Figure 1
Cisplatin triggers senescence and decreases proliferation. (A) HN30 cells were exposed to CDDP [5 µM] for 24–72 hours and stained with propidium iodide (PI). Flow cytometry was used to ascertain cellular fraction in each phase of the cell cycle. (B) Cells were grown at sub-confluence, treated with CDDP for 24 hours and then allowed to recover for 5 days. After 5 days, the cells were fixed and stained for beta-galactosidase activity. Senescence data are expressed as mean fraction of beta-galactosidase positive cells for each condition. Each experiment was carried out in triplicate (std = standard deviation). (C) Cells were exposed to CDDP for 48 hours. Relative cell number was measured using the Hoechst DNA assay and compared to the control condition. Error bars represent standard deviation; *indicates p < 0.05. Each experiment was carried out in triplicate. (D) Cells were exposed to CDDP for 24 hours and allowed to form colonies. Surviving fraction was ascertained 10–14 days later and expressed as a function of the control condition. Error bars represent standard deviation; *indicates p < 0.05.
