MK591, a Second Generation Leukotriene Biosynthesis Inhibitor, Prevents Invasion and Induces Apoptosis in the Bone-Invading C4-2B Human Prostate Cancer Cells: Implications for the Treatment of Castration-Resistant, Bone-Metastatic Prostate Cancer
Fig 7
Effects of MK591 on Akt and PKC-epsilon.
In (a and b), C4-2B cells were plated as in Fig 5 and then the cells were treated with MK591 as shown and incubated for 24 hours at 37°C. Cell lysate proteins were resolved by SDS-PAGE and levels of PKC-epsilon, or phospho-Akt (Ser-473) and total Akt were detected by Western blot using corresponding phospho-specific or regular antibodies. LY294002 (a PI3K inhibitor) was used as positive control which decreased phosphorylation of Akt but not the total protein of Akt. Note: MK591 does not affect the level of phospho-Akt or total Akt, but significantly decreases the protein level of PKC-epsilon. In (c), effect of FR236924 (an activator of PKC-epsilon) on MK591 treatment-induced loss of the transcriptional activity of c-Myc was detected by c-Myc-luciferase activity. Note: FR236924 significantly prevented the MK591 treatment-induced inhibition of c-Myc transcriptional activity. (d) Shows that MK591 and docetaxel synergistically affect the viability of C4-2B cells at low doses, Cells were plated as in Fig 1, and treated with MK591 and/or docetaxel as indicated for 48 hours. Cell viability was measured by MTS/PES Cell Titer assay as described in the “Methods” section.