Cathepsin E and subtypes of intestinal metaplasia in carcinogenesis of the human stomach.
BACKGROUND
Cathepsin E is found mainly over the gastric surface and foveolar epithelial cells, and it also is found in the metaplastic pyloric glands and cancer cells. The exact function of cathepsin E in gastric mucosa remains unclear. The colonic type (type III) of intestinal metaplasia (IM) is strongly associated with intestinal-type gastric carcinoma. IM is considered to be a precancerous lesion. The aim of this study was to find out the role of cathepsin E in IM, dysplasia and cancer of stomach.


METHODS
Sixty nine biopsy specimens with IM and dysplasia and 33 gastrectomy specimens with gastric carcinoma were fixed, sectioned and stained with PAS-alcian blue stain, high iron-diamine alcian blue stain to classify IM and immunohistochemical stain to localize cathepsin E. Those patients with dysplastic gastric lesions received regular endoscopic follow-up.


RESULTS
Fifteen of 69 patients with gastric dysplasia developed cancer in a median 10.5 months follow-up. Severe dysplasia developed carcinoma significantly higher than mild dysplasia (12/20 vs. 1/25, p < 0.001), and type III intestinal metaplasia seemed to have significantly predilection for severe dysplasia and gastric cancer. Cathepsin E was stained in intestinal metaplasia with dysplastic change in 44/69 specimens (63.8%), and carcinoma in 28/48 (58.3%) specimens, there was no significant difference between intestinal type and diffuse type carcinoma in cathepsin E staining. The positive staining for cathepsin E decreased significantly in severe dysplastic gastric mucosa.


CONCLUSIONS
Type III IM is commonly associated with severe dysplasia and cancer; it may be a precancerous lesion. The positive staining of cathepsin E decreased with the severity of gastric dysplasia, representing dedifferentiation of the cells.
Lin
C K
CK
Department of Internal Medicine, Kaohsiung Veterans General Hospital, Taiwan, ROC.
Lai
K H
KH
Lo
G H
GH
Cheng
J S
JS
Hsu
P I
PI
Mok
K T
KT
Tseng
H H
HH
D000368:Aged; D000818:Animals; D020059:Cathepsin E / Q000502:physiology*; D005260:Female; D005753:Gastric Mucosa / Q000201:enzymology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007422:Intestines / Q000473:pathology*; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D011230:Precancerous Conditions / Q000201:enzymology / Q000473:pathology; D011817:Rabbits; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology
D020059:Cathepsin E