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 …

Oct 1, 2008 · 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 …

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 ...

Aug 28, 2019 · 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.