Cholangiocyte microRNAs Regulate Mcl-1 and Cell Death

描述（由申请人提供）： 我的长期职业目标是成为一名独立的研究人员，研究细胞死亡在胃肠道疾病中的作用。我以前在细胞和分子生物学与细胞死亡相关的研究经验包括我的博士论文线粒体突变在年龄相关疾病中的作用。我已经确定了一个非常成功的导师在该地区的细胞死亡在肝胆疾病，包括癌症。该实验室位于罗切斯特的马约诊所消化疾病基础研究中心的有利环境中。该提案概述了一个可验证的假设，以定义microRNA作为胆管癌细胞凋亡调节因子的作用，胆管癌是一种在慢性胆管炎症存在下发生的恶性肿瘤。目前的提案将允许候选人通过提供肝胆疾病和癌症生物学方面的高级培训来改变研究方向，因为它与细胞死亡有关。短期职业目标包括癌症生物学和GI相关转化研究的高级培训。这些近期目标将通过职业发展计划来实现，其中包括研究、交流技能和辅导培训。该研究计划源于我们以前的观察，即抗凋亡蛋白Mcl-1在人胆管癌中过度表达，并且是细胞死亡的关键调节因子。Mcl-1调节的一个潜在机制是通过microRNA，短RNA作为蛋白质表达的序列特异性沉默子。我们的初步数据显示，Mcl-1表达是mir-29 b的预测靶点，并且mir-29的拮抗作用增加Mcl-1蛋白表达。此外，Mcl-1在胆管癌细胞中过表达，而mir-29 b表达降低。最后，阻断mir-29可以保护胆管细胞免于细胞死亡。这些广泛和原始的观察结果支持了这项授权的总体假设，即mir-29 b的表达失调导致Mcl-1的过度表达，使这种癌症细胞凋亡抵抗。为了解决这一假设，我们建立了先进的细胞培养模型和分子技术来检测和改变microRNA的表达。该项目与公共卫生有关，因为它解决了胆管癌如何抵抗细胞死亡，从而抵抗化疗。此外，通过测试一种控制癌细胞死亡的新途径，我们可以定义一组新的靶点，以改善对这种毁灭性疾病的治疗。

DESCRIPTION (provided by applicant): My long-term career goals are to become an independent investigator studying the role of cell death in diseases of the Gl tract. My previous research experience in cell and molecular biology related to cell death included my doctoral dissertation on the role of mitochondrial mutations in age-related disease. I have identified a highly successful mentor in the area of cell death in hepatobiliary diseases, including cancer. The lab is in the conducive environment of the Center for Basic Research in Digestive Diseases, at Mayo Clinic, Rochester. This proposal outlines a testable hypothesis to define the role of microRNAs as regulators of apoptosis in cholangiocarcinoma, a malignant neoplasm that occurs in the presence of chronic inflammation of bile ducts. The current proposal will allow the candidate to change research directions by providing advanced training in hepatobiliary disease and cancer biology as it relates to cell death. Short-term career goals include advanced training in cancer biology and Gl-related translational research. These immediate goals will be achieved by the career development plan, including research, communication skills, and mentoring training. The research plan stems from our previous observations that the antiapoptotic protein Mcl-1 is over-expressed in human cholangiocarcinoma and is a key regulator of cell death. One potential mechanism of Mcl-1 regulation is through microRNAs, short RNAs that act as sequence-specific silencers of protein expression. Our preliminary data shows that Mcl-1 expression is a predicted target of mir-29b, and antagonism of mir-29 increases Mcl-1 protein expression. Further, Mcl-1 is over-expressed in cholangio- carcinoma cells while mir-29b expression is decreased. Finally, blocking mir-29 protects cholangiocytes from cell death. These extensive and original observations support the OVERALL HYPOTHESIS of this grant that dysregulated expression of mir-29b results in over expression of Mcl-1, rendering this cancer apoptosis resistant. To address this hypothesis, we have established advanced cell culture models and molecular techniques to detect and alter expression of microRNAs. This project is relevant to public health as it addresses how bile duct cancers resist cell death, and as such resist chemotherapy. In addition, by testing a new pathway governing cancer cell death, we may define a novel set of targets to improve treatment of this devastating disease.