Figure 7. The inhibitory effects of telmisartan and candesartan on TPA-induced cell proliferation in colon cancer cells.

(A-D) Inhibitory effects of telmisartan, but not candesartan, on TPA-induced cell proliferation in HT29 cells (A), HCT116 (B), SW480 (C), and CaCo2 (D) with CCK-8 kit assay. After 24 h of plating, 2×10⁵ cells were incubated for 72 h in conditioned media with or without telmisartan, candesartan and/or TPA. Each bar represents the means of six independent experiments. *P<0.05 for the stimulus effect, and **P<0.05 for the inhibitory effect. (E and G) In growth curve assay, HT29 and HCT116 cell numbers were counted daily in three dependent colonies cultured in conditioned media. The values are means of three independent experiments. ×; Control (5%FBS), ▪; TPA (100 nM), ○; telmisartan (30 µM), •; TPA+telmisartan (30 µM), △; candesartan (30 µM), ▴; TPA+candesartan (30 µM). (F and H) Cell numbers in colonies cultured in conditioned media with or without TPA, telmisartan and candesartan on day 5 or 6. *P<0.05 for the stimulus effect, and **P <0.05 for the inhibitory effect. Lane 1; Control (5% FBS white box), 2; TPA (100 nM), 3; TPA+telmisartan (30 µM), 4; TPA+candesartan (30 µM), 5; telmisartan (30 µM), 6; candesartan (30 µM). (I) Knockdown of ADAM12 with siRNA. Probing with an anti-ADAM12 antibody (upper panel) and anti- β-actin antibody (lower panel). (J) Inhibitory effects of telmisartan on TPA-induced cell proliferation in HT29 cells with CCK-8 kit assay following knockdown of ADAM12 with siRNA. *P<0.05 for the stimulus effect, and **P <0.05 for the inhibitory effect. (K) Inhibitory effects of telmisartan and GW9662 on TPA-induced cell proliferation in HT29 cells with CCK-8 kit assay. *P<0.05 for the stimulus effect, and **P<0.05 for the inhibitory effect.