COMP is selectively up-regulated in degenerating acinar cells in chronic pancreatitis and in chronic-pancreatitis-like lesions in pancreatic cancer.
BACKGROUND
Chronic pancreatitis (CP) is an inflammatory disease of the pancreas characterized histomorphologically by progressive development of fibrosis and atrophy of the pancreatic parenchyma. Cartilage oligomeric matrix protein (COMP) is a member of the thrombospondin (TSP) family of extracellular glycoproteins that is expressed in CP tissues. In the present study, we characterized COMP mRNA and protein expression in the normal pancreas, chronic pancreatitis, and pancreatic cancer tissues.


METHODS
15 normal pancreatic tissues, 14 CP tissues and 14 pancreatic cancer tissues were analyzed by Northern blotting, Western blotting, in situ hybridization and immunohistochemistry.


RESULTS
COMP mRNA and protein were detected at moderate to high levels in chronic pancreatitis tissues, at moderate levels in pancreatic cancer tissues, but at low levels in normal pancreatic tissues and in four pancreatic cancer cell lines. COMP mRNA signals and immunoreactivity were strongly present in the cytoplasm of degenerating acinar cells in CP tissues as well as in CP-like lesions in pancreatic cancer tissues. COMP protein was also present in the fibrotic tissue in CP. In contrast, COMP expression was weak to absent in the cytoplasm of cancer cells in pancreatic cancer tissues, and in ductal cells and islet cells in normal pancreatic tissues.


CONCLUSIONS
COMP is preferentially expressed in degenerating acinar cells in CP and in CP-like areas in pancreatic cancer, suggesting a potential role of this gene in the course of acinar cell degeneration and dedifferentiation. COMP might thus serve as a marker for tissue destruction and disease activity in CP.
Liao
Q
Q
Dept. of General Surgery, University of Heidelberg, Heidelberg, Germany.
Kleeff
J
J
Xiao
Y
Y
Di Cesare
P E
PE
Korc
M
M
Zimmermann
A
A
Büchler
M W
MW
Friess
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D015152:Blotting, Northern; D015153:Blotting, Western; D064236:Cartilage Oligomeric Matrix Protein; D002478:Cells, Cultured; D002908:Chronic Disease; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D064235:Matrilin Proteins; D008875:Middle Aged; D010179:Pancreas / Q000378:metabolism / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D010195:Pancreatitis / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D015854:Up-Regulation
D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; D012333:RNA, Messenger; C577553:TSP5 protein, human