Features and impacts on the prognosis of gene mutations in patients with acute myeloid leukemia.

To explore features and impacts on the prognosis of common gene mutations in acute myeloid leukemia (AML), we assessed mutation status as well as variant allele frequency (VAF) of 24 genes in 81 AML patients by next-generation sequencing (NGS) technology. Eighty-six percentages of patients showed at least one mutation. Mutation in BCOR was associated with lower complete remission (CR) rate, whereas double mutation in CEBPA was associated with a favorable odds ratio for CR achievement. TP53 mutation was associated with inferior overall survival (OS) in univariate analysis. Multivariate analysis confirmed the negative effect of adverse cytogenetic abnormalities on survival. Mutation in RUNX1 and ZRSR2 had negative impacts on OS in patients with wild-type TP53. VAF of SRSF2 mutation was observed negatively correlated with OS. In conclusion, our study suggested that mutations in BCOR and spliceosomes might predict worse outcomes, and VAF of gene mutations may play a crucial role in outcomes of AML patients.

Elastin-Derived VGVAPG Fragment Decorated Cell-Penetrating Peptide with Improved Gene Delivery Efficacy.

Cell-penetrating peptides (CPPs) are attractive non-viral gene delivery vectors due to their high transfection capacity and safety. Previously, we have shown that cell-penetrating peptide RALA can be a promising gene delivery vector for chronic wound regeneration application. In this study, we engineered a novel peptide called RALA-E by introducing elastin-derived VGVAPG fragment into RALA, in order to target the elastin-binding protein on the cell surface and thus improve delivery efficacy of RALA. The transfection efficiency of RALA-E was evaluated by transfecting the HEK-293T and HeLa cell lines cells with RALA-E/pDNA complexes and the flow-cytometry results showed that RALA-E significantly increased the transfection efficiency by nearly 20% in both cell lines compared to RALA. Inhibition of pDNA transfection on HEK-293T cells via chlorpromazine, genistein and mßCD showed that the inhibition extent in transfection efficiency was much less for RALA-E group compared to RALA group. In addition, RALA-E/miR-146a complexes showed up to 90% uptake efficiency in macrophages, and can escape from the endosome and enter the nucleus to inhibit the expression of inflammation genes. Therefore, the developed RALA-E peptide has high potential as a safe and efficient vector for gene therapy application.

UNC13B Promote Arsenic Trioxide Resistance in Chronic Lymphoid Leukemia Through Mitochondria Quality Control.

In clinical practice, arsenic trioxide can be used to treat a subset of R/R CML patients, but resistance tends to reappear quickly. We designed an experiment to study arsenic trioxide resistance in K-562 cells. Previously, we identified the UNC13B gene as potentially responsible for arsenic trioxide resistance in K-562 cells via gene chip screening followed by high-content screening. We aimed to investigate the role and mechanism of the UNC13B gene in K-562 cells, an arsenic trioxide-resistant chronic myeloid leukemia cell line. In vitro lentiviral vector-mediated UNC13B siRNA transfection was performed on K-562 cells. The roles of UNC13B in cell proliferation, apoptosis and cell cycle pathways, and colony formation were analyzed by CCK-8 assay, fluorescence-activated cell sorting, and soft agar culture, respectively. Gene chip screening was used to define the possible downstream pathways of UNC13B. Western blot was performed to further validate the possible genes mediated by UNC13B for arsenic trioxide resistance in patients with chronic myeloid leukemia. UNC13B downregulation significantly inhibited growth, promoted apoptosis, decreased colony formation, reduced the duration of the G1 phase, and increased the duration of the S phase of K-562 cells. Western blot results confirmed that UNC13B may modulate the apoptosis and proliferation of arsenic trioxide-resistant chronic myeloid leukemia cells through the mediation of MAP3K7, CDK4, and PINK1. UNC13B is a potential therapeutic target for patients with arsenic trioxide-resistant chronic myeloid leukemia.

Prevention of acute graft-vs.-host disease by targeting glycolysis and mTOR pathways in activated T cells.

Graft-versus-host disease (GvHD) is a common life-threatening complication that can occur following allogeneic hematopoietic stem cell transplantation. This occurs if donor T cells recognize the host as foreign. During acute GvHD (aGVHD), activated T cells utilize glycolysis as the main source of energy generation. Therefore, inhibition of T cell glycolysis is a potential treatment strategy for aGVHD. In the present study, the effects of the combination of the glycolysis inhibitor 3-bromopyruvate (3-BrPA) and the mTOR inhibitor rapamycin (RAPA) on a mode of aGVHD were explored. In vitro mixed lymphocyte culture model was established by using splenocytes from C57BL/6 (H-2b) mice as responder and inactivated splenocytes from BALB/c (H-2d) mice as stimulator. In this model, 3-BrPA treatment (0-100 µmol/l) was found to suppress cell viability, increase cell apoptosis and reduce IFN-γ secretion, in a concentration-dependent manner. 3-BrPA treatment (0-100 µmol/l) was found to suppress cell viability, increase cell apoptosis and reduce IFN-γ secretion, in a concentration-dependent manner. In addition, combined treatment with 3-BrPA (0-100 µmol/l) alongside RAPA (20 µmol/l) exhibited synergistic effects on inhibiting cell viability and IFN-γ production, compared with those following either treatment alone. An aGVHD model was established by injection of bone marrow cells and spleen cells from the donor-C57BL/6(H-2b) mice to the receptor-BALB/c(H-2d) mice which were underwent total body irradiation first. In the aGVHD model, 3-BrPA (10 mg/kg/day), RAPA (2.5 and 5 mg/kg/day) and both in combination (5 and 2.5 mg/kg/day for 3-BrPA and RAPA, respectively) were all found to alleviate the damage caused by aGVHD, in addition to prolonging the survival time of mice with acute GvHD. In particular, the combined 3-BrPA and RAPA treatment resulted in the highest median survival time among all groups tested. In addition, the effects induced by combined 3-BrPA and RAPA treatment were found to be comparable to those in the 5 mg/kg/day RAPA group but superior to the 3-BrPA group with regards to the cumulative survival profile, GvHD score and lung histological score. The 3-BrPA and RAPA combination group also exhibited the lowest IFN-γ levels among all groups. Therefore, the combination of inhibiting both glycolysis and mTOR activity is a promising strategy for acute GvHD prevention.

In-situ formed elastin-based hydrogels enhance wound healing via promoting innate immune cells recruitment and angiogenesis.

Harnessing the inflammation and angiogenesis is extremely important in wound healing. In this study, we developed bioactive elastin-based hydrogels which can recruit and modulate the innate immune cells and accelerate angiogenesis in the wound site and subsequently improve wound regeneration. These hydrogels were formed by visible-light cross-linking of acryloyl-(polyethylene glycol)-N-hydroxysuccinimide ester modified elastin with methacrylated gelatin, in order to mimic dermal microenvironment. These hydrogels showed highly tunable mechanical properties, swelling ratios and enzymatic degradation profiles, with moduli within the range of human skin. To mimic the in vivo degradation of the elastin by elastase from neutrophils, in vitro co-culture of the hydrogels and neutrophils was conducted. The derived conditioned medium containing elastin derived peptides (EDP-conditioned medium) promoted the expression of both M1 and M2 markers in M1 macrophages in vitro. Additionally, the EDP-conditioned medium induced superior tube formation of endothelia cells in Matrigel. In mice wound model, these elastin-based hydrogels attracted abundant neutrophils and predominant M2 macrophages to the wound and supported their infiltration into the hydrogels. The outstanding immunomodulatory effect of the elastin-based hydrogels resulted in superior angiogenesis, collagen deposition and dermal regeneration. Hence, these elastin-based hydrogels can be a promising regenerative platform to accelerate wound repair.

[Establishment of a Xenografted Acute Myeloid Leukemia Model by using Zebrafish].

Objectve: To investigate the feasibility of establishing xenografted leukemia model by zebrafish, so as to provide the more direct model in vitro and experimental evidence for study of acute myeloid leukemia and screening of the drugs for targeting therapy. METHODS: Acute myeloid leukemia cell line KG-1a was labeled with red fluorescent dye-MitoRed, then the labeled cells were injected into the yolk sac of zebrafish embryos. Morphological observation, cell count and histopathological detection were used to analyse the infiltration and metastasis of KG-1a cells in zebrafish. RESULTS: KG1a cells could proliferate and gradually spread to the entire abdominal cavity of the zebrafish after KG-1a cells were injected into the yolk sac during 1-7, the results of cell counting in vitro also proved a significant proliferation of KG-1a cells in zebrafish, suggesting that the implanted leukemia stem cells could survive, proliferate and spread in zebrafish. Further study showed that the implanted cells could be transfered to the liver of zebrafish, these cells displayed the signature of KG-1a cells by hematoxylin-eosin(HE) staining. CONCLUSIONS: Human acute myeloid leukemia cells KG1a can survive, proliferate and migrate in zebrafish, suggesting xenografted leukemia model of zebrafish has been successfully established. This model may be benefitcial for the study of acute myeloid leukemia and the screening of the drugs for targeting therapy of acute myeloid leukemia.

[Synergistic Killing Effects of Arsenic Trioxide Combined with Itraconazole on KG1a Cells].

OBJECTIVE: To explore the effect of arsenic trioxide combined with itraconazole on proliferation and apoptosis of KG1a cells and its potential mechanism. METHODS: The cell morphology was observed with Wrighe-Giemsa staining; cell survival rate was examined by CCK-8; and colony formation capacity was measured by methylcellulose colony formation test; the flow cytometry was used to analyse the cell apoptosis rate and cell cycle; the protein expressions of BCL-2,caspase-3,BAX,SMO,Gli1 and Gli2 were detected by Western-blot. RESULTS: The arsenic trioxide and itraconazole alone both could inhibit the KG1a cell proliferation in dose-and time-dependent manner. In comparison between single and combined drug-treatment group, both the cell survival rate and the colony number of the single drug-treatment group were significantly lower(P<0.05), and the apoptosis rate was higher in the combined drug-treatment group. In the combined-treatment group, the protein expression of Caspase-3 and BAX was upregulated, while the protein expression of BCL-2,SMO,Gli1 and Gli2 was downregulated. CONCLUSION: Arsenic trioxide combined with itraconazole can inhibit the KG1a cell proliferation and induce apoptosis, which may be related with the inhibition of Hh signaling pathway and upregulation of both Caspase-3 and BAX protein expression, and provided experimental data of arsenic trioxide combined with itraconazole for the treatment of refractory AML.

[Honokiol combined with Gemcitabine synergistically inhibits the proliferation of human Burkitt lymphoma cells and induces their apoptosis].

This study was aimed to investigate the effect of Honokiol (HNK) combined with Gemcitabine (GEM) on the proliferation and apoptosis of human Burkitt lymphoma Raji cells. Cell proliferation was detected by CCK-8 method to study the role of Honokiol and Gemcitabine in Raji cells. The cell apoptosis and cell cycle status were analyzed by flow cytometry. The level of apoptosis-related protein BCL-2 was measured with Western blot. The results showed that compared with cells treated with mentioned above drugs alone, the proliferative potential of cells in combination group was significantly inhibited (P < 0.01) and the inhibition rate was related to the concentration and action time of HNK; and apoptosis rate markedly increased (P < 0.01), while most Raji cells were arrested at G0/G1 phase and decreased in S phase after treatment with combination of two drugs; the expression of BCL-2 protein decreased (P < 0.01). It is concluded that Honokiol combined Gemcitabine can synergistically inhibit the proliferation, induce cell apoptosis, and down-regulate the expression of BCL-2 in Raji cells. The possible mechanism of synergistic effect may be related with arrest of cell cycle at G0/G1 phase and downregulation of the expression of BCL-2.

γ-secretase inhibitor-I enhances radiosensitivity of glioblastoma cell lines by depleting CD133+ tumor cells.

BACKGROUND AND AIMS: Glioblastoma is a deadly primary brain tumor with great resistance to radiotherapy. To reverse its radioresistance is important for improving prognosis. Gamma-secretase inhibitors (GSI) have been proven to have anti-tumor effects, yet the knowledge of their influences on glioblastomas is still limited. METHODS: The cytotoxic effects of GSI-I (a tripeptide GSI) on glioblastoma cell lines U87 and U251 were assessed by MTT assay, and the low concentration that did not induce significant cell death was determined. The in vitro radiosensitization effects of this low concentration of GSI-I were evaluated by cell colony forming assays. The CD133+ cell fractions before and after radiation with or without treatment of GSI-I were analyzed by flow cytometry. Then CD133+ and CD133- glioblastoma cells were sorted by magnetic activated cell sorting (MACS), and the radiosensitization effects of GSI-I on the two cell subtypes were investigated separately. Finally, the cytotoxic effects of GSI-I on CD133+and CD133- glioblastoma cells were examined, respectively, and the expression of the Notch pathway components between the two cell subtypes were compared. In addition, the anti-tumor effects of GSI-I were confirmed by in vivo experiments. RESULTS: GSI-I at a low concentration sensitized U87 and U251 cells to radiation by depletion of radioresistant CD133+ cells. CD133+ U87/U251 cells displayed preferential sensitivity to low concentrations of GSI-I, which may be related to the higher expression of the Notch signaling pathway in these cells. CONCLUSIONS: Combining GSI-I with radiotherapy may represent a promising strategy for treating radioresistant gliomas.

[Expression and antibody preparation of FKBP38 and its application].

OBJECTIVE: To obtain recombinant N-and C-terminal of FKBP38 and prepare anti-FKBP38 polyclonal antibody for Western blotting (WB), immunohistochemical (IHC) and immunofluorescence (IF) analyses. METHODS: The N-terminal (1-207 aa) and C-terminal (209-387 aa) cDNA of FKBP38 were sub-cloned from the full-length cDNA of FKBP38 and ligated to prokaryotic expression plasmid pGEX-6P-1 for construction of the recombinant vectors pGEX-6P-1-FKBP38-N and pGEX-6P-1-FKBP38-C. After sequencing, the recombinant vectors were transformed into E.coli BL21 and GST-tagged FKBP38-NT and FKBP38-CT were induced by IPTG. The proteins were purified by Glutathione affinity chromatography column and characterized by SDS-PAGE. Rabbits were immunized with the purified recombinant protein to prepare the antiserum, which were analyzed by WB, IHC and IF. RESULTS: The recombinant vectors pGEX-6P-1-FKBP38-N and pGEX-6P-1-FKBP38-C were successfully constructed. After IPTG induction, the E.coli transformed with these plasmids expressed GST-tagged protein, which was successfully purified. Western blotting demonstrated that the purified antibody could specifically bind to FKBP38 in various cell lines. Immunofluorescence assay showed that FKBP38 was located mainly on the mitochondria. Immunohistochemical analysis revealed cytoplasmic location of FKBP38 in breast cells. CONCLUSION: We successfully expressed and purified N- and C-terminal of FKBP38, and FKBP38 polyclonal antibody we prepared can specifically recognize FKBP38 in SB, IF and IHC assays, which facilitates further functional investigation of FKBP38.