TLX activates MMP-2, promotes self-renewal of tumor spheres in neuroblastoma and correlates with poor patient survival

Cell Death Dis. 2014 Oct 30;5(10):e1502. doi: 10.1038/cddis.2014.449.

Abstract

Nuclear orphan receptor TLX (Drosophila tailless homolog) is essential for the maintenance of neural stem/progenitor cell self-renewal, but its role in neuroblastoma (NB) is not well understood. Here, we show that TLX is essential for the formation of tumor spheres in three different NB cell lines, when grown in neural stem cell media. We demonstrate that the knock down of TLX in IMR-32 cells diminishes its tumor sphere-forming capacity. In tumor spheres, TLX is coexpressed with the neural progenitor markers Nestin, CD133 and Oct-4. In addition, TLX is coexpressed with the migratory neural progenitor markers CD15 and matrix metalloproteinase-2 (MMP-2) in xenografts of primary NB cells from patients. Subsequently, we show the effect of TLX on the proliferative, invasive and migratory properties of IMR-32 cells. We attribute this to the recruitment of TLX to both MMP-2 and Oct-4 gene promoters, which resulted in the respective gene activation. In support of our findings, we found that TLX expression was high in NB patient tissues when compared with normal peripheral nervous system tissues. Further, the Kaplan-Meier estimator indicated a negative correlation between TLX expression and survival in 88 NB patients. Therefore, our results point at TLX being a crucial player in progression of NB, by promoting self-renewal of NB tumor-initiating cells and altering their migratory and invasive properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers, Tumor / metabolism
  • Cell Hypoxia
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Enzyme Activation
  • Humans
  • Matrix Metalloproteinase 2 / metabolism*
  • Mice, SCID
  • Neoplasm Invasiveness
  • Neoplastic Stem Cells / enzymology
  • Neoplastic Stem Cells / pathology
  • Neuroblastoma / enzymology*
  • Neuroblastoma / pathology*
  • Octamer Transcription Factor-3 / genetics
  • Orphan Nuclear Receptors
  • Promoter Regions, Genetic / genetics
  • Protein Binding / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Spheroids, Cellular / enzymology
  • Spheroids, Cellular / pathology*
  • Survival Analysis
  • Xenograft Model Antitumor Assays

Substances

  • Biomarkers, Tumor
  • NR2E1 protein, human
  • Octamer Transcription Factor-3
  • Orphan Nuclear Receptors
  • POU5F1 protein, human
  • Receptors, Cytoplasmic and Nuclear
  • Matrix Metalloproteinase 2