Behavioral stress inhibited apoptosis and delayed prostate tumor involution both in phosphatase and tensin homolog-deficient (PTEN-deficient) prostate cancer xenografts treated with PI3K inhibitor and in prostate tumors of mice with prostate-restricted expression of c-MYC (Hi-Myc mice) subjected to androgen ablation therapy with bicalutamide.
Similarly, IGF-I suppressed BMP4-induced transcription of the Id1, Id2, and Id3 genes that are crucially involved in prostate tumor progression through PI3K-dependent and mTORC1/2-dependent mechanisms.
We investigated the role of the PI3K-Akt signaling pathway in the invasion of prostate cancer cell lines and activation of this pathway in primary human prostate tumors.
These data show that apoptosis induced by blockade of the PI3K pathway in prostate tumor cells is mediated by an autocrine Fas/FasL apoptotic mechanism and the Fas apoptotic pathway is both necessary and sufficient to mediate apoptosis by PI3K inhibition.