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Overexpression of platelet-type 12-lipoxygenase promotes tumor cell survival by enhancing alpha(v)beta(3) and alpha(v)beta(5) integrin expression

Cancer Res. 2003 Jul 15;63(14):4258-67.

Abstract

Arachidonic acid metabolism leads to the generation of biologically active metabolites that regulate cell growth and proliferation, as well as survival and apoptosis. We have demonstrated previously that platelet-type 12-lipoxygenase (LOX) regulates the growth and survival of a number of cancer cells. In this study, we show that overexpression of platelet-type 12-LOX in prostate cancer PC3 cells or epithelial cancer A431 cells significantly extended their survival and delayed apoptosis when cultured under serum-free conditions. These effects were shown to be a result of enhanced surface integrin expression, resulting in a more spread morphology of the cells in culture. PC3 cells transfected with 12-LOX displayed increased alpha(v)beta(3) and alpha(v)beta(5) integrin expression, whereas other integrins were unaltered. Transfected A431 cells did not express alpha(v)beta(3); however, alpha(v)beta(5) integrin expression was increased. Treatment of both transfected cell lines with monoclonal antibody to alpha(v)beta(5) (and in the case of PC3 cells, anti-alpha(v)beta(3)) resulted in significant apoptosis. In addition, treatment with 100 nM 12(S)-hydroxy-eicosatetraenoic acid, the end product of platelet-type 12-LOX, but not other hydroxy-eicosatetraenoic acids, enhanced the survival of wild-type PC3 and A431 cells and resulted in increased expression of alpha(v)beta(5). Furthermore, Baicalein or N-benzyl-N-hydroxy-5-phenylpentamide, specific 12-LOX inhibitors, significantly decreased alpha(v)beta(5)-mediated adhesion and survival in 12-LOX-overexpressing cells. The results show that 12-LOX regulates cell survival and apoptosis by affecting the expression and localization of the vitronectin receptors, alpha(v)beta(3) and alpha(v)beta(5), in two cancer cell lines.

Publication types

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

MeSH terms

  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / metabolism
  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / pharmacology
  • Apoptosis / physiology
  • Arachidonate 12-Lipoxygenase / biosynthesis*
  • Arachidonate 12-Lipoxygenase / genetics
  • Arachidonate 12-Lipoxygenase / metabolism
  • Blood Platelets / enzymology
  • Carcinoma, Squamous Cell / enzymology
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / pathology
  • Cell Membrane / metabolism
  • Cell Survival / physiology
  • Flow Cytometry
  • Humans
  • Integrin alphaVbeta3 / biosynthesis*
  • Integrins / biosynthesis*
  • Male
  • Prostatic Neoplasms / enzymology
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • Receptors, Vitronectin / biosynthesis*
  • Transfection
  • Tumor Cells, Cultured

Substances

  • Integrin alphaVbeta3
  • Integrins
  • Receptors, Vitronectin
  • integrin alphaVbeta5
  • 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
  • Arachidonate 12-Lipoxygenase