TIC10 anti-tumor effect through regulation of Foxo3a and TRAIL

描述（由申请人提供）：TRAIL的效力和安全性促使重组蛋白作为一种新的人类癌症治疗方法进行临床试验。虽然TRAIL在杀伤肿瘤细胞方面非常活跃，但重组TRAIL的药物特性限制了其疗效，如血清半衰期短、不稳定以及无法穿过完整的血脑屏障。为了克服这些限制，我们确定了TRAIL基因的小分子诱导剂TIC10，它在稳定性、生物利用度、穿越血脑屏障的能力、生产成本和活性谱方面优于重组TRAIL。重要的是，我们的数据显示TIC10在几种侵袭性和治疗抵抗性癌症中高度活跃。在机制水平上，TIC10可引起有效的抗肿瘤作用和TRAIL诱导，这是由转录因子Foxo3a介导的，Foxo3a直接调控TRAIL基因启动子。此外，我们发现TIC10导致Akt和ERK的双重失活，从而抑制它们对Fox3a的组成磷酸化，并增强其向细胞核的易位和与TRAIL基因启动子的结合（Allen等人，Science Translational Medicine, in Press, 2013）。我们假设TIC10诱导有效的抗肿瘤作用需要Akt-和erk介导的Foxo3a核易位和TRAIL基因的转录激活。为了解决这一假设，我们提出以下具体目标：具体目标#1：确定tic10诱导的对Foxo3a表达、磷酸化和亚细胞定位的影响；具体目标#2：阐明Akt和ERK激酶在TIC10作用机制中的作用；具体目标#3：确定FOXO家族成员对TRAIL基因转录的差异调控。这些研究将全面了解TIC10如何利用Foxo3a来实现其有效的抗肿瘤活性，并有可能揭示具有生物学意义的Foxo3a活性的新调控机制。包括原位异种移植和转基因小鼠在内的临床前癌症模型以及原发人类肿瘤标本将证实TIC10和Foxo3a的有效性并验证其机制发现。总之，这些研究将阐明涉及Foxo3a和一流分子TIC10的关键和新的调控机制，从而深入了解其作用机制以及结肠癌疾病进展背景下的临床样本。我们的研究将通过临床前实验室研究的进一步发展，促进一种新型抗癌治疗剂的临床转化。

DESCRIPTION (provided by applicant): The potency and safety of TRAIL has prompted clinical trials with the recombinant protein as a novel treatment for human cancer. While TRAIL is very active in killing tumor cells, recombinant TRAIL possesses drug properties that limit its efficacy such as short serum half-life, instability, and the inability to cross the intact blood-brin barrier. To overcome these limitations we identified a small molecule inducer of the TRAIL gene, TIC10 that is superior to recombinant TRAIL in terms of stability, bioavailability, ability to cros the blood-brain barrier, cost of production, and spectrum of activity. Importantly, our data shows that TIC10 is highly active in several aggressive and therapy-resistant cancers. On a mechanistic level, TIC10 causes potent antitumor effects and TRAIL-induction that is mediated by the transcription factor Foxo3a, which directly regulates the TRAIL gene promoter. Furthermore, we found that TIC10 results in the dual inactivation of Akt and ERK, thereby inhibiting their constitutive phosphorylation of Fox3a and potentiating its translocation to the nucleus and binding to the TRAIL gene promoter (Allen et al, Science Translational Medicine, In Press, 2013). We hypothesize that TIC10 induces potent antitumor effects that require Akt- and ERK-mediated Foxo3a nuclear translocation and transcriptional activation of the TRAIL gene. To address the hypothesis we propose the following specific aims: Specific Aim #1: Identify TIC10-induced effects on Foxo3a expression, phosphorylation, and subcellular localization; Specific Aim #2: Elucidate the role of Akt and ERK kinases in the mechanism of action of TIC10; Specific Aim #3: Determine the differential regulation of TRAIL gene transcription by FOXO family members. These studies will create a comprehensive molecular understanding of how TIC10 harnesses Foxo3a to achieve its potent antitumor activity and also has the potential to undercover novel regulatory mechanisms of Foxo3a activity that are biologically significant. Preclinical cancer models including orthotopic xenografts and transgenic mice along with primary human tumor specimens will substantiate the efficacy and validate the mechanistic findings regarding TIC10 and Foxo3a. Together, these studies will elucidate key and novel regulatory mechanisms involving Foxo3a with the first-in-class molecule TIC10 to yield insight regarding its mechanism of action as well as in clinical samples in the context of colon cancer disease progression. Our studies will facilitate the clinical translation of a novel anti-cancer therapeutic agent through further development in preclinical laboratory studies.