Alteration of the miR-let-7c:Lin28 ratio as a predictor of therapy resistance in Prostate Cancer

摘要 前列腺癌是美国男性癌症相关死亡的主要原因之一，仅次于 到肺癌。原发性和晚期前列腺癌最初对雄激素消融治疗有反应，这是 随后，许多患者在短时间内进展为去势抵抗。最近一次 第二代抗雄激素药物苯扎鲁胺已被FDA批准用于治疗 化疗--单纯的前列腺癌和化疗后的前列腺癌。但与生俱来和后天的抵抗力 临床上已经观察到了苯扎鲁胺的治疗，其作用机制仍在研究中。使用 PSA作为生物标记物并不能预测患者可能的预后。 抵抗。识别有助于风险评估和预测哪些患者将做出反应的生物标志物 接受治疗将更好地为治疗选择提供信息，并改善患者护理。MicroRNAs可能是理想的 非侵入性生物标记物由于其对疾病发展的特异性和相称性。MicroRNAs可以 在血液、血清、尿液、血浆等生物体液中分析，以及从这些生物体液中分离的外体中分析。 我们的初步数据显示miR-let-7c在对苯扎鲁胺耐药的前列腺癌中下调，而 它的主要监管者LIN28被上调。我们还表明，let-7c和LIN28都可以可靠地测量 来自人类前列腺癌细胞的外切体中。因此，我们假设更改字母- 7C：LIN28比值可作为预测前列腺癌耐药的潜在指标 癌症。 在目标1中，我们将验证系统研究中的初步数据，该研究涉及测量 前列腺癌组织和UC肿瘤外切体中let-7c和Lin28的表达水平 戴维斯癌症中心生物信息库和前列腺癌生物信息库网络(PCBN) 实时定量聚合酶链式反应。在目标2中，我们将开发生物检测方法来评估肿瘤来源的let-7c：LIN28的状态 人前列腺癌细胞异种移植的外切体。这些生物测定将在有限的时间内进行验证 使用苯扎鲁胺治疗前列腺癌患者的血液样本进行的人类队列研究。血样 在服用苯扎鲁胺和前列腺癌患者的治疗过程中，将在4个时间点采集样本。 衍生的外切体将被分离。Let-7c/LIN28比值预测卵巢癌发生发展的能力 对苯扎鲁胺的耐药性将在测量LET-7c和LIN28水平后进行评估 利用实时荧光定量聚合酶链式反应检测外切体。这些研究将为评估 在一个更大的队列中，let-7c：LIN28的比率预测他们是否对苯扎鲁胺有反应的能力 病人。

Abstract Prostate cancer is one of the leading causes of cancer-related mortality in American men, second only to lung cancer. Primary and advanced prostate cancers respond to androgen ablation therapy initially, which is followed by progression to castration resistance within a short frame of time for many patients. Recently a second-generation anti-androgen, enzalutamide has been approved by the FDA for the treatment of chemotherapy-naïve as well as post-chemotherapy prostate cancers. But innate and acquired resistance to enzalutamide treatment has been observed in the clinic and the mechanisms are still being studied. Use of PSA as a biomarker does not predict the possible outcome of patients with respect to development of resistance. Identification of biomarkers which facilitate risk assessment and predict which patients will respond to treatment would better inform treatment choices and improve patient care. MicroRNAs may serve as ideal non-invasive biomarkers due to their specificity and proportionality to disease development. MicroRNAs can be analyzed in biofluids such as blood, sera, urine, plasma etc., and in exosomes isolated from these biofluids. Our preliminary data show that miR-Let-7c is downregulated in enzalutamide-resistant prostate cancer, while its master regulator, Lin28 is upregulated. We also show that both Let-7c and Lin28 can be reliably measured in exosomes derived from human prostate cancer cells. Hence, we hypothesize that the alteration of the Let- 7c:Lin28 ratio in tumor-derived exosomes may serve as a potential predictor of therapy-resistance in prostate cancer. In aim 1, we will validate preliminary data in a systematic study involving the measurement of expression levels of Let-7c and Lin28 in prostate cancer samples and tumor-derived exosomes from the UC Davis Cancer Center Biorepository and the Prostate Cancer Biorepository Network (PCBN) using quantitative real-time PCR. In aim 2, we will develop bioassays to assess the Let-7c:Lin28 status in tumor-derived exosomes from xenografts of human prostate cancer cells. These bioassays will be validated in a limited cohort human study using blood samples from patients with enzalutamide-treated prostate cancer. Blood samples will be collected at 4 time points during the treatment of patients with enzalutamide and prostate- derived exosomes will be isolated. The ability of the ratio of Let-7c:Lin28 to predict the development of resistance to enzalutamide will be evaluated following the measurement of Let-7c and Lin28 levels in exosomes using quantitative real-time PCR. These studies will provide a rationale for the assessment of the ability of the ratio of Let-7c:Lin28 to predict whether they will respond to enzalutamide in a larger cohort of patients.