title: A PSP94-derived peptide PCK3145 inhibits MMP-9 secretion and triggers CD44 cell surface shedding: implication in tumor metastasis.
abstract: OBJECTIVE
  PCK3145 is a synthetic peptide corresponding to amino acids 31-45 of prostate secretory protein 94, which can reduce experimental skeletal metastases and prostate tumor growth in vivo. Part of its biological action involves the reduction of circulating plasma matrix metalloproteinase (MMP)-9, a crucial mediator in extracellular matrix (ECM) degradation during tumor metastasis and cancer cell invasion. The antimetastatic mechanism of action of PCK3145 is however, not understood.
  
  
  METHODS
  HT-1080 fibrosarcoma cells were treated with PCK3145, and cell lysates used for immunoblot analysis of small GTPase RhoA and membrane type (MT)1-MMP protein expression. Conditioned media was used to monitor soluble MMP-9 gelatinolytic activity by zymography and protein expression by immunoblotting. RT-PCR was used to assess RhoA, MT1-MMP, MMP-9, RECK, and CD44 gene expression. Flow cytometry was used to monitor cell surface expression of CD44 and of membrane-bound MMP-9. Cell adhesion was performed on different purified ECM proteins, while cell migration was specifically performed on hyaluronic acid (HA).
  
  
  RESULTS
  We found that PCK3145 inhibited HT-1080 cell adhesion onto HA, laminin-1, and type-I collagen suggesting the common implication of the cell surface receptor CD44. In fact, PCK3145 triggered the shedding of CD44 from the cell surface into the conditioned media. PCK3145 also inhibited MMP-9 secretion and binding to the cell surface. This effect was correlated to increased RhoA and MT1-MMP gene and protein expression.
  
  
  CONCLUSIONS
  Our data suggest that PCK3145 may antagonize tumor cell metastatic processes by inhibiting both MMP-9 secretion and its potential binding to its cell surface docking receptor CD44. Such mechanism may involve RhoA signaling and increase in MT1-MMP-mediated CD44 shedding. Together with its beneficial effects in clinical trials, this is the first demonstration of PCK3145 acting as a MMP secretion inhibitor.
authors.affiliation: Laboratoire d'Oncologie Moléculaire, Département de Chimie-Biochimie, Université du Québec à Montréal, Montreal, Quebec, Canada.
authors.forename: Borhane
authors.initials: B
authors.lastname: Annabi
authors.forename: Mounia
authors.initials: M
authors.lastname: Bouzeghrane
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Currie
authors.forename: Robert
authors.initials: R
authors.lastname: Hawkins
authors.forename: Hélène
authors.initials: H
authors.lastname: Dulude
authors.forename: Luc
authors.initials: L
authors.lastname: Daigneault
authors.forename: Marcia
authors.initials: M
authors.lastname: Ruiz
authors.forename: Jan
authors.initials: J
authors.lastname: Wisniewski
authors.forename: Seema
authors.initials: S
authors.lastname: Garde
authors.forename: Shafaat A
authors.initials: SA
authors.lastname: Rabbani
authors.forename: Chandra
authors.initials: C
authors.lastname: Panchal
authors.forename: Jinzi J
authors.initials: JJ
authors.lastname: Wu
authors.forename: Richard
authors.initials: R
authors.lastname: Béliveau
mesh_terms: D005354:Fibrosarcoma / Q000473:pathology; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009362:Neoplasm Metastasis / Q000503:physiopathology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011091:Polyesters; D029584:Prostatic Secretory Proteins / Q000737:chemistry*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D018960:Hyaluronan Receptors; D010446:Peptide Fragments; D011091:Polyesters; D029584:Prostatic Secretory Proteins; C043076:beta-microseminoprotein; C506581:tigapotide; C016240:polycaprolactone; D020780:Matrix Metalloproteinase 9