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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ability of α-TEA, alone or in combination with selenium, to induce human prostate cancer cells to undergo apoptosis via enhancement of pro-apoptotic Fas signaling and suppression of pro-life Akt signaling pathways

Jia, Li, 1973- 28 August 2008 (has links)
In the present study, the anti-tumor efficacy of α-TEA, a derivative of RRR-α-tocopherol, was investigated in LNCaP and PC-3-GFP human prostate cancer cells. Data show that α-TEA induced apoptosis in both cell lines in a time- and dose-dependent manner. Data show that α-TEA induces apoptosis through the activation of pro-apoptotic Fas signaling and inhibition of pro-survival Akt signaling pathways. The role of FADD and Daxx in α-TEA-induced apoptosis was determined. Data show that α-TEA promotes the association of FADD with Fas. FADD siRNA significantly reduced α-TEA-induced apoptosis in LNCaP cells. However, in PC-3-GFP cells, FADD siRNA caused apoptosis in the absence of α-TEA, and in the presence of FADD siRNA, α-TEA-induced apoptosis was significantly enhanced, indicating pro-survival activity of FADD in PC-3-GFP cells. Although α-TEA did not change the total protein levels of Daxx, it did promote the association of Daxx with Fas. α-TEA-induced apoptosis was significantly reduced by Daxx siRNA, and enhanced by overexpression of wild type Daxx, showing the pro-apoptotic role of Daxx in α-TEA-induced apoptosis. α-TEA inhibited phosphorylation of all three Akt isoforms; namely, Akt1, Akt2, and Akt3, thereby removed the phosphorylation inhibition on FOXO1 and FOXO1-mediated upregulation of FasL enhanced apoptosis through Fas signaling pathway. Studies have shown that selenium is of value in prostate cancer prevention. Here we document that methylseleninic acid (MSA) acts synergistically with α-TEA to induce apoptosis in LNCaP and PC-3-GFP human prostate cancer celld in culture. Western blot analyses indicate the involvement of caspases-8, -9, and -3, as well as Akt, in the synergistic effect of α-TEA and MSA. In a preclinical PC-3-GFP xenograft mouse model, α-TEA and MSC separately and together significantly reduced tumor burden and metastatic lesions in lungs and lymph nodes. However, synergism with the combination that in cell culture were not obtained in the animal study. α-TEA alone was as effective as, perhaps better than, the combination treatment in ruducing tumor burden and inhibiting metastases. Thus, data support α-TEA alone, rather than α-TEA plus selenium, as a treatment for human prostate cancer. / text
2

Targeting the androgen receptor as a therapeutic strategy for prostate cancer.

Marrocco, Deborah Lydia January 2006 (has links)
Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / "The objectives of this thesis were to characterise the effects fo AR-targeting agents on the growth of prostate cancer cells and to determine whether combining these agents to target the AR (androgen receptor) at more than one level in the signalling pathway would provide a more complete block of androgen signalling and prostate cancer cell growth." --p. v. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289482 / Thesis (Ph.D.) -- University of Adelaide, School of Medicine,2006
3

Targeting the androgen receptor as a therapeutic strategy for prostate cancer.

Marrocco, Deborah Lydia January 2006 (has links)
Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / "The objectives of this thesis were to characterise the effects fo AR-targeting agents on the growth of prostate cancer cells and to determine whether combining these agents to target the AR (androgen receptor) at more than one level in the signalling pathway would provide a more complete block of androgen signalling and prostate cancer cell growth." --p. v. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289482 / Thesis (Ph.D.) -- University of Adelaide, School of Medicine,2006
4

Design of hyperthermia protocols for inducing cardiac protection and tumor destruction by controlling heat shock protein expression

Rylander, Marissa Nichole 28 August 2008 (has links)
Not available / text
5

Chemosensitivity of prostatic tumour cell lines under conditions of G2 block abrogation

Serafin, Antonio Mendes January 2000 (has links)
Thesis (MTech (Biomedical Technology))--Cape Technikon, 2011. / Cancer of the prostate gland is now recognised as one of the principal medical problems in males. In the USA, cancer of the prostate is the second most commonly diagnosed cancer after skin cancer and the second most common cause of death from cancer after lung cancer. In South Africa, prostate cancer is the second most common cancer, with an estimated annual incidence of 19.1 per LOO000 men (Sitas, 1994). However, this incidence is probably under-estimated, due to incomplete records. Comparison of the incidence of prostate cancer in the different racial groups shows that it is the second most common malignancy in the White, Black (African) and Mixed (Coloured) race groups, and the fourth most common malignancy in Asian (Indian) men in South Africa. Metastatic prostate cancer is refractory to hormone therapy and remains incurable. Hence, novel therapeutic approaches are needed. These anticancer drugs can be tested in tumour cell lines, and cell culture methods also permit testing of optimum conditions.
6

Daily Image Guided Radiation Therapy for Prostate Cancer: An assessment of treatment plan reproducibility.

Knight, Kellie Ann January 2006 (has links)
Doctor of Health Science / It is well documented that for prostate cancer patients undergoing radiation therapy there is a correlation between target volume displacement and changes in bladder and rectal volumes. However, these studies have used a methodology that has captured only a subset of all treatment positions. This research used daily Computer Tomography (CT) imaging to comprehensively assess organ volumes, organ motion and their effect on dose, something that has never been performed previously, thus adding considerably to the understanding of the topic. Daily CT images were obtained using a Siemens Primus Linear Accelerator equipped with an in-room Somatom CT unit in the accelerator suite, marketed as ‘Primatom’, to accurately position the patient prior to treatment delivery. The internal structures of interest were contoured on the planning workstation by the investigator. The daily volume and location of the organs were derived from the computer to assess and analyse internal organ motion. The planned dose distribution was then imported onto the treatment CT datasets and used to compare the planned dose to i) the actual isocentre, where the isocentre was actually placed for that fraction, ii) the uncorrected isocentre, by un-doing any on-line corrections performed by the treatment staff prior to treatment delivery, and iii) the future isocentre, by placing the isocentre relative to internal organ motion on a daily basis. The results of this study did not confirm a statistically significant decrease in rectum volumes over time (hypothesis 1), however large fluctuations in bladder volume were confirmed (hypothesis 2). Internal organ motion for the rectum and bladder was demonstrated to be related to organ filling. Ideal planning volumes for these organs have been reported to minimise systematic and random uncertainty in the treatment volumes. An observed decrease in prostate volume over time, a systematic uncertainty in the location of the prostate at the time of the planning CT scan and a significant relationship between prostate centre of volume and rectum and bladder volumes has resulted in a recommendation that patients should be re-scanned during treatment to ensure appropriate clinical target volume coverage. A significant relationship between rectal and bladder volumes and the dose delivered to these organs was found (hypothesis 3). The dose delivered to the planning target volume was not related to the rectal or bladder volumes, although it was related to the motion of these organs. Despite these results only minimal effects on the dose delivered to any of the three isocentres occurred, indicating that the planned dose was accurately delivered using the methodology presented here (hypothesis 4). However the results do indicate that the patient preparation instructions need to be improved if margins are to be reduced in the future. It is unrealistic to assume that Image Guided Radiation Therapy will ever become routine practice due to infrastructure costs and time limitations. This research will inform radiation therapy centres of the variables associated with prostate cancer treatment on a daily basis, something that has never before been realistically achievable. As a result centres will be able to devise protocols to improve treatment outcomes.
7

P38 MAPKs coordinately regulate distinct phases of autophagy and lysomal biogenesis

Varadarajan, Shankar 07 September 2012 (has links)
p38 mitogen-activated protein kinases (MAPKs) control the endocytic trafficking of various growth-related cell surface receptors and transporters. Herein, I demonstrate that p38 MAPKs also regulate autophagy, or the process of self-cannibalism. In my studies, inhibition of p38 MAPKs triggered rapid formation of autophagosomes in prostate cancer cells, even under nutrient-rich conditions, and remarkably, the autophagosomal membranes emanated from endoplasmic reticulum exit sites via the concerted actions of the small GTPases, ARF1 and SAR1. Once formed, the autophagosomes fused with late endosomes and/or lysosomes, in a Rab7-dependent manner, to form “hybrid organelles” that were co-labeled with ER, autophagic, late endosomal, and lysosomal markers. Unlike other inducers of autophagy, however, inhibition of p38 MAPKs suppressed the fission of hybrid organelles, resulting in a profound but reversible accumulation of large cytoplasmic vacuoles. Thus, in addition to their previously reported roles in endocytosis, p38 MAPKs appear to coordinately regulate autophagy and the downstream biogenesis and fission of hybrid organelles. / text
8

Daily Image Guided Radiation Therapy for Prostate Cancer: An assessment of treatment plan reproducibility.

Knight, Kellie Ann January 2006 (has links)
Doctor of Health Science / It is well documented that for prostate cancer patients undergoing radiation therapy there is a correlation between target volume displacement and changes in bladder and rectal volumes. However, these studies have used a methodology that has captured only a subset of all treatment positions. This research used daily Computer Tomography (CT) imaging to comprehensively assess organ volumes, organ motion and their effect on dose, something that has never been performed previously, thus adding considerably to the understanding of the topic. Daily CT images were obtained using a Siemens Primus Linear Accelerator equipped with an in-room Somatom CT unit in the accelerator suite, marketed as ‘Primatom’, to accurately position the patient prior to treatment delivery. The internal structures of interest were contoured on the planning workstation by the investigator. The daily volume and location of the organs were derived from the computer to assess and analyse internal organ motion. The planned dose distribution was then imported onto the treatment CT datasets and used to compare the planned dose to i) the actual isocentre, where the isocentre was actually placed for that fraction, ii) the uncorrected isocentre, by un-doing any on-line corrections performed by the treatment staff prior to treatment delivery, and iii) the future isocentre, by placing the isocentre relative to internal organ motion on a daily basis. The results of this study did not confirm a statistically significant decrease in rectum volumes over time (hypothesis 1), however large fluctuations in bladder volume were confirmed (hypothesis 2). Internal organ motion for the rectum and bladder was demonstrated to be related to organ filling. Ideal planning volumes for these organs have been reported to minimise systematic and random uncertainty in the treatment volumes. An observed decrease in prostate volume over time, a systematic uncertainty in the location of the prostate at the time of the planning CT scan and a significant relationship between prostate centre of volume and rectum and bladder volumes has resulted in a recommendation that patients should be re-scanned during treatment to ensure appropriate clinical target volume coverage. A significant relationship between rectal and bladder volumes and the dose delivered to these organs was found (hypothesis 3). The dose delivered to the planning target volume was not related to the rectal or bladder volumes, although it was related to the motion of these organs. Despite these results only minimal effects on the dose delivered to any of the three isocentres occurred, indicating that the planned dose was accurately delivered using the methodology presented here (hypothesis 4). However the results do indicate that the patient preparation instructions need to be improved if margins are to be reduced in the future. It is unrealistic to assume that Image Guided Radiation Therapy will ever become routine practice due to infrastructure costs and time limitations. This research will inform radiation therapy centres of the variables associated with prostate cancer treatment on a daily basis, something that has never before been realistically achievable. As a result centres will be able to devise protocols to improve treatment outcomes.
9

The characterisation of the catalytic activity of human steroid 5α-reductase towards novel C19 substrates

Quanson, Jonathan Luke 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This study describes: • The UPLC-MS/MS analyses and quantification of novel 5α-reduced steroids using response factors. • The kinetic characterisation of human steroid 5α-reductase type 1 (SRD5A1), expressed in HEK-293 cells, towards 11OHA4 and 11OHT and their keto derivatives by progress curve analysis. • The subcloning, transformation and functional expression of SRD5A1 in the yeast expression system, P. pastoris. • The conversion of 11OHA4 and 11OHT and their keto derivatives by SRD5A1 expressed in P. pastoris. • The endogenous enzymatic activity in P. pastoris towards the 5α-reduced metabolites in the 11OHA4- and alternate 5α-dione pathways. • The potential application of P. pastoris as a biocatalyst in the production of 5α- reduced C19 steroids. / AFRIKAANSE OPSOMMING: Hierdie ondersoek beskryf: • Die UPLC-MS/MS analise en kwantifisering van nuut-ondekte 5α-gereduseerde steroïede met behulp van responsfaktore. • Die kinetiese karakterisering van menslike steroïed 5α-reduktase tipe 1 (SRD5A1), uitgedruk in HEK-293 selle, vir 11OHA4 en 11OHT en hul ketoderivate deur middel van progressiekurwe-analise. • Die subklonering, transformasie en funksionele uitdrukking van SRD5A1 in die gis P. pastoris. • Die omsetting van 11OHA4 en 11OHT en hul ketoderivate deur SRD5A1 uitgedruk in P. pastoris. • Die omsetting van 5α-gereduseerde steroïede in die 11OHA4 en alternatiewe 5α-dioon paaie deur endogene ensieme in P. pastoris • ‘n Ondersoek na die toepassing van die gisuitdrukkingstelsel as ‘n moontlike OR potensiële biokatalis vir die produksie van 5α-gereduseerde C19 steroïede.
10

Nitric oxide donors for the treatment of prostate cancer

Nortcliffe, Andrew January 2013 (has links)
Chapter One provides a general introduction into the biology and chemistry of nitric oxide, with particular focus on the role of nitric oxide in cardiovascular disease, cancer and hypoxia. It also details the types of organic functional groups used as nitric oxide donors, with detailed discussion of nitrate esters, furoxans and sydnonimines. Chapter Two discusses prostate cancer. It provides an overview into the development of prostate cancer, prostate cancer staging, and treatment. The key molecular aspects of prostate cancer are detailed, and the types of treatment available outlined. Chapter Three details the synthesis and activity of NCX-1102, a nitric oxide-donating analogue of the non-steroidal anti-inflammatory drug sulindac, and the synthetic work in the preparation of analogues of NCX-1102, using nitrate esters, furoxans and sydnonimines as nitric oxide-donating functional groups. The compounds prepared were tested against a prostate cancer cell line (PC3) and the cytotoxicity results are presented. Chapter Four describes the synthesis of nitric-oxide donating analogues of abiraterone, a CYP17 inhibitor for the treatment of prostate cancer. The results of cytotoxicity assays against PC3 cells are detailed. Chapter Five discusses the application of nitric oxide-donating functional groups in tandem with biologically active motifs. The synthesis of nitric oxide-donating amino acids, and their application to the preparation of nitric oxide-donating RGD peptides and prostate-specific membrane antigen inhibitors is presented, along with representative biological evaluation. Chapter Six introduces possible future work for the continuation of the project, suggesting the synthesis of fluorinated sydnonimines, prostate-specific membrane antigen inhibitors combined with for prostate cancer imaging and a “tool-box” of nitric oxide-donating bioconjugation reagents.

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