Pharmacogenomics and Mechanisms of Cytidine Analogues

胞苷类似物的药物基因组学和机制

• 批准号: 7630968
• 负责人: Liewei Wang
• 金额: $ 31.35万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7630968
• 关键词: AKT inhibition; Affect; Amino Acid Sequence; Animal Model; Apoptotic; Biological Markers; Biological Models; Breast; Breast Cancer Treatment; Cancer Patient; Candidate Disease Gene; Cells; Clinical; Correlation Studies; Cytidine; DNA; DNA Resequencing; DNA Sequence; Data; Drug Delivery Systems; Enzymes; Exons; Future; Gene Expression; Genes; Genetic Polymorphism; Genetic Variation; Genotype; Human; Immunophilins; Inhibitory Concentration 50; Introns; Knowledge; Malignant neoplasm of pancreas; Mediator of activation protein; Metabolism; Non-Small-Cell Lung Carcinoma; Nucleic Acid Regulatory Sequences; Nude Mice; Ovarian; Pancreas; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacogenomics; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Play; Process; Proto-Oncogene Proteins c-akt; RNA; RNA Splicing; Resistance; Role; Sampling; Screening procedure; Series; Signal Transduction; Single Nucleotide Polymorphism; Testing; Tissue Sample; Tissues; Tumor Cell Line; Tumor Tissue; Variant; analog; anticancer research; base; chemotherapy; cytotoxicity; drug metabolism; follow-up; functional genomics; gemcitabine; genome-wide; in vivo; insight; lymphoblastoid cell line; mouse model; novel; protein function; protein protein interaction; public health relevance; research study; response; tumor

DESCRIPTION (provided by applicant): The cytidine analogue gemcitabine is first line chemotherapy for the treatment of pancreatic cancer, and it has also shown promising results in the treatment of breast cancer and non-small cell lung cancer. Gemcitabine has its effect as a result of a "pathway" that includes drug transporters, enzymes catalyzing drug activation and inactivation, and drug targets. However, very little is known with regard to determinants of variation in gemcitabine response, especially single nucleotide polymorphisms (SNPs) in genes outside of the pathway described by our current knowledge of this drug. In order to identify additional genes of importance for variation in gemcitabine response, we have used 300 Human Variation Panel lymphoblastoid cell line as a model system for common genetic variation to perform genome-wide expression association studies to identify genes with expression levels that were significantly associated with variation in gemcitabine cytotoxicity (IC50 values). One top candidate gene, FKBP5, a gene encoding a 51 kDa immunophilin, was shown to affect the apoptotic pathway in response to gemcitabine. Specifically, lower expression of FKBP5 was associated with resistance to gemcitabine-induced cytotoxicity. We also demonstrated an inhibitory role for FKBP5 in AKT phosphorylation. As a result, we hypothesize that FKBP5 affects gemcitabine response by negatively regulating AKT activation and that genetic variation associated with FKBP5 gene expression and protein function might contribute significantly to variation in gemcitabine response. In this application, we propose to determine mechanisms by which FKBP5 regulates AKT activation, followed by testing the role of FKBP5 in gemcitabine response using mice models and tumor samples from pancreatic cancer patients treated with gemcitabine. In addition, we will also determine gene sequence variation that is associated with FKBP5 gene expression and response to gemcitabine using 300 lymphoblastoid cell lines, followed by performing functional genomic studies with these SNPs. Finally, we will perform a genotype-phenotype correlation study with DNA from pancreatic cancer patients to determine whether SNPs that affect FKBP5 expression and/or protein function might influence response to gemcitabine when used to treat pancreatic cancer. In summary, this comprehensive series of experiments will enhance our understanding of mechanisms of gemcitabine resistance and may identify biomarkers that might help predict gemcitabine response in the treatment of pancreatic cancer. PUBLIC HEALTH RELEVANCE: The cytidine analogue gemcitabine is first line chemotherapy for the treatment of pancreatic cancer. However, very little is known with regard to determinants of variation in gemcitabine response, especially single nucleotide polymorphisms (SNPs) in genes outside of the "pathway" described by our current knowledge of the metabolism and "targets" for this drug. In order to identify additional genes of importance for variation in gemcitabine response, we have used 300 Human Variation Panel lymphoblastoid cell lines as a model system, together with genome-wide approaches to identify one top candidate gene, FKBP5, for which expression was significantly associated with gemcitabine sensitivity. In this application, based on extensive preliminary data, we propose to investigate mechanisms by which FKBP5 regulates response to gemcitabine and to identify genetic variation in FKBP5 that might be used as a biomarker to help predict gemcitabine response in the treatment of pancreatic cancer.

描述（由申请人提供）：胞苷模拟吉西他滨是治疗胰腺癌的第一线化学疗法，它在治疗乳腺癌和非小细胞肺癌的治疗方面还显示出令人鼓舞的结果。吉西他滨的作用是“途径”，其中包括药物转运蛋白，催化药物激活和失活的酶以及药物靶标。然而，关于吉西他滨反应变异的决定因素，尤其是在我们目前对该药物所描述的途径之外的基因中，尤其是单核苷酸多态性（SNP），鲜为人知。为了确定吉西他滨反应变化的其他重要性基因，我们使用了300个人类变异面板淋巴细胞细胞系作为常见遗传变异的模型系统，以执行全基因组表达缔合研究，以鉴定具有表达水平的基因，这些基因与gemcitabine cytotoxoxicity的变异显着相关（IC50值）。一个顶级候选基因FKBP5是一种编码51 kDa免疫蛋白的基因，可影响吉西他滨的凋亡途径。具体而言，较低的FKBP5表达与对吉西他滨诱导的细胞毒性的抗性有关。我们还证明了FKBP5在Akt磷酸化中的抑制作用。结果，我们假设FKBP5通过负调节AKT激活来影响吉西他滨反应，并且与FKBP5基因表达和蛋白质功能相关的遗传变异可能对吉西他滨反应的变异产生重大影响。在此应用中，我们建议确定FKBP5调节AKT激活的机制，然后使用小鼠模型和用吉西他滨治疗的胰腺癌患者的小鼠模型和肿瘤样品来测试FKBP5在吉西他滨反应中的作用。此外，我们还将使用300个淋巴母细胞系确定与FKBP5基因表达和对吉西他滨对吉西他滨反应相关的基因序列变异，然后使用这些SNP进行功能基因组研究。最后，我们将使用胰腺癌患者的DNA进行基因型 - 表型相关研究，以确定影响FKBP5表达和/或蛋白质功能的SNP是否会影响用于治疗胰腺癌的吉西他滨的反应。总而言之，这一全面的实验将增强我们对吉西他滨耐药机制的理解，并可以鉴定出可能有助于预测吉西他滨反应在治疗胰腺癌中的生物标志物。公共卫生相关性：胞苷类模拟吉西他滨是治疗胰腺癌的第一线化学疗法。然而，关于吉西他滨反应变异的决定因素，尤其是在我们目前对这种药物的代谢和“靶标”所描述的“途径”之外的基因中的单核苷酸多态性（SNP）。为了确定吉西他滨反应变化的其他重要性基因，我们使用了300个人类变异面板淋巴细胞细胞系作为模型系统，以及全基因组范围的方法，以识别一个顶级候选基因FKBP5，其中表达与Gemcitabine敏感性显着相关。在此应用中，基于广泛的初步数据，我们建议研究FKBP5调节对吉西他滨的反应的机制，并鉴定FKBP5中的遗传变异，这些遗传变异可能被用作生物标志物，以帮助预测吉西他滨在治疗胰腺癌中的反应。