Mechanism study on regulation of glioblastoma cell proliferation and apoptosis by sciadopitysin combined with CX-4945 through Notch1 pathway / 国际肿瘤学杂志

ABSTRACT

Objective:To investigate the effects and mechanism of sciadopitysin combined with CK2 inhibitor CX-4945 on proliferation and apoptosis of glioblastoma U87 cells.Methods:Glioblastoma U87 cells were cultured in vitro, and treated with 0.01, 0.10, 1.00, 10.00, 100.00 μmol/L of sciadopitysin respectively. U87 cells were treated with 1.25, 2.50, 5.00, 10.00, 20.00 μmol/L of CX-4945. U87 cells were divided into control group (without any treatment), sciadopitysin group (100.00 μmol/L of sciadopitysin), CX-4945 group (5.00 μmol/L of CX-4945), sciadopitysin combined with CX-4945 group (100.00 μmol/L of sciadopitysin plus 5.00 μmol/L of CX-4945). MTT method was used to detect cell viability, Caspase3/7 activity assay and Annexin Ⅴ/ PI double staining were used to detect cell apoptosis, and Western blotting was used to detect the expressions of Notch1 pathway related proteins ICN1, HES1 and DLL3. Results:The cell viabilities of U87 cells treated with 0, 0.01, 0.10, 1.00, 10.00, 100.00 μmol/L of sciadopitysin were (100.00±6.30) %, (112.02±7.63) %, (140.84±6.73) %, (113.92±7.92) %, (102.60±7.12) % and (73.16±2.74) % respectively, and there was a statistically significant difference ( F=55.21, P<0.001). There were statistically significant differences in the cell viabilities of U87 cells between 0 μmol/L and 0.01, 0.10, 1.00, 100.00 μmol/L of sciadopitysin treatment ( P=0.009; P<0.001; P=0.003; P<0.001). The cell viability of U87 cells was inhibited by 100.00 μmol/L of sciadopitysin, while sciadopitysin at other low concentrations manifested as enhancement or no obvious effect. The cell viabilities of U87 cells treated with 0, 1.25, 2.50, 5.00, 10.00, 20.00 μmol/L of CX-4945 were (100.00±5.53) %, (108.70±10.24) %, (93.14±2.82) %, (81.46±4.92) %, (56.92±3.99) % and (31.24±2.67) % respectively, and there was a statistically significant difference ( F=135.18, P<0.001). There were statistically significant differences in the cell viabilities of U87 cells between 0 μmol/L and 1.25, 5.00, 10.00, 20.00 μmol/L of CX-4945 treatment ( P=0.022; P<0.001; P<0.001; P<0.001). Low concentration (1.25 μmol/L) of CX-4945 enhanced the cell viability of U87 cells, however higher concentrations (5.00, 10.00, 20.00 μmol/L) of CX-4945 shown inhibitory effect. The cell viabilities of U87 cells in the control group, sciadopitysin group, CX-4945 group and sciadopitysin combined with CX-4945 group were (100.00±5.53) %, (71.96±2.10) %, (77.66±4.12) % and (42.56±4.22) % respectively, and there was a statistically significant difference ( F=160.56, P<0.001). There were statistically significant differences between the control group and each treatment groups (all P<0.001). There were statistically significant differences between the sciadopitysin combined with CX-4945 group and sciadopitysin group, CX-4945 group (both P<0.001). The Caspase3/7 activities of U87 cells in the above four groups were 2.34±0.47, 4.02±0.22, 3.67±0.32 and 5.85±0.28 respectively, and there was a statistically significant difference ( F=55.80, P<0.001). The apoptosis rates of each groups were (0.40±0.10) %, (17.37±0.57) %, (3.00±0.66) % and (33.47±0.87) % respectively, and there was a statistically significant difference ( F=1 822.18, P<0.001). Further pairwise comparison showed that there were statistically significant differences in Caspase3/7 activities and apoptosis rates between the control group and each treatment groups ( P<0.001, P=0.001, P<0.001; P<0.001, P=0.001, P<0.001). There were statistically significant differences in Caspase3/7 activities and apoptosis rates between the sciadopitysin combined with CX-4945 group and sciadopitysin group, CX-4945 group (all P<0.001). The protein expression levels of Notch 1 pathway related proteins ICN1 (0.55±0.07 vs. 1.01±0.09), HES1 (0.66±0.08 vs. 1.00±0.06) and DLL3 (0.74±0.04 vs. 1.01±0.09) in U87 cells decreased significantly after treatment with 100.00 μmol/L of sciadopitysin ( t=5.94, P=0.004; t=5.15, P=0.007; t=4.00, P=0.016) . Conclusion:Sciadopitysin can synergize with CK2 inhibitor CX-4945 to inhibit the proliferation and promote apoptosis of glioblastoma U87 cells by inhibiting Notch1 signaling pathway.