LOX-1 activation by oxLDL triggers an epithelial mesenchymal transition and promotes tumorigenic potential in prostate cancer cells

Cancer Lett. 2018 Feb 1:414:34-43. doi: 10.1016/j.canlet.2017.10.035. Epub 2017 Nov 14.

Abstract

Obesity is related to an increased risk of developing prostate cancer with high malignancy stages or metastasis. Recent results demonstrated that LOX-1, a receptor associated with obesity and atherosclerosis, is overexpressed in advanced and metastatic prostate cancer. Furthermore, high levels of oxLDL, the main ligand for LOX-1, have been found in patients with advanced prostate cancer. However, the role of LOX-1 in prostate cancer has not been unraveled completely yet. Here, we show that LOX-1 is overexpressed in prostate cancer cells and its activation by oxLDL promotes an epithelial to mesenchymal transition, through of lowered expression of epithelial markers (E-cadherin and plakoglobin) and an increased expression of mesenchymal markers (vimentin, N-cadherin, snail, slug, MMP-2 and MMP-9). Consequently, LOX-1 activation by oxLDL promotes actin cytoskeleton restructuration and MMP-2 and MMP-9 activity inducing prostate cancer cell invasion and migration. Additionally, LOX-1 increased the tumorigenic potential of prostate cancer cells and its expression was necessary for tumor growth in nude mice. In conclusion, our results suggest that oxLDL/LOX-1 could be ones of mechanisms that explain why obese patients with prostate cancer have an accelerated tumor progression and a greater probability of developing metastasis.

Keywords: EMT; LOX-1 receptor; Prostate cancer; Tumorigenic potential; oxLDL.

MeSH terms

  • Animals
  • Carcinogenesis / drug effects*
  • Carcinogenesis / genetics
  • Carcinogenesis / pathology
  • Cell Line, Tumor
  • Enzyme Activation / drug effects
  • Epithelial-Mesenchymal Transition / drug effects*
  • Epithelial-Mesenchymal Transition / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Lipoproteins, LDL / pharmacology*
  • Male
  • Mice, Nude
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / therapy
  • RNA Interference
  • RNAi Therapeutics / methods
  • Scavenger Receptors, Class E / genetics
  • Scavenger Receptors, Class E / metabolism*
  • Tumor Burden / drug effects
  • Tumor Burden / genetics
  • Xenograft Model Antitumor Assays / methods

Substances

  • Lipoproteins, LDL
  • OLR1 protein, human
  • Scavenger Receptors, Class E
  • oxidized low density lipoprotein