Targeting early events in prostate cancer lineage plasticity

项目总结/摘要 前列腺癌是男性最常见的非皮肤癌。前列腺癌细胞依赖于 一种被称为雄激素受体（AR）的转录因子，由雄激素睾酮激活， 双氢睾酮因此，晚期前列腺癌患者的有效治疗是 雄激素剥夺疗法，阻断雄激素的作用，抑制AR，并停止生长， 前列腺癌细胞虽然这种形式的治疗对晚期前列腺癌非常有效， 这种疗法的有效性最终将导致前列腺癌细胞产生耐药性。约25-30% 前列腺癌治疗的压力会导致前列腺癌细胞转化为细胞癌， 他们不再像原来的疾病。这些前列腺癌细胞呈现出 通过一个叫做谱系可塑性的过程来改变细胞类型。这些谱系可塑性前列腺癌是 非常难以治疗，因为它们不含AR，并且没有有效的治疗方法。 此外，标准前列腺癌疗法可引起前列腺癌谱系的过程 可塑性是知之甚少。这项提案旨在了解前列腺癌谱系的生物学 可塑性和开发新的治疗策略来治疗，预防或逆转这种疾病阶段。我们 初步数据表明，干细胞转录因子KLF 5是上调的标准前列腺 抑制AR的癌症疗法。KLF 5的上调增强了雄激素非依赖性生长， 前列腺癌细胞，以及迁移和集落形成表型。从功能上讲， 由上调的KLF 5启动的程序与由AR激活的转录程序冲突。因为 AR转录程序控制前列腺癌细胞身份，KLF 5上调打破了这一点 身份和促进前列腺癌细胞谱系可塑性的非常早期的步骤。我们假设 靶向治疗诱导的前列腺癌谱系可塑性的这一早期步骤将阻断导致前列腺癌的后期事件。 非常具有攻击性，难以治疗的疾病表现。我们已经确定ERBB 2为焦点 这场AR和KLF 5之间的拉锯战，并表明ERBB 2抑制剂可以阻断AR和KLF 5的致癌作用。 KLF 5。为了推进这些发现并确定该途径中的其他治疗漏洞，我们建议 2具体目标在目的1中，我们将研究CRPC中KLF 5的诱导和谱系可塑性表型。在目标2中， 我们将测试阻断CRPC谱系可塑性的早期步骤的治疗潜力。成功的结果可以 导致临床试验的快速发展，测试这些治疗策略用于治疗或预防 谱系可塑性前列腺癌。

PROJECT SUMMARY/ABSTRACT Prostate cancer is the most common non-cutaneous cancer in males. Prostate cancer cells are dependent on a transcription factor called the androgen receptor (AR), which is activated by the androgens testosterone and dihydrotestosterone. Accordingly, an effective treatment for patients with advanced prostate cancer is androgen deprivation therapy, which blocks the effects of androgens, inhibits the AR, and halts the growth of prostate cancer cells. Although this form of treatment is very effective for advanced prostate cancer, the stress of this therapy will eventually lead to the prostate cancer cells developing resistance. In approximately 25-30% of cases, the stress of prostate cancer therapy will cause the prostate cancer cells to transform into cellular states where they no longer resemble the original disease. These prostate cancer cells take on features of alternative cell types through a process called lineage plasticity. These lineage plastic prostate cancers are very difficult to treat because they do not contain AR and there are no effective therapeutics available. Additionally, the processes by which standard prostate cancer therapies can cause prostate cancer lineage plasticity is poorly understood. This proposal seeks to understand the biology of prostate cancer lineage plasticity and develop new therapeutic strategies to treat, prevent, or reverse this disease stage. Our preliminary data demonstrates the stem cell transcription factor KLF5 is up-regulated by standard prostate cancer therapies that inhibit the AR. Up-regulation of KLF5 enhances androgen-independent growth of prostate cancer cells, as well as migration and colony formation phenotypes. Functionally, the transcriptional program initiated by up-regulated KLF5 clashes with the transcriptional program activated by the AR. Because the AR transcriptional program controls prostate cancer cell identity, KLF5 up-regulation breaks down this identity and promotes very early steps in lineage plasticity of prostate cancer cells. We hypothesize that targeting this early step in therapy-induced prostate cancer lineage plasticity will block later events that lead to very aggressive, treatment-resistant manifestations of the disease. We have identified ERBB2 as a focal point of this tug-of-war between AR and KLF5, and shown that ERBB2 inhibitors can block the oncogenic effects of KLF5. To advance these findings and identify additional therapeutic vulnerabilities in this pathway, we propose 2 Specific Aims. In Aim 1, we will study induction of KLF5 and lineage plasticity phenotypes in CRPC. In Aim 2, we will test therapeutic potential of blocking early steps in CRPC lineage plasticity. A successful outcome can lead to rapid development of clinical trials testing these therapeutic strategies for treatment or prevention of lineage plastic prostate cancer.