Therapeutic potential of microRNA let-7: tumor suppression or impeding normal stemness

Cell Transplant. 2014;23(4-5):459-69. doi: 10.3727/096368914X678418.


The first microRNA, let-7, and its family were discovered in Caenorhabditis elegans and are functionally conserved from worms to humans in the regulation of embryonic development and stemness. The let-7 family has been shown to have an essential role in stem cell differentiation and tumor-suppressive activity. Deregulating expression of let-7 is commonly reported in many human cancers. Emerging evidence has accumulated and suggests that reestablishment of let-7 in tumor cells is a valuable therapeutic strategy. However, findings reach beyond tumor therapeutics and may impinge on stemness and differentiation of stem cells. In this review, we discuss the role of let-7 in development and differentiation of normal adult stem/progenitor cells and offer a viewpoint of the association between deregulated let-7 expression and tumorigenesis. The regulation of let-7 expression, cancer-relevant let-7 targets, and the application of let-7 are highlighted.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Genetic Therapy
  • Humans
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neoplasms / genetics
  • Neoplasms / pathology
  • Neoplasms / therapy*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • Stem Cells / cytology
  • Stem Cells / metabolism


  • LIN-28 protein, human
  • MicroRNAs
  • RNA-Binding Proteins
  • mirnlet7 microRNA, human