LNCaPH cells were treated with si Vav3, 5 nM docetaxel, or si Vav3 plus Enzastaurin MM 5 nM docetaxel for 48 h. Treatment with si Vav3 Inhibitors,Modulators,Libraries led to the attenuation of Akt phosphorylation Inhibitors,Modulators,Libraries at Ser 473, a site required for Akt activation, and ERK phosphorylation at Thr 202 and Tyr 204, which are sites required for ERK activation, but no effect was observed on JNK phosphoryl ation. Similarly, docetaxel treatment attenu ated Akt and ERK phosphorylation and strongly induced JNK phosphorylation at Thr 183 and Tyr 185, which are sites required for JNK activation. When LNCaPH cells were treated with si Vav3 plus docetaxel, Akt phosphorylation was completely abolished with the inhibition of ERK phosphorylation and JNK acti vation. Figure 2E summarizes the results of possibility that Vav3 induced intracellular signaling may be a therapeutic target for the treatment of HRPC.

LNCaPH cells were transiently transfected with either si Vav3 or si Scr. After 72 h, cells were harvested and subjected to immunoblot analysis, revealing that si Vav3 effectively downregulated the expression of Vav3 com pared with its control expression. Conversely, Vav3 Inhibitors,Modulators,Libraries expression was unaffected by docetaxel treatment. To determine Inhibitors,Modulators,Libraries the docetaxel sensitivity of si Vav3 treated cells, cells transfected with si Vav3 or si Scr were treated with 5 nM docetaxel for 72 h and assayed for cell prolifer ation and live death analyses. Treatment with docetaxel or si Vav3 inhibited cell growth in a time dependent manner, and when LNCaPH cells were treated with si Vav3 in the presence of docetaxel, sensitivity to docetaxel was signifi cantly enhanced.

We further con firmed this enhanced cell growth inhibition with the results of the cell live death assay. The assay stains live cells with a green fluorescence dye and dead cells with a red fluorescence dye. We observed that control si Scr and three independent experiments. These results suggest that LNCaPH cells display Akt and ERK activation Inhibitors,Modulators,Libraries and that si Vav3 negatively regulates PI3K Akt and ERK pathway activation, enhancing the effects of docetaxel. Effects of si Vav3 and docetaxel on the apoptotic cell death of LNCaPH cells To investigate whether the growth inhibitory effects of the combination of si Vav3 and docetaxel may be triggered by increased apoptosis in LNCaPH cells, we evaluated the apoptotic cells by flow cytometry, which assessed a sub G1 population of apoptotic cells, and enzyme linked im munosorbent assay using Cell Death Detection ELISAPLUS. Treatment with 5 nM docetaxel led to in creased apoptosis in LNCaPH cells in a time dependent manner, but the sub G1 population was slightly increased may by si Vav3 alone.