Figure 1.

Metformin inhibits LCA-induced IL-8 expression in HCT116 CRC cells. (A) Three CRC cell lines, SW480, HT29, HCT116, were treated with 10 mM metformin for 1 h. The cells were then incubated with 30 µM LCA for 4 h. Then, mRNA was extracted, and IL-8 expression was evaluated by RT-PCR. (B) HCT116 cells pretreated with 0–20 mM metformin for 1 h were exposed to 30 µM LCA for 4 h. The cells were then extracted for mRNA, and IL-8 expression was evaluated by RT-PCR. (C) HCT116 cells transfected with the pGL2-IL-8 plasmid were pretreated with 0–20 mM metformin for 1 h. The cells were then incubated with 30 µM LCA for 12 h, lysed with passive lysis buffer, and submitted for the luciferase assay. (D) HCT116 cells were pretreated with 0–20 mM metformin for 1 h and incubated with 30 µM LCA for 24 h. The culture media were harvested and utilized for ELISA to check the levels of secreted IL-8 cytokine. Agarose gel images were cropped for clarity of the presentation. ^#P < 0.05 versus control; *P < 0.05 versus LCA. The above data represent the means ± SD from triplicate measurements.