Sub-cytotoxic MJ suppressed the Sp1 expression and binding on MMP-14 promoter in gastric cancer cells. A and B, cancerous (C) and adjacent non-neoplastic (N) tissues from twenty gastric cancer patients were collected for the analysis of Sp1, MMP-14, and VEGF expression. Western blot and real-time quantitative RT-PCR indicated that the expression of Sp1, MMP-14, and VEGF was significantly higher in gastric cancer tissues than that of adjacent neoplastic tissues. C, Pearson’s coefficient correlation analysis demonstrated a positive correlation between Sp1 protein and MMP-14 transcript levels in gastric cancer tissues (r = 0.917, P < 0.001). D and E, western blot and real-time quantitative RT-PCR indicated that administration of 0.1 and 0.2 mM MJ to SGC-7901 and MKN-45 cells for 24 hrs, resulted in decreased Sp1 expression than that of solvent-treated (mock) cells. F, ChIP assay and real-time quantitative PCR indicated that administration of 0.1 and 0.2 mM MJ to SGC-7901 and MKN-45 cells for 24 hrs, resulted in decreased Sp1 binding on MMP-14 promoter than that of mock cells. There were no PCR products for “no-antibody” (No Ab) control. The symbols (* and △) indicate a significant decrease and a significant increase from adjacent tissues or mock, respectively.
Zheng et al. BMC Cancer 2013 13:74 doi:10.1186/1471-2407-13-74