VEGF induces Mcl-1 up-regulation and protects multiple myeloma cells against apoptosis

Blood. 2004 Nov 1;104(9):2886-92. doi: 10.1182/blood-2004-05-1760. Epub 2004 Jun 24.

Abstract

Interleukin-6 (IL-6) triggers multiple myeloma (MM) cell proliferation and protects against apoptosis by up-regulating myeloid cell leukemia 1 (Mcl-1). Vascular endothelial growth factor (VEGF) induces modest proliferation of MM cells and induces IL-6 secretion in a paracrine loop involving MM cells and bone marrow stromal cells. Using murine embryonic fibroblast cell lines as a model (Mcl-1(wt/wt) and Mcl-1(Delta/null) MEFs), we here demonstrate that deletion of Mcl-1 reduces fetal bovine serum (FBS)-, VEGF-, and IL-6-induced proliferation. We also show that VEGF up-regulates Mcl-1 expression in a time- and dose-dependent manner in 3 human MM cell lines and MM patient cells. Importantly, we demonstrate that the pan-VEGF inhibitor, GW654652, inhibits VEGF-induced up-regulation of Mcl-1 and, as with Mcl-1 siRNA, is associated with decreased proliferation and induction of apoptosis. Finally, we show that VEGF protects MM patient cells against FBS starvation-induced apoptosis. Our studies therefore demonstrate that VEGF-induced MM cell proliferation and survival are mediated via Mcl-1, providing the preclinical framework for novel therapeutics targeting Mcl-1 and/or VEGF to improve patient outcome in MM.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Bone Marrow / pathology
  • Cell Line
  • Cell Proliferation
  • Culture Media, Serum-Free / pharmacology
  • Humans
  • Interleukin-6 / pharmacology
  • Mice
  • Multiple Myeloma / pathology*
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Neoplasm Proteins / biosynthesis*
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology*
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis*
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / physiology*
  • RNA, Small Interfering / pharmacology
  • Serum Albumin, Bovine / pharmacology
  • Tumor Cells, Cultured
  • Up-Regulation / drug effects
  • Vascular Endothelial Growth Factor A / pharmacology*

Substances

  • Culture Media, Serum-Free
  • Interleukin-6
  • Mcl1 protein, mouse
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Neoplasm Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Small Interfering
  • Vascular Endothelial Growth Factor A
  • Serum Albumin, Bovine