PTEN loss increases efficiency of breast tumor metastasis

PTEN 缺失提高乳腺肿瘤转移效率

• 批准号: 8634745
• 负责人: MICHELE I VITOLO
• 金额: $ 10.48万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8634745
• 关键词: Actins; Adherence; Adjuvant; Affect; Anoikis; Apoptosis; Apoptotic; Binding; Binding Proteins; Bioluminescence; Blood Circulation; Breast; Breast Cancer Cell; Breast Epithelial Cells; Cancer Patient; Carcinoma; Cell Cycle; Cell Death; Cell Line; Cell Nucleus; Cell Survival; Cell membrane; Cells; Cessation of life; Characteristics; Clinical; Critiques; Cytoplasm; Data; Diagnostic Neoplasm Staging; Discipline; Disease; Disease Progression; Distant; Dominant-Negative Mutation; ERBB2 gene; Early Diagnosis; Epigenetic Process; Epithelial; Epithelial Cells; Epithelium; Extravasation; Faculty; Foundations; Frequencies; Generations; Goals; Growth; Her2/erbb2/neu Staining Method; Human; In Vitro; Individual; Knock-out; Lead; Length; Lipids; Locales; Location; Lung; Lymphatic; MAP Kinase Gene; MCF10A cells; Malignant - descriptor; Malignant Neoplasms; Mammary Neoplasms; Mammary gland; Membrane; Metastatic to; Microtubule Stabilization; Microtubules; Mitotic; Modeling; Molecular; Mus; Mutation; Neoplasm Circulating Cells; Neoplasm Metastasis; Oncogene ErbB2; Oncogenes; Oncogenic; Operative Surgical Procedures; Organ; Outcome; PDZ protein; PTEN gene; Pathway interactions; Patients; Phenotype; Phosphoric Monoester Hydrolases; Population; Positioning Attribute; Primary Neoplasm; Process; Production; Protein Binding Domain; Protein phosphatase; Publications; Recurrence; Research; Research Personnel; Resistance; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Somatic Cell; Structure; Testing; Time; Tissues; Training; Trastuzumab; Tubulin; Tumor Cell Line; Tumor Suppressor Proteins; Update; Woman; Writing; Xenograft procedure; base; cancer genetics; chemotherapy; design; experience; in vivo; in vivo imaging; inhibitor/antagonist; interest; lymph nodes; malignant breast neoplasm; meetings; metastatic process; monolayer; mutant; neoplastic cell; novel; novel therapeutics; prevent; public health relevance; rho GTP-Binding Proteins; skills; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): The long term objectives of this project are to investigate the molecular mechanisms by which PTEN loss promotes metastatic efficiency of circulating tumor cells. PTEN loss confers apoptotic resistance and production of microtentacles (McTNs) mammary epithelial cells upon detachment. The McTNs are increased in frequency, and number and length per cell as compared to their isogenic, PTEN expressing parental counterparts. These novel structures (McTNs) are structurally distinct from classical actin based extensions of adherent cells, persist for days in breast tumor lines that are resistant to anoikis, and aid in the reattachment to matrix or cell monolayers. Therefore, the combination of apoptotic resistance and enhanced McTNs expression due to PTEN loss may have important consequences for facilitating tumor cell extravasation and efficient adherence to new sites. We will determine the role of PTEN early in metastatic process by examining microtentacles (McTNs) formation and anoikis, as well as cell survival after dissemination, and finally metastatic outgrowth. We will test the hypothesis that PTEN loss increases metastatic efficiency of breast cancer cells through a unique combination of anoikis resistance, cytoskeletal alterations, and cell dormancy. In the first specific aim, the aberrant signaling pathways due to PTEN loss necessary for McTNs promotion and dormant cell survival will be identified. In Aim 2, the cellular locale and/or PDZ binding domain requirement for McTNs suppression and anoikis will be determined. Both Aims will employ the isogenic mammary epithelial MCF-10A and MCF- 10A/PTEN-/- cells in combination with other human metastatic cell lines that lack PTEN expression. In Aim 3, we will investigate the molecular mechanisms of cell survival after dissemination, tumor cell dormancy, and metastatic outgrowth due to PTEN loss in combination with the known oncogene ErbB2 (Her2/Neu). A large fraction of breast tumors carry oncogenic mutations that cause hyperactivation of ErbB2, and tumor cells with active ErbB2 that have lost PTEN are resistant to trastuzumab, posing a significant clinical problem Overall, the signaling mechanisms identified in each specific aim may provide new targets for therapies aimed at preventing metastasis. The immediate goals of the candidate are to supplement broad experience in cellular signal transduction with training in the use of confocal and in vivo imaging update and enhance skills in the discipline of cancer genetics, and develop critical skills for a successful transition to an independent faculty position. The proposed studies can be transferred freely and will provide a foundation for the establishment as an independent investigator. The PTEN isogenic somatic cell knock-out model, in combination with in vitro and in vivo imaging, should provide a unique niche for research focused on the molecular mechanisms by which PTEN loss promotes metastatic spread.

描述（由申请人提供）：本项目的长期目标是研究PTEN缺失促进循环肿瘤细胞转移效率的分子机制。PTEN缺失赋予细胞凋亡抗性并在脱离时产生微触角（McTNs）乳腺上皮细胞。与其同基因的表达PTEN的亲本对应物相比，McTN在频率、数量和每个细胞的长度上增加。这些新结构（McTN）在结构上不同于粘附细胞的经典的基于肌动蛋白的延伸，在抗失巢凋亡的乳腺肿瘤系中持续数天， 并有助于重新附着到基质或细胞单层上。因此，凋亡抗性和由于PTEN丢失而增强的McTNs表达的组合可能对促进肿瘤细胞外渗和有效粘附到新位点具有重要的后果。我们将通过检查微触角（McTNs）的形成和失巢凋亡，以及扩散后的细胞存活和最终转移生长来确定PTEN在转移过程早期的作用。 我们将测试的假设，PTEN的损失增加乳腺癌细胞的转移效率，通过一个独特的组合失巢凋亡的阻力，细胞骨架的改变，细胞休眠。在第一个具体目标中，将鉴定由于MCTNs促进和休眠细胞存活所必需的PTEN损失而导致的异常信号传导途径。在目的2中，将确定McTN抑制和失巢凋亡的细胞区域和/或PDZ结合结构域要求。两个目的都将采用等基因乳腺上皮MCF-10A和MCF- 10A/PTEN-/-细胞与缺乏PTEN表达的其他人转移性细胞系的组合。在目标3中，我们将研究由于PTEN丢失与已知的癌基因ErbB 2（Her 2/Neu）结合而导致的扩散后细胞存活、肿瘤细胞休眠和转移性生长的分子机制。很大一部分乳腺肿瘤携带致癌突变，导致ErbB 2的过度激活，而失去PTEN的具有活性ErbB 2的肿瘤细胞对曲妥珠单抗具有耐药性，这构成了一个重大的临床问题。总的来说，在每个特定目标中确定的信号传导机制可能为旨在预防转移的治疗提供新的靶点。候选人的直接目标是补充细胞信号转导的广泛经验，培训使用共聚焦和体内成像更新，提高癌症遗传学学科的技能，并发展成功过渡到独立教师职位的关键技能。拟议的研究可以自由转让，并将为建立独立的调查机构奠定基础。PTEN同基因体细胞敲除模型，结合在体外和体内成像，应提供一个独特的利基研究集中在PTEN损失促进转移扩散的分子机制。