Figure 3.

Side population response to chemotherapy, hypoxia, and radiation. (A) Cells were exposed to clinically relevant increasing doses of gemcitabine: 0.2µg/ml; 0.01mg/ml; and 1mg/ml. There is no statistical significance in the relative proportion of the SP in 4 of 5 cell lines tested. Only in BxPC-3 does there appear to be a statistical trend (+, 0.01 < p < 0.05, adjusted to multiple comparisons) where 0.01mg/ml and 1mg/ml may increase the relative proportion of the side population relative to control cell. (Significance evaluated by Dunnett’s test, n = 3). (B) Cells exposed to 1% oxygen were compared with cells under normal culture conditions in terms of side population. There is a statistically significant increase in side population under hypoxic conditions in panc-1 and Su86.86 cells. (*, p = 0.009 and p = 0.004, respectively). In SW1990 cells, there is a statistical trend (+, p = 0.015) toward increased side population with hypoxic exposure (adjusted to multiple comparisons). Significance was evaluated by a 2-sample t-test. (C) Cells exposed to 4 Gy radiation were compared with cells under normal culture conditions. Although in 2 of 4 cell lines tested the SP increased after radiation, there is no statistically significant difference between radiated cells and control cells. Significance was evaluated by a 2- sample t-test. Results are an average of 3 repetitions.