Figure 6
RUNX inhibitor Chb-M’ down-regulates ErbB2/HER2 pathway through attenuating SOS1 expression in gastric cancer cells. (a) Relative densitometric quantification of phospho-RTK array spots in Chb-M’-treated MKN45 cells compared to the control. Cells were treated with DMSO or 1 μM Chb-M’ for 48 hours, then the cells were lysed for the phospho-RTK array. Each receptor was spotted in duplicates (see Supplementary Fig. 4a for the immunoblot image). (b) Down-regulation of SOS1 expression in Chb-M’-treated NUGC4 and MKN45 cells. Cells were treated with the indicated concentrations of Chb-M’. Six hours after treatment, total RNA was prepared and analyzed by real-time RT-PCR. Values were normalized to that of DMSO-treated control cells (n = 3). (c) Down-regulation of SOS1 and dephosphorylation of HER2 in Chb-M’-treated NUGC4 and MKN45 cells. Cells were treated as in (b). Forty-eight hours after treatment, cell lysates were prepared and subjected to immunoblotting. Data are mean ± SEM values. *P < 0.05, **P < 0.01, n.s.; not significant, by two-tailed Student’s t-test.
