New cell delivery system CellSaic with adipose-derived stromal cells promotes functional angiogenesis in critical limb ischemia model mice.

Current therapies for patients with critical limb ischemia have not reduced amputation risk owing to poor cell engraftment. The recombinant peptide Cellnest increases the engraftment rate of administered cells by forming a complex with the cells (CellSaic). We hypothesized that CellSaic containing adipose-derived stromal cells (ADSCs) could improve lower limb blood flow better than ADSCs alone, resulting in better transplanted cell engraftment. ADSCs were extracted from 8-week-old C57BL/6N mice. Thirty-two critical limb ischemia model mice were established by ligating femoral arteries. They were divided into CellSaic (n = 11), ADSC (n = 10), saline (n = 9), and Cellnest (n = 9) groups. Blood flow rate (affected side blood flow / healthy side blood flow × 100%) was evaluated using a laser Doppler blood flow meter every week. Mice were euthanized on day 28 for histological evaluation. Compared with the ADSC group (54.5 ± 17.2%), treated side blood flow rate of the CellSaic group (78.0 ± 24.9%) showed significant improvement on day 28 after administration (p < 0.05). CD31 staining showed significantly higher number of capillary vessels in the CellSaic group (53.0 ± 8.9 cells/mm3) than in the ADSC group (43.0 ± 6.8 cells/mm3) (p < 0.05). Fluorescent staining showed significantly higher number of arterioles containing both CD31 and αSMA double-positive cells in the CellSaic group than in the ADSC group (p < 0.05). CellSaic containing ADSCs exhibited superiority to ADSC transplantation alone in promoting functional angiogenesis, suggesting its potential in improving clinical outcomes of angiogenic therapy for ischemic limbs.

Optimized creation of glioblastoma patient derived xenografts for use in preclinical studies.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common and lethal brain tumor in adults, highlighting the need for novel treatment strategies. Patient derived xenografts (PDX) represent a valuable tool to accomplish this task. METHODS: PDX were established by implanting GBM tissue subcutaneously. Engraftment success was compared between NMRI Foxn1nu and NOD/SCID as well as between fresh and cryopreserved tissue. Established PDX were analyzed histologically and molecularly. Five PDX were experimentally treated with different drugs to assess their potential for preclinical drug testing. RESULTS: Establishment of PDX was attempted for 36 consecutive GBM cases with an overall success rate of 22.2% in NMRI Foxn1nu mice. No difference was observed between fresh or cryopreserved (20-1057 days) tissue in direct comparison (n = 10 cases). Additionally, engraftment was better in NOD/SCID mice (38.8%) directly compared to NMRI Foxn1nu mice (27.7%) (n = 18 cases). Molecular data and histology of the PDX compare well to the primary GBM. The experimental treatment revealed individual differences in the sensitivity towards several clinically relevant drugs. CONCLUSIONS: The use of vitally frozen GBM tissue allows a more convenient workflow without efficiency loss. NOD/SCID mice appear to be better suited for initial engraftment of tumor tissue compared to NMRI Foxn1nu mice.

Optimal Organ for Patient-derived Xenograft Model in Pancreatic Cancer and Microenvironment that Contributes to Success.

BACKGROUND: We aimed to investigate the difference in engraftment rates depending on the transplant site for a patient-derived xenograft (PDX) of pancreatic ductal adenocarcinoma (PDAC) and the effects of the microenvironment on engraftment. MATERIALS AND METHODS: Frozen cancer tissues from PDAC tumors were used, and tumor fragments were directly implanted into the subcutaneous, orthotopic pancreas, peritoneum, and liver of X-linked severe combined immunodeficiency (XSCID) rats. We assessed the success of engraftment in each organ. Additionally, to evaluate the effect of the microenvironment in each organ, we performed immunohistochemical analysis. RESULTS: Subcutaneous transplantation was successful in 8 of 10 PDAC cases (16 of 30 rats). This was a higher rate than for other organ transplants. The vascular endothelial cells in the stroma were replaced with those from rats instead of humans. Vascular endothelial growth factor-A (VEGF-A) and cluster of differentiation-31 (CD31) was significantly more strongly expressed in the subcutaneous transplantation model (VEGF-A: p<0.001, CD31: p=0.0036). CONCLUSION: The engraftment rate was significantly higher for the subcutaneous PDX model than for the orthotopic pancreatic, peritoneal, and liver PDX models. Blood vessels of the PDX stroma had been replaced by rat-derived vessels instead of the original human vessels, suggesting that angiogenesis in the PDX microenvironment may be a major factor in engraftment.

The Essential Factors of Establishing Patient-derived Tumor Model.

Establishing an applicable preclinical model is vital for translational cancer research. Patient-derived xenograft has been important preclinical model systems and widely used for cancer research. Patient-derived xenograft models that represent the tumors of the patients are necessary to better translate research discoveries and to test potential therapeutic approaches. However, research in this field is hampered by the limited engraftment rate. In this review, we go over a large number of researches on patient-derived xenograft transplantation and firstly systematically summarize the main factors in methodology to successfully establish models. These results will be applied to the development of patient-derived xenograft leading to better preclinical research.

Correlation between Progenitor Cell Dose and the Rate of Engraftment in Autologous Peripheral Blood Stem Cell Transplantation and Allogeneic Bone Marrow Transplantation / 대한수혈학회지

BACKGROUND: Bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT) following high dose chemotherapy has been an important therapeutic option for patients with hematologic malignancies or some solid tumors. The number of progenitor cells in the collection products has been used to determine the optimum time to stop the collections and to predict the hematopoietic engraftment after transplantation. In this study, we investigated the relationship between end-product cell counts measured by different methods and the influence of the infused cell dose on the engraftment rate. METHODS: Twenty five patients receiving autologous PBSCT and 25 patients receiving allogeneic BMT were studied. The number of total nucleated cells (TNC), of mononuclear cells (MNC), of CD34+ cells, and of CFU-GM (colony-forming unit-granulocyte monocyte) colonies were measured in each collection product. The number of days required to achieve an absolute neutrophil count (ANC) of 0.5x109/L with TNC count of 1.0x109/L and platelet count of 20x109/L without transfusions was taken as an arbitrary measure of the engraftment rate. RESLUTS: A close correlation between CD34+ cells/kg and CFU-GM/kg was observed in both collection products (p<0.05). However, MNC/kg also showed significant correlations with CD34+ cells/kg and CFU-GM/kg in allogeneic bone marrow collection products (p<0.05). The CFU-GM amount in the PBSC products was greater than that in the bone marrow collection products (p<0.05). Time to engraftment was a median of 14 (range 9-50) days in autologous PBSCT group, but 29 (range 17-57) days in allogeneic BMT group. In autologous PBSCT, infused CD34+ cells/kg and CFU-GM/kg correlated significantly with ANC recovery (p<0.05). CONCLUSIONS: The number of CD34+ cells was correlated with that of CFU-GM in the collection products, and the infused cell doses showed positive relation to the engraftment rate in autologous PBSCT. These findings suggest that measurement of CD34+ cell counts alone would be a sufficient parameter to predict the engraftment rate in autologous PBSCT.