Table 3.
[Na]i and [Ca] are represented to rise starting 2–6 hours and stay elevated for up to 24 hours following exposure of PC3 cells to the antineoplastic drugs taxotere or VP16.
| Exposure Time (in hours) | Change in SBFI ratio | [Na]i change (in mM) | Normalized [Ca]i (Fura II/AM(in × 102)) | |
| Ionomycin | Monensin | |||
| 0 | 1.00 ± 0.02 | 0 | 1.0 | 1.0 |
| 2 | 1.03 ± 0.02 | 1.02 ± 0.02 | - | - |
| 4 | - | - | - | - |
| 5 | - | - | 1.21 ± 0.24+ | 1.82 ± 0.21++ |
| 6 | 1.1 ± 0.12* | 1.13 ± 0.11** | 1.22 ± 0.12* | 1.22 ± 0.14** |
| 15 | 1.08 ± 0.41* | 1.06 ± 0.52** | 1.81 ± 0.22 | - |
| 18 | 1.11 ± 0.12 | - | 1.62 ± 0.21+ | 2.61 ± 0.32++ |
| 22 | 1.14 ± 0.21 | - | 1.52 ± 0.13+ | 2.41 ± 0.32++ |
| 25 | 1.09 ± 0.13 | - | 2.04 ± 0.4 1 | - |
Student 't' test P values are shown as * vs ** non-significant and + vs ++ significant P < 0.0001. PC3 cells were plated in black, low autofluorescent 96 well plates. Taxotere or VP16 was added at indicated times prior to measurement with ion sensing fluorescent dyes for Na+(SBFI/AM, Molecular Probes; left panel) or Ca++(Fura II/AM, Molecular Probes). Following drug exposure and dye loading, plates were run on Titretek Fluroscan II fluorescent plate reader and ratios obtained from 345 versus 390 nm excitation (with 510 nm emission). Each reading represents a minimum of 5 wells from each experiment. [Ca]i and [Na]i are manipulated with ionophores (ionomycin, monensin) combined with changes in extracellular ions. All mean ion concentrations at 6 hours or later were greater than control (p < 0.05). Ratios were plotted as changes relative to control (see Figure 6).