help button home button Am J Pathol Angiogenesis Meeting
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

This Article
Right arrow Order Full text via Infotrieve
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Dong, Q.
Right arrow Articles by Ts'ao, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dong, Q.
Right arrow Articles by Ts'ao, C.

American Journal of Pathology, Vol 138, 1103-1110, Copyright © 1991 by American Society for Investigative Pathology

REGULAR ARTICLES

Importance of viability and attachment to an ascites tumor in the release of plasminogen activator

Q Dong, M Zhou, V Subbarao and C Ts'ao
Department of Pathology, Northwestern University School of Medicine, Chicago, Illinois 60611.

Tumor plasminogen activator (PA) has been alleged to play a role in the growth and metastasis of tumors. Before such a role can be realized, PA first must be released from tumor cells. Having determined intra- and extracellular PA and PA-inhibitor activities in an experimental pancreatic ascites tumor grown in hamsters, the release of PA from these cells was investigated. No PA activity was detected in the suspension medium of freshly isolated tumor cells; inclusion of plasminogen, fibrinogen, or collagen in the medium yielded similar negative results. On the other hand, PA activity was demonstrated to be released in a time-dependent manner from these tumor cells embedded in fibrin clots. Plasminogen activator activity also was not found in the suspension medium of frozen-thawed tumor cells, despite the fact that most of them had breaks on their cell membrane. Unlike freshly isolated tumor cells, PA was not released from frozen-thawed cells embedded in fibrin clots. Full PA activity was demonstrated in frozen-thawed cells treated with Triton X-100, however. Frozen-thawed cells exhibited signs of severe damage, and more than 80% of them failed to exclude trypan blue. Obviously PA is released from viable tumor cells embedded in fibrin clots but not suspended in artificial medium. The PA-release mechanism, not PA itself, is destroyed in cells rendered nonviable by freeze thawing.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1991 by the American Society for Investigative Pathology.