CD44/Variant Cytoskeleton in Breast Cancer Progression

CD44/变异细胞骨架在乳腺癌进展中的作用

• 批准号: 7624689
• 负责人: Lilly YW Bourguignon
• 金额: $ 24.38万
• 依托单位: NORTHERN CALIFORNIA INSTITUTE/RES/EDU
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7624689
• 关键词: 1-Phosphatidylinositol 3-Kinase; Actins; Ankyrins; Behavior; Binding; Biochemical; Biological; Breast; Breast Cancer Detection; Breast Carcinoma; CD44 Antigens; CD44 gene; Cancer Patient; Cathepsins; Clinical; Cytoskeleton; Development; Doctor of Philosophy; Dominant-Negative Mutation; Drug Delivery Systems; Early Diagnosis; Enzyme Activation; Enzymes; Epithelial Cells; Evaluation; Event; Extracellular Matrix; Figs - dietary; Growth; Human; Hyaluronan; Hyaluronidase; Immunohistochemistry; Laboratories; Link; Malignant - descriptor; Mammary Neoplasms; Mediating; Membrane Microdomains; Modeling; Molecular; NHE1; Neoplasm Metastasis; Oncogenic; Pathway interactions; Patients; Phosphotransferases; Play; Property; Protein Isoforms; RNA Interference; Research Personnel; Research Proposals; Rho-associated kinase; Role; SRC gene; Signal Pathway; Signal Transduction; Signaling Molecule; Staining method; Stains; Structure; Techniques; Testing; Therapeutic; Tissues; Tumor Cell Invasion; Tumor Markers; Variant; bone; cell growth; human EMS1 protein; immunocytochemistry; malignant breast neoplasm; migration; neoplastic cell; novel; outcome forecast; overexpression; programs; protein-tyrosine kinase c-src; tumor progression

DESCRIPTION (provided by applicant): It is now certain that oncogenic signaling and cytoskeleton function are directly involved in breast cancer progression. Our laboratory has determined that overexpression of CD44 variant (CD44v) isoforms [hyaluronan (HA) receptors] appears to confer the malignant properties of increased growth, migration and invasion on breast epithelial cells. In this continuation research proposal, we plan to test the hypothesis that the interaction between CD44v isoforms (CD44v3, CD44v10 and CD44v6/7) and specific signaling activators [e.g. RhoGEFs/RacGEF (Tiam1) and c-Src kinase] plays an important role in HA-mediated oncogenic signaling such as the RhoA-activated ROK pathway, Tiam1-regulated Rac1-PKNgamma kinase pathway and c-Src-induced cortactin and Gab-1/PI3 kinase-AKT pathways. These activation events induce various tumor cell-specific behaviors (e.g. cellular acidification, ECM degradation, cytoskeleton function, tumor cell growth/survival, migration and invasion) leading to breast cancer progression. To test this hypothesis, we plan to use a variety of biochemical, molecular biological techniques and immunohistochemical staining to elucidate HA-CD44v isoform interaction with the various signaling molecules. We will evaluate the functional ramifications of these interactions with respect to specific downstream effector functions (e.g. NHE1-related acidic pH enzyme activation, ankyrin/cortactin-actin binding and PI3 kinase/AKT-mediated biological activities) required for ECM degradation, cytoskeleton function and metastatic tumor cell properties. In addition, we plan to analyze the co-expression of CD44v isoforms and various signaling molecules (e.g. RhoGEF, Tiam1, ROK, PKNgamma and c-Src) in human breast carcinoma tissues obtained from breast cancer patients using immunocytochemistry. We will also employ novel signaling perturbation strategies to impair HA-CD44v isoform-mediated oncogenic signaling by constructing dominant-negative mutants of certain signaling molecules (e.g. ROK, PKNgamma, c-Src, and cortactin). Finally, we will develop therapeutic antisense and small interference RNAs (siRNAs) specifically targeting CD44 in order to effectively block CD44 expression, inhibit HA-mediated downstream oncogenic signaling events and block breast tumor progression. We believe that the information obtained from this proposal has particularly important clinical utility and could establish CD44v isoforms and associated signaling molecules (e.g. RhoGEF, Tiam1, ROK, PKNgamma and c-Src) as important tumor markers for early detection and evaluation of oncogenic potential, as well as allow the development of new drug targets to inhibit breast tumor metastasis and cancer progression.

描述（由申请人提供）：现在可以肯定致癌信号和细胞骨架功能直接参与乳腺癌进展。我们的实验室已经确定，CD 44变体（CD 44 v）亚型[透明质酸（HA）受体]的过度表达似乎赋予乳腺上皮细胞生长、迁移和侵袭增加的恶性特性。在这个继续的研究计划中，我们计划测试CD 44 v亚型之间的相互作用的假设，（CD 44 v3、CD 44 v10和CD 44 v6/7）和特异性信号传导激活剂[例如RhoGEF/RacGEF（Tiam 1）和c-Src激酶]在HA介导的致癌信号传导如RhoA激活的ROK途径中起重要作用，Tiam 1调节Rac 1-PKNgamma激酶通路和c-Src诱导的corpine和Gab-1/PI 3激酶-AKT通路。这些活化事件诱导各种肿瘤细胞特异性行为（例如细胞酸化、ECM降解、细胞骨架功能、肿瘤细胞生长/存活、迁移和侵袭），导致乳腺癌进展。为了验证这一假设，我们计划使用各种生物化学，分子生物学技术和免疫组化染色来阐明HA-CD 44 v亚型与各种信号分子的相互作用。我们将评估这些相互作用在ECM降解、细胞骨架功能和转移性肿瘤细胞特性所需的特定下游效应子功能（例如NHE 1相关酸性pH酶激活、锚蛋白/皮质素-肌动蛋白结合和PI 3激酶/AKT介导的生物活性）方面的功能性后果。此外，我们计划使用免疫细胞化学分析从乳腺癌患者获得的人乳腺癌组织中CD 44 v亚型和各种信号分子（例如RhoGEF、Tiam 1、ROK、PKNgamma和c-Src）的共表达。我们还将采用新的信号干扰策略，通过构建某些信号分子（如ROK、PKN γ、c-Src和cornea）的显性阴性突变体来削弱HA-CD 44 v亚型介导的致癌信号。最后，我们将开发特异性靶向CD 44的治疗性反义和小干扰RNA（siRNA），以有效阻断CD 44表达，抑制HA介导的下游致癌信号传导事件并阻断乳腺肿瘤进展。我们认为，从该提案中获得的信息具有特别重要的临床实用性，可以将CD 44 v亚型和相关信号分子（例如RhoGEF、Tiam 1、ROK、PKN γ和c-Src）确立为早期检测和评估致癌潜力的重要肿瘤标志物，并允许开发新的药物靶点以抑制乳腺肿瘤转移和癌症进展。