Fibroblast growth factor receptor 3 inhibition by short hairpin RNAs leads to apoptosis in multiple myeloma

Mol Cancer Ther. 2005 May;4(5):787-98. doi: 10.1158/1535-7163.MCT-04-0330.

Abstract

The presence of t(4;14)(p16.3;q32.3) in multiple myeloma cells results in dysregulated expression of the fibroblast growth factor receptor 3 (FGFR3). FGFR3 acts as an oncogene to promote multiple myeloma cell proliferation and antiapoptosis. These encourage the clinical development of FGFR3-specific inhibitors. Three short hairpin RNAs (shRNA) targeting different sites of FGFR3 were selected and subsequently transfected into KMS-11, OPM-2, and NCI-H929 human myeloma cell lines, all of which are characterized by t(4;14) and FGFR3 over expression. The combination of these three shRNAs can effectively inhibit FGFR3 expression in all three cell lines. Sequential immunocytochemistry/fluorescence in situ hybridization was employed to validate that the shRNAs specifically inhibited FGFR3 expression in OPM-2 cells. Decreased expression of B-cell chronic lymphocytic leukemia/lymphoma 2 (BCL2) and myeloid cell leukemia sequence 1 (MCL1) proteins and increased staining of Annexin V-positive cells showed that inhibition of FGFR3 induces apoptosis. After confirming down-regulation of FGFR3 by real-time PCR, HU-133 plus 2.0 array was employed to compare the gene expression profile of shRNA-treated sample with that of the control. Besides the down-regulation of FGFR3, expression of the antiapoptotic genes CFLAR, BCL2, MCL1, and some members of NF-kappaB family decreased, whereas expression of the proapoptotic genes CYC, BID, CASP2, and CASP6 increased. Microarray results also revealed changes in genes previously implicated in multiple myeloma pathogenesis (RAS, RAF, IL-6R, and VEGF), as well as others (TLR4, KLF4, and GADD45A) not previously linked to multiple myeloma. Our observations indicate that shRNAs can specifically and effectively inhibit FGFR3 expression. This targeted approach may be worth testing in multiple myeloma patients with t(4;14) and FGFR3 overexpression in the future.

MeSH terms

  • Apoptosis*
  • Chromosomes, Human, Pair 14 / genetics
  • Chromosomes, Human, Pair 4 / genetics
  • Gene Expression Profiling*
  • Humans
  • Multiple Myeloma / metabolism*
  • Multiple Myeloma / pathology
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • RNA Interference*
  • RNA, Small Interfering / administration & dosage
  • RNA, Small Interfering / pharmacology*
  • Receptor, Fibroblast Growth Factor, Type 3
  • Receptors, Fibroblast Growth Factor / antagonists & inhibitors*
  • Receptors, Fibroblast Growth Factor / genetics
  • Receptors, Fibroblast Growth Factor / metabolism
  • Translocation, Genetic
  • Tumor Cells, Cultured

Substances

  • MCL1 protein, human
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Neoplasm Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Small Interfering
  • Receptors, Fibroblast Growth Factor
  • FGFR3 protein, human
  • Protein-Tyrosine Kinases
  • Receptor, Fibroblast Growth Factor, Type 3