Cathepsin B expression in tumour cells and laminin distribution in pulmonary adenocarcinoma.
OBJECTIVE
To determine the correlation between cathepsin B expression and laminin distribution in pulmonary adenocarcinoma tissue.


METHODS
The distribution of cathepsin B and laminin was examined in 28 formalin fixed, paraffin wax embedded specimens of pulmonary adenocarcinoma tissue, using a double immunostaining technique with commercially available antibodies to cathepsin B and laminin, respectively.


RESULTS
Tumour cells in 23 (82%) cases reacted to cathepsin B: 13 cases were weakly positive and 10 were strongly positive. Laminin in tumour associated basement membrane produced various staining patterns: two cases had an almost continuous distribution of laminin in tumour associated basement membrane in the tumour tissues, while a moderately discontinuous laminin distribution pattern was found in 12 cases, and a highly fragmented pattern was found in 14 cases. The degree of cathepsin B expression in tumour cells was significantly correlated with the break up of laminin staining. In some cases a discontinuous pattern of tumour associated laminin was frequently observed adjacent to cathepsin B positive tumour cell nests.


CONCLUSIONS
Considering that cathepsin B has the capacity to degrade basement membrane components, including laminin, the inverse correlation shown in this study between the increase in cathepsin B expression by tumour cells and the diminution of laminin in tumour associated basement membrane could reflect local progression and spread by pulmonary adenocarcinoma.
Higashiyama
M
M
Department of Thoracic Surgery, Centre for Adult Diseases, Osaka, Japan.
Doi
O
O
Kodama
K
K
Yokouchi
H
H
Tateishi
R
R
D000230:Adenocarcinoma / Q000737:chemistry* / Q000201:enzymology; D001485:Basement Membrane / Q000737:chemistry; D002401:Cathepsin B / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques; D007797:Laminin / Q000032:analysis*; D008175:Lung Neoplasms / Q000737:chemistry* / Q000201:enzymology; D009363:Neoplasm Proteins / Q000032:analysis*
D007797:Laminin; D009363:Neoplasm Proteins; D002401:Cathepsin B