Characterisation of the HSP70-HSP90 organising protein gene and its link to cancer
- Authors: Weeks, Stacey
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/56006 , vital:26764
- Description: HOP (Heat shock protein 70/ Heat shock protein 90 organising protein) is a co-chaperone essential for client protein transfer from HSP70 to HSP90 within the HSP90 chaperone machine and has been found to be up-regulated in various cancers. However, minimal in vitro information can be found on the regulation of HOP expression. The aim of this study was to analyse the HOP gene structure across known orthologues, identify and characterise the HOP promoter, and identify the regulatory mechanisms influencing the expression of HOP in cancer. We hypothesized that the expression of HOP in cancer cells is likely regulated by oncogenic signalling pathways linked to cis-elements within the HOP promoter. An initial study of the evolution of the HOP gene speciation was performed across identified orthologues using Mega5.2. The evolutionary pathway of the HOP gene was traced from the unicellular organisms to fish, to amphibian and then to land mammal. The synteny across the orthologues was identified and the co-expression profile of HOP analysed. We identified the putative promoter region for HOP in silico and in vitro. Luciferase reporter assays were utilized to demonstrate promoter activity of the upstream region in vitro. Bioinformatic analysis of the active promoter region identified a large CpG island and a range of putative cis-elements. Many of the cis-elements interact with transcription factors which are activated by oncogenic pathways. We therefore tested the regulation of HOP levels by rat sarcoma viral oncogene homologue (RAS). Cancer cell lines were transfected with mutated RAS to observe the effect of constitutively active RAS expression on the production of HOP using qRT-PCR and Western Blot analyses. Additionally, inhibitors of the RAS signalling pathway were utilised to confirm the regulatory effect of mutated RAS on HOP expression. In cancer cell lines containing mutated RAS (Hs578T), HOP was up-regulated via a mechanism involving the MAPK signalling pathway and the ETS-1 and C/EBPβ cis-elements within the HOP promoter. These findings suggest for the first time that Hop expression in cancer may be regulated by RAS activation of the HOP promoter. Additionally, this study allowed us to determine the murine system to be the most suited genetic model organism with which to study the function of human HOP.
- Full Text:
- Date Issued: 2015
- Authors: Weeks, Stacey
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/56006 , vital:26764
- Description: HOP (Heat shock protein 70/ Heat shock protein 90 organising protein) is a co-chaperone essential for client protein transfer from HSP70 to HSP90 within the HSP90 chaperone machine and has been found to be up-regulated in various cancers. However, minimal in vitro information can be found on the regulation of HOP expression. The aim of this study was to analyse the HOP gene structure across known orthologues, identify and characterise the HOP promoter, and identify the regulatory mechanisms influencing the expression of HOP in cancer. We hypothesized that the expression of HOP in cancer cells is likely regulated by oncogenic signalling pathways linked to cis-elements within the HOP promoter. An initial study of the evolution of the HOP gene speciation was performed across identified orthologues using Mega5.2. The evolutionary pathway of the HOP gene was traced from the unicellular organisms to fish, to amphibian and then to land mammal. The synteny across the orthologues was identified and the co-expression profile of HOP analysed. We identified the putative promoter region for HOP in silico and in vitro. Luciferase reporter assays were utilized to demonstrate promoter activity of the upstream region in vitro. Bioinformatic analysis of the active promoter region identified a large CpG island and a range of putative cis-elements. Many of the cis-elements interact with transcription factors which are activated by oncogenic pathways. We therefore tested the regulation of HOP levels by rat sarcoma viral oncogene homologue (RAS). Cancer cell lines were transfected with mutated RAS to observe the effect of constitutively active RAS expression on the production of HOP using qRT-PCR and Western Blot analyses. Additionally, inhibitors of the RAS signalling pathway were utilised to confirm the regulatory effect of mutated RAS on HOP expression. In cancer cell lines containing mutated RAS (Hs578T), HOP was up-regulated via a mechanism involving the MAPK signalling pathway and the ETS-1 and C/EBPβ cis-elements within the HOP promoter. These findings suggest for the first time that Hop expression in cancer may be regulated by RAS activation of the HOP promoter. Additionally, this study allowed us to determine the murine system to be the most suited genetic model organism with which to study the function of human HOP.
- Full Text:
- Date Issued: 2015
Self-concept as a measure of success in the military environment
- Authors: Besener, Paul Robert
- Date: 1987
- Subjects: Self-perception , Control , Recruits , Soldiers , Military , National service , South Africa , Pupils , Learners , Guidance , School curriculum
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1363 , http://hdl.handle.net/10962/d1001429
- Description: This piece of research is an attempt to evaluate the relationship between military 'success' and the psychological preparedness of recruits in terms of their self-concepts and locus of control orientations. The new recruit is forced to adapt to the military environment which will, in turn, attempt to change him into an effective soldier. It was noticed by the researcher, who was involved in military training at the time, that a number of recruits, even some with seemingly limited potential, coped well, while others who seemed to have the ability failed to cope adequately. Recruits completed questionnaires which provided the researcher with biographical data and background information. In addition, the Bledsoe Self-Concept Scale and the Nowicki and Strickland Locus of Control Scale were used in order to determine their self-concepts and locus of control orientations respectively, prior to the beginning of national service. Detailed unstructured interviews were also conducted with a sample of military personnel, to provide another basis for gathering data and for clarifying some of the issues involved. Briefly, the chief conclusion of this researcher is that a significant majority of 'successful' recruits in the military environment have a positive self-concept and an internal locus of control. On the basis of the above finding, it is suggested that there is a need to guide pupils about certain aspects of military life before they begin their National Service. There would seem to be a need for this guidance to be incorporated into the school curriculum, together with such practical aspects as cadets, shooting, etc. There is a shortage of this kind of research on the military situation in South Africa, and it is suggested that numerous issues in this field need to be researched for the benefit of future conscripts and the military alike.
- Full Text:
- Date Issued: 1987
- Authors: Besener, Paul Robert
- Date: 1987
- Subjects: Self-perception , Control , Recruits , Soldiers , Military , National service , South Africa , Pupils , Learners , Guidance , School curriculum
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1363 , http://hdl.handle.net/10962/d1001429
- Description: This piece of research is an attempt to evaluate the relationship between military 'success' and the psychological preparedness of recruits in terms of their self-concepts and locus of control orientations. The new recruit is forced to adapt to the military environment which will, in turn, attempt to change him into an effective soldier. It was noticed by the researcher, who was involved in military training at the time, that a number of recruits, even some with seemingly limited potential, coped well, while others who seemed to have the ability failed to cope adequately. Recruits completed questionnaires which provided the researcher with biographical data and background information. In addition, the Bledsoe Self-Concept Scale and the Nowicki and Strickland Locus of Control Scale were used in order to determine their self-concepts and locus of control orientations respectively, prior to the beginning of national service. Detailed unstructured interviews were also conducted with a sample of military personnel, to provide another basis for gathering data and for clarifying some of the issues involved. Briefly, the chief conclusion of this researcher is that a significant majority of 'successful' recruits in the military environment have a positive self-concept and an internal locus of control. On the basis of the above finding, it is suggested that there is a need to guide pupils about certain aspects of military life before they begin their National Service. There would seem to be a need for this guidance to be incorporated into the school curriculum, together with such practical aspects as cadets, shooting, etc. There is a shortage of this kind of research on the military situation in South Africa, and it is suggested that numerous issues in this field need to be researched for the benefit of future conscripts and the military alike.
- Full Text:
- Date Issued: 1987
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