Perifosine regulates human brain glioma U251 cell proliferation, apopto-sis and autophagy through suppression of PI3 K/Akt pathway / 中国病理生理杂志

AIM:To investigate the effect of perifosine, an inhibitor of protein kinase B ( PKB/Akt) , on the cell cycle, apoptosis and autophagy in human brain glioma U251 cells, and to determine the relationship between perifos-ine-induced autophagy and apoptosis of glioma.METHODS:The cell growth inhibition was determined by MTT assay. The cell cycle distribution of U251 cells was examined by flow cytometry.The cell apoptosis was analyzed by Annexin V-FITC apoptosis detection kit.The protein expression of P21, P27, cyclin B1, caspase-9 and PARP was examined by Wes-tern blot analysis.The distribution and expression of LC3-Ⅱ, an autophagy marker, was observed to determine the effect of perifosine-induced autophagy.RESULTS:Perifosine inhibited the cell viability in a dose-dependent manner.In perifos-ine-treated U251 cells, the cell cycle was arrested in G2 phase and the expression of cyclin B1 was inhibited.Perifosine in-duced apoptosis of U251 cells through activation of caspase-9 cleavage, PARP cleavage and survivin inhibition.In addi-tion, suppression of autophagy by chloroquin, an inhibitor of autophagy, increased the number of apoptotic cells.CON-CLUSION:Perifosine inhibits cell proliferation and triggers apoptosis and autophagy in human U251 cells.Blocking auto-phagy magnifies perifosine-induced glioma cell apoptosis.

Study on different β-cyclodextrin and its derivatives for solubilization and dissolution of entecavir / 中国生化药物杂志

Objective To prepared inclusion complex of β-cyclodextrin (β-CD) and its derivatives (methyl -β-cyclode-xtrin, 2,6-dimethyl -β-cyclodextrin, hydroxypropyl -β-cyclodextrin ) with entrcavir, and explore effect of different inclusion complex on the solubility and dissolution of entecavir.Methods Regression equation was established,prepared the inclusion complexes by a magnetic stiring method,grinding method and ultrasonic method.While inclusion rate was an index,the effects of reaction process was inquired by mole ratio, inclusion temperature, inclusion time and stirring rate and the most suitable method and technology of inclusion was optimized.Determinated the solubility with HPLC method and investigated in vitro dissolution with a small cup method.Results The regression equation was A=1.026 ×106C+4248.8, R2 =0.9999 (n=6), in the range of 0.497~4.97 g/mL, linear relationship was good.The best inclusion method was magnetic stirring, the best process conditions were: mole ratio was 1 ︰1, stirring speed was 300 r/min, inclusion time was 4 hours, inclusion temperature was 50 ℃.The four inclusion complexes all were white loose powder materials.The solubility of ETV,β-CD-ETV,HP-β-CD-ETV,RM-β-CD-ETV,2,6-DM-β-CD-ETV were 2.51, 13.4, 18.9, 37.6 and 89.5 g/L.The dissolution rates was ETV<β-CD-ETV

Cloning and prokaryotic expression of LEN-5 β-lactamase gene / 中国人兽共患病学报

In order to express the gene of LEN-5 β-lactamase from a Klebsiella pneumoniae strain,plasmids in the strain were extracted and an 879bp product of LEN-5 gene was obtained with PCR.After being digested with Nde I and Xho I,LEN-5 gene was cloned into pET-26b (+) vector.Then it was confirmed by digestion and DNA sequencing in recombinant plasmid before transformed into E.coli BL21 (DE3).After inducing by IPTG,LEN-5 β-lactamase was expressed.Protein extraction was processed by ultrasonic and protein activity was detected by nitrocefin.The isoelectric focusing electrophoresis showed a pI of 7.6.These results indicated that the LEN-5 gene has been cloned and expressed in prokaryote cell successfully.