随着高通量测序技术在小RNA研究领域中的广泛应用，新小RNA不断出现，小RNA的来源亦不断得到拓展。既往研究表明rRNA可产生大量小RNA分子，但这些小RNA的产生机制及功能尚不清楚。本课题组前期研究发现rRNA衍生小RNA具有特殊的来源分布模式，即小RNA主要来自rRNA末端，其中以28s rRNA 5’末端衍生小RNA最为丰富，且这类rRNA末端衍生小RNA（rRNA-terminal-derived small RNA，rtsRNA）与过氧应激相关并具有与miRNA类似的调控功能。据此，本课题拟探索以下问题：1）rtsRNA在乳腺癌组织、癌旁组织中的表达及其与患者预后的关系；2）rtsRNA的加工生成机制；3）rtsRNA调控的下游靶基因及其生物学功能。本课题的完成，将深化我们对“rRNA降解过程具有主动生物学调控意义”的认识，同时扩展我们对小RNA来源及调控功能的认识。

Along with the development of small RNA high-throughput sequencing, many novel small RNAs were discovered and the source of small RNAs was greatly expanded. Peer-research showed that many small RNAs were originated from rRNA. But the biogenesis process and the function of these rRNA-derived small RNA is unknown. Basing on previous research, we found that these rRNA-derived small RNA mainly came from the terminal end of rRNA, especially from the 5’ terminal of 28s rRNA. Moreover, these rtsRNA (rRNA-terminal-derived small RNA) could be induced by peroxynitrite stress and could function as a miRNA. Our current project has triple-aims: 1) to dig out the relationship between rtsRNA expression and breast cancer; 2) to figure out the processing pathway of rtsRNA; 3) to find out the target genes and the biological function of rtsRNA. Our research will facilitate us to better understand the regulatory function of rRNA degradation and broaden our knowledge of the small RNA world.