Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA.
PLoS One. 2013 Aug 1;8(8):e70216. doi: 10.1371/journal.pone.0070216. Print 2013.
FKBP51, (FKBP5), is a negative regulator of Akt. Variability in FKBP5 expression level is a major factor contributing to variation in response to chemotherapeutic agents including gemcitabine, a first line treatment for pancreatic cancer. Genetic variation in FKBP5 could influence its function and, ultimately, treatment response of pancreatic cancer.
We set out to comprehensively study the role of genetic variation in FKBP5 identified by Next Generation DNA resequencing on response to gemcitabine treatment of pancreatic cancer by utilizing both tumor and germline DNA samples from 43 pancreatic cancer patients, including 19 paired normal-tumor samples. Next, genotype-phenotype association studies were performed with overall survival as well as with FKBP5 gene expression in tumor using the same samples in which resequencing had been performed, followed by functional genomics studies.
In-depth resequencing identified 404 FKBP5 single nucleotide polymorphisms (SNPs) in normal and tumor DNA. SNPs with the strongest associations with survival or FKBP5 expression were subjected to functional genomic study. Electromobility shift assay showed that the rs73748206 "A(T)" SNP altered DNA-protein binding patterns, consistent with significantly increased reporter gene activity, possibly through its increased binding to Glucocorticoid Receptor (GR). The effect of rs73748206 was confirmed on the basis of its association with FKBP5 expression by affecting the binding to GR in lymphoblastoid cell lines derived from the same patients for whom DNA was used for resequencing.
This comprehensive FKBP5 resequencing study provides insights into the role of genetic variation in variation of gemcitabine response.
FKBP51（FKBP5）是 Akt 的负调节剂。FKBP5 表达水平的变异性是导致对包括吉西他滨在内的化疗药物反应变化的主要因素，吉西他滨是胰腺癌的一线治疗药物。FKBP5 的遗传变异可能会影响其功能，并最终影响胰腺癌的治疗反应。
我们着手通过利用 43 名胰腺癌患者的肿瘤和种系 DNA 样本（包括 19 对正常-肿瘤样本），全面研究通过下一代 DNA 重测序鉴定的 FKBP5 遗传变异对吉西他滨治疗胰腺癌反应的作用。接下来，使用进行重测序的相同样本进行全因生存和肿瘤中 FKBP5 基因表达的基因型-表型关联研究，随后进行功能基因组学研究。
深入重测序在正常和肿瘤 DNA 中鉴定出 404 个 FKBP5 单核苷酸多态性（SNP）。与生存或 FKBP5 表达相关性最强的 SNP 进行了功能基因组学研究。电泳迁移率变动分析显示，rs73748206“A（T）”SNP 改变了 DNA-蛋白质结合模式，与报告基因活性显著增加一致，可能是通过其与糖皮质激素受体（GR）的结合增加。基于 rs73748206 与 FKBP5 表达的关联，通过影响从用于重测序的相同患者衍生的淋巴母细胞系中与 GR 的结合，证实了其对 FKBP5 表达的影响。
这项全面的 FKBP5 重测序研究为遗传变异在吉西他滨反应变化中的作用提供了深入了解。
