双向负反馈环路lin28-let-7与肿瘤

A double-negative feedback loop lin28-1et-7 and tumor

let-7家族是重要的肿瘤抑制因子，在于细胞分化和肿瘤抑制中起重要作用。RNA结合蛋白lin28是重要的干细胞因子，能维持细胞干性，促进细胞恶性转化。lin28可与let-7前体结合，阻断let-7成熟；而let-7可结合至lin28 mRNA的3’-非翻译区（UTR），抑制lin28表达。lin28-let-7形成一个双向负反馈环路，参与干细胞分化、肿瘤发生、侵袭转移、耐药复发等生物过程，可作为肿瘤治疗新靶点。

The microRNA let-7 family, functioning as a tumor suppressor, has emerged as a regulator of stem cell differentiation and tumor repression. The RNA-binding protein lin28 is a stem cell pluripotency factor, which contributes to the maintenance of stem cell characteristics and promoting cell malignant transformation, lin28 can block the maturity of let-7 by combining with the precursors of let-7 family miRNAs, which is itself able to repress lin28 by binding to the 3＇-UTR of lin28 transcripts, thus forming a feedback loop. The double-negative feedback loop comprising lin28 and let-7 is involved in several biological processes such as differentiation of stem cell, tumorigenesis, invasion and metastasis, drug resistance and relapse, which could be a potential target for cancer therapy.