whereas substituent with halogens and/or trifuoro methyl or trifluormethoxy gro

Our data implicate S1P in mediating activation of Akt in the context of AC expression. The vast majority of S1P mediated phenomena have been attributed to the signaling of its five GPCRs, S1PR1?5. S1PR 4 and 5 are relatively restricted in their expression to the immune c-Met Inhibitor system and the nervous system. S1PR1?3 are ubiquitously expressed, and have numerous roles in diverse phenomena. S1P is characterized to mediate Gi stimulation of PI3K, and thereby cause activation of Akt as well as MAPK signaling. These effects have been associated with S1PR1 and, to a lesser degree, with S1PR3, and both receptors have been shown to enhance cell proliferation and migration through Rac activation. In contrast, S1PR2 is thought to predominantly couple with G12 and thereby antagonize Akt activation by Rho mediated recruitment of PTEN to the cell membrane. This effect, coupled with its suppression of Rac activity, has resulted in S1P2 being designated as an antimigratory, antiproliferative receptor, which largely Eumycetoma opposes the oncogenic signaling of S1PR1 and 3. The present study breaks this dogma by showing that S1PR2 can activate oncogenic Akt signaling in prostate cancer. It is important to note that S1PR2 couples to Gi, G12/13 and Gq, with effects of G12/ 13 predominating in many functional assays. In our study, interdiction of Gi signaling substantially reduced AC induced Akt activation, suggesting that S1PR2 has adopted a Gi dominant downstream signal. Interestingly, the prostate cancer cell lines studied here had far more abundant S1PR2 Dacomitinib mRNA than S1PR1 or 3, which may explain why inhibition of S1PR2 had an strong impact on cell signaling and phenotype, however it does not explain why a typically tumor suppressive receptor now signals to activate Akt. One hypothesis is that S1PR2 is initially upregulated in response to AC overexpression in neoplastic tissues as a means to suppress the oncogenic effects of AC. In the hyperselective tumor environment, cancer cells may evolve to favor Gi signaling through S1PR2, compounding the oncogenic insult of AC by further increasing the impact of the downstream metabolite S1P. In support of this, we found that primary prostate epithelial cells had equal expression of S1PR1?3, suggesting that receptor expression is altered at some point during malignant transformation, although we did not observe AC induced upregulation of S1PR2 in primary cells. Our study clearly identifies a role for SphK1 in mediating ACinduced Akt activation, with knockout or knockdown of SphK2 having little or no effect. We believe that this may be due to the cellular localizations of the different SphK isoforms. SphK1 has been found to be primarily cytoplasmic or associated with the plasma membrane, whereas SphK2 is largely located in the nucleus or endoplasmic reticulum.