Activation of EDTA-resistant gelatinases in malignant human tumors.
Among the many proteases associated with human cancer, seprase or fibroblast activation protein alpha, a type II transmembrane glycoprotein, has two types of EDTA-resistant protease activities: dipeptidyl peptidase and a 170-kDa gelatinase activity. To test if activation of gelatinases associated with seprase could be involved in malignant tumors, we used a mammalian expression system to generate a soluble recombinant seprase (r-seprase). In the presence of putative EDTA-sensitive activators, r-seprase was converted into 70- to 50-kDa shortened forms of seprase (s-seprase), which exhibited a 7-fold increase in gelatinase activity, whereas levels of dipeptidyl peptidase activity remained unchanged. In malignant human tumors, seprase is expressed predominantly in tumor cells as shown by in situ hybridization and immunohistochemistry. Proteins purified from experimental xenografts and malignant tumors using antibody- or lectin-affinity columns in the presence of 5 mmol/L EDTA were assayed for seprase activation in vivo. Seprase expression and activation occur most prevalently in ovarian carcinoma but were also detected in four other malignant tumor types, including adenocarcinoma of the colon and stomach, invasive ductal carcinoma of the breast, and malignant melanoma. Together, these data show that, in malignant tumors, seprase is proteolytically activated to confer its substrate specificity in collagen proteolysis and tumor invasion.
Chen
Donghai
D
Department of Medicine, Stony Brook University, Stony Brook, New York 11794, USA.
Kennedy
Alanna
A
Wang
Jaw-Yuan
JY
Zeng
Wei
W
Zhao
Qiang
Q
Pearl
Michael
M
Zhang
Mengzhen
M
Suo
Zhenhe
Z
Nesland
Jahn M
JM
Qiao
Yuhuan
Y
Ng
Ah-Kau
AK
Hirashima
Naoko
N
Yamane
Tetsu
T
Mori
Yoshiyuki
Y
Mitsumata
Masako
M
Ghersi
Giulio
G
Chen
Wen-Tien
WT
D000818:Animals; D002460:Cell Line; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology*; D010450:Endopeptidases; D004789:Enzyme Activation; D018093:Gelatinases / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000882:Haplorhini; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D009369:Neoplasms / Q000201:enzymology* / Q000473:pathology; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012697:Serine Endopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000099167:Fibroblast Activation Protein Alpha
D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D004492:Edetic Acid; D010450:Endopeptidases; D018093:Gelatinases; D008565:Membrane Proteins; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D000099167:Fibroblast Activation Protein Alpha