Role of Tumor Stem Cells Recurrent Prostate Cancer

从初始的癌症干细胞（CSC）到临床意义，最终到治疗失败后的复发，癌症的进展是CSC和“干细胞生态位”之间不断演变的相互作用的高潮。本研究假设雄激素剥夺干扰了前列腺内皮细胞调节前列腺组织微环境中雄激素环境和干细胞“生态位”的关键作用，促进/加速去势复发性前列腺癌的发生。为了验证该假设，我们提出以下具体目标。目的1将描述内皮细胞小泡在循环雄激素穿过内皮细胞屏障的胞吞作用，循环雄激素的内吞作用，导致与内皮细胞稳态和信号传导相关的基因的ar转激活，以及通过循环雄激素的细胞表面受体介导的“非基因组信号传导”中的作用。目的2将确定雄激素剥夺诱导的前列腺内皮细胞的杀伤是否会导致前列腺微血管内皮细胞的短暂或不可逆的扰动，从而导致组织雄激素环境的失调（使用LC/MS/MS表征），以及独特的、可靶向的“表位”或“血管地址”的产生/揭露（使用噬菌体肽展示技术表征）。目的3将确定雄激素剥夺对前列腺干细胞与成体干细胞（ASCs）中差异表达的基因和基因通路的影响，鉴定前列腺ASCs/CSCs的细胞表面“表位”指纹，并确定干细胞“生态位”的扰动是否会导致前列腺CSCs中HNF-4（正方形）转录网络的表观遗传调节失调。Aims 1-3中产生的数据和试剂将支持Aim 4的研究，重点是开发利用雄激素剥夺的新方法，通过验证：雄激素剥夺使ASC/CSC暴露于靶向治疗；可以抑制循环雄激素的胞吞作用，而不破坏内皮细胞的稳态；内皮细胞启动的ASCs/CSCs信号可以被重新编程，诱导干细胞退出“生态位”并致力于分化。

The progression of a cancer from the initiating cancer stem cell (CSC) to clinical significance, and ultimately to recurrence after treatment failure, is the culmination of a continuously evolving reciprocal interaction between the CSC and the "stem cell niche". The hypothesis of this proposal is that androgen deprivation perturbs the critical role of the prostate endothelial cell in regulation of the androgenic milieu of the prostate tissue microenvironment, and in regulation of the stem cell "niche", facilitating/accelerating the emergence of castration-recurrent prostate cancer To validate the hypothesis, the following Specific Aims are proposed. Aim 1 will characterize the role of endothelial cell caveolae in transcytosis of circulating androgens across the endothelial cell barrier, in endocytosis of circulating androgens resulting in AR-transactivation of genes associated with endothelial cell homeostasis and signaling, and in "non-genomic signaling" mediated through cell surface receptors for circulating androgens. Aim 2 will determine if androgen-deprivation induced killing of prostate endothelial cells results in transient, or irreversible, perturbation of the endothelial cells of the prostate microvasculature resulting in dysregulation of the tissue androgenic milieu (characterized using LC/MS/MS) and in creation/unmasking of unique, targetable "epitopes" or "vascular addresses" (characterized using phage peptide-display technology). Aim 3 will identify the effect of androgen deprivation on genes and gene pathways that are differentially expressed in prostate CSCs compared to adult stem cells (ASCs), identify the cell surface "epitope" fingerprint of prostate ASCs/CSCs, and determine if perturbation of the stem cell "niche" results in epigenetically-modulated dysregulation of the HNF-4(square) transcription network in prostate CSCs. The data and reagents generated in Aims 1-3 will support the studies of Aim 4 focused on development of novel approaches for utilizing androgen-deprivation to enable prostate-specific therapies by validating that: androgen deprivation exposes the ASC/CSC to targeted therapy; transcytosis of circulating androgens can be inhibited without perturbation of endothelial cell homeostasis; and endothelial cell initiated signaling to ASCs/CSCs can be reprogrammed to induce the stem cell to exit the "niche" and commit to differentiation.