ABSTRACT
Objective To investigate the molecular mechanisms of effect of glycogen synthase kinase -3beta( GSK3β) on proliferation of human osteosarcoma cells .Methods Normal osteoblast hFO and osteosarcoma cell lines were examined for GSK 3βexpression and activity by Western blot and in vitro kinase assay ( NIRKA) . The effects of small molecule GSK3βinhibitors on cell proliferation and apoptosis were examined .Depletion of en-dogenous GSK3βby GSK 3βsiRNA detected the expression and phosphorylation of p 27 and its downstream cy-clinD1-CDK-Rb pathway factor by Western blot .Human osteosarcoma cell xenografts ,in athymic mice model , were treated with DMSO as control or with GSK 3βinhibitor SB-216763 or AR-A014418 by intraperitoneal in-jection,3 times a week.The tumor growth and body weight were observed in nude mice .Results Osteosarcoma cell lines showed increased GSK 3βexpression and decreased serine 9 phosphorylation compared with normal oste-oblast cells.Inhibition of GSK3βresulted in attenuated cell proliferation and increased apoptosis in most osteosar-coma cell lines in vitro and in vivo in MG 63 xenografts in rodents but not in hFOB cells .We decreased endoge-nous GSK3b activity,tumor growth was inhibited in SB216763,AR -A014418 group compared with control group.There was statistical significance(P<0.05).GSK3βinhibition in osteosarcoma cells was associated with decreased p27 expression, Rb expression and phosphorylation level of decline , CDK2, 4, 6 protein level de-creased,the upregulation of cyclin D1 expression but the phosphorylation level of no effect .Conclusion In this research,we demonstrate that deregulated GSK 3βsustains osteosarcoma cells survival through modulation of p27and cyclinD1-CDK-Rb pathway.The result will open up a potential target for clinical treatment of osteosar -coma.
ABSTRACT
The Yellow River Delta (YRD) is a typical agricultural and petrochemical industrial area of China. To assess the current status of phthalate esters (PAEs) of soil residues, soil samples (0â¼20 cm) (n = 82) were collected in Bincheng District, at the geographic center of the YRD. PAEs were detected in all topsoil samples analyzed, which indicated that PAEs are ubiquitous environmental contaminants. Concentrations of 11 PAEs are in the range of 0.794â¼19.504 µg g(-1), with an average value of 2.975 µg g(-1). It was presented that PAEs pollution in this area was weak and monotonously increasing along the rural-urban gradient. Higher concentrations were observed from roadsides (and/or gutters), densely anthropogenic activities areas (such as the urbanization and industrialization), and agriculture influence district, which mainly originated from construction waste, municipal sewage, agricultural waste and pesticide, discarded plastic effusion and atmospheric depositions. Concentrations of PAEs were weakly positivity correlated with soil organic carbon content and pH, which suggested both of them can affect the distribution of PAEs. The concentration of di (2-ethylhexyl) phthalate and di-n-butyl phthalate dominated in the 11 PAEs, with the average values of 0.735 and 1.915 µg g(-1), respectively, and accounted for 92.1 % of the whole PAEs' concentrations. No significant differences of PAE congeneric profiles were observed between our work and others previously reported, which is consistent with the use of similar commercial PAEs around the world.
