Silencing of ROR1 and FMOD with siRNA results in apoptosis of CLL cells

Br J Haematol. 2010 Nov;151(4):327-35. doi: 10.1111/j.1365-2141.2010.08362.x. Epub 2010 Aug 31.


We have previously demonstrated that ROR1 and FMOD (fibromodulin) are two genes upregulated in chronic lymphocytic leukaemia (CLL) cells compared to normal blood B cells. In this study, siRNAs were used to specifically silence ROR1 and FMOD expression in CLL cells, healthy B cells and human fibroblast cell lines. siRNA treatment induced a specific reduction (75-95%) in FMOD and ROR1 mRNA. Western blot analysis with specific antibodies for FMOD and ROR1 demonstrated that the proteins were significantly downregulated 48 h after siRNA treatment. Silencing of FMOD and ROR1 resulted in statistically significant (P ≤ 0·05-0·001) apoptosis of CLL cells but not of B cells from normal donors. Human fibroblast cell lines treated with FMOD and ROR1 siRNA did not undergo apoptosis. This is the first report demonstrating that ROR1 and FMOD may be involved in the survival of CLL cells. ROR1 in particular is further explored as potential target for therapy in CLL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics*
  • Extracellular Matrix Proteins / biosynthesis
  • Extracellular Matrix Proteins / genetics*
  • Fibromodulin
  • Gene Silencing*
  • Genes, Neoplasm
  • Humans
  • Leukemia, Lymphocytic, Chronic, B-Cell / genetics*
  • Leukemia, Lymphocytic, Chronic, B-Cell / pathology
  • Neoplasm Proteins / biosynthesis
  • Neoplasm Proteins / genetics
  • Proteoglycans / biosynthesis
  • Proteoglycans / genetics*
  • RNA, Neoplasm / genetics
  • RNA, Small Interfering / genetics
  • Receptor Tyrosine Kinase-like Orphan Receptors / biosynthesis
  • Receptor Tyrosine Kinase-like Orphan Receptors / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Transfection
  • Tumor Cells, Cultured


  • Extracellular Matrix Proteins
  • FMOD protein, human
  • Neoplasm Proteins
  • Proteoglycans
  • RNA, Neoplasm
  • RNA, Small Interfering
  • Fibromodulin
  • ROR1 protein, human
  • Receptor Tyrosine Kinase-like Orphan Receptors