The liver is responsible for many metabolic, endocrine and exocrine functions. Approximately 2 million deaths per year are associated with liver failure. Modern 3D bioprinting technologies allied with autologous induced pluripotent stem cells (iPS)-derived grafts could represent a relevant tissue engineering approach to treat end stage liver disease patients. However, protocols that accurately recapitulates liver’s epithelial parenchyma through bioprinting are still underdeveloped. Here we evaluated the impacts of using single cell dispersion (i.e. obtained from conventional bidimensional differentiation) of iPS-derived parenchymal (i.e. hepatocyte-like cells) versus using iPS-derived hepatocyte-like cells spheroids (i.e. three-dimensional cell culture), both in combination with non-parenchymal cells (e.g. mesenchymal and endothelial cells), into final liver tissue functionality. Single cell constructs showed reduced cell survival and hepatic function and unbalanced protein/amino acid metabolism when compared to spheroid printed constructs after 18 days in culture. In addition, single cell printed constructs revealed epithelial-mesenchymal transition, resulting in rapid loss of hepatocyte phenotype. These results indicates the advantage of using spheroid-based bioprinting, contributing to improve current liver bioprinting technology towards future regenerative medicine applications and liver physiology and disease modeling.

Zika virus (ZIKV) is largely known for causing brain abnormalities due to its ability to infect neural progenitor stem cells during early development. Here, we show that ZIKV is also capable of infecting and destroying stem-like cancer cells from aggressive human embryonal tumors of the central nervous system (CNS). When evaluating the oncolytic properties of Brazilian Zika virus strain (ZIKV) against human breast, prostate, colorectal, and embryonal CNS tumor cell lines, we verified a selective infection of CNS tumor cells followed by massive tumor cell death. ZIKV was more efficient in destroying embryonal CNS tumorspheres than normal stem cell neurospheres. A single intracerebroventricular injection of ZIKV in BALB/c nude mice bearing orthotopic human embryonal CNS tumor xenografts resulted in a significantly longer survival, decreased tumor burden, fewer metastasis, and complete remission in some animals. Tumor cells closely resembling neural stem cells at the molecular level with activated Wnt signaling were more susceptible to the oncolytic effects of ZIKV Furthermore, modulation of Wnt signaling pathway significantly affected ZIKV-induced tumor cell death and viral shedding. Altogether, these preclinical findings indicate that ZIKV could be an efficient agent to treat aggressive forms of embryonal CNS tumors and could provide mechanistic insights regarding its oncolytic effects. Brazilian Zika virus strain kills aggressive metastatic forms of human CNS tumors and could be a potential oncolytic agent for cancer therapy. .

Mesenchymal stem cells (MSC) display tumor tropism and have been addressed as vehicles for delivery of anti-cancer agents. As cellular components of the tumor microenvironment, MSC also influence tumor progression. However, the contribution of MSC in brain cancer is not well understood since either oncogenic or tumor suppressor effects have been reported for these cells. Here, MSC were found capable of stimulating human Glioblastoma (GBM) cell proliferation through a paracrine effect mediated by TGFB1. Moreover, when in direct cell-cell contact with GBM cells, MSC elicited an increased proliferative and invasive tumor cell behavior under 3D conditions, as well as accelerated tumor development in nude mice, independently of paracrine TGFB1. A secretome profiling of MSC-GBM co-cultures identified 126 differentially expressed proteins and 10 proteins exclusively detected under direct cell-cell contact conditions. Most of these proteins are exosome cargos and are involved in cell motility and tissue development. These results indicate a dynamic interaction between MSC and GBM cells, favoring aggressive tumor cell traits through alternative and independent mechanisms. Overall, these findings indicate that MSC may exert pro-tumorigenic effects when in close contact with tumor cells, which must be carefully considered when employing MSC in targeted cell therapy protocols against cancer.

Duchenne muscular dystrophy (DMD) is a lethal X-linked disorder caused by null mutations in the dystrophin gene. Although the primary defect is the deficiency of muscle dystrophin, secondary events, including chronic inflammation, fibrosis, and muscle regeneration failure are thought to actively contribute to disease progression. Despite several advances, there is still no effective therapy for DMD. Therefore, the potential regenerative capacities, and immune-privileged properties of mesenchymal stromal cells (MSCs), have been the focus of intense investigation in different animal models aiming the treatment of these disorders. However, these studies have shown different outcomes according to the sources from which MSCs were obtained, which raise the question whether stem cells from distinct sources have comparable clinical effects. Here, we analyzed the protein content of the secretome of MSCs, isolated from three different sources (adipose tissue, skeletal muscle, and uterine tubes), obtained from five donors and evaluated their in vitro properties when cocultured with DMD myoblasts. All MSC lineages showed pathways enrichment related to protein metabolic process, oxidation-reduction process, cell proliferation, and regulation of apoptosis. We found that MSCs secretome proteins and their effect in vitro vary significantly according to the tissue and donors, including opposite effects in apoptosis assay, indicating the importance of characterizing MSC secretome profile before its use in animal and clinical trials. Despite the individual differences a pool of conditioned media from all MSCs lineages was able to delay apoptosis and enhance migration when in contact with DMD myoblasts.