The role of JMJD2C in HIF-1 activation and breast cancer progression

项目摘要 低氧诱导因子（Hypoxia-inducible factors，HIF）是由α和β亚基组成的异源二聚体转录因子， 调节器对减少的O2可用性的反应。已经鉴定了三种HIF（HIF-1、HIF-2和HIF-3）。 HIF-1和HIF-2是激活超过1000个靶基因转录的两个关键调节因子，其蛋白质 产品促进癌症生长、侵袭和转移。然而，HIF-1和HIF-2分别控制 转录调节癌症进展的不同方面的独特靶基因。分子 HIF-1对HIF-2反式激活的差异调节机制还不清楚。 理解HIF-1和HIF-2介导的转录激活的调节机制将对以下方面产生影响： 了解和治疗人类癌症。我的长期目标是阐明 在人类癌症中潜在的HIF-1和HIF-2介导的反式激活，以鉴定治疗靶点， 开发治疗人类癌症的有效药物。我发现了一种组蛋白去甲基化酶，jumonji 含结构域蛋白（JM JD）2C，选择性结合HIF-1α并刺激HIF-1介导的 在人乳腺癌细胞中的反式激活。但JMJD 2C不能与HIF-2α相互作用，也不能调节HIF-2 靶基因转录。我还发现，JMJD 2C在人类乳腺癌中高度扩增，并促进 乳腺癌的生长和转移。在这个项目中，我将测试一个假设，即JMJD 2C促进人类 乳腺癌的生长和转移通过共激活HIF-1，我将确定新的JMJD 2C抑制剂， 对人类乳腺癌治疗有价值。在辅导K99阶段，我将研究分子机制 JMJD 2C选择性共激活人乳腺癌细胞中的HIF-1，并鉴定JMJD 2C控制的 HIF-1在全基因组范围内靶向基因。在独立R 00阶段，我将通过以下方式定义机制： 该JMJD 2C促进人乳腺癌生长和转移，并鉴定新的JMJD 2C抑制剂。 该项目的成功完成将为分子机制提供创新见解 乳腺癌中HIF-1和HIF-2介导的反式激活的潜在差异调节。它还将 鉴定新治疗靶点并为乳腺癌治疗提供潜在工具。实现 提出的目标，我已经组建了一个强大的指导团队，由博士格雷格L。Semenza（Mentor），an 国际公认的HIF-1和癌症生物学领域的领导者，Saraswati Sukumar博士（共同导师）， 全国公认的乳腺癌专家Shyam Biswal博士（合作者），全国公认的 全基因组转录分析专家，以及国际公认的 药物研发专家为了成功地完成所提出的研究，我将获得老鼠训练， 人类癌症的原位和尾静脉模型，全基因组ChIP-seq和mRNA-seq分析，以及高 通过药物筛选，并将获得先进的知识，在癌症生物学，生物信息学和药物 发展以及在奖励期间负责任地进行研究的全面培训。 总的来说，约翰霍普金斯大学医学院良好的研究培训环境， 彭博公共卫生学院将促进拟议研究的成功完成，巩固 扩大我的专业知识，并确保我成功地过渡到一个独立的调查员。

Project Summary Hypoxia-inducible factors (HIFs), heterodimeric transcription factors consisting of α and β subunits, are master regulators of responses to reduced O2 availability. Three HIFs (HIF-1, HIF-2, and HIF-3) have been identified. HIF-1 and HIF-2 are two key regulators that activate transcription of over 1000 target genes, whose protein products promote cancer growth, invasion, and metastasis. However, HIF-1 and HIF-2 each controls transcription of unique target genes that regulate different aspects of cancer progression. The molecular mechanism for differential regulation of transactivation by HIF-1 vs HIF-2 is not well understood. Understanding regulatory mechanisms of HIF-1- and HIF-2-mediated transactivation will have implications for understanding and treating human cancer. My long-term goals are to elucidate regulatory mechanisms underlying HIF-1- and HIF-2-mediated transactivation in human cancers, to identify therapeutic targets, to develop effective drugs for treatment of human cancers. I have identified a histone demethylase, jumonji domain containing protein (JMJD) 2C, which selectively binds to HIF-1α and stimulates HIF-1-mediated transactivation in human breast cancer cells. But JMJD2C fails to interact with HIF-2α or to regulate HIF-2 target gene transcription. I also found that JMJD2C is highly amplified in human breast cancers and promotes breast cancer growth and metastasis. In this project, I will test a hypothesis that JMJD2C promotes human breast cancer growth and metastasis by coactivating HIF-1, and I will identify novel JMJD2C inhibitors that may be valuable for human breast cancer therapy. In the mentored K99 phase, I will study molecular mechanisms by which JMJD2C selectively coactivates HIF-1 in human breast cancer cells and identify JMJD2C-controlled HIF-1 target genes on a genome-wide scale. In the independent R00 phase, I will define the mechanisms by which JMJD2C promotes human breast cancer growth and metastasis and identify novel JMJD2C inhibitors. The successful completion of the project will provide innovative insights into the molecular mechanism underlying differential regulation of HIF-1- and HIF-2-mediated transactivation in breast cancer. It will also identify a novel therapeutic target and provide potential tools for breast cancer treatment. To achieve the proposed goals, I have assembled a strong mentoring team consisting of Dr. Gregg L. Semenza (Mentor), an internationally recognized leader in the field of HIF-1 and cancer biology, Dr. Saraswati Sukumar (Co-mentor), a nationally recognized expert in breast cancer, Dr. Shyam Biswal (Collaborator), a nationally recognized expert in genome-wide transcriptional analysis, and Dr. Jun Liu (Collaborator), an internationally recognized expert in drug discovery. To successfully accomplish the proposed research, I will obtain training in mouse orthotopic and tail vein models of human cancers, genome-wide ChIP-seq and mRNA-seq analyses, and high- throughput drug screening, and will acquire advanced knowledge in cancer biology, bioinformatics, and drug development as well as comprehensive training in responsible conduct of research during the award period. Overall, the excellent environment of research training at the Johns Hopkins University School of Medicine and Bloomberg School of Public Health will facilitate the successful completion of the proposed research, solidify and expand my expertise, and assure me to make a successful transition to an independent investigator.