Honokiol enhanced the phosphatase SHP-1 activity and the interaction with STAT-3 in gastric cancer cells and endothelial cells and the SHP-1 protein expression in tumors.

<p>Cells were treated with honokiol (HK) for various time courses as indicated. (A) Cells were treated with honokiol (HUVECs, 20 µM; SVECs, 20 µM; AGS, 20 µM; SCM-1, 40 µM) at the indicated times, and then the SHP-1 activities were measured. Data are presented as mean±SEM (n = 7). *P<0.05 as compared with control. (B) Immunohistochemistry for SHP-1 expression in metastatic tumors isolated from mice with or without HK treatment is shown. The sections were stained with anti-SHP-1 antibody. (C) Interaction of STAT-3 and SHP-1 was detected in AGS cells or HUVECs. Immunoprecipitated proteins were collected and subjected to SDS-PAGE and immunoblotting with anti-STAT-3 or anti-SHP-1 antibodies. In A and B, data are presented as mean ± SEM (n = 5). *p<0.05 as compared with control. In C, the results shown are representative of at least four independent experiments.