selleckchem However, activation of the AR can also activate the PI3K pathway. Additionally, activa tion of the PI3K pathway can activate cell cycle through bypassing the AR via mTOR/RPS6. Comparison of phosphoprotein alterations between LNCaP, MDA PCa 2b, and PC3 cell lines The differences between the signaling of the three different cell lines used were examined by taking the mean phospho protein level across Inhibitors,Modulators,Libraries all treatments, with the exception of inhibitor treatments in LNCaP cells. Several observations were noted in this data including the consistent trend across p Akt, p RPS6, and p GSK3 of higher values in the LNCaP cells, somewhat reduced values in the PC3 cells, and the lowest amount of phosphoprotein in MDA PCa 2b cells. These phosphosites are part of the PI3K pathway which likely explains their similar levels of activation.

When p Erk levels were measured in MDA Inhibitors,Modulators,Libraries PCa 2b cells, consistently lower amounts of this phosphoprotein were found as compared to LNCaP and PC3 cells. Based on the substantial weight placed on the p Erk re gression coefficient, this explains one of the major reasons for reduced castration resistance in MDA PCa 2b cells. A final observation made regarding the mean phospho protein levels across all treatments was the decreasing levels of phosphorylation in JNK from MDA PCa 2b cells to LNCaPs Inhibitors,Modulators,Libraries and then PC3 cells. Ini tially, this was a counterintuitive observation due to the fact that this phosphosite has previously been described as an oncogene, and we have measured castration resistance in the cell lines inverse to the amount of p JNK.

However, this observation corrobo rates recent work indicating that JNK acts as an oncogene in tumor development and a tumor suppressor in regards to castration resistant growth. In order to better illustrate the activation of phosphopro teins Inhibitors,Modulators,Libraries between cell lines in response to treatments, graphs were created which plot the phosphoprotein response as a function of edge thickness. Upon examining these graphs substantial variation between the cell lines is observed with the most castration resistant cell line, PC3, having the weakest response generally to the various treatments, followed by moderate responses in LNCaP cells, and strong sensitivity to certain growth factors in MDA PCa Inhibitors,Modulators,Libraries 2b cells. Furthermore, there were differences between the cell lines in response to the same growth factor.

In PC3 and LNCaP cells EGF stimu lates Erk to various extents, however in MDA PCa 2b cells EGF had little effect on Erk and strongly increased U0126 manufacturer p RPS6 along with IGF1 which was not seen to have an effect LNCaP or PC3 cells. Modeling the effect of treatments and targeted inhibitors The effect of treatment with five targeted kinase inhibitors on protein phosphorylation and the LNCaP cell survival in androgen depleted media as compared to controls can be seen.