Sphingosine-1-Phosphate Receptor-1 Promotes Environment-Mediated and Acquired Chemoresistance

Mol Cancer Ther. 2017 Nov;16(11):2516-2527. doi: 10.1158/1535-7163.MCT-17-0379. Epub 2017 Jul 17.


Drug resistance is a major barrier for the development of effective and durable cancer therapies. Overcoming this challenge requires further defining the cellular and molecular mechanisms underlying drug resistance, both acquired and environment-mediated drug resistance (EMDR). Here, using neuroblastoma (NB), a childhood cancer with high incidence of recurrence due to resistance to chemotherapy, as a model we show that human bone marrow-mesenchymal stromal cells induce tumor expression of sphingosine-1-phosphate receptor-1 (S1PR1), leading to their resistance to chemotherapy. Targeting S1PR1 by shRNA markedly enhances etoposide-induced apoptosis in NB cells and abrogates EMDR, while overexpression of S1PR1 significantly protects NB cells from multidrug-induced apoptosis via activating JAK-STAT3 signaling. Elevated S1PR1 expression and STAT3 activation are also observed in human NB cells with acquired resistance to etoposide. We show in vitro and in human NB xenograft models that treatment with FTY720, an FDA-approved drug and antagonist of S1PR1, dramatically sensitizes drug-resistant cells to etoposide. In summary, we identify S1PR1 as a critical target for reducing both EMDR and acquired chemoresistance in NB. Mol Cancer Ther; 16(11); 2516-27. ©2017 AACR.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Bone Marrow Cells / drug effects
  • Drug Resistance, Neoplasm / genetics
  • Etoposide / administration & dosage*
  • Fingolimod Hydrochloride / administration & dosage
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene-Environment Interaction*
  • Humans
  • Mesenchymal Stem Cells / drug effects
  • Mice
  • Neoplasm Recurrence, Local / drug therapy
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / pathology
  • Neuroblastoma / drug therapy*
  • Neuroblastoma / genetics
  • Neuroblastoma / pathology
  • RNA, Small Interfering
  • Receptors, Lysosphingolipid / antagonists & inhibitors
  • Receptors, Lysosphingolipid / genetics*
  • STAT3 Transcription Factor / genetics*
  • Sphingosine-1-Phosphate Receptors
  • Xenograft Model Antitumor Assays


  • RNA, Small Interfering
  • Receptors, Lysosphingolipid
  • S1PR1 protein, human
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Sphingosine-1-Phosphate Receptors
  • Etoposide
  • Fingolimod Hydrochloride