Expression of TMS1/ASC gene and activation of caspase-Ⅰ and NF-κB induced by gemcitabine in pancreatic carcinoma cell line PANC-1 / 中华内分泌外科杂志

ABSTRACT

Objective To investigate the expression of TMS1/ASC gene induced by gemcitabine(GEM) in pancreatic carcinoma cell line PANC-1.To study the relationship between cysteine aspartase(caspase-1),nuclear factor-κB(NF-κB) and the expression of TMS1/ASC.Methods The pancreatic carcinoma cell line PANC-1 was cultured in Dnlbecco's modification of Eagle's medium(DMEM).Methyl thiazolyl tetrazolium (MTT)method was used to measure the effect of GEM at different time points(24,48 h)at different concentrations(1,2,4,8,16 μg/ml) on growth of PANC-l.RT-PCR was used to detect the expression of TMS1/ASC mRNA stimulated by medium alone and by GEM(4.27μg/ml)for 24 h and 48 h.Western blot analysis was performed with inhibitory protein of NF-κB multiclonal antibody,caspase-1 multiclonal antibody and β-actin monoclonal antibody to observe the expression of β-actin,caspase-1 and IκBα in GEM group and in the control group.The activation state of caspase-1 and NF-κB was examined.Results GEM inhibited the growth of PANC-1 cells in a concentrationand-time-dependent manners and its half maximal inhibitory concentration(IC50)was 4.27 μg/ml on 24 h.The expression of TMS1/ASC was 0.3 ±0.004 and 0.63 ±0.007 respectively in GEM group while it was 0.1 ±0.001 and 0.21 ± 0.006 in the control group on 24h and 48h.The difference between the 2 groups at the same time point had statistical significance (P ＜ 0.01).Western blot showed that GEM caused the activation of caspase-1.The expression of IκBα had no obvious differencebetween the 2 groups.GEM couldn't induce the activation of NF-κB.Conclusions GEM can inhibit proliferation of PANC-1 cells and induce their apoptosis.The drug sensitivity decreased with prolongation of exposure time.GEM might induce and increase the expression of TMS1/ASC,which might influence the apoptosis of the cells later.The apoptosis of PANC-1 cells induced by GEM is dependent of caspase-1 signaling pathway and independent of NF-κB signaling pathway.