Gene expression regulations by long noncoding RNAs and their roles in cancer

Cancers are deadly diseases. The general mystery of carcinogenesis, primary and acquired drug resistance and distant organ metastasis are still puzzles to be solved. Long noncoding RNAs (lncRNAs) are receiving more and more attention in recent years since their roles in transcriptional regulation have been unveiled. Detailed functional annotations of lncRNAs have showed that their regulatory roles are largely determined by their binding partners. LncRNAs directly bind to DNA, RNA and proteins and regulate gene expression at transcriptional, post-transcriptional and post-translational levels. Here we review the current understanding of molecular functions of lncRNAs, will emphasize on their binding partners and summarize their biological roles in cancer.