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 .

对于高度同源的let-7家族成员会在let-7后加一个字母以示区分,例如let-7的基因簇2(cluster2)就是由let-7a、let-7d和let-7f基因组成的。 另外,来自染色体不同位置的pre-let-7 miRNA可以产生相同的成熟let-7序列,通过在名称后加阿拉伯数字来区分 [9]。 例如,在人类基因组中存在13个pre-let-7 miRNA,产生10个成熟的let-7家族成员,是由于其中有3个不同的pre-let-7 miRNAs经剪切产生相同的成熟序列let-7a。 在这种情况下,可将let-7a再分为let-7a-1、let-7a-2和let-7a-3以示其转录本的 …

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 · Here, we review let-7 -family conservation and the recent advances in understanding how let-7 -expression is regulated at the transcriptional and post-transcriptional levels across species. A greater understanding of what controls let-7 expression might enable the development of treatments to fight or prevent many cancers.

2019年7月3日 · Our results revealed that several miRNAs are differently expressed during chemotherapy exposure. Amongst them, let-7a was the most profoundly downregulated and targets genes involved in crucial...

2023年5月29日 · Let-7a, a type of low-expressed microRNAs in cancer cells, has been investigated as a promising biomarker and therapeutic target for tumor suppression. Developing simple and sensitive detection methods for let-7a is important for cancer diagnosis and treatment.

2019年7月1日 · Let-7 has emerged as a central regulator of systemic energy homeostasis and it displays remarkable plasticity in metabolic responses to nutrients availability and physiological activities. In this review, we discuss recent studies highlighting post-transcriptional mechanisms that govern metabolic reprogramming in distinct cells by let-7.

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 …

To generate a let-7 miRNA, a primary transcript is produced by RNA polymerase II and then subsequently processed by Drosha/DGCR8, TUTase, and Dicer. Because dysregulation of let-7 processing is deleterious, biogenesis of let-7 is tightly regulated by cellular factors, such as the RNA binding proteins, LIN28A/B and DIS3L2.

2015年9月1日 · MicroRNA-Let-7a (miR-Let-7a) is a tumor suppressor miRNA that has been reported to target transcripts that encode proteins involved in apoptosis. In the present study, we examined the essential role of miR-Let-7a in inflammatory stress by over-expressing miR-Let-7a to investigate its role in determining the BV2 microglial phenotype, a cell line ...