Inhibition of MMP-9 secretion by the anti-metastatic PSP94-derived peptide PCK3145 requires cell surface laminin receptor signaling.
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. These anti-metastatic and anti-tumoral effects of PCK3145 are partially explained by the in-vivo and in-vitro decrease in matrix metalloproteinase (MMP)-9 extracellular levels through as yet unidentified molecular mechanisms of action. Gelatin zymography and immunoblots were used to monitor the levels of secreted MMP-9 from HT-1080 cells. Flow cytometry was used to monitor HT-1080 cell surface binding of FITC-labeled PCK3145 and biotin-labeled laminin. PCK3145-coated cell culture dishes were used to monitor cell adhesion. HT-1080 cell lysates were used for immunoblotting of HuR, extracellular signal-regulated protein kinase (ERK) and phospho-ERK. Total RNA was isolated and RT-PCR used to monitor HuR gene expression. We found that PCK3145 bound to the HT-1080 cell surface and that this binding rapidly triggered ERK phosphorylation that, ultimately, led to a reduction of secreted MMP-9. Laminin inhibited both cell surface binding and ERK phosphorylation by PCK3145. Overexpression of the 67-kDa laminin receptor led to an increased binding of the cells to PCK3145. HuR, a protein that can bind to and stabilize MMP-9 mRNA, was found to be downregulated by PCK3145. The mitogen-activated protein kinase/ERK (MEK) inhibitor PD98059 as well as native laminin and SIKVAV laminin-derived peptide prevented that downregulation. Our data suggest that PCK3145 rapidly triggers intracellular signaling through cell surface laminin receptors. This leads to decreased HuR expression and subsequent destabilization of MMP-9 transcripts. This is the first molecular evidence demonstrating the intracellular signaling and anti-metastatic mechanism of action of PCK3145 that leads to the inhibition of MMP-9 secretion.
Annabi
Borhane
B
Laboratoire d'Oncologie Moléculaire, Département de Chimie, Centre BioMed Université du Québec à Montréal, Montreal, Quebec, Canada.
Bouzeghrane
Mounia
M
Currie
Jean-Christophe
JC
Dulude
Hélène
H
Daigneault
Luc
L
Garde
Seema
S
Rabbani
Shafaat A
SA
Panchal
Chandra
C
Wu
Jinzi J
JJ
Béliveau
Richard
R
D000954:Antigens, Surface / Q000378:metabolism; D001859:Bone Neoplasms / Q000201:enzymology / Q000517:prevention & control / Q000556:secondary; D045744:Cell Line, Tumor; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007797:Laminin / Q000494:pharmacology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D009842:Oligopeptides / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D029584:Prostatic Secretory Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D016601:RNA-Binding Proteins / Q000378:metabolism; D017474:Receptors, Laminin / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
D000954:Antigens, Surface; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; D005419:Flavonoids; D007797:Laminin; D061965:Matrix Metalloproteinase Inhibitors; D009842:Oligopeptides; D010446:Peptide Fragments; D029584:Prostatic Secretory Proteins; D016601:RNA-Binding Proteins; D017474:Receptors, Laminin; C043076:beta-microseminoprotein; C077583:seryl-isoleucyl-lysyl-valyl-alanyl-valinamide; C506581:tigapotide; D017346:Protein Serine-Threonine Kinases; D020780:Matrix Metalloproteinase 9; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one