Isolation, purification and partial characterisation of cancer procoagulant from placental amnion-chorion membranes and its role in angiogenesis inflammation and metastasis
- Authors: Krause, Jason
- Date: 2014
- Subjects: Coagulation , Amnion , Chorion , Metastasis , Inflammation , Neovascularization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10350 , http://hdl.handle.net/10948/d1020897
- Description: Cancer procoagulant (EC 3.4.22.26) is an enzyme that is derived from tumour and foetal tissue, but not normal tissue. It is a direct activator of factor X and has been isolated from amnion-chorion membranes as well as from extracts and cells from human melanoma. The presence of cancer procoagulant has been associated with the malignant phenotype, as well as having a particularly high activity in metastatic cells. Cancer procoagulant activity is elevated in the serum of early stage breast cancer patients and decreased to normal in the advanced stages of the disease. In this study, cancer procoagulant was successfully isolated from amnion-chorion membranes and purified to homogeneity. The molecular weight of cancer procoagulant was determined using SDS-PAGE and was found to be 68 kDa. Cancer procoagulant was delipidated and it was shown that its activity was increased by the presence of lipids in a dose-dependent manner. Recovery of cancer procoagulant after delipidation is poor, consequently, a larger mass of sample is required to obtain sufficient amounts of delipidated material for N-terminal amino acid analysis. The optimum pH of cancer procoagulant was determined to be pH 8 and its optimal temperature was found to be 50°C. Novel synthetic substrates were designed to assay for cancer procoagulant activity. Currently, 2 potential candidates have been identified, namely, PQVR-AMC and AVSQSKP-AMC. Cancer procoagulant-induced expression of cytokines is differently modulated in the less aggressive MCF-7 cell line as compared to the metastatic and more aggressive MDA-MB-231 cell line. There are marked similarities in the inflammatory response produced by cancer procoagulant in hTERT-HDLEC and MDA-MB-231 cells, which are both associated with migratory capacity. Furthermore, cancer procoagulant-induced PDGF-β expression in hTERT-HDLEC and MDA-MB-231 cells could point to involvement of cancer procoagulant in wound healing and metastatic spread, respectively. Cancer procoagulant induced the motility of MDA-MB-231, MCF-7 and hTERT- cells in vitro in a time- and dose-dependent manner. Together, these results suggest that cancer procoagulant plays a role in the migration of breast cancer cells as well as the migration of endothelial cells.
- Full Text:
- Date Issued: 2014
Modeling of arsenic removal from aqueous media using selected coagulants
- Authors: Majavu, Avela
- Date: 2010
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Coagulation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10426 , http://hdl.handle.net/10948/d1017100
- Description: The waste water from the industrial production of the herbicide monosodium methyl arsenate was treated using coagulation. The coagulation process as developed in this research proved to be suitable for arsenic removal in aqueous media using chromium (III), calcium (II), and combination of calcium (II) and chromium (III), and magnesium (II). The results obtained suggest that the coagulation process can be used for the treatment of the waste water from the monosodium methyl arsenate production. Response surface methodology was used to study the effects of the various parameters, namely pH, mole ratios (Cr:As, Ca:As, and Mg:As), concentration of flocculent and initial arsenic concentration. To optimize the process conditions for the maximum removal of arsenic. Central composite and factorial designs were used to study the effects of these variables and to predict the effect of each. ANOVA was used to identify those factors which had significant effects on model quality and performance. The initial arsenic concentration appeared to be the only significant factor. These models were statistically tested and verified by confirmation experiments.
- Full Text:
- Date Issued: 2010