Fig. 7: CeapinA7 reduces BRCA-1, increases DNA damage, and the sensitivity to Adriamycin also in HCT116 p53−/− cells treated by DPE or Thapsigargin.

HCT116 p53−/− cells were pre-treated or not with ceapinA7 (12 μM) for 1 h and then treated or not with DPE (100 μM) or Thapsigargin (Tg) (30 nM) or left untreated, as control, for 48 h. A, B Western blot analysis showing the expression level of BRCA-1, PARP cleavage and γH2AX. β-Actin was used as loading control and one representative experiment is shown. The histograms represent the densitometric analysis of the ratio of specific protein/β-Actin of three different experiments. Data are represented as the mean plus S.D. p value: *< 0.05. HCT116 p53−/− cells were pre-treated or not with ceapinA7 (12 μM) for 1 h and then treated or not with DPE (100 μM) or Thapsigargin (Tg) (30 nM) or left untreated, as control. After 3 h of culture, Adriamycin (1 μg/ml) was added or not to the cultures. C Cell viability was measured by a Trypan Blue exclusion assay after 48 h of culture, the histograms represent the mean ± S.D. of live cells as percent of untreated control cells. p value: *< 0.05. By using the KERN index (R), we found that ceapinA7 induced a synergistic cytotoxic effect when combined with Thapsigargin, Adriamycin and DPE/Adriamycin (R > 1) while in combination with DPE and Thapsigargin/Adriamycin the effect of ceapinA7 was additive (R = 1). D Cell proliferation was measured by MTT assay after 48 h of culture, the histograms represent the mean ± S.D. of the ratio between the OD of treated cells and control cells. p value: *< 0.05.