Amplified HMGA2 promotes cell growth by regulating Akt pathway in AML

J Cancer Res Clin Oncol. 2016 Feb;142(2):389-99. doi: 10.1007/s00432-015-2036-9. Epub 2015 Aug 30.

Abstract

Purpose: The aim of this study was to investigate how the amplification of HMGA2 contributes to acute myeloid leukemia (AML) cell proliferation.

Methods: The amplification and expression of HMGA2 were examined by FISH, qRT-PCR and Western blot in AML cases. The effect of HMGA2 knockdown on cell proliferation was analyzed with XTT, colony-forming assays and BrdUrd incorporation assays. The effects of HMGA2 knockdown on cell cycle were studied by flow cytometry analysis. The progression of AML cells in vivo was examined by the xenografted tumor model. The interaction between Akt pathway and HMGA2 was examined by Western blot.

Results: HMGA2 is amplified in AML, and the levels of HMGA2 messenger RNA (mRNA) and protein expressed in AML cells were significantly higher than those in normal cells, which may be related to NR and prognosis of AML patients. Reduction in HMGA2 expression in AML cells inhibited cell proliferation through a decrease in the protein expression of pAkt and pmTOR, compared with control cells.

Conclusions: HMGA2 is predominantly amplified and expressed in AML cells, and that aberrant expression of HMGA2 induces AML cell proliferation through the PI3K/Akt/mTOR signaling pathway. Inhibition of HMGA2 expression represents an attractive target for AML therapy.

Keywords: AML; Akt pathway; HMGA2; Proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Animals
  • Cell Growth Processes / genetics
  • Cell Line, Tumor
  • Gene Amplification
  • Gene Knockdown Techniques
  • HL-60 Cells
  • HMGA2 Protein / biosynthesis
  • HMGA2 Protein / genetics*
  • HMGA2 Protein / metabolism*
  • Heterografts
  • Humans
  • In Situ Hybridization, Fluorescence
  • Leukemia, Myeloid, Acute / genetics*
  • Leukemia, Myeloid, Acute / metabolism*
  • Leukemia, Myeloid, Acute / pathology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Middle Aged
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism
  • Young Adult

Substances

  • HMGA2 Protein
  • MTOR protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases