Mouse islets are commonly used in diabetes-related studies. Adequate amounts of good quality islets are prerequisites for a reliable investigation. We describe a protocol for islet isolation from mouse pancreas. Three major manipulations are employed in the islet isolation procedure: in situ pancreas perfusion with collagenase, pancreas digestion and islet purification. The whole procedure takes 30-45 min for each individual mouse. By using this protocol, a reasonable number of islets can be obtained in a relatively short period of time. This protocol has been proven to be practicable and reproducible. It can be easily followed by individuals who do not have previous experience in the related research field.

The main challenges for programmed cell death 1(PD-1)/PD-1 ligand (PD-L1) checkpoint blockade lie in a lack of sufficient T cell infiltration, tumor immunosuppressive microenvironment, and the inadequate tumor accumulation and penetration of anti-PD-1/PD-L1 antibody. Resetting tumor-associated macrophages (TAMs) is a promising strategy to enhance T-cell antitumor immunity and ameliorate tumor immunosuppression. Here, mannose-modified macrophage-derived microparticles (Man-MPs) loading metformin (Met@Man-MPs) are developed to efficiently target to M2-like TAMs to repolarize into M1-like phenotype. Met@Man-MPs-reset TAMs remodel the tumor immune microenvironment by increasing the recruitment of CD8+ T cells into tumor tissues and decreasing immunosuppressive infiltration of myeloid-derived suppressor cells and regulatory T cells. More importantly, the collagen-degrading capacity of Man-MPs contributes to the infiltration of CD8+ T cells into tumor interiors and enhances tumor accumulation and penetration of anti-PD-1 antibody. These unique features of Met@Man-MPs contribute to boost anti-PD-1 antibody therapy, improving anticancer efficacy and long-term memory immunity after combination treatment. Our results support Met@Man-MPs as a potential drug to improve tumor resistance to anti-PD-1 therapy.

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Safety and reliability of transgene integration in human genome continue to pose challenges for stem cell-based gene therapy. Here, we report a baculovirus-transcription activator-like effector nuclease system for AAVS1 locus-directed homologous recombination in human induced pluripotent stem cells (iPSCs). This viral system, when optimized in human U87 cells, provided a targeted integration efficiency of 95.21% in incorporating a Neo-eGFP cassette and was able to mediate integration of DNA insert up to 13.5 kb. In iPSCs, targeted integration with persistent transgene expression was achieved without compromising genomic stability. The modified iPSCs continued to express stem cell pluripotency markers and maintained the ability to differentiate into three germ lineages in derived embryoid bodies. Using a baculovirus-Cre/LoxP system in the iPSCs, the Neo-eGFP cassette at the AAVS1 locus could be replaced by a Hygro-mCherry cassette, demonstrating the feasibility of cassette exchange. Moreover, as assessed by measuring γ-H2AX expression levels, genome toxicity associated with chromosomal double-strand breaks was not detectable after transduction with moderate doses of baculoviral vectors expressing transcription activator-like effector nucleases. Given high targeted integration efficiency, flexibility in transgene exchange and low genome toxicity, our baculoviral transduction-based approach offers great potential and attractive option for precise genetic manipulation in human pluripotent stem cells.

Background: Hepatocyte growth factor (HGF) and its receptor play an important role in the formation and progression of glioma and can promote tumor proliferation. In this study, we investigated the ability of HGF to promote the proliferation and invasion of U251n cells; we also tested the effects of HGF on stromal cell-derived factor 1 (SDF1) and CXCR4 mRNA expression. Methods: We measured the effect of HGF on the proliferation of U251n cells using enzyme-linked immunosorbent assays (ELISAs) to detect incorporated bromodeoxyuridine (BrdU) as a marker of DNA synthesis. The effects of HGF and SDF-1 on U251n cell invasion and proliferation were measured using the inhibitors K252a to c-Met and AMD3100 to CXCR4. SDF-1 and CXCR4 mRNA and protein expression were measured using quantitative polymerase chain reaction (PCR) and fluorescence-activated cell sorter (FACS) analysis. Small interfering (si)RNAs were also used to down-regulate HGF and c-Met expression in U251n cells. Results: HGF significantly increased U251n cell proliferation and invasion in a dose-dependent manner; K252a blocked this. AMD3100 blocked invasion but not proliferation. CXCR4 and SDF-1 mRNAs were up-regulated when cells were treated with HGF. CXCR4 and SDF-1 mRNA levels and HGF and c-Met protein levels were down-regulated after cells were transfected with siRNAs. Conclusions: HGF has a direct effect on glioma cell proliferation and invasion. HGF up-regulates SDF-1 and CXCR4 mRNA expression and contributes to cell invasion.

This study reports the successful reprogramming of human fibroblasts into a state of pluripotency by baculoviral transduction‐mediated, site‐specific integration of OKSM transcription factor genes into the AAVS1 locus in human chromosome 19. Methods based on site‐specific integration of reprogramming factor genes as reported here hold the potential for efficient generation of genetically amenable induced pluripotent stem cells suitable for future gene therapy applications.

Hepatocyte growth factor (HGF) has been shown to be overexpressed in gliomas, and high-grade gliomas (glioblastoma multiforme) express more HGF than lower-grade astrocytoma, and HGF enhances their resistance to radiotherapy. To examine the effect of serum HGF levels on the likelihood of response to radiotherapy and the disease-free survival in patients with glioma, the blood samples of the patients were collected before commencing treatment and serum HGF was measured by quantitative ELISA in 48 patients with glioma grade I-IV, and all patients underwent primary conventionally fractionated radiotherapy. For statistical analysis, SPSS Version 13.0 software was used. Thirty-eight of the 48 patients had a response to treatment, and ten patients had persistent disease at 3 months. Overall, the median serum HGF level was 1,219.5 pg/ml (range 650.4-2,264.7 pg/ml). Eight patients with local failure had HGF levels >1,219.5 pg/ml, and 28 patients with response had serum HGF level of ≤ 1,219.5 pg/ml (P = 0.01). The median time to progression was 6 months in patients with HGF level of >1,219.5 pg/ml compared with 17 months in patients with HGF level of ≤ 1,219.5 pg/ml (log-rank, P = 0.041). In multivariate analysis, serum HGF, the KPS, tumour size and pathological grade, but not the patient's age, gender and oligodendroglial component influenced the progression-free survival. Elevated pre-therapeutic serum HGF levels are associated with poor response and a shorter time to progression in patients with glioma undergoing primary radiotherapy.

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