Impact of Extracellular Vesicle Isolation Methods on Downstream Mirna Analysis in Semen: A Comparative Study

Seminal plasma (SP) contains a unique concentration of miRNA, mostly contained in small extracellular vesicles (sEVs) such as exosomes, some of which could be clinically useful for diagnosis and/or prognosis of urogenital diseases such as prostate cancer (PCa). We optimized several exosome-EV isolation technologies for their use in semen, evaluating EV purifying effectiveness and impact on the downstream analysis of miRNAs against results from the standard ultracentrifugation (UC) method to implement the use of SP sEV_miRNAs as noninvasive biomarkers for PCa. Our results evidenced that commercial kits designed to isolate exosomes/EVs from blood or urine are mostly applicable to SP, but showed quantitative and qualitative variability between them. ExoGAG 3500× g and the miRCURY Cell/Urine/CSF 1500× g methods resulted as equivalent alternative procedures to UC for isolating exosomes/sEVs from semen for nanoparticle characteristics and quality of RNA contained in vesicles. Additionally, the expression profile of the altered semen sEV-miRNAs in PCa varies depending on the EV isolation method applied. This is possibly due to different extraction techniques yielding different proportions of sEV subtypes. This is evidence that the exosome-EV isolation method has a significant impact on the analysis of the miRNAs contained within, with important consequences for their use as clinical biomarkers. Therefore, miRNA analysis results for EVs cannot be directly extrapolated between different EV isolation methods until clear markers for delineation between microvesicles and exosomes are established. However, EV extraction methodology affects combined models (semen exosome miRNA signatures plus blood Prostate specific antigen (PSA) concentration for PCa diagnosis) less; specifically our previously described (miR-142-3p + miR-142-5p + miR-223-3p + PSA) model functions as molecular marker from EVs from any of the three isolation methods, potentially improving the efficiency of PSA PCa diagnosis.

Biomimetic device and foreign body reaction cooperate for efficient tumour cell capture in murine advanced ovarian cancer

Metastasis is facilitated by the formation of pre-metastatic niches through the remodelling of the extracellular matrix (ECM) promoted by haematopoietic and stromal cells. The impact of these primed sites is pronounced for intraperitoneal metastases, where the cavity-exposed ECM supports the attachment of the disseminating tumour cells. Likewise, implantation of biomaterial scaffolds influences metastatic progression systemically through a foreign body reaction (FBR). In this study, we integrated the concept of creating an artificial niche to capture tumour cells actively disseminating in the peritoneal cavity with a therapeutic strategy modulating the interactions of metastatic cells with the ECM. The aim was to transform a disseminated disease into a focal disease. For this, we designed and developed a 'biomimetic' ECM composed of a nonresorbable three-dimensional scaffold with collagen coating and characterized the FBR to the implanted biomaterial. We also analysed the safety of the implanted devices and their ability to capture tumour cells in different murine preclinical models of advanced ovarian cancer. Implantation of the biomimetic devices resulted in an initial inflammatory reaction that transformed progressively into a fibrous connective tissue response. The adhesive capabilities of the scaffold were improved with the ancillary effect of the FBR and showed clinical utility in terms of the efficacy of capture of tumour cells, disease focalization and survival benefit. These results demonstrated the performance and safety of this 'biomimetic' ECM in preclinical models of advanced ovarian cancer. Translated into the clinical setting, this new therapeutic strategy represents the possibility for control of peritoneal carcinomatosis upon primary ovarian debulking surgery and to expand the percentage of patients who are candidates for second rescue surgeries at the time of relapse.

CD105+-mesenchymal stem cells migrate into osteoarthritis joint: An animal model

Mesenchymal stem cells are being the focus of connective tissue technology and regenerative medicine, presenting a good choice cell source for improving old and well recognized techniques of cartilage defect repair. For instance, the autologous chondrocyte transplantation using new concepts of regenerative medicine. The present study investigated the risk of xenogenicity of human synovial membrane-derived MSCs, injected into the monkeys using intravenous and intra-articular administration. The animal models used were adult monkeys Rhesus which had been injured into the left knee to create an Osteoarthritis (OA) animal model. CD105+-MSCs were injected twice into the OA monkeys with an interval of one week between them. The animals were euthanized one month after treatment. Immunohistochemistry analysis of different organs: spleen, heart, fat, liver, gut, pancreas, lung, skeletal muscle and kidney from the animals revealed that CD105+-MSCs migrated towards the injured knee joint. MSCs naive were found statistically significant increased in the injured knee in front of healthy one. CD105+-MSCs were negatives for CD68 and the area where CD105+-MSCs were found presented SDF-1 increased levels in front of healthy knee. We concluded that a characterized MSCs subset could be a safe alternative for cell therapy in clearly localized pathologies.

M-Trap: Exosome-Based Capture of Tumor Cells as a New Technology in Peritoneal Metastasis

BACKGROUND

Remodeling targeted tissues for reception of tumor cells metastasizing from primary lesions is a consequence of communication between the tumor and the environment that governs metastasis. This study describes a novel approach that aims to disrupt the process of metastasis by interfering with this intense dialogue.

METHODS

Proteomics and adhesion assays identified exosomes purified from the ascitic fluid of ovarian cancer patients (n = 9) as intermediaries of tumor cell attachment. A novel tumor cell capture device was fabricated by embedding exosomes onto a 3D scaffold (metastatic trap [M-Trap]). Murine models of ovarian metastasis (n = 3 to 34 mice per group) were used to demonstrate the efficacy of M-Trap to capture metastatic cells disseminating in the peritoneal cavity. Kaplan-Meier survival curves were used to estimate cumulative survival probabilities. All statistical tests were two-sided.

RESULTS

The exosome-based M-Trap device promoted tumor cell adhesion with a nonpharmacological mode of action. M-Trap served as a preferential site for metastasis formation and completely remodeled the pattern of peritoneal metastasis in clinically relevant models of ovarian cancer. Most importantly, M-Trap demonstrated a statistically significant benefit in survival outcomes, with mean survival increasing from 117.5 to 198.8 days in the presence of M-Trap; removal of the device upon tumor cell capture further improved survival to a mean of 309.4 days (P < .001).

CONCLUSIONS

A potent artificial premetastatic niche based on exosomes is an effective approach to impair the crosstalk between metastatic cells and their environment. In the clinical setting, the capacity to modulate the pattern of dissemination represents an opportunity to control the process of metastasis. In summary, M-Trap transforms a systemic, fatal disease into a focalized disease where proven therapeutic approaches such as surgery can extend survival.

Influence of flap prefabrication on seeding of subcutaneously injected mesenchymal stem cells in microvascular beds in rats

BACKGROUND

In this article, the authors investigated whether the prefabrication of an autologous pedicled flap by isolation from the surrounding with artificial skin substitutes would increase mesenchymal stem cell (MSC) seeding.

METHODS

Mesenchymal stem cells were isolated from human umbilical cords and were cultured and characterized by fluorescence-activated cell sorting. Oxacarbocyanine and its green fluorescence emission were used to label the MSCs population.Sixteen adult Wistar rats were randomized in 4 groups (n = 4 animals per group). In group 1, a prefabricated groin flap (GF) with skin substitutes was harvested without cell injection; in group 2, 1 million MSCs were injected subcutaneously in the area corresponding to the GF without flap harvesting; in Group 3, a prefabricated GF with skin substitutes was harvested and 1 million MSCs were injected subcutaneously; and in Group 4, a prefabricated GF with skin substitutes was harvested and 2 million MSCs were injected subcutaneously. All procedures were performed bilaterally in each animal. Animals were sacrificed 2 weeks after the surgery. Flap viability was then assessed by clinical inspection and histology, and seeding of MSCs was observed.

RESULTS

All flaps survived 2 weeks after the surgery. Oxacarbocyanine-labeled cells were found in all prefabricated flaps injected (Groups 3 and 4) in higher number in comparison with the group where subcutaneous injection without flap harvesting was performed (Group 2). This difference was statistically significant (P < 0.05).

CONCLUSIONS

Prefabricated skin flaps with skin substitutes may provide a useful vehicle for the implantation of MSCs to serve as an autologous microvascular bioscaffold.