Gene therapy has been considered a promising approach for glioblastoma therapy. To avoid side effects and increase the specificity of gene expression, gene expression should be tightly regulated. In this study, glioma and hypoxia dual-specific plasmids (pEpo-NI2-SV-Luc and pEpo-NI2-SV-HSVtk) were developed by combining the erythropoietin (Epo) enhancer and nestin intron 2 (NI2). In the in vitro studies, pEpo-NI2-SV-Luc showed higher gene expression under hypoxia than normoxia in a glioblastoma-specific manner. The MTT and caspase assays demonstrated that pEpo-NI2-SV-HSVtk specifically induced caspase activity and cell death in hypoxic glioblastoma cells. For in vivo evaluation, subcutaneous and intracranial glioblastoma models were established. Dexamethasone-conjugated-polyethylenimine (PEI-Dexa) was used as a gene carrier, since PEI-Dexa efficiently delivers plasmid to glioblastoma cells and also has an antitumor effect due to the effect of dexamethasone. In the in vivo study in the subcutaneous and intracranial glioblastoma models, the tumor size was reduced more effectively in the pEpo-NI2-SV-HSVtk group than in the control and pSV-HSVtk groups. In addition, higher levels of HSVtk gene expression and TUNEL-positive cells were observed in the pEpo-NI2-SV-HSVtk group compared with the control and pSV-HSVtk groups, suggesting that pEpo-NI2-SV-HSVtk increased the therapeutic efficacy in hypoxic glioblastoma. Therefore, pEpo-NI2-SV-HSVtk/PEI-Dexa complex may be useful for glioblastoma-specific gene therapy.
Obatoclax, a pan-Bcl2 inhibitor, shows antitumor activities in various solid malignancies. Bcl2-deficient mice have shown the importance of Bcl2 in osteoclasts, as the bone mass of the mice was increased by the induced apoptosis of osteoclasts. Despite the importance of Bcl2, the effects of obatoclax on the proliferation and differentiation of osteoclast precursors have not been studied extensively. Here, we describe the anti-proliferative effects of obatoclax on osteoclast precursors and its negative role on fusion of the cells. Stimulation with low doses of obatoclax significantly suppressed the proliferation of osteoclast precursors in a dose-dependent manner while the apoptosis was markedly increased. Its stimulation was sufficient to block the activation of ERK MAP kinase by RANKL. The same was true when PD98059, an ERK inhibitor, was administered to osteoclast precursors. The activation of JNK1/2 and p38 MAP kinase, necessary for osteoclast differentiation, by RANKL was not affected by obatoclax. Interestingly, whereas the number of TRAP-positive mononuclear cells was increased by both obatoclax and PD98059, fused, multinucleated cells larger than 100 μm in diameter containing more than 20 nuclei were completely reduced. Consistently, obatoclax failed to regulate the expression of osteoclast marker genes, including c-Fos, TRAP, RANK and CtsK. Instead, the expression of DC-STAMP and Atp6v0d2, genes that regulate osteoclast fusion, by RANKL was significantly abrogated by both obatoclax and PD98059. Taken together, these results suggest that obatoclax down-regulates the proliferation and fusion of osteoclast precursors through the inhibition of the ERK1/2 MAP kinase pathway.
BACKGROUNDPolymyxin B hemoperfusion (PMX-HP) has been used as a treatment for intra-abdominal septic shock by absorbing and removing endotoxins of gram-negative bacilli.AIMTo investigate the clinical efficacy of PMX-HP in patients with gram-negative septic shock who underwent abdominal surgery.METHODSFrom January 2012 to December 2018, patients who had septic shock secondary to peritonitis were enrolled. They were classified into PMX-HP treated and control groups based on postopreative intervention using PMX-HP. The clinical outcomes were compared using 1:1 propensity score matching methods to balance the overall distribution between the two groups.RESULTSAfter propensity score matching, 40 patients were analyzed (20 patients in the PMX group and 20 patients in the control group). The scores of total Sequential Organ Failure Assessment (SOFA) score, renal SOFA and coagulation SOFA were significantly improved in the PMX group but not in the control group. (from 11.2 ± 5.8 to 4.7 ± 3.5 in PMX group vs 10.0 ± 4.0 to 8.7 ± 7.3 in control group, P = 0.047 from 2.6 ± 1.0 to 0.7 ± 1.0 in PMX group vs 2.6 ± 1.5 to 2.8 ± 1.6 in control group, P = 0.000, from 1.6 ± 1.5 to 1.3 ± 1.3 in PMX group vs 1.2 ± 1.2 to 2.8 ± 1.8 in control group, P = 0.014, respectively). Further, the length of intensive care unit (ICU) stay was significantly shorter in PMX group. However, no statistically significant difference was found in ICU mortality (50% in PMX group vs 50% in control group).CONCLUSIONPMX-HP is a feasible adjunct treatment for peritonitis in ICU patients with peritonitis for improved organ impairment and to stabilize hemodynamics. It would be helpful to enhance clinical outcomes especially in patients with complete elimination of the source of gram-negative bacilli infection by surgical procedure accompanied with conventional treatment of sepsis.
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