RNA-seq from archival FFPE breast cancer samples: molecular pathway fidelity and novel discovery

作者：Nathan D. Pennock, Sonali Jindal, Wesley Horton, Duanchen Sun, Jayasri Narasimhan, Lucia Carbone, Suzanne S. Fei, Robert P. Searles, Christina A. Harrington, Julja Burchard, Sheila Weinmann, Pepper Schedin, Zheng Xia · 发表于：BMC Medical Genomics · 年份：2019 · DOI：10.1186/s12920-019-0643-z · 被引用次数：70 · 研究领域：Single-cell and spatial transcriptomics、Cancer Genomics and Diagnostics、Molecular Biology Techniques and Applications

BACKGROUND: Formalin-fixed, paraffin-embedded (FFPE) tissues for RNA-seq have advantages over fresh frozen tissue including abundance and availability, connection to rich clinical data, and association with patient outcomes. However, FFPE-derived RNA is highly degraded and chemically modified, which impacts its utility as a faithful source for biological inquiry. METHODS: True archival FFPE breast cancer cases (n = 58), stored at room temperature for 2-23 years, were utilized to identify key steps in tissue selection, RNA isolation, and library choice. Gene expression fidelity was evaluated by comparing FFPE data to public data obtained from fresh tissues, and by employing single-gene, gene set and transcription network-based regulon analyses. RESULTS: We report a single 10 μm section of breast tissue yields sufficient RNA for RNA-seq, and a relationship between RNA quality and block age that was not linear. We find single-gene analysis is limiting with FFPE tissues, while targeted gene set approaches effectively distinguish ER+ from ER- breast cancers. Novel utilization of regulon analysis identified the transcription factor KDM4B to associate with ER+ disease, with KDM4B regulon activity and gene expression having prognostic significance in an independent cohort of ER+ cases. CONCLUSION: Our results, which outline a robust FFPE-RNA-seq pipeline for broad use, support utilizing FFPE tissues to address key questions in the breast cancer field, including the delineation betwee...