The generation of human antibodies to the multiple drug resistance protein, P-glycoprotein (Pgp), has been a challenge in the field of cancer chemotherapy since drug resistance was first described. Pgp was identified as being an intrinsic factor in the resistance to chemotherapeutic drugs, as its levels were found to escalate after primary drug challenges. Further investigation into the structure and function of P-glycoprotein elucidated that its activity was ATP dependent, and that it had broad spectrum specificity. In order to augment the success of chemotherapeutic treatment of patients it was deemed necessary to regulate the activity of this protein. This was possible by physical inhibition of its activity or through regulation at the genetic level. This project addresses the former of the two options, the physical inhibition of Pgp activity. It was considered that by the generation of antibodies to the extracellular regions of Pgp it would be possible to inhibit its activities. For such antibodies to be effective in the human model, the antibodies would have to bear human determinants in order that the human immune system would not attach and destroy these antibodies before they had the desired effect. Therefore it was decided that recombinant phage technology should be used. This is a system which selects single chain antibodies with human determinants from a large and diverse population of antibodies with a variety of specificities. Initially, attempts were made to generate a phage library <I>de novo</I> using a commercial kit designed for this purpose. However, after repeated attempts at this process, this approach was found to be beyond technical abilities, and was rejected in favour of a more rudimentary approach. Two libraries were screened for antibodies which would bind to membrane preparations from two leukaemic cell lines, CCRF CEM and CCRF CEM VLB. The former cell line was a drug-sensitive cell line which responded favourably to drug challenge, and the latter was a drug-resistant cell line which thrived in drug-rich environments. The drug-resistant cell line was derived from the drug-sensitive cell line, and was considered to be identical in all respects except drug sensitivity. Antibodies obtained from a large multicombinatorial library, the Lox library, were found to display selective binding to CCRF CEM VLB cell membranes in favour of CCRF CEM cell membranes. Antibodies were also generated to peptides representing the 6 extracellular loops of Pgp. From these selections antibodies were generated which were found to selectively bind the peptide to which they had been raised.

Thesis (M.Sc. (Pharmacology))--University of Pretoria, 2008. / Summary in English. Includes bibliographical references.

Nucleosides possess many physiological and pharmacological properties. Among nucleosides, adenosine is a particularly important as it regulates many physiological functions in cardiovascular system. For instance, adenosine possesses anti-inflammatory effect through its action on endothelial cells. The functions of adenosine are indirectly controlled by the human equilibrative nucleoside transporters (hENTs). These transporters mediate the uptake of adenosine, thereby reducing the amount of extracellular adenosine available for the adenosine receptors and hence reducing its vascular protective effects. Nucleoside analogs such as gemcitabine, are commonly used as anti-cancer drugs in chemotherapy. Most of the anti-cancer nucleoside drugs require human concentrative nucleoside transporters (hCNTs) for their transport into cancer cells. On the other hand, hENTs is supposed to be responsible for the efflux of anti-cancer nucleoside drugs out of the cancer cells. In theory, hENT inhibitors should reduce the removal of adenosine from extracellular compartment by endothelial cells and hence increase and prolong the cardioprotective effect of adenosine. hENT inhibitors should also inhibit the efflux of anti-cancer nucleoside drugs, that in turn increases the drug accumulation in the cancer cells, resulting in a higher efficacy. Some typical and clinically used hENT inhibitors have side effects which limit their uses. Emodin, an active ingredient in many herbs, has been proven to have cardioprotective and anti-tumor properties. However, the mechanisms are not fully understood. We hypothesized that these properties may relate to its interaction with nucleoside transporters. The aims of this study were to investigate the pharmacological effects of emodin on hENTs and its implications on vascular functions and anti-cancer therapy. Our result showed that emodin inhibited both hENT-1 and hENT-2 dose-dependently with no priority to any subtypes of hENTs. The inhibitory effect of emodin on hENTs was reversible and non-competitive, indicating that emodin may interact with the allosteric sites on hENTs. 1,8-dihdroxy-3-methyl anthraquinone, which is similar to emodin in terms of chemical structure but it lacks hydroxyl group at position 3,did not inhibit hENTs. It implied that the presence of 3-hydroxyl group was critical for the inhibitory effect of emodin. Our result also demonstrated that emodin reduced the lipopolysaccharide-induced expression of adhesion molecule in human umbilical vein endothelial cells, reflecting its anti-inflammatory effect. Emodin also enhanced the cytotoxic effect of gemcitabine in HepG2, a liver cancer cell line. Nevertheless, these effects may not be due to the inhibitory effect of emodin on hENTs and further investigation is required. / published_or_final_version / Pharmacology and Pharmacy / Master / Master of Philosophy

The naturally occurring compound 3,6-bis-(5-chloro-2-piperidyl)-2,5-piperazinedione (1) is a promising new antitumor drug. The mechanisms of action of antitumor alkylating agents, particularly the nitrogen mustards and sesquiterpene lactones, suggest possible modes of antitumor activity of compound 1. A possible synthetic scheme for compound 1 is developed by consideration of methods of synthesis of piperidines, (alpha)-substituted-(alpha),(beta)-unsaturated esters, and (beta)-amino alcohols. / A synthesis of (alpha)-chloro-(alpha),(beta)-unsaturated esters from carbonyl compounds and t-butyl (alpha)-chloro-(alpha)-trimethylsilyl acetate is developed. Oxyamination of the terminal double bond of t-butyl 2-chloro-2,6-heptadienoate occurs by epoxidation and reaction with an amine or azide ion and by osmium tetroxide catalyzed reaction with Chloramine-T. The piperidine ring is formed by an internal Michael raction of t-butyl 2-chloro-6-t-butyldimethylsilyloxy-7-tosylamino-2-heptenoate. The amino acid (1-tosyl-5-hydroxy-2-piperidyl) glycine is synthesized and found to be unstable to acidic esterification conditions. / Strategies for overcoming the problems encountered in the synthesis are discussed.

No description available.

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Mucositis is a common side-effect of chemotherapy, which is characterised by ulceration to the epithelium lining of the gastrointestinal tract. Recently, a non-invasive breath test, the ¹³C-sucrose breath test (SBT), has been developed and applied as a biomarker to detect small intestinal damage associated with methotexate (MTX)-induced mucositis in rats. This thesis extended this work, and concluded that the non-invasive SBT is a biomarker of small intestinal function that can be applied easily and cost-effectively, in both animals and humans, to monitor gut function in relation to chemotherapy agents and/or potential anti-mucositis treatments. This thesis has illustrated the important application of the SBT in the arena of supportive cancer care, where new chemotherapy and anti-mucositis agents can be assessed in relation to small intestinal toxicity. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1277572 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2007

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Mucositis is a common side-effect of chemotherapy, which is characterised by ulceration to the epithelium lining of the gastrointestinal tract. Recently, a non-invasive breath test, the ¹³C-sucrose breath test (SBT), has been developed and applied as a biomarker to detect small intestinal damage associated with methotexate (MTX)-induced mucositis in rats. This thesis extended this work, and concluded that the non-invasive SBT is a biomarker of small intestinal function that can be applied easily and cost-effectively, in both animals and humans, to monitor gut function in relation to chemotherapy agents and/or potential anti-mucositis treatments. This thesis has illustrated the important application of the SBT in the arena of supportive cancer care, where new chemotherapy and anti-mucositis agents can be assessed in relation to small intestinal toxicity. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1277572 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2007

No description available.

No description available.

A dissertation submitted in fulfillment of the requirements for the degree of Master of Science to the Faculty of Science, University of the Witwatersrand, Johannesburg, 2019 / Lung cancer is the second most common form of cancer, accounting for approximately 13% of all new cancer cases.Of these cancers about 85% are non-small cell lung car cinoma (NSCLC). The epidermal growth factor (EGF) receptor is a protein kinase, which is crucial in a cell’s life cycle, from cell growth to cell death. The over expres sion of the EGF receptor is observed in many forms of cancers including NSCLC, breast, ovarian, colorecteral and brain cancers. Although there are current kinase inhibitors on the market, they su↵er from dose limiting toxicity or drug resistance due to mutations in the kinase domain of EGFR. The focus of this body of work is on the development of more ecacious EGFR inhibitors that can overcome drug resistance issues associated with current EGFR inhibitors, as well as being less toxic to the body. This class of inhibitor should be a covalent inhibitor, requiring it to react with the solvent exposed cysteine residue that is positioned on the edge of the ATP binding pocket of EGFR. The carbonyl group of the ketoamide should undergo a 1,2 addition with this cysteine residue to form a covalent, yet reversible bond. We report herein our progress towards the synthesis and biological evaluation of a novel class of quinazoline ketoamides. The key step in this synthesis route was to form a thiol on the quinazoline core. This was to be achieved by the addition of a thiocabamoyl group to the exposed alcohol 33 to form O-4-[(3-bromophenyl)amino] 7-methoxyquinazolin-6-yldimethylcarbamothioate 49, this compound successfully un derwent the Miyazaki-Newman-Kwart rearrangement, in which the oxygen and sulfur are exchanged to form S-4-[(3-bromophenyl)amino]-7-methoxyquinazolin-6-yldimethyl carbamothioate 48 , allowing the sulfur to be on the quinazoline core. the characterisation for this compound included 1H NMR spectroscopy and 13C NMR spec troscopy to confirm it’s structure. The same rearrangement was attempted on the 3 chloro-4-fluoro analogue O-4-[(3-chloro-4-fluorophenyl)amino]-7-methoxyquinazolin 6-yldimethylcarbamothioate 66, however this rearrangement was not successfully iso lated and characterised. The next step required the carbamoyl group to be removed to expose the thiol. Although this step was attempted on both analogues, the products 4-[(3-bromo)amino]-7-methoxyquinazolin-6-thiol 47 and 4-[(3-chloro-4-fluoro)amino] 7-methoxyquinazolin-6-thiol 67 were not successfully synthesised and isolated. / TL (2020)