LIV-1 promotes prostate cancer epithelial-to-mesenchymal transition and metastasis through HB-EGF shedding and EGFR-mediated ERK signaling

PLoS One. 2011;6(11):e27720. doi: 10.1371/journal.pone.0027720. Epub 2011 Nov 16.

Abstract

LIV-1, a zinc transporter, is an effector molecule downstream from soluble growth factors. This protein has been shown to promote epithelial-to-mesenchymal transition (EMT) in human pancreatic, breast, and prostate cancer cells. Despite the implication of LIV-1 in cancer growth and metastasis, there has been no study to determine the role of LIV-1 in prostate cancer progression. Moreover, there was no clear delineation of the molecular mechanism underlying LIV-1 function in cancer cells. In the present communication, we found increased LIV-1 expression in benign, PIN, primary and bone metastatic human prostate cancer. We characterized the mechanism by which LIV-1 drives human prostate cancer EMT in an androgen-refractory prostate cancer cells (ARCaP) prostate cancer bone metastasis model. LIV-1, when overexpressed in ARCaP(E) (derivative cells of ARCaP with epithelial phenotype) cells, promoted EMT irreversibly. LIV-1 overexpressed ARCaP(E) cells had elevated levels of HB-EGF and matrix metalloproteinase (MMP) 2 and MMP 9 proteolytic enzyme activities, without affecting intracellular zinc concentration. The activation of MMPs resulted in the shedding of heparin binding-epidermal growth factor (HB-EGF) from ARCaP(E) cells that elicited constitutive epidermal growth factor receptor (EGFR) phosphorylation and its downstream extracellular signal regulated kinase (ERK) signaling. These results suggest that LIV-1 is involved in prostate cancer progression as an intracellular target of growth factor receptor signaling which promoted EMT and cancer metastasis. LIV-1 could be an attractive therapeutic target for the eradication of pre-existing human prostate cancer and bone and soft tissue metastases.

Publication types

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

MeSH terms

  • Animals
  • Antibodies / immunology
  • Bone Neoplasms / secondary
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / immunology
  • Cation Transport Proteins / metabolism*
  • Cell Line, Tumor
  • Disease Progression
  • Epithelial-Mesenchymal Transition*
  • ErbB Receptors / metabolism*
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Gene Expression Regulation, Neoplastic
  • HEK293 Cells
  • Heparin-binding EGF-like Growth Factor
  • Humans
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Male
  • Matrix Metalloproteinase 2 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • Neoplasm Metastasis
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / immunology
  • Neoplasm Proteins / metabolism*
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / pathology*
  • Signal Transduction*
  • Soft Tissue Neoplasms / secondary

Substances

  • Antibodies
  • Cation Transport Proteins
  • HBEGF protein, human
  • Hbegf protein, mouse
  • Heparin-binding EGF-like Growth Factor
  • Intercellular Signaling Peptides and Proteins
  • Neoplasm Proteins
  • SLC39A6 protein, human
  • ErbB Receptors
  • Extracellular Signal-Regulated MAP Kinases
  • Matrix Metalloproteinase 2
  • Matrix Metalloproteinase 9