Target, Function and Mechanism of LLS30 in Castration Resistant Prostate Cancer

综述：美国转移性去势抵抗前列腺癌(MCRPC)的治疗模式 退伍军人健康管理局(VHA)在过去几年中发生了重大变化。患有VHA的患者 MCRPC仍在接受雄激素剥夺疗法(ADT)和黄体生成素释放激素的治疗 (LHRH)激动剂最初。然而，最近的一项研究表明，目前77%的VHA mCRPC 在ADT方面取得进展的患者正在接受第二代抗雄激素的进一步治疗：CYP17A1 阿比特龙(ABI)联合泼尼松或雄激素受体(AR)抑制剂苯扎鲁胺(Enza)，而 23%的患者使用化疗药物多西他赛进行治疗。一项事后分析报告称，多西紫杉醇是 在遵循方案进展的患者中，最常见和最有效的首次后续治疗(FST)- 使用ABI进行指定治疗。然而，这些患者中多西紫杉醇的中位治疗时间为4.2 因此，我们的目标是找到延长多西紫杉醇对ABI VHA后mCRPC患者的疗效的方法。 多项研究表明Galectin-1(Gal-1)在肿瘤的形成和侵袭性中起作用 多西紫杉醇耐药CRPC。我们证明在CRPC中Gal-1升高，而Gal-1抑制 抑制细胞生长、侵袭和迁移。基于这些观察，我们现在开发了一部小说 GAL-1抑制剂LLS30，它是以苯并咪唑为基础的，因此毒性较小，疗效优异 与传统的和现有的Gal-1抑制剂相比。LLS30具有显著的细胞毒作用 高表达Gal-1的CRPC细胞株表达Gal-1，但不表达Gal-1，并破坏高Gal1细胞的细胞黏附。LLS30 在高表达Gal-1的mCRPC模型中，也使ABI耐药细胞系对多西紫杉醇敏感。 基于这些观察，我们假设ABI/Enza治疗促进了Gal-1的表达，Gal-1 核易位，在那里它诱导AR剪接变异体的形成，从而诱导对ABI/Enza的抗性。 我们认为Gal-1靶向核膜是由微管动力学介导的，即 通过随后用多西紫杉醇治疗来防止；以及通过核孔进入来防止，这可以通过以下方式来防止 LLS30。多西紫杉醇耐药通常与p-糖蛋白(p-gp)的表达和激活有关，p-gp 促进多药耐药。研究表明，Gal-1诱导p-gp表达；因此LLS30将 通过抑制p-gp的表达和抑制Gal-1的核定位来防止多西紫杉醇耐药。 目的1：确定Gal-1参与多西紫杉醇耐药的机制及其可能的作用 对于LLS30来说，克服这种阻力将检验AR活性抑制Gal-1表达的假设 和/或亚细胞定位，以及核Gal-1是否通过促进 缺乏AR-LBD的AR剪接变异体的表达。此外，我们将确定LLS30是否可以防止Gal- 1通过抑制其与核孔复合体的结合来进行核定位。多西紫杉醇与紫杉醇的合作 LLS30通过抑制Gal-1核转位抑制ABI/Enza耐药CRPC模型进展 也要进行调查，特别是考虑到p-gp的作用。目的2：检测Gal-1在细胞周期调控中的作用 新型抑制剂LLS30对ABI-2患者来源异种移植模型反应的影响 CRPC对多西紫杉醇耐药。PDX肿瘤来源于ABI后CRPC-TO患者的活检材料 多西紫杉醇将用于评估LLS30对CRPC对多西紫杉醇反应的影响。我们将研究 去势、LLS30和/或多西紫杉醇是否影响Gal-1在肿瘤中的定位，以及 LLS30或多西紫杉醇诱导的GAL-1与AR及其剪接变异体的表达密切相关。目标3.调查 进展期患者血清Gal-1水平与多西紫杉醇治疗的关系 ABI/Enza方案在VANCHCS治疗mCRPC。在这里，我们将检验这一假设，即血清Gal- 1在ABI/Enza后的患者中，CRPC与他们随后对多西他赛的反应相关。患者标准 和计划。此外，我们还将确定多西紫杉醇或ABI或Enza治疗是否会影响血清GAL-1水平。

SUMMARY: Treatment patterns for metastatic castration-resistant prostate cancer (mCRPC) at the US Veterans Health Administration (VHA) have changed substantially in the past few years. VHA patients with mCRPC are still treated with androgen deprivation therapy (ADT) with luteinizing hormone releasing hormone (LHRH) agonists initially. Nevertheless, a recent publication demonstrated that currently, 77% VHA mCRPC patients who progress on ADT are being further treated with 2nd generation anti-androgens: the CYP17A1 inhibitor abiraterone (ABI) with prednisone or the androgen receptor (AR) inhibitor enzalutamide (ENZA), while 23% are treated with the chemotherapy agent docetaxel. A post hoc analysis reported that docetaxel was the most common and effective first subsequent therapy (FST) among patients who progressed following protocol- specified treatment with ABI. However, the median docetaxel treatment duration among these patients was 4.2 months; hence, our goal is to find ways to prolong the efficacy of docetaxel in post-ABI VHA mCRPC patients. Multiple studies have pointed to a role for Galectin-1 (Gal-1) in tumor formation and aggressiveness in docetaxel resistant CRPC. We demonstrate that Gal-1 was elevated in CRPC, while inhibition of Gal-1 inhibited cell growth, invasion and migration. Based on these observations, we have now developed a novel Gal-1 inhibitor, LLS30, which is benzimidazole-based, and is therefore less toxic and of superior efficacy compared to conventional and existing Gal-1 inhibitors. LLS30 demonstrated significant cytotoxic effects in Gal-1 expressing, but not Gal-1 low, CRPC cell lines, and disrupted cell adhesion in high Gal1 cells. LLS30 also sensitized ABI-resistant cell lines to docetaxel in models of mCRPC that expressed high Gal-1. Based on these observations, we hypothesize that ABI/ENZA treatment promotes Gal-1 expression, and Gal-1 nuclear translocation, where it induces the formation of AR splice variants that induce resistance to ABI/ENZA. We propose that Gal-1 targeting to the nuclear envelope is mediated by microtubule dynamics, which is prevented by subsequent treatment with docetaxel; and by nuclear pore entry, which may be prevented by LLS30. Docetaxel resistance is often traced to the expression and activation of p-glycoprotein (p-gp), which promotes multi-drug resistance. Studies have shown that Gal-1 induces p-gp expression; hence LLS30 will prevent docetaxel resistance by suppressing p-gp expression and also inhibit Gal-1 nuclear localization. Aim 1: To determine the mechanism of Gal-1 involvement in docetaxel resistance and a potential role for LLS30 in overcoming that resistance will test the hypothesis that AR activity suppresses Gal-1 expression and/or subcellular localization, and whether nuclear Gal-1 induces resistance to ABI/ENZA by promoting expression of AR splice variants that lack the AR-LBD. Further, we will determine whether LLS30 prevents Gal- 1 nuclear localization by inhibiting its binding to the nuclear pore complex. Cooperation between docetaxel and LLS30 to impede progression in ABI/ENZA-resistant CRPC models by inhibiting Gal-1 nuclear translocation will also be investigated, especially in view of a role of p-gp. Aim 2: Test the role of Gal-1 in mediating the effects of the novel inhibitor LLS30 on the response of patient derived xenograft (PDX) models of ABI- resistant CRPC to docetaxel. PDX tumors derived from biopsy material of patients with post-ABI CRPC to docetaxel will be used to evaluate the effects of LLS30 on the response of CRPC to docetaxel. We will examine whether castration, LLS30 and/or docetaxel affect Gal-1 localization in the tumor, and whether translocation of Gal-1 by LLS30 or docetaxel correlate with the expression of AR and its splice variants. Aim 3. To investigate the relationship between serum Gal-1 levels and docetaxel treatment in patients who progress on ABI/ENZA treatment for mCRPC at the VANCHCS. Here we will test the hypothesis that serum levels of Gal- 1 in patients with post-ABI/ENZA CRPC correlate with their subsequent response to docetaxel. Patient Criteria and Plan. Also, we will determine whether docetaxel or treatments with ABI or ENZA affects serum gal-1 levels.