Research Paper Volume 12, Issue 1 pp 611—627

Aspirin enhances the sensitivity of colon cancer cells to cisplatin by abrogating the binding of NF-κB to the COX-2 promoter

Figure 2. Aspirin synergizes the inhibiting effect of Cisplatin on cell proliferation in colon cancer cells. (A) Human colon cancer cells RKO and LoVo were treated with Cisplatin alone or Aspirin alone or their combination at indicated dose for 48 h. The representative images of cell morphology were taken by inverted microscope, Scale bars, 200 μm. (B) The colony formation assay of human colon cancer cells RKO and LoVo treated with Cisplatin alone or Aspirin alone or their combination at indicated dose was taken to detect the capacity of cell proliferation (n=4). (C) The expression levels of main PI3K/AKT signaling pathway-related proteins p110-α, p110-β, p110-γ, p-p85, p-PDK1, Akt, p-Akt(S473) and Pten in human colon cancer cell RKO and LoVo treated with Cisplatin alone (15 μM) or Aspirin alone (10 mM) or their combination for 48 h were detected by Western blot assay (n=3). (D) Human colon cancer cells RKO and LoVo were treated with Cisplatin alone (15 μM) or Aspirin alone (10 mM) or their combination for 48 h, and the expression levels of main RAF-MEK-ERK signaling pathway-related proteins p-c-Raf, p-mek1/2, Erk1/2 and p-Erk1/2 were detected by western blot assay (n=3). (E) Human colon cancer cells RKO and LoVo were pretreated with PI3K inhibitor LY294002 (50 μM) or MEK inhibitor U0126 (10 μM) for 8 h, and then incubated with combination of Aspirin and Cisplatin. After 48 h, cell viability was determined by MTT analysis (n=6). (F) Human colon cancer cells RKO and LoVo were transfected with specified siRNAs for 24 hours, and then incubated with the combination of Aspirin and Cisplatin. After 48 h, cell viability was determined by MTT analysis (n=6). All the data were presented as means ± SD, *P<0.05, **P<0.01, ***P<0.001.