A novel mitotic regulatory axis in neuroendocrine prostate cancer

神经内分泌前列腺癌(Nepc)是抗去势转移性前列腺癌的致死性亚型。 (MCRPC)具有侵袭性的临床特征和较差的总存活率。虽然从头开始很少发生，但 发生于前列腺癌(PAC)的与治疗相关的NEPC(t-NEPC)的发生率约为25%或更高 晚期mCRPC，众所周知，它很难治疗，而且对抗雄激素治疗耐药。有一件急事 需要新的靶点和治疗方法。在这项研究中，我们试图确定pkd在t-nepc和开发中的作用。 PKD抑制剂治疗t-nepc的潜力。PRKD被扩增和/或上调 在近60%的NEPC肿瘤中。PKD，尤其是PKD2的蛋白表达和活性在NEPC中升高 肿瘤组织。敲除NEPC细胞中的主要PKD PKD2/3，减少NE生物标志物，抑制 体内细胞增殖/存活和肿瘤生长，而PKD2过表达通过促进NE编程 诱导NE标记和抑制AR靶向基因，这与主要驱动因素N-myc的作用平行 NEPC。PKD2的过度表达也赋予雄激素非依赖性，并降低对 雄激素敏感的PAC细胞中的化疗药物。我们进一步鉴定了AURKA/Aurora-A激酶 一种新的PKD下游靶点。Aurora-A，一种关键的有丝分裂调节因子，与 N-myc在NEPC肿瘤中，通过结合和稳定N-myc促进NEPC进展。我们的数据显示 Aurora-A/N-myc复合体的稳定需要PKD活性。PKD表型的过表达， 当PKD被阻断时，N-myc在前列腺癌细胞中的功能被阻断，提示PKD在前列腺癌中的作用 调节Aurora-A/N-myc复合体。此外，PKD对Aurora-A的稳定是有丝分裂所必需的 进入，这一功能可能有助于紫杉烷类药物的治疗抵抗。重要的是，对PKD的抑制 PKD抑制剂CRT0066101(CRT)阻断NEPC肿瘤细胞的增殖/存活、迁移/侵袭和 抑制NEPC肿瘤移植瘤生长，减少体内骨转移。CRT还具有协同效应 多西紫杉醇和PI3K抑制剂在NEPC细胞中的作用，提示它们在联合治疗中的潜在应用。基于 这些发现，我们假设，增加PKD的表达和活性促进有丝分裂编程 Aurora-A/N-myc复合体的稳定性影响N-myc驱动的t-NEPC进程。我们进一步 假设PKD抑制剂将衍生出一种新的治疗策略，以更好地治疗NEPC。我们建议：目标： 1.确定PKD作为t-NEPC的潜在生物标志物，并评估PKD激活的功能相关性 T-nepc细胞治疗耐药的有丝分裂程序。目的2.检验PKD促进t-NEPC的假设 通过稳定Aurora-A/N-myc复合体来影响N-myc驱动的肿瘤发生。目标3.确定 PKD抑制剂对转移性NEPC小鼠模型和TRAMP的治疗潜力 老鼠。

Neuroendocrine prostate cancer (NEPC) is a lethal subset of metastatic castration-resistant prostate cancer (mCRPC) with aggressive clinical features and poor overall survival. Although rarely occurs de novo, the treatment-related NEPC (t-NEPC) derived from prostatic adenocarcinoma (PAC) can arise in about 25% or more late stage mCRPC, which is notoriously hard to treat and resistant to antiandrogen therapy. There is an urgent need for novel targets and therapies. In this study, we seek to determine the roles of PKD in t-NEPC and exploit the therapeutic potential of PKD inhibitors for the treatment of t-NEPC. PRKDs were amplified and/or upregulated in nearly 60% of NEPC tumors. PKD, particularly PKD2, protein expression and activity were elevated in NEPC tumor tissues. Knockdown of PKD2/3, the predominant PKDs in NEPC cells, decreased NE biomarkers, inhibited cell proliferation/survival, and tumor growth in vivo, while PKD2 overexpression promoted NE programing by inducing NE markers and suppressing AR-targeted genes, which paralleled the effects of N-myc, a major driver of NEPC. Overexpression of PKD2 also conferred androgen independence and reduced sensitivity to chemotherapeutic agents in in androgen-sensitive PAC cells. We further identified AURKA/Aurora-A kinase as a novel downstream target of PKD. Aurora-A, a key mitotic regulator that is co-amplified and upregulated with N-myc in NEPC tumors, promotes NEPC progression by binding and stabilizing N-myc. Our data indicated that PKD activity was required for the stabilization of Aurora-A/N-myc complex. Overexpression of PKD phenocopied, while knockdown of PKD blocked, the functions of N-myc in prostate cancer cells, implying a role of PKD in regulating Aurora-A/N-myc complex. Moreover, the stabilization of Aurora-A by PKD is necessary for mitotic entry, a function that may contribute to taxane-based therapy resistance. Importantly, inhibition of PKD by the PKD inhibitor CRT0066101 (CRT) blocked NEPC tumor cell proliferation/survival, migration/invasion, and suppressed the growth of NEPC tumor xenografts and reduced bone metastasis in vivo. CRT also synergized with docetaxel and PI3K inhibitor in NEPC cells, implying their potential use in combination therapy. Based on these findings, we hypothesize that increased PKD expression and activity promote mitotic programing and Aurora-A/N-myc complex stability to impinge upon N- myc-driven t-NEPC progression. We further posit that PKD inhibitors will derive a new therapeutic strategy to better treat NEPC. We propose to: Aim 1. Determine PKD as a potential biomarker for t-NEPC and assess the functional relevance of PKD-activated mitotic programing to therapeutic resistance in t-NEPC. Aim 2. Test the hypothesis that PKD promotes t-NEPC by stabilizing Aurora-A/N-myc complex to impinge upon N-myc-driven oncogenesis. Aim 3. Determine the therapeutic potential of PKD inhibitors for treatment of NEPC in a metastatic NEPC mouse model and TRAMP mice.