A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements of the degree of Masters of Science. February 2017. / Cancer has become a problematic fatal disease in developing and industrialised countries with pancreatic cancer as the seventh leading cause of cancer-related deaths, with an average survival rate of less than 5%. Environmental risk factors associated with pancreatic cancer include smoking, obesity, diet, alcohol etc. Furthermore, pancreatic cancer is commonly diagnosed at a late stage where its response to current anti-cancer agents is poor. Consequently, with South Africa being a 3rd world country and the cost of chemotherapy being so high, this has led to us trying to identify new, cheaper therapeutics for cancer cells. A majority (80%) of the South African population relies on traditional medicines, hence in this study we aimed to assess Lobostemon fruticosus for anti-proliferative effects on pancreatic cancer cell line (AsPC-1). This was achieved by the use of methanol and butanol extracts of L. fruticosus to screen for induction of apoptosis and inhibition of cell proliferation. The plant was collected, dried, crushed and dissolved in butanol and methanol to obtain experimental extracts. Cytotoxicity of the plant on Aspc-1 was determined using MTT Assay, xCELLigence and cell cycle analysis. MRC-5 cell line was used as a positive control cell line. L. fruticosus extracts induced cell death at IC50 of 60µg/ml (methanol extract) and 50µg/ml (butanol extract) at 48hour treatments on AsPC-1 cell line. Western Blots showed that the methanol and butanol extracts of L. fruticosus led to slight upregulation of the apoptotic gene p53 in AsPC-1 cell line, which was further confirmed by FACS apoptosis detection. Cell cycle analysis further showed the plant extracts do promote cell cycle arrest. LC/MS of the extracts gave spectra of active compounds presumed to play a role in induction of apoptosis on the pancreatic cancer cell line. The data obtained implies that the methanol and butanol extracts of L. fruticosus does have, to a certain extent, growth inhibiting and apoptosis inducing potential on the pancreatic cancer cell line. KEYWORDS: Lobostemon fruticosus, Pancreatic Cancer, methanol extract, butanol extract, AsPC-1 / LG2017

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy of Science. Johannesburg, 2013 / Chemotherapy, while representing a vital component of cancer treatment modalities, has so far not fulfilled basic expectations with unsatisfactory cure rates and frequent relapse due to limited effectiveness of the therapeutic drugs, severe side effects and resistance problems. The platinumcontaining drugs used in present clinical practice are no exception to this generalized finding. While highly effective against a small number of malignancies, they generally share in the deficiencies of other anticancer agents. To address this issue, intense research is being undertaken to develop novel platinum-compounds offering enhanced therapeutic effectiveness. To accomplish this, several new avenues of development are being pursued world-wide, and one of these involving the binding of monomeric anticancer drug systems to water-soluble, biocompatible and biodegradable polymeric carriers, was utilized in the current research. As part of the ongoing research, this dissertation demonstrates the preparation of several water-soluble polymeric carriers bearing pre-synthesized monomers aimed to anchor the platinum drug. The monomers of interest were aspartic acid, p-aminobenzoic acid and p-aminosalicylic acid derivatives; while the water-soluble carriers were polyaspartamides, prepared by an aminolytic ring-opening process of polysuccinimide. The platination agents were conjugated to the polymer backbone both via amine and via leaving-group ligands, such as dihydroxylato, dicarboxylato and carboxylatohydroxylato. In order to demonstrate the multidrug-binding capacity of the carriers, platinum complexes were co-conjugated to polymeric conjugates containing ferrocene. The in vitro studies against a human breast cancer (MCF-7) cell line showed IC50 values ranging from 48.92 μg.mL-1 to 281.37 μg.mL-1 for the platinum conjugates, 13.18 μg.mL-1 to 149.67 μg.mL-1 for ferrocene conjugates and 6.22 μg.mL-1 to 83.86 μg.mL-1 for platinum/ferrocene co-conjugates; and these values were on average 4 fold more active than the parent drug. The results of these preliminary tests provide proof of the principle that polymer-drug conjugates can play a role in future cancer therapy.

Photocopy of typescript. / Digitized by Kansas Correctional Industries

Purpose: The proportion of the United States population in older adulthood is growing rapidly, and with that growth comes an increase in diseases such as cancer. As rates of illness increase, there is a concomitant increase in cognitive and psychological correlates of illnesses like cancer. There is evidence that some cancer treatments, particularly chemotherapy, affect cognition for cancer patients, although these results are inconsistent. Additionally, depression, and other health factors such as activities of daily living (ADLs) have been found to relate to cognitive impairment among older adults with cancer. Method: The current study used latent class growth analysis (LCGA) to explore longitudinal data from the Health and Retirement Study. The primary goal was to investigate possible trajectories of cognitive functioning in older adults diagnosed with, and surviving cancer. Possible psychological, health, and demographic predictors of membership in these cognitive trajectories were investigated. Results: Findings indicated that three classes of cognitive functioning best fit the data: these were High Recall, Middle Recall and Low Recall Classes, which represented fairly stable trajectories from pre-diagnosis to a period four years later. Various covariates of class membership were included in the analyses. Treatment with chemotherapy significantly predicted membership in the High Recall Class, however this finding is accounted for by an interaction with younger age. More symptoms of depression after diagnosis (but not prior to diagnosis) were significantly predictive of membership in the Low Recall Class. A higher self-reported probability of living to the age of 85 pre-diagnosis predicted membership in the High Recall Class, and greater difficulty with ADLs post-diagnosis predicted membership in the Low Recall Class. Finally, individuals in the High Recall Class were significantly more likely to be younger, female, and more highly educated, when compared to both the Middle and Low Recall Classes. Limitations: The current study is limited by the wide spacing of data collection and dearth of sensitive and varied measures of cognitive functioning, which in turn limits the generalizability and specificity of the findings. Additionally, a lack of data on cancer type, staging and treatment variables make more nuanced analysis difficult. It is not possible to generalize these findings to individuals who passed away within two years of their diagnosis, not to individuals of minority status, who were underrepresented in this sample. Conclusions: These results may inform the understanding of cognitive functioning in older adults surviving cancer, as it relates to psychological, demographic and other health factors, with implications for timing and targeting of interventions.

No description available.

Abstract not available

Mucositis is the damage that occurs to the alimentary canal from anti - cancer therapies. It is caused by chemotherapy, radiotherapy and combination therapy and affects a large proportion of patients. Despite its prevalence, an effective anti - mucositis agent has yet to be developed that protects the whole tube, although the use of keratinocyte growth factor ( Amgen ' s Palifermin ) has recently been approved for the prevention of oral mucositis. It is important to understand mechanisms controlling mucositis so that treatment can be targeted appropriately. This thesis has investigated some of the key components identified as being involved in mucositis as well as identifying new genes which contribute to chemotherapy - induced intestinal injury. The research chapters investigated : 1 ) Gene expression of the apoptosis - regulating Bcl - 2 family, p53 and caspase - 3, and the changes which occur in the intestine following chemotherapy treatment for cancer. 2 ) The effect of different chemotherapeutic agents on intestinal cells in vitro and the role p53 plays. 3 ) The mucositis caused by single dose irinotecan in the rat with breast cancer and the role of p53 in induction of intestinal damage. 4 ) The early gene changes that occur in the small intestine of the rat with breast cancer following irinotecan treatment. Firstly, to investigate the difference in susceptibility to damage between the small and large intestine, the protein expression of 8 members of the Bcl - 2 family ( 4 pro - apoptotic ; Bax, Bak, Bid, Bim and 4 anti - apoptotic ; Bcl - 2, Bcl - xL, Bcl - w, Mcl - 1 ) was quantified in jejunal and colonic sections taken from rats inoculated with breast cancer. It was found that there was significantly higher expression of the pro - apoptotic proteins, Bax, Bak, Bim and Bid, in the crypts of the jejunum compared to the colon. Furthermore, expression of the anti - apoptotic proteins, Bcl - 2, Bcl - xL and Bcl - w, was significantly lower in jejunal crypts compared to colonic crypts. Mcl - 1 expression was similar in both regions. Thus, the small intestine is an environment balanced to favour apoptosis through specific Bcl - 2 family protein expression profiles. The Bcl - 2 family regulates apoptosis in response to a variety of chemotherapy agents. However, it is unknown how Bcl - 2 family gene expression changes along with other apoptogenic factors following cytotoxic therapy in the normal intestine. To investigate this, sections of rat jejunum treated with methotrexate and duodenal biopsies from chemotherapy patients treated with various regimens for cancer were subjected to quantitative immunohistochemistry to detect Bcl - 2 family proteins, p53 and caspase - 3. Treatment caused expression of p53 and caspase - 3 to increase within the crypts and follow a similar pattern to apoptosis levels. Pro - apoptotic Bcl - 2 family members, Bax and Bak, were increased, while the anti - apoptotic protein, Mcl - 1, was significantly reduced. A significant increase in mRNA expression for Bax and Bak was noticed at 6 h, without a concurrent decrease in Mcl - 1. Thus, Bcl - 2 family genes were altered in the small intestine in both humans and rats, and this was irrespective of chemotherapy agent or regimen used. The best characterised changes which occur during chemotherapy - induced damage in the intestine are in the epithelial layer, although it is thought that pan #45 mucosal alterations are involved. Two intestinal cell lines were chosen to investigate changes in apoptosis, proliferation and protein expression following cytotoxic treatment with various chemotherapeutic agents. These were the rat IEC - 6 and human FHs 74 cell lines, which represent untransformed epithelial cells. The human breast carcinoma cell line, MCF - 7, was also used as a positive control. Intestinal cells were resistant to the occurrence of methotrexate toxicities within 24 h of treatment, modestly affected by irinotecan and extremely sensitive to doxorubicin. Doxorubicin caused a marked increase in p53 and p21 expression, which for irinotecan was less pronounced. The effect of cytotoxic treatment on Bcl - 2 family expression in intestinal cells varied, however the pro - apoptotic proteins, Bax and Bak, were generally upregulated following doxorubicin. Temporary inhibition of p53 using pifithrin alpha resulted in a significant improvement in cell survival in cancerous cell only and did not alter Bcl - 2 family expression. It was concluded that cultured epithelial cells exhibit varying sensitivities to different chemotherapeutic agents which is dependent on induction of p53 gene expression. The topoisomerase I inhibitor, irinotecan, is a chemotherapeutic agent commonly used in the treatment of colorectal cancer. It often induces severe mucositis with the most common symptom being diarrhoea. Previous research has shown that irinotecan damages the small and large bowel equally, which is unusual. This is characterised by an increase in apoptosis and a reduction in proliferation within epithelial crypts, an increase in inflammatory cell infiltrate in the lamina propria and excess mucin production. These investigations used two sequential doses of irinotecan. The early effect of a single dose of irinotecan on the intestine have yet to be studied. Thus the primary aim of this experiment was to examine in detail the changes caused by irinotecan at 6 and 48 h in the rat. A secondary aim was to investigate the role of p53 on induction of apoptosis and cell cycle arrest within intestinal crypts and the effect of temporary inhibition of the protein. Single dose irinotecan caused a decrease in body and small intestinal weight by 48 h after treatment. This was accompanied by crypt and villous degeneration, increased apoptosis and reduced proliferation within crypt epithelium as well as inflammatory infiltrate throughout lamina propria. An increase in Bax expression was seen at 6 h, however p53 protein levels remained relatively low until 48 h. Rats also treated with pifithrin alpha to inhibit p53 and had a significantly lower peak in apoptosis in the colon at 6 h, however did not show improvements in any other parameters tested. It was concluded that irinotecaninduced damage in the rat intestine is primarily p53 - independent, and that pifithrin alpha acts to inhibit apoptosis in the large intestine via a p53 - independent pathway. A study was designed to investigate the early genome - wide changes which occur following irinotecan treatment in the rat small intestine. Microarray analysis found that regulation of many genes was altered at 6 h following dual dose irinotecan. These genes were involved in apoptosis, cell cycle regulation, immune function, calcium homeostasis and protein turnover. Multiple genes from the MAP kinase pathway were also activated by irinotecan. The cystine protease, caspase - 1 was upregulated and was chosen for further investigations due to its role in apoptosis and inflammation. Real time PCR analysis confirmed the increase in gene expression at 6 h and also showed a return to baseline levels by 24 h which was followed by another modest increase at 48 h. It was concluded that irinotecan induces a wide range of gene changes within the intestine and that apoptosis and inflammatory damage pathways are activated during treatment. This thesis described key molecules in apoptosis and their role in induction of chemotherapy - induced intestinal mucositis. It has provided evidence of the importance of apoptosis in mucosal injury and also highlighted areas requiring further research. Results presented herein show that the Bcl - 2 family is involved in intestinal damage following many chemotherapy agents, whereas p53 is agent - specific. It has also shown that irinotecan causes intestinal damage via a mainly p53 - independent manner in the rat. It can be concluded that gastrointestinal mucositis is complex and activates multiple pathways to induce damage. Findings from this thesis will aid targeting of new anti - mucotoxic agents. / Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2006.

Copy of author's previously published article inserted. / Bibliography: leaves 210-234. / xiii, 235 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the effect of chemotherapy on the mucosa of the small intestine and the prevalence, duration and severity of mucositis, both in humans and in rats. / Thesis (M.D.)--University of Adelaide, Depts. of Gastroenterology and Haematology/Oncology, 1998

Copy of author's previously published article inserted. / Bibliography: leaves 210-234. / xiii, 235 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the effect of chemotherapy on the mucosa of the small intestine and the prevalence, duration and severity of mucositis, both in humans and in rats. / Thesis (M.D.)--University of Adelaide, Depts. of Gastroenterology and Haematology/Oncology, 1998

published_or_final_version / Public Health / Master / Master of Public Health