Cathepsin D expression in human colorectal cancer: relationship with tumour type and tissue differentiation grade.
OBJECTIVE
Cathepsin D (CD) is one of the main proteolytic enzymes contributing to the development of cancer. The aim of this study was to CD activity assay in the homogenates of tissues from the centre of the tumour (0) and tumour free area 2 cm, and 5 cm from the tumour border in human colorectal cancer. Activity in the centre of the tumour was compared with immunohistochemical expression CD.


METHODS
CD activity was measured using acid denatured Hb as a substrate. For immunohistochemical staining peroxidase method was used.


RESULTS
Activity of CD was significantly higher (15-fold) in tumour tissue homogenates in comparison to normal mucosa adjacent (control) (p < or = 0.0001) and raised parallel to the stage of tumour tissue differentiation grade. CD activity decreased significantly (p < or = 0.0001) with the distance from the tumour border 2 cm (12.7 fold) and 5 cm (5.7 fold) in comparison to the centre of the tumour. In immunohistochemical examinations CD was detected as diffuse cytoplasmic as well as fine granular staining of the cytoplasm, with occasional coarse cytoplasmic granules staining in the same cases that were positive for both. Positive staining was observed in 2 of 3 in well-differentiated (66%), 4 of 10 in moderately-differentiated (40%) and 4 of 5 in poorly-differentiated (80%), tubular adencarcinomas represented: 3 of 7 (42%) and 9 of 13 in invasive adencarcinoma (69%).


CONCLUSIONS
We have observed a wide range of cathepsin D and their antigen expressions patterns in colorectal tumours with the development the disease stage, this finding may be used as a daignostic tumor marker in colorectal cancer.
Department of Pathophysiology, Medical University of Wroclaw, Marcinkowski 1 Street, Wroclaw, Poland.
Tadeusz
T
Sebzda
Yousif
Y
Saleh
Jakub
J
Gburek
Ryszard
R
Andrzejak
Jan
J
Gnus
Maciej
M
Siewinski
Zygmunt
Z
Grzebieniak
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D000328:Adult; D000368:Aged; D002402:Cathepsin D / Q000032:analysis*; D002454:Cell Differentiation; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000201:enzymology; D008875:Middle Aged
D002402:Cathepsin D