The Msi Family of RNA-Binding Proteins Function Redundantly as Intestinal Oncoproteins

Cell Rep. 2015 Dec 22;13(11):2440-2455. doi: 10.1016/j.celrep.2015.11.022. Epub 2015 Dec 8.

Abstract

Members of the Msi family of RNA-binding proteins have recently emerged as potent oncoproteins in a range of malignancies. MSI2 is highly expressed in hematopoietic cancers, where it is required for disease maintenance. In contrast to the hematopoietic system, colorectal cancers can express both Msi family members, MSI1 and MSI2. Here, we demonstrate that, in the intestinal epithelium, Msi1 and Msi2 have analogous oncogenic effects. Further, comparison of Msi1/2-induced gene expression programs and transcriptome-wide analyses of Msi1/2-RNA-binding targets reveal significant functional overlap, including induction of the PDK-Akt-mTORC1 axis. Ultimately, we demonstrate that concomitant loss of function of both MSI family members is sufficient to abrogate the growth of human colorectal cancer cells, and Msi gene deletion inhibits tumorigenesis in several mouse models of intestinal cancer. Our findings demonstrate that MSI1 and MSI2 act as functionally redundant oncoproteins required for the ontogeny of intestinal cancers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Transformation, Neoplastic
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / pathology
  • Disease Models, Animal
  • Female
  • Genes, Reporter
  • HCT116 Cells
  • Humans
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology
  • Mechanistic Target of Rapamycin Complex 1
  • Mice
  • Mice, Knockout
  • Mice, Nude
  • Mice, Transgenic
  • Multiprotein Complexes / metabolism
  • Nerve Tissue Proteins / antagonists & inhibitors
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • PTEN Phosphohydrolase / genetics
  • PTEN Phosphohydrolase / metabolism
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Pyruvate Dehydrogenase Acetyl-Transferring Kinase
  • RNA Interference
  • RNA-Binding Proteins / antagonists & inhibitors
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • TOR Serine-Threonine Kinases / metabolism
  • Transplantation, Heterologous
  • beta Catenin / antagonists & inhibitors
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Msi1h protein, mouse
  • Msi2h protein, mouse
  • Multiprotein Complexes
  • Nerve Tissue Proteins
  • Pyruvate Dehydrogenase Acetyl-Transferring Kinase
  • RNA-Binding Proteins
  • beta Catenin
  • Mechanistic Target of Rapamycin Complex 1
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • PTEN Phosphohydrolase