ABSTRACT
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anti-cancer agent.However,emergence of drug resistance limits its potential use.Plumbagin is a natural quinonoid compound isolated from plant.In this study,induced apoptosis effect of the combined treatment with plumbagin and TRAIL on human melanoma A375 cell line was examined and possible mechanism was investigated.The cells were divided into four groups:control group,plumbagin group (plumbagin,5 or 10 μmol/L),TRAIL group (TRAIL,30 ng/mL) and plumbagin+TRAIL group (combined treatment group).The apoptosis,and the expression of DR4 and DR5 were detected by flow cytometry.The activities of caspase-8 and caspase-3 were determined by colorimetric assay.The results showed that the apoptosis rate was 8.3% in TRAIL group,10.35%-16.94% in plumbagin group and 52.39%-55.39% in combined treatment group,respectively,with the difference being significant between combined treatment group and plumbagin or TRAIL group (P＜0.05 for each).Moreover,plumbagin alone could markedly up-regulate DR5 mRNA and protein expression,and slightly increase DR4 mRNA and protein expression.Treatment of human melanoma A375 cells with plumbagin resulted in the activation of Caspase-3,but not Caspase-8.These results suggest that plumbagin might be useful for TRAIL-based treatment for melanoma.
ABSTRACT
Progesterone has nongenomic effects on inducible nitric oxide synthase(iNOS),which is mediated by mitogen activated protein kinase(MAPK)pathways.This effect is supposed to have some potential association with asymptomatic gonococcal infections in women by immunological depression.In this study,polymorphonuclear leukocytes(PMNs)challenged by gonococci were used to study the nongenomic effects of progesterone.The activation of iNOS was assessed by measuring[3H]L-arginine converses to[3H]L-citruiline,and the activity of MAPK was detected by Western blot.It was found that the activity of iNOS and the yields of NO were enhanced significantly in gonococci-challenged PMNs compared with the controls(P<0.01).Progesterone could repress the activation of iNOS through P38MAPK pathway within PMNs(P<0.05),which could be blocked by SB203580(P<0.01),but not by actinomycin D(P>0.05).It was also found subsequently that in the serum specimens collected from gonococci-infected but asymptomatic women,the progesterone level was higher than that in women with severe symptoms(P<0.01).Moreover,the yield of NO had an inverse correlation with progester-one.With these results it suggested that the rapid nongenomic effects of progesterone may inhibit iNOS activation and NO yields mediated by P38MAPK pathways,which were supposed to be concerned with asymptomatic women infected with gonococci.
ABSTRACT
To identify the genomic species of Neisseria gonorrhoeae, evaluate the difference between two molecular epidemiological methods and examine the relationship between sex partners and genotypes of bacteria, 24 strains of Neisseria gonorrhoeae isolated from the outpatients with gonorrhea were identified by using the Opa genotyping and NG-MAST genotyping and the relationship between genotypes and phenotypes was studied. Twenty-four strains of Neisseria gonorrhoeae fell into 10 ST genotypes by NG-MAST genotyping, whereas these strains were classified into 12 OT Opa genotypes by Opa genotyping. A new epidemic strain of ST genotype (217-86% homologisation 178) in China was identified. It is concluded that genotypes of each pair of strains from a pair of patient/sex partner besides 45/46 are the same, indicating that contagious infection take place between patient and the sex partner. Opa genotyping was more effective than NG-MAST genotyping in identifying the genomic species of Neisseria gonorrhoeae. ST genotype could be further classified into different Opa-types.