SCAMP3 as a regulator of EGFR/STAT3 axis in triple-negative breast cancer

项目摘要 这项提案将调查分子驱动程序，有助于发展的一个最 侵袭性和转移性乳腺癌。三阴性乳腺癌（TNBC）的特征是： 缺乏激素受体（雌激素和孕激素）和HER 2表达， 20%的乳腺癌。由于其异质性和缺乏确定的特异性分子靶点，TNBC 治疗仍然具有挑战性。因此，本研究试图阐明分泌载体的分子作用， 相关膜蛋白3（SCAMP 3）对TNBC发病机制的影响，目的是开发新的治疗方法 这将提高患者的存活率。最近，SCAMP 3被发现过表达，并与 在肝细胞癌、黑色素瘤、神经胶质瘤和乳腺癌中预后不良，这表明， SCAMP 3在肿瘤发生中具有关键作用。然而，SCAMP 3如何促进TNBC的分子机制 进展知之甚少。SCAMP 3是表皮生长因子受体（EGFR）运输的调节剂 内体膜促进受体再循环。EGFR介导的内吞作用是一种机制， 癌症相关信号蛋白的转运，如信号转导子和转录激活子3 （STAT3）。EGFR和STAT 3与TNBC增殖、侵袭、转移和癌症相关。 干细胞（CSC）维持。我们的目标是确定SCAMP 3促进 TNBC的进展，并确定SCAMP 3/EGFR和STAT 3信号通路之间的相互作用。我们 假设：1）SCAMP 3/EGFR介导的内吞作用调节STAT 3的活化。2)SCAMP3 信号传导途径通过EGFR/STAT 3的调节促进和维持TNBC干性，和3） SCAMP 3有助于TNBC肿瘤形成和转移。为了验证这些假设，我们提出了 以下目的：1）阐明SCAMP 3对STAT 3激活的作用机制; 2）确定SCAMP 3在STAT 3激活中的作用。 SCAMP 3在TNBC和CSC中经由STAT 3调节的调节： 2b）研究SCAMP 3在肿瘤发生和分化中的作用， 转移我们提出的实验将监测EGFR和STAT 3的内化，STAT 3 DNA结合， 活性和转录活性。我们将确定维持癌症干性的相关驱动基因， 使用RNAseq的SCAMP 3过表达细胞，这将在患者样本中得到证实。这些研究表明， 有可能迅速转化为临床，并显著减少与疾病相关的死亡发生率和数量。 TNBC的。

Project Summary This proposal will investigate the molecular drivers that contribute to the progression of one of the most aggressive and metastatic types of breast cancer. Triple Negative Breast Cancer (TNBC) is characterized by the lack of hormone receptors (estrogen and progesterone) and HER2 expression and accounts for approximately 20% of all breast cancers. Due to its heterogeneity and dearth of defined specific molecular targets, TNBC treatment remains challenging. Accordingly, this study seeks to elucidate the molecular role of secretory carrier- associated membrane protein 3 (SCAMP3) on TNBC pathogenesis, with the goal of developing new therapies that will improve the survival rate of patients. Recently, SCAMP3 has been found overexpressed and associated with poor prognosis in hepatocellular carcinoma, melanoma, glioma, and breast cancer, suggesting that SCAMP3 has a key role in oncogenesis. However, the molecular mechanisms of how SCAMP3 promotes TNBC progression are poorly understood. SCAMP3 is a regulator of epidermal growth factor receptor (EGFR) trafficking within endosomal membranes promoting receptor recycling. EGFR mediated endocytosis is a mechanism of transport of cancer-associated signaling proteins, such as signal transducer and activator of transcription 3 (STAT3). EGFR and STAT3 have been associated with TNBC proliferation, invasion, metastasis, and cancer stem cell (CSC) maintenance. Our objectives are to determine the mechanisms by which SCAMP3 promotes TNBC progression and determine the interplay between SCAMP3/EGFR and STAT3 signaling pathways. We hypothesize that: 1) SCAMP3/EGFR mediated endocytosis regulates the activation of STAT3. 2) SCAMP3 signaling pathway promotes and maintains TNBC stemness via the modulation of EGFR/STAT3, and 3) SCAMP3 contributes to TNBC tumor formation and metastasis. To test these hypotheses, we propose the following aims: 1) To elucidate the mechanism of action of SCAMP3 on STAT3 activation; 2) Define the role of SCAMP3 in TNBC and CSCs regulation via STAT3 modulation: 2a) To elucidate the molecular mechanisms of SCAMP3 in CSCs maintenance in vitro; 2b) To investigate the effect of SCAMP3 in tumorigenesis and metastasis. We propose experiments that will monitor EGFR and STAT3 internalization, STAT3 DNA-binding activity, and transcriptional activity. We will identify the relevant driver genes that maintain cancer stemness in SCAMP3 overexpressing cells using RNAseq, which will be confirmed in patient samples. The studies have the potential to be rapidly translated to the clinic and significantly reduce the incidence and number of deaths related to TNBC.