A PSP94-derived peptide PCK3145 inhibits MMP-9 secretion and triggers CD44 cell surface shedding: implication in tumor metastasis.
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.
Annabi
Borhane
B
Laboratoire d'Oncologie Moléculaire, Département de Chimie-Biochimie, Université du Québec à Montréal, Montreal, Quebec, Canada.
Bouzeghrane
Mounia
M
Currie
Jean-Christophe
JC
Hawkins
Robert
R
Dulude
Hélène
H
Daigneault
Luc
L
Ruiz
Marcia
M
Wisniewski
Jan
J
Garde
Seema
S
Rabbani
Shafaat A
SA
Panchal
Chandra
C
Wu
Jinzi J
JJ
Béliveau
Richard
R
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
D018960:Hyaluronan Receptors; D010446:Peptide Fragments; D011091:Polyesters; D029584:Prostatic Secretory Proteins; C043076:beta-microseminoprotein; C506581:tigapotide; C016240:polycaprolactone; D020780:Matrix Metalloproteinase 9