Characterization of ILEI/LIFR Axis-induced Intracellular Signaling

项目摘要 我们的实验室先前已经确定了转化生长因子β(转化生长因子β)介导的机制 小鼠乳腺上皮向间充质转化(EMT)我们已经展示了 白细胞介素样EMT诱导物(ILEI)蛋白是诱导小鼠乳腺细胞EMT所必需的 在接触转化生长因子β之后。ILEI还被证明可以增加上皮细胞的自我更新能力 EMT后，通过与白血病抑制因子受体(LIFR)的相互作用，提示 ILEI/LIFR信号轴促进乳腺癌干细胞(BCSC)表型。此外，我们的实验室已经证明 转化生长因子β诱导的LIFR上调是ILEI依赖性的。在来自小鼠肿瘤进展模型的细胞中 由我们实验室创造的，在非贴壁细胞培养条件下形成球体的能力减弱如下 不是ILEI就是LIFR击倒。此外，带有ILEI或LIFR基因敲除的细胞原位移植显示 与对照细胞相比，肿瘤生长和转移减少。我们推测转化生长因子β诱导的LIFR 监管导致了转移。 ILEI介导的EMT和BCSC诱导的确切机制尚不清楚。在此，我们的目标是 询问ILEI/LIFR轴介导的转化生长因子β暴露下游影响(1)调控的机制 LIFR蛋白表达和(2)随之而来的自我更新能力和疾病进展的维持 在我们的模型中。在特定目标1中，将检查LIFR启动子序列以确定调控的关键因素 LIFR表达式。在具体目标2中，将在ILEI/LIFR基因敲除之后检查转录数据，以确定 ILEI/LIFR调控基因表达的特征及其与自我更新能力的关系。具体而言 目的3、在体内研究LIFR的作用，以确定其表达对卵巢癌生长的影响。 免疫缺陷小鼠尾静脉注射细胞后的肺部肿瘤。 来自我们实验的数据将表征与BCSC维护和 将有可能确定新的治疗靶点。我们的发现可能会转化为治疗休眠的新方法 并在人类转移性乳腺癌中复发。

Project Summary Our lab has previously identified a mechanism of transforming growth factor beta (TGFβ)-mediated epithelial-to-mesenchymal transition (EMT) in murine mammary epithelium. We have shown that expression of the interleukin-like EMT inducer (ILEI) protein is necessary to induce EMT in murine mammary gland cells following exposure to TGFβ. ILEI has also been shown to increase the self-renewal capacity of epithelial cells following EMT, through its interaction with leukemia inhibitory factor receptor (LIFR), suggesting that the ILEI/LIFR signaling axis promotes breast cancer stem-cell (BCSC) phenotype. Further, our lab has shown that TGFβ-induced upregulation of LIFR is ILEI-dependent. In cells derived from a mouse tumor progression model created by our lab, spheroid formation capacity in non-adherent cell culture conditions is attenuated following either ILEI or LIFR knockdown. Additionally, orthotopic grafts of cells with ILEI or LIFR knockdown display a decrease in tumor growth and metastasis relative to control cells. We hypothesize that TGFβ-induced LIFR regulation contributes to metastases. The precise mechanisms of ILEI-mediated EMT and BCSC induction are unknown. Herein we aim to interrogate ILEI/LIFR axis-mediated mechanisms downstream of TGFβ exposure that influence (1) the regulation of LIFR protein expression and (2) the ensuing maintenance of self-renewal capacity and disease progression in our model. In Specific Aim 1, the LIFR promoter sequence will be examined to identify key factors regulating LIFR expression. In Specific Aim 2, transcriptomic data will be examined following ILEI/LIFR knockout to identify a signature of ILEI/LIFR-regulated gene expression and its association with self-renewal capacity. In Specific Aim 3, the role of LIFR will be examined in vivo to determine the impact of its expression upon outgrowth of pulmonary tumors following tail vein injection of cells into immunodeficient mice. Data from our experiments will characterize a signaling pathway associated with BCSC maintenance and will potentially identify novel therapeutic targets. Our findings may translate to novel treatments for dormancy and relapse in human metastatic breast cancer.