The Positive and Negative Transcriptional Regulation of N-cadherin Expression During the Progression of Prostate Cancer

Persistent Link:
http://hdl.handle.net/10150/195426
Title:
The Positive and Negative Transcriptional Regulation of N-cadherin Expression During the Progression of Prostate Cancer
Author:
Alexander, Nelson Ray
Issue Date:
2005
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
For cancer cells to initiate cell migration and progress to metastasize, epithelial genes must be silenced and the expression of mesenchymal genes must be upregulated. During prostate carcinogenesis, E-cadherin expression is downregulated through multiple mechanisms, the majority of which combine to silence E-cadherin expression through transcriptional regulation at the level of the E-cadherin promoter. Recently it has been discovered that there is transcriptional upregulation of the mesenchymal cadherin, N-cadherin during prostate cancer metastasis. Although N-cadherin expression can be detected in human prostate cancer and in prostate carcinoma cell lines, the mechanisms controlling the transcriptional regulation of N-cadherin in cancer are uncharacterized. This body of work offers the first evidence for the mechanisms controlling the transcriptional upregulation of N-cadherin expression in prostate carcinoma. We utilized anchorage independent culture to induce downregulation of N-cadherin expression, and then analyzed the necessary events for N-cadherin upregulation when cells attached to Fibronetin (FN). In order to determine the functional regions of the N-cadherin proximal promoter that were involved in the upregulation of N-cadherin expression, we cloned regions of the human N-cadherin 5’ proximal promoter, and regions of the first intron of the N-cadherin gene into a luciferase reporter vector. It was determined that the bHLH transcription factor Twist1 controlled the upregulation of N-cadherin transcription in PC-3 cells, through β1 integrin dependent nuclear localization of Twist1. A cis-element located in the first intron of the N-cadherin gene was shown to be necessary for Twist1 mediated effects on the N-cadherin promoter. We then determined the requirements for cell-type specific expression of the N-cadherin promoter. It was determined that an additional cis-element located in the first intron of the N-cadherin gene was necessary to repress N-cadherin promoter activity in cells lacking N-cadherin. Through deletion analysis of the N-cadherin promoter luciferase construct, a DNA binding site for the transcription factor FoxP1 was discovered. FoxP1 binds to the repressive cis-element in vitro, and mutation of the FoxP1 DNA binding site eliminated cell-type specific activity of the N-cadherin promoter. Therefore, we have documented that the aberrant expression of N-cadherin in prostate carcinoma involves alterations in both positive and negative transcriptional regulators.
Type:
text; Electronic Dissertation
Keywords:
N-cadherin; integrin; twist1; FoxP1; prostate cancer; transcriptional regulation
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Cancer Biology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Heimark, Ronald L
Committee Chair:
Heimark, Ronald L

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleThe Positive and Negative Transcriptional Regulation of N-cadherin Expression During the Progression of Prostate Canceren_US
dc.creatorAlexander, Nelson Rayen_US
dc.contributor.authorAlexander, Nelson Rayen_US
dc.date.issued2005en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractFor cancer cells to initiate cell migration and progress to metastasize, epithelial genes must be silenced and the expression of mesenchymal genes must be upregulated. During prostate carcinogenesis, E-cadherin expression is downregulated through multiple mechanisms, the majority of which combine to silence E-cadherin expression through transcriptional regulation at the level of the E-cadherin promoter. Recently it has been discovered that there is transcriptional upregulation of the mesenchymal cadherin, N-cadherin during prostate cancer metastasis. Although N-cadherin expression can be detected in human prostate cancer and in prostate carcinoma cell lines, the mechanisms controlling the transcriptional regulation of N-cadherin in cancer are uncharacterized. This body of work offers the first evidence for the mechanisms controlling the transcriptional upregulation of N-cadherin expression in prostate carcinoma. We utilized anchorage independent culture to induce downregulation of N-cadherin expression, and then analyzed the necessary events for N-cadherin upregulation when cells attached to Fibronetin (FN). In order to determine the functional regions of the N-cadherin proximal promoter that were involved in the upregulation of N-cadherin expression, we cloned regions of the human N-cadherin 5’ proximal promoter, and regions of the first intron of the N-cadherin gene into a luciferase reporter vector. It was determined that the bHLH transcription factor Twist1 controlled the upregulation of N-cadherin transcription in PC-3 cells, through β1 integrin dependent nuclear localization of Twist1. A cis-element located in the first intron of the N-cadherin gene was shown to be necessary for Twist1 mediated effects on the N-cadherin promoter. We then determined the requirements for cell-type specific expression of the N-cadherin promoter. It was determined that an additional cis-element located in the first intron of the N-cadherin gene was necessary to repress N-cadherin promoter activity in cells lacking N-cadherin. Through deletion analysis of the N-cadherin promoter luciferase construct, a DNA binding site for the transcription factor FoxP1 was discovered. FoxP1 binds to the repressive cis-element in vitro, and mutation of the FoxP1 DNA binding site eliminated cell-type specific activity of the N-cadherin promoter. Therefore, we have documented that the aberrant expression of N-cadherin in prostate carcinoma involves alterations in both positive and negative transcriptional regulators.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectN-cadherinen_US
dc.subjectintegrinen_US
dc.subjecttwist1en_US
dc.subjectFoxP1en_US
dc.subjectprostate canceren_US
dc.subjecttranscriptional regulationen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineCancer Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHeimark, Ronald Len_US
dc.contributor.chairHeimark, Ronald Len_US
dc.contributor.committeememberCress, Anne E.en_US
dc.contributor.committeememberNagle, Raymond B.en_US
dc.contributor.committeememberRunyan, Raymond B.en_US
dc.contributor.committeememberVaillancourt, Richard R.en_US
dc.identifier.proquest1316en_US
dc.identifier.oclc137354996en_US
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