Human DNA Topoisomerase I (hTopo I) has been identified to be an efficient target of many effective antitumor drugs. Natural hTopo I is not convenient to be used in screening because of its low concentration in cells. In order to fast screen new anticancer drugs targeting at hTopo I from natural compounds in vitro, hTopo I gene open reading frame (ORF) has been successfully cloned and overexpressed in Pichia pastoris. Total RNA extracted from Hela cells was reversely transcripted to synthesize cDNA with the hTopo I specific antisense primer and the hTopo I ORF was synthesized by PCR. After digestion with EcoR I and Kpn I, the synthesized fragment was inserted into pPICZaA, gave rise to pPICZalpha-hTopoI. After digestion with Sac I, the lined pPICZalpha-hTopoI was transformed into Pichia pastoris strains (KM71, X33 and SMD1168) by electroporation and integrated into their genome. After screened on YPDS plates (containing 1000 ug/mL zeocin), the high-copy recombinant strains (KM-hTopoI, X33-hTopoI and SMD-hTopol) could overexpress recombinant hTopo I, which was fused to the alpha-factor secretion signal and could be secreted into the supernatant in the culture. alpha-factor could be cleaved from the expressed protein during secretion. A higher activity amount of the enzyme was secreted by the particular strain SMD-hTopoI because of its absence of proteimase A than by other strains which possess proteinase A activity. After optimizing the fermentation conditions, a relatively higher enzyme activity in the culture supernatant could be obtained when SMD-hTopoI was induced in BMMY (pH7.25) at 20 degrees C , with addition of 0.5% (V/V) methanol and 3% (V/V) nutrient liquid every 24h. The enzyme activity reached 43 000 u/mL, the yield reached 11 mg/L, achieving approximate 10% of total protein in the culture supernatant. SDS-PAGE and Western blot analyses showed that the mass of the recombinant hTopo I was 91 kD with no glycosylation.
DNA Topoisomerases, Type I ; biosynthesis ; genetics ; Fermentation ; Humans ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

OBJECTIVETo optimize the process for preparing genipin with enzymolyzed geniposide by an orthogonal experiment.

METHODThe optimal enzymolysis process was selected by an orthogonal experiment, with the concentration of geniposide as the index as well as enzyme quantity, pH of enzymolysis solution, enzymolysis time and enzymolysis temperature as considerations.

RESULTThe optimal hydrolysis conditions were as follow: rough genipin samples at the concentration of 40 g x L(-1) were selected and shook on a table concentrator at a speed of 100 r x min(-1), added with beta-glucosidase-geniposide 1 : 1 (weight proportion), with pH of enzymolysis solution at 4.5, hydrolyzation temperature at 50 degrees C, the conversion rate of genipin could reach 85.8%.

CONCLUSIONThe process is so stable and feasible that it can provide theoretical basis for the preparation of genipin with enzymolyzed geniposide.

Hydrolysis ; Iridoids ; chemistry ; Technology, Pharmaceutical

Background/Aims: Depression and anxiety are associated with poorer outcomes in patients with hepatocellular carcinoma (HCC). However, the prevalence of depression and anxiety in HCC are unclear. We aimed to establish the prevalence of depression and anxiety in patients with HCC. Methods: MEDLINE and Embase were searched and original articles reporting prevalence of anxiety or depression in patients with HCC were included. A generalized linear mixed model with Clopper-Pearson intervals was used to obtain the pooled prevalence of depression and anxiety in patients with HCC. Risk factors were analyzed via a fractional-logistic regression model. Results: Seventeen articles involving 64,247 patients with HCC were included. The pooled prevalence of depression and anxiety in patients with HCC was 24.04% (95% confidence interval [CI], 13.99–38.11%) and 22.20% (95% CI, 10.07–42.09%) respectively. Subgroup analysis determined that the prevalence of depression was lowest in studies where depression was diagnosed via clinician-administered scales (16.07%;95% CI, 4.42–44.20%) and highest in self-reported scales (30.03%; 95% CI, 17.19–47.01%). Depression in patients with HCC was lowest in the Americas (16.44%; 95% CI, 6.37–36.27%) and highest in South-East Asia (66.67%; 95% CI, 56.68–75.35%). Alcohol consumption, cirrhosis, and college education significantly increased risk of depression in patients with HCC. Conclusions One in four patients with HCC have depression, while one in five have anxiety. Further studies are required to validate these findings, as seen from the wide CIs in certain subgroup analyses. Screening strategies for depression and anxiety should also be developed for patients with HCC.