M.Sc Thesis

M.Sc StudentBar-on Ortal
SubjectHuman Cancer Procoagulant Purification and
DepartmentDepartment of Medicine
Supervisors PROFESSOR EMERITUS Benjamin Brenner
DR. Galit Sarig


Thrombotic disorders associated with malignant disease may be related to the presence of cancer procoagulant (CP). CP is a cysteine proteinase that activates factor X and was found in a variety of human and animals malignant tissues and in human amnion chorion mambrane (hACM).

The aim of this study was to purify and characterize the activity of CP from human breast cancer cell line - MDA-MB 231 compared with the activity purified from hACM.

Differences in elution concentrations from glycerol gradient and chromatography on DE-52 were observed in CP activity extracted from MDA-MB 231 compared with the activity extracted from hACM. Furthermore, differences in CP activity from the two sources were observed in the presence of divalent metal ions. CP activity extracted from MDA-MB 231 and  hACM was equally inhibited by HgCl2 and Leupeptin, but not by the cysteine protease inhibitor Iodoacetamide. These results suggest that CP activity in both extracts may not be classified as a cysteine protease.

The possible association between CP activity and  lipoprotein was demonstrated by the decreased activity in the presence of detergents such as: Triton X-100, Tergitol and CHAPS.

In conclusion: although CP activity from MDA-MB 231 cell line and hACM extracts were similarly  inhibited by protease inhibitors and by detergents, differences were observed in elution concentrations from DE-52 chromatography column and from glycerol gradient and in CP activity in the presence of metal divalent ions.  These may suggest differences in biochemical characteristics such as steric structure, electric charge, molecular size and ionic strength between CP extracted from MDA-MB 231 and  hACM.