Role of Cancer Stem Cells in Malignant Progression of Ductal Carcinoma in Situ.

描述(申请人提供)：我的具体目标是研究癌症干细胞及其微环境在人类乳腺癌癌前亚型--导管原位癌(DCIS)恶性进展中的作用。目的是测试癌前细胞系SUM225、MCF10ATDCIS.com和人类DCIS的亚型是否包含独特的癌症干细胞亚群，这些亚群显示出独特的癌症干细胞特性，即增强自我更新潜力、静止性和致瘤性。我的策略是使用荧光激活细胞分类(FACS)和已知的表面标记来分离干细胞/祖细胞和分化的亚群，并检测其肿瘤干细胞特性，其中包括：1)通过标准乳房试验和Matrigel克隆形成分别检测体外的自我更新和分化潜能；2)通过一种新的策略将长期和短期的自我更新分别移植到人源化的小鼠脂肪垫基质中；3)通过生长速度和形成侵袭性病变的潜能来检测肿瘤的致瘤性；以及4)通过长期标记保留研究使其处于静止状态。此外，将通过体外共培养和体内联合移植研究来检验内皮细胞在建立癌症干细胞利基微环境中的作用。我的理论基础是，癌症干细胞和正常组织干细胞表达相似的表面标记，可以用来识别和表征它们。一旦确定了癌症干细胞，就将致力于确定它们独特的基因图谱。这些研究将为发现针对DCIS亚型的风险评估、预防复发和恶性进展的分子靶点提供基础。我的长期职业目标是领导一个研究小组，致力于在转化性研究环境中预防人类乳腺癌的恶性进展。在获得细胞信号和小鼠乳腺干细胞生物学基础科学的博士学位和博士后培训之前，我曾担任过七年的学术和临床药理学家。职业发展奖是与贝勒医学院乳腺癌中心合作，在人类乳腺癌研究方面获得更多经验的绝佳机会。贝勒医学院拥有卓越的研究中心和设施，并为科学合作和教育提供了充足的机会。 相关性：乳腺癌前病变可能含有罕见的癌症干细胞。癌症干细胞对于不同类型的癌前病变可能是独一无二的，这可能解释了为什么一些患者会复发或发展为浸润性癌症，而另一些患者则不会。我的目标是研究癌症干细胞在癌前病变亚型的侵袭进展中的作用，并为浸润性乳腺癌的风险评估和预防制定个性化的策略。

DESCRIPTION (provided by applicant): My specific aims are to examine the role of cancer stem cells and their niche microenvironment in malignant progression of subtypes of human breast premalignancy, ductal carcinoma in situ (DCIS). The objectives are to test whether premalignant cell lines, SUM225, MCF10ATDCIS.com, and subtypes of human DCIS contain distinct cancer stem cell subpopulations which exhibit unique cancer stem cell properties of increased self-renewal potential, quiescence, and tumorigenicity. My strategy is to use fluorescent activated cell sorting (FACS) and known surface markers to isolate stem/progenitor and differentiated subpopulations and to examine their cancer stem cell properties which include, 1) in vitro self-renewal and differentiation potential by standard mammosphere assay and colony formation in Matrigel, respectively, 2) in vivo long term and short term self-renewal by using a novel strategy of xenotransplantation into humanized stroma of mice fat pads, 3) tumorigenicity by growth rate and potential to form invasive lesions, and 4) quiescence by long term label retaining studies. Furthermore, the role of endothelial cells in establishing a cancer stem cell niche microenvironment will be examined by in vitro co-culture and in vivo co-transplantation studies. My rationale is that cancer stem cells and normal tissue stem cells express similar surface markers by which they may be identified and characterized. Once cancer stem cells are identified, efforts will be aimed at defining their unique gene profiles. These studies will provide a basis for discovery of molecular targets for risk assessment, prevention of recurrence, and malignant progression tailored to subtypes of DCIS. My long term career goal is to lead a research group focused towards prevention of human breast cancer malignant progression in a translational research environment. I served as an academic and clinical pharmacologist for seven years before obtaining a Ph.D. and post-doctoral training in basic sciences in cellular signaling and mouse mammary gland stem cell biology. The Career Development Award is an excellent opportunity to gain additional experience in research in human breast cancer in collaboration with the Breast Cancer Center at Baylor College of Medicine. Baylor College of Medicine houses exceptional research centers and facilities and provides an ample opportunity for scientific collaboration, and education. Relevance: Breast pre-cancer lesions may contain a rare population of cancer stem cells. Cancer stem cells may be unique to different types of pre-cancer lesions and may explain why some patients will experience recurrences or develop invasive cancers while others do not. My goal is to examine the role of cancer stem cells in invasive progression of subtypes of pre-cancer lesions and to develop individualized strategies for risk assessment and prevention of invasive breast cancer.