Abstract:

Objective： To investigate the effect of Schisandra chinensis polysaccharide （SCP） on the proliferation and apoptosis of human bladder cancer T24 cells， and to elucidate its possible mechanisms. Methods The human bladder cancer T24 cells were cultured in vitro and divided into control group and 50， 100， and 200 mg·L^－1 SCP groups. After 24－48 h of intervention with different doses of SCP， the inhibitory rates of proliferation of T24 cells in various groups were detected by MTT method， the apoptosis of T24 cells in various groups was detected by Hoechst 33258 fluorescence staining method，the apoptotic rates of T24 cells in various groups were detected by Annexin Ⅴ-FITC/propidium iodide（PI） double staining method， the percentages of T24 cells in different cell cycles and the apoptotic rates of T24 cells in various groups were detected by flow cytometry， and the expression levels of phosphatase and tensin homolog deleted on chromosome ten（PTEN）， phosphorylated phosphatidylinositol-3 kinase （p-PI3K），protein kinase B （Akt） and phosphorylated Akt （p-Akt） proteins in the T24 cells in various groups were detected by Western blotting method. Results Compared with control group， the inhibitory rates of proliferation of T24 cells in 50，100，and 200 mg·L^－1 SCP groups were significantly increased（P<0.05 or P<0.01）； the apoptotic rates of T24 cells were significantly increased （P<0.05 or P<0.01）；the percentages of T24 cells in 50，100 and 200 mg·L^－1 SCP groups in G₀/G₁ phase were significantly increased （P<0.05 or P<0.01）， the percentages of T24 cells in 100 and 200 mg·L^－1 SCP groups in S phase and G₂/M phase were significantly decreased （P<0.01）； the expression levels of PTEN protein in the T24 cells in 50，100，and 200 mg·L^－1 SCP groups were significantly increased （P<0.05 or P<0.01）， the expression levels of p-PI3K protein and the ratios of p-Akt/Akt in the T24 cells were significantly decreased （P<0.05 or P<0.01）. Conclusion SCP can inhibit the proliferation of T24 cells and promote their apoptosis，and its mechanism may be related to the regulation of expressions of PTEN and PI3K/Akt signaling pathway-related proteins.

Key words: Schisandra chinensis polysaccharide, Human bladder cancer Cells, Cell proliferation, Apoptosis, Phosphatase and tensin homolog deleted on chromosome ten, Phosphatidylinositol-3 kinase, Protein kinase B