The let-7 microRNA family refers to the many slight variations of let-7 that exist both within a single organism and across species. In humans, for example, there are ten unique let-7 family member sequences: let-7 a through g , let-7i , mir-98 , and mir-202 .

let-7基因最早在线虫中被发现，是一种关键的发育调节因子，并成为已知的第两种 microRNA 之一（另一种是 lin-4）。 [1] 很快，"let-7"在果蝇中也被发现，并通过 BLAST （基本局部比对搜索工具）研究被确认为第一个已知的人类 miRNA。 [2] let-7 家族成员的成熟形式在物种间高度保守。 尽管在未分化细胞中检测不到成熟的let-7成员的水平，但是let-7的初级转录本和 发夹 结构前体存在于这些细胞中。 [5] 这表明成熟的let-7 miRNA可能以 转录后 （英语：Post-transcriptional …

2008年10月1日 · let-7 remains one of the key miRNA regulators in development and cancer. The let-7-family miRNAs are highly conserved across animal species in sequence, at what developmental stage they are expressed and in their organization as clusters or within specific coding genes in the genome.

let-7是最早發現的兩種microRNA之一（第一種是lin-4），2000年由加里·魯夫昆等人發現於模式生物 秀麗隱桿線蟲的基因組中 [1] ，之後通過BLAST在果蠅和人類基因組中發現了同源物 [2] ，形成了let-7非編碼RNA家族。人類miR-98 microRNA前體是let-7家族成員。

let-7 microRNA是发现较早的一类miRNA, 最早在线虫中发现能调控细胞分裂的时序。 此后大量证据表明,let-7参与动物多个器官发育的调控过程, 并与人类疾病发生密切相关。 该文综述了近年来let-7 调控动物脑、神经及心肺系统等器官发育的研究成果, 初步阐述了let-7 调控动物器官发育可能的作用机制, 以期为深入研究let-7 的功能奠定基础。 关键词:microRNA ; let-7 ; 器官发育; 调控机制中图分类号:Q522.2 ;Q954.48文献标识码:A. Progress of animal organs development regulated …

Let-7的家族成员已被证明在Burkitt淋巴瘤中靶向原癌基因Myc的表达 ，而Myc表达降低与滤泡性淋巴瘤向弥漫大B细胞淋巴瘤转化高度相关 。 Let-7i也可能是一些神经系统疾病的生物标志物和药物治疗靶点。

通过转录后调控机制,let-7可以特异性结合到信使RNA(mRNA)上,从而降解靶基因mRNA或抑制其翻译。 研究表明,let-7家族在干细胞与肿瘤干细胞中参与多种调控机制,在维持干细胞特性(stemness),即高增殖、低分化和自我更新能力的过程中起到重要调控作用。 本文将从干细胞与肿瘤干细胞两个方面,综述let-7与细胞“干性”间存在的联系和调控机制。

In this review, we discuss the multifaceted roles of let-7 and provide an overview of its regulation at multiple levels. MicroRNAs (miRNAs) are a group of small noncoding RNAs capable of regulating specific gene expression. Let-7 miRNA was first discovered in Caenorhabditis elegans and it is highly conserved in human tissues.

The first two known microRNAs (miRNAs), lin-4 and let-7, were originally discovered in the nematode Caenorhabditis elegans and control the timing of stem-cell division and differentiation. let-7 was subsequently found as the first known human miRNA. let-7 and its family members are highly conserved across species in sequence and function, and ...

2019年8月28日 · Here, we review let-7 function as tumor suppressor and oncogene, considering let-7 as a potential diagnostic and prognostic marker, and a therapeutic target for cancer treatment. We explain the complex regulation and function of different let-7 family members, pointing to abnormal processes involved in carcinogenesis.