Tumor IsomiR Encyclopedia (TIE): a pan-cancer database of miRNA isoforms

A Summary: MicroRNAs (miRNAs) are master regulators of gene expression in cancers. Their sequence variants or isoforms (isomiRs) are highly abundant and possess unique functions. Given their short sequence length and high heterogeneity, mapping isomiRs can be challenging; without adequate depth and data aggregation, low frequency events are often disregarded. To address these challenges, we present the Tumor IsomiR Encyclopedia (TIE): a dynamic database of isomiRs from over 10 000 adult and pediatric tumor samples in The Cancer Genome Atlas (TCGA) and The Therapeutically Applicable Research to Generate Effective Treatments (TARGET) projects. A key novelty of TIE is its ability to annotate heterogeneous isomiR sequences and aggregate the variants obtained across all datasets. Results can be browsed online or downloaded as spreadsheets. Here, we show analysis of isomiRs of miR-21 and miR-30a to demonstrate the utility of TIE.

Automated summary

MicroRNAs (miRNAs) play a key role in regulating gene expression in cancers, with their sequence variants or isoforms (isomiRs) possessing unique functions. The Tumor IsomiR Encyclopedia (TIE) is a dynamic database that aggregates isomiR variants from over 10,000 tumor samples in TCGA and TARGET projects, addressing challenges in mapping isomiRs and overcoming the disregard of low frequency events. TIE's ability to annotate heterogeneous isomiR sequences and provide results for online browsing or download showcases its utility in analyzing miR-21 and miR-30a isomiRs.