Anthrax Toxin Receptor as a marker and target of breast cancer stem cells

炭疽毒素受体作为乳腺癌干细胞的标记和靶标

• 批准号: 8113776
• 负责人: Harikrishna Nakshatri
• 金额: $ 20.1万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-17 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8113776
• 关键词: Affinity; Archives; Basal Cell; Binding; Biological Assay; Biological Markers; Breast; Breast Cancer Cell; CD44 gene; Cancer cell line; Cancerous; Cell division; Cell surface; Cells; Cleaved cell; Collagen; Data Set; Disease; Drug resistance; Dyes; Endothelial Cells; Epithelial; Epithelial Cells; Estrogen Antagonists; Extracellular Domain; Future; Gene Expression; Genes; Heterogeneity; Immunohistochemistry; In Vitro; Ligands; Malignant Neoplasms; Mammary Neoplasms; Mammary gland; Matrix Metalloproteinases; Measures; Mediating; Molecular Profiling; NOD/SCID mouse; Neoplasm Metastasis; Nodal; Normal Cell; Nuclear; Nuclear Receptors; Outcome; PKH 26; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Phosphorylation; Play; Property; Radiation; Recurrence; Reporting; Resistance; Role; Signal Transduction; Solid Neoplasm; Stem cells; TACSTD2 gene; Testing; Tumorigenicity; Up-Regulation; Urokinase; aldehyde dehydrogenase 1; aldehyde dehydrogenases; anthrax lethal factor; anthrax protective factor; anthrax toxin; anthrax toxin receptors; base; cancer cell; cancer stem cell; cell transformation; cell type; chemotherapy; cohort; conventional therapy; cytotoxic; docetaxel; epithelial to mesenchymal transition; hormone therapy; in vivo; inhibitor/antagonist; lipoprotein receptor-related protein 6; malignant breast neoplasm; multicatalytic endopeptidase complex; mutant; neoplastic cell; overexpression; progenitor; radiation resistance; response; self-renewal; small hairpin RNA; small molecule; stem; stemness; stromelysin 3; therapeutic target; therapy development; tumor; v-src Oncogenes

DESCRIPTION (provided by applicant): Breast cancer cells with the cell surface marker expression profile of CD44? or expressing higher levels of aldehyde dehydrogenase 1 are described as cancer stem cells (CSCs). Recent studies have identified additional markers that can further distinguish multiple subpopulations of CD44? cells that are resistant to radiation or chemotherapy. For example, CD44? cells retaining higher levels of the dye PKH26 after cell division or with lower proteosome activity are resistant to radiation. CD44? cells expressing mammosphere-enriched genes are resistant to anti-estrogen and chemotherapies. Despite this enormous progress, very few CSC markers are direct therapeutic targets. Therefore, further refining of CD44? cells based on additional markers is essential to characterize and target intrinsically drug-resistant or metastasis-prone cancer cells. Our studies have identified a subpopulation of CD44? cells enriched for the expression of anthrax toxin receptor 1 (ANTXR1). ANTXR1 was also elevated in primary breast epithelial cells with stem cell phenotype compared to luminal progenitor or mature cells. Only a subpopulation of breast cancer cells in primary breast cancer expresses ANTXR1. Activation of ANTXR1 through its natural ligand C5A increased Wnt activity as measured by phosphorylation of GSK3 and increased mammosphere formation. Based on these observations, we hypothesize that ANTXR1 is a functional marker of CSCs/drug-resistant cancer cells that controls self-renewal of CSCs through Wnt pathway. Two aims are proposed: 1) Disrupt ANTXR1 signaling in normal and cancerous breast epithelial cells and investigate stemness and sensitivity to chemotherapy. 2) Investigate whether ANTXR1-positive cells are enriched for Wnt activity in breast cancers and whether co- expression of ANTXR1 and Wnt pathway molecules in cancer cells is associated with disease parameters. For the first aim, we will use ANTXR1 antagonists such as mutant anthrax protective antigen with high affinity for ANTXR1 or soluble extracellular domain of ANTXR1 to investigate the effects on mammosphere forming ability, self-renewal and sensitivity to the chemotherapeutic drug docetaxel both in vitro and in vivo. In the second aim, we will determine ANTXR1, phospho-LRP6 (Wnt receptor) and nuclear 2-catenin expression by immunohistochemistry in primary breast cancers and correlate the expression with breast cancer subtypes, nodal status, grade, and the Oncotype DX recurrence score. Results of this study will have a significant impact in predicting response to conventional therapy as well as developing therapies against drug-resistant breast cancer. Prior studies on ANTXR1 in cancer were focused mainly on tumor-associated endothelial cells. This study will delineate its function in cancer cells in the context of CSC hypothesis as well as Wnt pathway modulation in cancer cells. Based on the results, future R01 type proposals will be developed, which will focus on small molecules that bind to ANTXR1:LRP6 and inhibit Wnt signaling in cancer cells. PUBLIC HEALTH RELEVANCE: This proposal will determine the role of anthrax toxin receptor 1 (ANTXR1) in breast cancer stem cells. ANTXR1 is expressed at a higher level in breast cancer stem cells compared to mature cells and may control the function of Wnt pathway in cancer stem cells. Inhibitors of ANTXR1, such as mutant protective antigen of anthrax or soluble ANTXR1 may inhibit ANTXR1 activity and sensitize cancer stem cells to chemotherapy.

描述（由申请方提供）：具有CD 44细胞表面标志物表达谱的乳腺癌细胞？或表达更高水平的醛脱氢酶1的细胞称为癌症干细胞（CSC）。最近的研究已经确定了其他标志物，可以进一步区分多个亚群的CD 44？对放疗或化疗有抵抗力的细胞。例如，CD 44？在细胞分裂后保留较高水平的染料PKH 26或具有较低蛋白体活性的细胞对辐射具有抗性。CD44？表达乳腺球富集基因的细胞对抗雌激素和化疗具有抗性。尽管取得了巨大的进展，但很少有CSC标志物是直接的治疗靶点。因此，进一步细化CD 44？基于另外的标记物的癌细胞标记对于表征和靶向固有耐药性或易转移的癌细胞是必要的。我们的研究已经确定了CD 44？富集炭疽毒素受体1（ANTXR 1）表达的细胞。与管腔祖细胞或成熟细胞相比，ANTXR 1在具有干细胞表型的原代乳腺上皮细胞中也升高。在原发性乳腺癌中，只有乳腺癌细胞亚群表达ANTXR 1。通过其天然配体C5 A激活ANTXR 1增加了Wnt活性，如通过GSK 3磷酸化和增加的乳腺球形成所测量的。基于这些观察，我们假设ANTXR 1是CSC/耐药癌细胞的功能性标志物，其通过Wnt途径控制CSC的自我更新。提出了两个目标：1）破坏正常和癌性乳腺上皮细胞中的ANTXR 1信号传导，并研究干性和对化疗的敏感性。2)研究乳腺癌中ANTXR 1阳性细胞是否富含Wnt活性，以及癌细胞中ANTXR 1和Wnt通路分子的共表达是否与疾病参数相关。 对于第一个目标，我们将使用ANTXR 1拮抗剂，如对ANTXR 1具有高亲和力的突变炭疽保护性抗原或ANTXR 1的可溶性胞外结构域，以研究在体外和体内对乳腺球形成能力，自我更新和对化疗药物多西他赛的敏感性的影响。在第二个目标中，我们将通过免疫组化确定原发性乳腺癌中ANTXR 1、磷酸化LRP 6（Wnt受体）和核2-连环蛋白的表达，并将表达与乳腺癌亚型、淋巴结状态、分级和Oncotype DX复发评分相关联。这项研究的结果将在预测对常规治疗的反应以及开发针对耐药乳腺癌的治疗方面产生重大影响。先前关于癌症中ANTXR 1的研究主要集中在肿瘤相关的内皮细胞上。本研究将在CSC假说的背景下描述其在癌细胞中的功能以及癌细胞中Wnt通路的调节。基于这些结果，将开发未来的R 01型提案，该提案将专注于与ANTXR 1：LRP 6结合并抑制癌细胞中Wnt信号传导的小分子。 公共卫生相关性：该提案将确定炭疽毒素受体1（ANTXR 1）在乳腺癌干细胞中的作用。与成熟细胞相比，ANTXR 1在乳腺癌干细胞中以更高的水平表达，并且可能控制癌症干细胞中Wnt通路的功能。ANTXR 1的抑制剂，如炭疽的突变保护性抗原或可溶性ANTXR 1，可以抑制ANTXR 1活性并使癌症干细胞对化疗敏感。