Reactive astrocytes potentiate tumor aggressiveness in a murine glioma resection and recurrence model

Surgical resection is a universal component of glioma therapy. Little is known about the postoperative microenvironment due to limited preclinical models. Thus, we sought to develop a glioma resection and recurrence model in syngeneic immune-competent mice to understand how surgical resection influences tumor biology and the local microenvironment

Engineered 3D bioimplants using elastomeric scaffold, self-assembling peptide hydrogel, and adipose tissue-derived progenitor cells for cardiac regeneration

[EN] Contractile restoration of myocardial scars remains a challenge with important clinical implications. Here, a combination of porous elastomeric membrane, peptide hydrogel, and subcutaneous adipose tissue-derived progenitor cells (subATDPCs) was designed and evaluated as a bioimplant for cardiac regeneration in a mouse model of myocardial infarction. SubATDPCs were doubly transduced with lentiviral vectors to express bioluminescent-fluorescent reporters driven by constitutively active, cardiac tissue-specific promoters. Cells were seeded into an engineered bioimplant consisting of a scaffold (polycaprolactone methacryloyloxyethyl ester) filled with a peptide hydrogel (PuraMatrix(TM)), and transplanted to cover injured myocardium. Bioluminescence and fluorescence quantifications showed de novo and progressive increases in promoter expression in bioactive implant-treated animals. The bioactive implant was well adapted to the heart, and fully functional vessels traversed the myocardium-bioactive implant interface. Treatment translated into a detectable positive effect on cardiac function, as revealed by echocardiography. Thus, this novel implant is a promising construct for supporting myocardial regeneration.The research leading to these results received funding from the European Union Seventh Framework Programme (Project RECATABI, 7FP/2007-2013) under grant agreement number 229239. This work was also supported by Ministerio de Ciencia e Innovación (SAF2011- 30067-C02-01), Fundació La Marató de TV3 (080330), Red de Terapia Celular-TerCel (RD12/0019/0029), Red Cardio-vascular (RD12/0042/0047), Sociedad Española de Cardiología, and Fundació Privada Daniel Bravo AndreuSoler-Botija, C.; Bago, JR.; Llucia-Valldeperas, A.; Vallés Lluch, A.; Castells-Sala, C.; Martinez-Ramos, C.; Fernandez-Muinos, T.... (2014). Engineered 3D bioimplants using elastomeric scaffold, self-assembling peptide hydrogel, and adipose tissue-derived progenitor cells for cardiac regeneration. American Journal of Translational Research. 6:291-301. http://hdl.handle.net/10251/63949S291301

Intercellular Mitochondrial Transfer in the Tumor Microenvironment

Cell-to-cell communication is a fundamental process in every multicellular organism. In addition to membrane-bound and released factors, the sharing of cytosolic components represents a new, poorly explored signaling route. An extraordinary example of this communication channel is the direct transport of mitochondria between cells. In this review, we discuss how intercellular mitochondrial transfer can be used by cancer cells to sustain their high metabolic requirements and promote drug resistance and describe relevant molecular players in the context of current and future cancer therapy

Intercellular Mitochondrial Transfer in the Tumor Microenvironment

Cell-to-cell communication is a fundamental process in every multicellular organism. In addition to membrane-bound and released factors, the sharing of cytosolic components represents a new, poorly explored signaling route. An extraordinary example of this communication channel is the direct transport of mitochondria between cells. In this review, we discuss how intercellular mitochondrial transfer can be used by cancer cells to sustain their high metabolic requirements and promote drug resistance and describe relevant molecular players in the context of current and future cancer therapy

Fibrin matrices enhance the transplant and efficacy of cytotoxic stem cell therapy for post-surgical cancer

Tumor-homing cytotoxic stem cell (SC) therapy is a promising new approach for treating the incurable brain cancer glioblastoma (GBM). However, problems of retaining cytotoxic SCs within the post-surgical GBM resection cavity are likely to significantly limit the clinical utility of this strategy. Here, we describe a new fibrin-based transplant approach capable of increasing cytotoxic SC retention and persistence within the resection cavity, yet remaining permissive to tumoritropic migration. This fibrin-based transplant can effectively treat both solid and post-surgical human GBM in mice. Using our murine model of image-guided model of GBM resection, we discovered that suspending human mesenchymal stem cells (hMSCS) in a fibrin matrix increased initial retention in the surgical resection cavity 2-fold and prolonged persistence in the cavity 3-fold compared to conventional delivery strategies. Time-lapse motion analysis revealed that cytotoxic hMSCs in the fibrin matrix remain tumoritropic, rapidly migrating from the fibrin matrix to co-localize with cultured human GBM cells. We encapsulated hMSCs releasing the cytotoxic agent TRAIL (hMSC-sTR) in fibrin, and found hMSC-sTR/fibrin therapy reduced the viability of multiple 3-D human GBM spheroids and regressed established human GBM xenografts 3-fold in 11 days. Mimicking clinical therapy of surgically resected GBM, intra-cavity seeding of therapeutic hMSC-sTR encapsulated in fibrin reduced post-surgical GBM volumes 6-fold, increased time to recurrence 4-fold, and prolonged median survival from 15 to 36 days compared to control-treated animals. Fibrin-based SC therapy could represent a clinically compatible, viable treatment to suppress recurrence of post-surgical GBM and other lethal cancer types

Intra-cavity stem cell therapy inhibits tumor progression in a novel murine model of medulloblastoma surgical resection

<div><p>Background</p><p>Cytotoxic neural stem cells (NSCs) have emerged as a promising treatment for Medulloblastoma (MB), the most common malignant primary pediatric brain tumor. The lack of accurate pre-clinical models incorporating surgical resection and tumor recurrence limits advancement in post-surgical MB treatments. Using cell lines from two of the 5 distinct MB molecular sub-groups, in this study, we developed an image-guided mouse model of MB surgical resection and investigate intra-cavity NSC therapy for post-operative MB.</p><p>Methods</p><p>Using D283 and Daoy human MB cells engineered to express multi-modality optical reporters, we created the first image-guided resection model of orthotopic MB. Brain-derived NSCs and novel induced NSCs (iNSCs) generated from pediatric skin were engineered to express the pro-drug/enzyme therapy thymidine kinase/ganciclovir, seeded into the post-operative cavity, and used to investigate intra-cavity therapy for post-surgical MB.</p><p>Results</p><p>We found that surgery reduced MB volumes by 92%, and the rate of post-operative MB regrowth increased 3-fold compared to pre-resection growth. Real-time imaging showed NSCs rapidly homed to MB, migrating 1.6-fold faster and 2-fold farther in the presence of tumors, and co-localized with MB present in the contra-lateral hemisphere. Seeding of cytotoxic NSCs into the post-operative surgical cavity decreased MB volumes 15-fold and extended median survival 133%. As an initial step towards novel autologous therapy in human MB patients, we found skin-derived iNSCs homed to MB cells, while intra-cavity iNSC therapy suppressed post-surgical tumor growth and prolonged survival of MB-bearing mice by 123%.</p><p>Conclusions</p><p>We report a novel image-guided model of MB resection/recurrence and provide new evidence of cytotoxic NSCs/iNSCs delivered into the surgical cavity effectively target residual MB foci.</p></div

Daoy human MB cells engineered to express GFP and firefly luciferase form orthotopic xenografts in vivo.

<p>Cultured Daoy human MB cells transduced with lentiviral vectors encoding GFP-FLuc (Daoy-GFPFL) express GFP and luciferase in vitro as determined by white light (A, B) and fluorescence imaging (C, D). Daoy-GFPFL cell number showed linear correlation with Fluc activity (R² = 0.978, P = 0.001, E). Daoy-GFPFL xenografts showed exponential growth with a doubling time of 5.6 days <i>in vivo</i> measured by bioluminescence imaging. Representative bioluminescence images are shown for days 14, 24 and 42 after injection of Daoy-GFPFL cells (F). Representative hematoxylin and eosin staining (G-J) of brain sections show large intra-cerebellar tumors 63 days after injection of Daoy-GFPFL cells. Tumors showed histopathological features of MB, including frequent cell wrapping (white arrowheads) and heightened level of mitosis (black arrowheads). Original magnifications: 15X (G), 40X (A, C), 100X (B, D), 200X (H), 400X (I), 600X (J). Scale bars, 100 μm (A-D) and 200 μm (G-J). n = 5.</p

NSCs migrate towards human MB in vitro and in vivo.

<p>Migration of NSC-mcF cells (red) the presence (+Daoy) or absence (control) of MB cells (Daoy-GFPFL cells, green) was monitored over 24h (A). Time-lapse images were captured every 20 mins and used to construct single cell tracings (B). Quantitative analysis of single cell tracings demonstrated the presence of Daoy-GFPFL increases the migratory velocity of NSCs (1.61-fold; ****P<0.0001, C), and euclidean distance traveled (1.8-fold; P<0.0001, D). Illustration of NSC and Daoy-GFPFL cells implanted in opposite cerebellar hemispheres (E). Fluorescent images (F-H) 21 days after stem cell implantation shows NSCs co-localize with Daoy-GFPFL tumor cells. Original magnifications: 100X (A, B,), 200X (F, G). n = 4 in panel E.</p

Cytotoxic human pediatric stem cells derived from patient skin suppress and delay regrowth of post-surgical medulloblastoma.

<p>Illustration of the reprogramming scheme which converts human pediatric fibroblasts into cytotoxic human pediatric induced neural stem cells (hp-iNSC^tk, A). hp-iNSC express the thymidine kinase/RFP lentiviral vector as determined by white light (B) and fluorescent (C) images. Schematic depiction of hp-iNSC^tk migration assay in the presence (+D283) or absence (control) of MB cells (D). The cells were seeded 500 μm apart from each other and migration was tracked over the course of 24h by fluorescent and white light imaging (E). Summary graph shows hp-iNSC^tk cells migrate further in the presence D283-GFPFL cells than in the absence of these cells (3.3-fold, P < 0001, F). D283-GFPFL cells were seeded with varying concentrations of hp-iNSC^tk and tumor cell viability was measured by luminescence 24h after GCV administration (G). Representative BLI images (H) and summary graph (I) showing the <i>in vivo</i> therapeutic efficacy of cytotoxic NSC therapy (hp-iNSC^tk/GCV) compared to control (hp-iNSC^tk). hp-iNSC^tk/GCV treatment extended survival of mice compared to the control hp-iNSC^tk (53 vs 43 days) (J). Post-mortem histopathological analysis showed the presence of larger recurrent tumors in control mice (K) compared with treatment (L) groups. RC and T denotes resection cavity and tumor, respectively. Original magnification: 100X (B, C, E, K, L). Scale bars = 100 μm. n = 5–6 in each group.</p