dbDEMC (database of Differentially Expressed MiRNAs in human Cancers) is an integrated database that designed to store and display differentially expressed microRNAs (miRNAs) in human cancers detected by high-throughput methods. In this updated version of dbDEMC, a total of 209 newly published data sets were collected from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). The limma package embedded in R (http://www.r-project.org/) was used to screen the differentially expressed miRNAs (with FDR < 0.05) from different types of experiments, which include the cancer versus normal comparison, cancer subtypes comparison, cancer grade comparision, cancer outcome comparision, blood sample comparision, respectively. The current version contains 2224 differentially expressed miRNAs in 35 cancer types, curated from 436 experiments. An easy-to-use interface was constructed to facilitate the query and browse the resulust in the database. In addition, an enhanced miRNA page is provide to demonstrate the basic miRNA description, expression profiles across multiple caners in each analysis type, related analysis experiments and results from low throughput validation assays. For a set of miRNAs and multiple cancer types, differential expression profile can be visualized in a heatmap to explore the difference and similarity between cancers. We try to make dbDEMC a valuable resource to facilitate cancer research and contribute to miRNA related biomarker discovery for cancer.

Zhen Yang, Fei Ren, Changning Liu, et al. "dbDEMC: a database of differentially expressed miRNAs in human cancers". BMC Genomics. 2010; 11(Suppl 4): S5.