Figure 3 | Cell Death & Disease

Figure 3

From: Cryptotanshinone inhibits human glioma cell proliferation in vitro and in vivo through SHP-2-dependent inhibition of STAT3 activation

Figure 3

Inhibitory effect of CTS on glioma cell proliferation is dependent on the suppression of persistent STAT3 activation. (a) U251 cells were treated with the indicated concentration of CTS for 2 h. The expression of proteins was analyzed by western blotting with indicated antibodies. The bands were then quantified by ImageJ software. Results are the mean±S.E.M. (n=3 for each group). *P<0.05, **P<0.01 versus control. (b) U251 cells were treated with 10 μM CTS for the indicated time, followed by western blot with the indicated antibodies. The bands were then quantified by ImageJ software. Results are the mean±S.E.M. (n=3 for each group). ***P<0.001 versus control. (c) U251 cells were treated with CTS (10 μM) for 120 min. Representative confocal immunofluorescent images revealed the nuclear levels of STAT3 (green). (d) U251 cells were treated with CTS (10 μM) for 120 min, followed by nuclear protein isolation. The expression levels of STAT3 in whole-cell lysates and nucleus were analyzed by western blotting. GAPDH or Histone H3 was used as a control. Right: relative expression of STAT3 in whole-cell lysates and nucleus were quantified by densitometry. Results are the mean±S.E.M. (n=3 for each group). #P<0.01 versus CTS 0 μM group. (e) U251 cells were transfected with empty vector or STAT3C plasmid for 24 h, and then treated with CTS at the indicated concentrations for another 24 h. Cell growth was measured by MTT assay. Vehicle-treated cells were used as a control. Data are expressed as a percentage versus control (100%). Data are expressed as mean±S.E.M.; n=3 for each group. *P<0.05, **P<0.01, ***P<0.001 versus empty vector (EV) control; #P<0.05, ##P<0.01. (f) Cell lysates from EV or STAT3C-transfected U251 cells were analyzed by western blotting with specific antibodies of STAT3 and STAT3-regulated proteins cyclin D1 and survivin. (g and h) U251 cells were treated with the indicated concentration of CTS for 24 h. The expression of proteins was analyzed by western blotting with indicated antibodies (g). Expression of cyclin D1, cyclin E and survivin relative to GAPDH were quantified by densitometry (h). Results are the mean±S.E.M. (n=3 for each group). *P<0.05, **P<0.01, ***P<0.001 versus CTS 0 μM group

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