High-throughput RNAi screening for novel modulators of vimentin expression identifies MTHFD2 as a regulator of breast cancer cell migration and invasion

Oncotarget. 2013 Jan;4(1):48-63. doi: 10.18632/oncotarget.756.

Abstract

Vimentin is an intermediate filament protein, with a key role in the epithelial to mesenchymal transition as well as cell invasion, and it is often upregulated during cancer progression. However, relatively little is known about its regulation in cancer cells. Here, we performed an RNA interference screen followed by protein lysate microarray analysis in bone metastatic MDA-MB-231(SA) breast cancer cells to identify novel regulators of vimentin expression. Out of the 596 genes investigated, three novel vimentin regulators EPHB4, WIPF2 and MTHFD2 were identified. The reduced vimentin expression in response to EPHB4, WIPF2 and MTHFD2 silencing was observed at mRNA and protein levels. Bioinformatic analysis of gene expression data across cancers indicated overexpression of EPHB4 and MTHFD2 in breast cancer and high expression associated with poor clinical characteristics. Analysis of 96 cDNA samples derived from both normal and malignant human tissues suggested putative association with metastatic disease. MTHFD2 knockdown resulted in impaired cell migration and invasion into extracellular matrix as well as decreased the fraction of cells with a high CD44 expression, a marker of cancer stem cells. Furthermore, MTHFD2 expression was induced in response to TGF-β stimulation in breast cancer cells. Our results show that MTHFD2 is overexpressed in breast cancer, associates with poor clinical characteristics and promotes cellular features connected with metastatic disease, thus implicating MTHFD2 as a potential drug target to block breast cancer cell migration and invasion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminohydrolases / genetics*
  • Aminohydrolases / metabolism
  • Antineoplastic Agents / pharmacology
  • Blotting, Western
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Cadherins / genetics
  • Cadherins / metabolism
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cell Line, Tumor
  • Cell Movement / genetics*
  • Cell Proliferation / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Hyaluronan Receptors / genetics
  • Hyaluronan Receptors / metabolism
  • Methylenetetrahydrofolate Dehydrogenase (NADP) / genetics*
  • Methylenetetrahydrofolate Dehydrogenase (NADP) / metabolism
  • Microfilament Proteins
  • Microscopy, Confocal
  • Multienzyme Complexes / genetics*
  • Multienzyme Complexes / metabolism
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • RNA Interference*
  • Receptor, EphB4 / genetics
  • Receptor, EphB4 / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transforming Growth Factor beta / pharmacology
  • Vimentin / genetics*
  • Vimentin / metabolism

Substances

  • Antineoplastic Agents
  • CD44 protein, human
  • Cadherins
  • Carrier Proteins
  • Hyaluronan Receptors
  • Microfilament Proteins
  • Multienzyme Complexes
  • Transforming Growth Factor beta
  • Vimentin
  • WIPF2 protein, human
  • methylene tetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase
  • Methylenetetrahydrofolate Dehydrogenase (NADP)
  • Receptor, EphB4
  • Aminohydrolases