Inhibition of the proprotein convertases represses the invasiveness of human primary melanoma cells with altered p53, CDKN2A and N-Ras genes.
BACKGROUND
Altered tumor suppressor p53 and/or CDKN2A as well as Ras genes are frequently found in primary and metastatic melanomas. These alterations were found to be responsible for acquisition of invasive and metastatic potential through their defective regulatory control of metalloproteinases and urokinase genes.


RESULTS
Using primary human melanoma M10 cells with altered p53, CDKN2A and N-Ras genes, we found that inhibition of the proprotein convertases (PCs), enzymes involved in the proteolytic activation of various cancer-related protein precursors resulted in significantly reduced invasiveness. Analysis of M10 cells and their gastric and lymph node derived metastatic cells revealed the presence of all the PCs found in the secretory pathway. Expression of the general PCs inhibitor alpha1-PDX in these cells in a stable manner (M10/PDX) had no effect on the mRNA expression levels of these PCs. Whereas, in vitro digestion assays and cell transfection experiments, revealed that M10/PDX cells display reduced PCs activity and are unable to process the PCs substrates proIGF-1R and proPDGF-A. These cells showed reduced migration and invasion that paralleled decreased gelatinase MMP-2 activity and increased expression and secretion of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. Furthermore, these cells showed decreased levels of urokinase-type plasminogen activator receptor (uPAR) and increased levels of plasminogen activator inhibitor-1 (PAI-1).


CONCLUSIONS
Taken together, these data suggest that inhibition of PCs activity results in decreased invasiveness of primary human melanoma cells despite their altered p53, CDKN2A and N-Ras genes, suggesting that PCs may serve as novel therapeutic targets in melanoma.
Lalou
Claude
C
INSERM, UMRS940, Equipe Avenir, Institut de Génétique Moléculaire, Hôpital Saint-Louis, Université Paris 7, Paris, France.
Scamuffa
Nathalie
N
Mourah
Samia
S
Plassa
Francois
F
Podgorniak
Marie-Pierre
MP
Soufir
Nadem
N
Dumaz
Nicolas
N
Calvo
Fabien
F
Basset-Seguin
Nicole
N
Khatib
Abdel-Majid
AM
D019942:Genes, p16; D016158:Genes, p53 / Q000235:genetics; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D008545:Melanoma / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D009361:Neoplasm Invasiveness; D043484:Proprotein Convertases / Q000037:antagonists & inhibitors*; D013270:Stomach / Q000473:pathology; D014407:Tumor Cells, Cultured; D000515:alpha 1-Antitrypsin / Q000494:pharmacology
D061965:Matrix Metalloproteinase Inhibitors; D000515:alpha 1-Antitrypsin; C113421:alpha 1-antitrypsin Portland; D043484:Proprotein Convertases; D020778:Matrix Metalloproteinase 2
J Biol Chem. 2002 Mar 29;277(13):10804-12
11792711
Oncogene. 2004 Mar 25;23(13):2330-8
14743206
Med Res Rev. 2007 Sep;27(5):631-48
17019676
Cancer Res. 2003 Apr 1;63(7):1458-63
12670890
BMC Cancer. 2005 Nov 17;5:149
16293189
Cancer Res. 2000 Apr 1;60(7):1800-4
10766161
Oncogene. 1997 Oct 23;15(17):2049-57
9366522
J Biol Chem. 2001 Aug 17;276(33):30686-93
11402025
Cancer Res. 1996 Dec 1;56(23):5475-83
8968104
J Clin Invest. 2008 Jan;118(1):352-63
18064302
Mol Cell Biol. 2000 Aug;20(16):5828-39
10913166
J Biol Chem. 1989 Oct 15;264(29):17374-8
2793861
Cell Oncol. 2007;29(4):289-99
17641413
J Biol Chem. 1999 Apr 23;274(17):11535-40
10206959
Infect Immun. 1996 Feb;64(2):524-7
8550202
Melanoma Res. 1999 Jun;9(3):279-91
10465584
J Biol Chem. 2008 Jul 11;283(28):19570-80
18469003
J Cell Physiol. 2006 Jul;208(1):246-52
16575904
Int J Cancer. 1997 Jul 17;72(2):241-7
9219827
J Mol Med (Berl). 2005 Nov;83(11):856-64
16133424
EMBO J. 1997 May 1;16(9):2319-32
9171346
J Clin Invest. 1993 Mar;91(3):1183-90
8450047
Int J Cancer. 2009 Jan 1;124(1):16-26
18814281
Am J Surg Pathol. 2008 Jan;32(1):36-44
18162768
Am J Respir Cell Mol Biol. 2008 Sep;39(3):364-72
18390474
Cancer Res. 2007 Oct 1;67(19):9030-4
17909005
Mol Carcinog. 2005 Nov;44(3):151-61
16167351
Pathology. 2006 Aug;38(4):287-301
16916716
Cancer Res. 1994 Aug 15;54(16):4547-52
8044805
Genes Dev. 1995 Apr 15;9(8):935-44
7774811
Am J Pathol. 2002 Jun;160(6):1921-35
12057895
Mol Cell Biol. 1997 Nov;17(11):6330-8
9343394
Oncogene. 2002 Jan 3;21(1):87-95
11791179
Glia. 2008 Jun;56(8):917-24
18383343
Proc Natl Acad Sci U S A. 2001 Aug 28;98(18):10326-31
11517338
Curr Med Chem. 2007;14(4):387-91
17305541
Nat Rev Cancer. 2002 Aug;2(8):594-604
12154352
Hum Reprod. 2008 Oct;23(10):2273-81
18635530
Methods Mol Biol. 2009;487:267-81
19301652