ABSTRACT
This study examined the effect of saponins from Tupistra chinensis Bak (STCB) on the growth of sarcoma S-180 cells in vitro and in mouse xenografts as well as the underlying mechanisms.Cell proliferation was assessed by MTT assay.Cell cycle distribution was determined by flow cytometry.Sarcoma S-180 tumor-bearing mice were treated with different doses of STCB with 10 μg/mL 5-fluorouracil (5-Fu) as a positive control.The activity of nuclear factor (NF)-κB was detected by gel mobility shift assay.The mRNA level of NF-κB was determined by real-time quantitative RT-PCR.The results showed that in vitro STCB inhibited the growth of S-18 0 cells in a concentration-dependent manner,which was accompanied by cell cycle arrest at S-phase.In vivo STCB significantly inhibited the growth of S-180 tumor mouse xenografts in a dose-dependent manner with apparent induction of cell apoptosis.Moreover,STCB inhibited the activity of NF-κB p65 and reduced the expression of NF-κB p65 mRNA in mouse xenografts.It was concluded that STCB inhibits the proliferation and cell cycle progression of S-180 cells by suppressing NF-κB signaling in mouse xenografts.Our findings suggest STCB is a promising agent for the treatment of sarcoma.
ABSTRACT
This study examined the effect of saponins from Tupistra chinensis Bak (STCB) on the growth of sarcoma S-180 cells in vitro and in mouse xenografts as well as the underlying mechanisms.Cell proliferation was assessed by MTT assay.Cell cycle distribution was determined by flow cytometry.Sarcoma S-180 tumor-bearing mice were treated with different doses of STCB with 10 μg/mL 5-fluorouracil (5-Fu) as a positive control.The activity of nuclear factor (NF)-κB was detected by gel mobility shift assay.The mRNA level of NF-κB was determined by real-time quantitative RT-PCR.The results showed that in vitro STCB inhibited the growth of S-18 0 cells in a concentration-dependent manner,which was accompanied by cell cycle arrest at S-phase.In vivo STCB significantly inhibited the growth of S-180 tumor mouse xenografts in a dose-dependent manner with apparent induction of cell apoptosis.Moreover,STCB inhibited the activity of NF-κB p65 and reduced the expression of NF-κB p65 mRNA in mouse xenografts.It was concluded that STCB inhibits the proliferation and cell cycle progression of S-180 cells by suppressing NF-κB signaling in mouse xenografts.Our findings suggest STCB is a promising agent for the treatment of sarcoma.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the roles of NF-κB in factor VIIa-induced proliferation and migration of a colon cancer cell line (SW620) in vitro and its possible mechanism.</p><p><b>METHODS</b>The expression levels of NF-κB (p65), inhibitory protein of NF-κB (IκB-α), caspase-7, interleukin 8 (IL-8) and tissue factor (TF) in SW620 cells treated with factor VIIa, PDTC (an inhibitor of NF-κB) and other factors were measured by Western-blotting and real-time PCR. Proliferation and migration of the cells were analyzed by flow cytometry and Transwell assay, respectively.</p><p><b>RESULTS</b>Factor VIIa down-regulated the IκB-α level in SW620 cells and increased the intranuclear level of NF-κB. Those effects of factor VIIa were blocked by anti-TF or anti-PAR2 antibodies. The effects of factor VIIa on proliferation and migration of SW620 cells, expression of IL-8, TF as well as caspase-7, were interfered by PDTC (the inhibitor of NF-κB).</p><p><b>CONCLUSIONS</b>TF/VIIa complex activates NF-κB pathway via PAR2, thereby up-regulates IL-8 and down-regulates caspase-7 expression in SW620 cells, finally promotes proliferation and migration of colon cancer cells. In addition, TF/VIIa/PAR2/NF-κB pathway also upregulates TF expression, thus to create a positive feedback loop of TF/VIIa/PAR2/NF-κB/TF.</p>