LncRNA的结构、功能及其与疾病的关系

70%的人类基因组能够被转录，而其中仅有1%～2%的转录本能够编码蛋白，余下98%均为非编码RNA（non-coding RNA，ncRNA）.在ncRNA中,长度大于200核苷酸称为长链非编码RNA（long non-coding RNA，LncRNA），占全部ncRNA的80%～90%．LncRNA除了数量庞大以外，还具有表达量较低、物种间保守性较差及细胞表达特异性等特点，使LncRNA结构及作用机制等研究充满挑战．目前关于LncRNA的研究主要集中于功能方面．LncRNA能够广泛参与生物体的各种生理及病理过程，如表观遗传学调控、癌症、神经系统功能等．LncRNA作用机制众多，能够以分子诱饵、分子向导、分子支架及信号通路的调节剂等多种角色参与调节机体各种生物学过程．解析LncRNA的分子结构、深入研究其在生物体生理及病理过程中所发挥的作用，并揭示其作用机制，不仅能够加深对生物体生理及病理过程的认识，同时也能给某些疾病的诊断、防治提供新的思路及解决途径．本文综述了近年来有关LncRNA结构、功能及作用机制相关研究进展，以期为后续LncRNA相关研究提供参考.

Structures and Functions of Long Non-coding RNAs and Its Roles in Diseases

In human, over 70% of genome is continuously transcribed. In fact, only 1%～2% of the genome are coding genes, while 80%～90% non-coding regulatory elements are transcribed into long non-coding RNAs (LncRNA). Studies of LncRNAs have the potential to be more challenging than other RNAs. LncRNA tends to be poorly conserved interspecies and its expression often shows more cell type specific than protein coding genes. In addition, LncRNA also shows low expression levels. It is now well appreciated that LncRNA was involved in a wide variety of biological processes, such as epigenetics, cancer, and brain function. Current evidence suggests that LncRNA could regulate gene expression by diverse mechanisms (execute molecular functions as scaffold molecules, molecular guides, molecular decoys, and mediators on signaling pathway) and it may largely depend on the structure of LncRNA. Comprehensive discovery of the structure, function and mechanism of LncRNA not only provides a useful explanations of the physiological and pathological processes of the organism, but also gives us a new perspective to diagnosis, prevent and treatment some clinical diseases. Here we review the recent progress of the structure, function and underlying functional mechanisms of LncRNA.