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（申请人提供）：胞苷类似物吉西他滨是治疗胰腺癌的一线化疗药物，在治疗乳腺癌和非小细胞肺癌方面也显示出良好的效果。吉西他滨的作用是由药物转运蛋白、催化药物激活和失活的酶以及药物靶点组成的“途径”的结果。然而，对于吉西他滨反应变异的决定因素知之甚少，特别是我们目前对该药物的了解所描述的途径之外的基因中的单核苷酸多态性（SNP）。为了鉴定对吉西他滨反应变异重要的其他基因，我们使用 300 个人类变异面板淋巴母细胞系作为常见遗传变异的模型系统来进行全基因组表达关联研究，以鉴定其表达水平与吉西他滨细胞毒性变异（IC50 值）显着相关的基因。一个顶级候选基因 FKBP5（一种编码 51 kDa 亲免蛋白的基因）被证明会影响吉西他滨响应的细胞凋亡途径。具体而言，FKBP5 的较低表达与对吉西他滨诱导的细胞毒性的抵抗相关。我们还证明了 FKBP5 在 AKT 磷酸化中的抑制作用。因此，我们假设 FKBP5 通过负向调节 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化有显着影响。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接受吉西他滨治疗的胰腺癌患者的肿瘤样本测试 FKBP5 在吉西他滨反应中的作用。此外，我们还将使用 300 个类淋巴母细胞系确定与 FKBP5 基因表达和吉西他滨反应相关的基因序列变异，然后利用这些 SNP 进行功能基因组研究。最后，我们将对胰腺癌患者的 DNA 进行基因型-表型相关性研究，以确定影响 FKBP5 表达和/或蛋白质功能的 SNP 是否可能影响吉西他滨治疗胰腺癌时的反应。总之，这一系列综合实验将增强我们对吉西他滨耐药机制的理解，并可能确定有助于预测吉西他滨治疗胰腺癌反应的生物标志物。公共卫生相关性：胞苷类似物吉西他滨是治疗胰腺癌的一线化疗药物。然而，对于吉西他滨反应变异的决定因素知之甚少，特别是我们目前对该药物的代谢和“靶点”知识所描述的“途径”之外的基因中的单核苷酸多态性（SNP）。为了识别对吉西他滨反应变异重要的其他基因，我们使用 300 个人类变异面板淋巴母细胞系作为模型系统，并结合全基因组方法来识别一个顶级候选基因 FKBP5，该基因的表达与吉西他滨敏感性显着相关。在此应用中，基于广泛的初步数据，我们建议研究 FKBP5 调节吉西他滨反应的机制，并鉴定 FKBP5 的遗传变异，这些变异可能用作生物标志物，帮助预测吉西他滨治疗胰腺癌的反应。