CircRNA to Cancer DataBase (C2CDB): Comprehensive Database for cancer-related circRNA

Circular RNAs (circRNAs) are a class of endogenous RNAs with covalently closed structure that generated by back-splicing. CircRNAs have been demonstrated to exert essential regulatory functions in physiological and pathological processes including cancers via various mechanisms, such as sponging miRNA, translation into peptide, acting as decoy for RNA binding proteins. However, the functions and mechanisms of majority of circRNAs still need to be investigated.

C2CDB recognized and quantified a total of 592,636 cancer-related circRNAs from 2,510 cancer samples, and integrated different information as expression value, biological trait and molecular mechanism.

C2CDB provides users: 1) expression profile of circRNAs in 2,510 samples of over 20 types of cancers and section for differential expression ananlysis of circRNAs ; 2) detailed information of biological mechanism of cancer-related circRNAs, including miRNA sponge, RBP binding, coding potential, base modification, mutation, and secondary structure; 3) experimental data from published articles, including biological function, mechanism and molecular tools like RT-qPCR primers, Northern-blot probes and shRNA sequences, and a commenting system for these articles; 4) powerful searching tool to allow users to search circRNAs by IDs or names, as well as their interacting miRNAs and RBPs. In addition, users can use the Blast tool to find circRNAs based on the sequence across junction sites; 5) friendly visual interface to help users obtain important information intuitively; 6) a new naming system integrating the names of circRNAs in different databases and articles, which will help to solve the trouble caused by inconsistent naming methods for a long time, and help users to get the useful information accurately and quickly.