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 4. Aspirin enhanced the Cisplatin-induced apoptosis in colon cancer cells. (A) A FACS analysis was used to detect cell apoptosis in human colon cancer cells RKO and LoVo treated with Cisplatin alone or Aspirin alone or their combination at indicated dose for 48 h. The percentage of apoptotic cells was further calculated (n=4). (B) Human colon cancer cells RKO and LoVo treated with cisplatin alone or aspirin alone or their combination at indicated dose for 48 h were stained with acridine orange and ethidium bromide to observe cell apoptosis. The representative images were taken by inverted fluorescence microscope. Scale bars, 200 μm (n=3). (C) The expression levels of main apoptosis-related proteins PARP, cleaved PARP, Bcl-2 and Bax in human colon cancer cell RKO treated with Cisplatin alone (15 μM) or Aspirin alone (10 mM) or their combination for 48h were detected by western blot assay (n=3). (D) Immunofluorescence assay of human colon cancer cell LoVo treated with Cisplatin alone (2.5 μM) or Aspirin alone (4 mM) or their combination for 48 h was implemented to monitor cytochrome-c release from intermembrance space of mitochondria into cytoplasm. The representative images were taken by laser scanning confocal microscope. Scale bars, 25 μm (n=3). Data were presented as means ± SD, *P<0.05, **P<0.01, ***P<0.001.