Long noncoding RNAs (lncRNAs), which lack significant protein-coding capacity, regulate various biological processes through diverse and as yet poorly understood molecular mechanisms. However, a number of studies in the past few years have documented important functions for lncRNAs in human diseases. Among these lncRNAs, lincRNA-p21 has been proposed to be a novel regulator of cell proliferation, apoptosis and DNA damage response, and involved in the initiation and progression of human diseases. In this review, we summarize the current knowledge of lincRNA-p21, mainly focus on the known biological functions and its underlying mechanisms. Moreover, we highlight the growing body of evidences for the importance of lincRNA-p21 in diverse human diseases, which indicate lincRNA-p21 as a potential diagnostic marker and/or a valuable therapeutic target for these diseases.

LincRNA-p21 plays an important role in the pathogenesis and progression of coronary artery disease (CAD). To date, the biological significance of polymorphisms inlincRNA-p21on CAD risk remains unknown. Here we aimed to evaluate the influence oflincRNA-p21polymorphisms on individual susceptibility to CAD. Genotyping of four tagSNPs (rs9380586, rs4713998, rs6930083, and rs6931097) withinlincRNA-p21gene was performed in 615 CAD and 655 controls. The haplotype analysis showed that the haplotype G-A-A-G (rs9380586-rs4713998-rs6930083-rs6931097) was statistically significantly associated with the reduced risk for CAD (OR = 0.78,P= 0.023). Stratified analysis revealed that G-A-A-G haplotype was at a significantly lower risk for myocardial infarction (MI) (OR = 0.68,P= 0.010). We also found that haplotype G-A-A-G had a more pronounced decreased risk for premature CAD or MI subjects (OR = 0.67,P= 0.017 for premature CAD, and OR = 0.65,P= 0.041 for premature MI, resp.). Our data provide the first evidence that the G-A-A-G haplotype oflincRNA-p21is associated with decreased risk of CAD and MI, particularly among premature CAD/MI in the Chinese Han population. Further studies with more subjects and in diverse ethnic populations are warranted to clarify the general validity of our findings.