majoritairement des hommes, d’âge moyen 54,7 ans, avec un œdème érythémateux médio facial, parfois des télangiectasies, papules ou pustules mais pas d’atteinte labiale ou comédon. Un tiers des patients avait une rosacée. L’examen histologique n’était pas spécifique. Les nombreux traitements prescrits donnaient des réponses variables. La maladie du Morbihan est un diagnostic d’élimination, dont la physiopathologie n’est pas élucidée. L’œdème solide du visage lié à l’acné survient chez des patients ayant un profil et un terrain différents. Au terme de notre travail, nous considérons la maladie du Morbihan comme un « phénotype lymphœdémateux » de la rosacéeMorbihan’s disease was first described by Degos in 1957. We performed a literature review in order to specify its demographic, clinical and histological features, to set out the treatment options and pathophysiological hypotheses, as well as the nosological framework. A total of 117 cases were reviewed, mostly men, whose average age was 54.7 years, with erythema and edema of the midface, sometimes telangiectasia, papules or pustules but no labial involvement or comedones. One third of the patients had rosacea. Histological examination was not specific. Many treatments were prescribed, with varying responses. Morbihan’s disease is a diagnosis of exclusion and its pathophysiology is not clear. Acne-related solid facial edema occurs in patients with different profiles and backgrounds. By the end of our work, we consider Morbihan’s disease as a "lymphedematous phenotype" of rosace

Nuclear localization of tetrahydrobiopterin biosynthetic enzymes

Biosynthesis of the tetrahydrobiopterin (BH4) cofactor, essential for catecholamines and serotonin production and nitric oxide synthase (NOS) activity, requires the enzymes GTP cyclohydrolase I (GTPCH), 6-pyruvoyl-tetrahydropterin synthase (PTPS), and sepiapterin reductase (SR). Upon studying the distribution of GTPCH and PTPS with polyclonal immune sera in cross sections of rat brain, prominent nuclear staining in many neurons was observed besides strong staining in peri-ventricular structures. Furthermore, localization studies in transgenic mice expressing a Pts-LacZ gene fusion containing the N-terminal 35 amino acids of PTPS revealed β-galactosidase in the nucleus of neurons. In contrast, PTPS-β-galactosidase was exclusively cytoplasmic in the convoluted kidney tubules but nuclear in other parts of the nephron, indicating again that nuclear targeting may occur only in specific cell categories. Furthermore, the N terminus of PTPS acts as a domain able to target the PTPS-β-galactosidase fusion protein to the nucleus. In transiently transfected COS-1 cells, which do not express GTPCH and PTPS endogenously, we found cytoplasmic and nuclear staining for GTPCH and PTPS. To further investigate nuclear localization of all three BH4- biosynthetic enzymes, we expressed Flag-fusion proteins in transiently transfected COS-1 cells and analyzed the distribution by immunolocalization and sub-cellular fractionation using anti-Flag antibodies and enzymatic assays. Whereas 5-10% of total GTPCH and PTPS and ∼1% of total SR were present in the nucleus, only GTPCH was confirmed to be an active enzyme in nuclear fractions. The in vitro studies together with the tissue staining corroborate specific nuclear localization of BH4-biosynthetic proteins with yet unknown biological function. © 2003 Elsevier B.V. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe