Investigating the role of non-coding RNAs in doxorubicin-induced cardiotoxicity
File(s)
Author(s)
Yiu, Cheuk Ting (Angela)
Type
Thesis
Abstract
Long non-coding RNAs (lncRNAs) are emerging as important regulators in many biological processes. However, despite over thousands of lncRNAs have been identified, only a few have been functionally characterised, especially in cardiac diseases and development.
The use of anthracyclines such as doxorubicin (DOX) has improved mortality and morbidity in cancer patients, yet associated risks of cardiomyopathy have limited their clinical application. DOX-induced cardiomyopathy (DIC) is frequently irreversible and typically progresses to heart failure. However, little is known about the role of lncRNAs in the underlying mechanisms of DOX-induced cardiotoxicity.
RNA-sequencing analysis of a DIC rat model revealed that the highly conserved lncRNA Cyrano was significantly down-regulated by DOX. To evaluate the functions and mechanisms of Cyrano, the highly conserved region and the promoter site were deleted separately by genome editing. Transcriptomic profiling of the transgenic lines showed that gene regulation by Cyrano does not solely depend on its conserved site. Capture hybridisation analysis of RNA targets revealed that Cyrano interacts with 3’UTRs of mRNAs and PABPN1, a crucial component of the mRNA 3’-end processing machinery. The depletion of Cyrano led to widespread 3’UTR lengthening of mRNAs. We propose that Cyrano may contribute to the dysregulation of alternative polyadenylation (APA) induced by DOX through its interaction with PABPN1 in cardiomyocytes.
As genes and pathways important in cardiac development are often re-activated in heart failure, we hypothesised that Cyrano also regulates APA in cardiomyocyte differentiation. During the differentiation of cardiomyocytes from human induced pluripotent stem cells (hiPSCs), Cyrano showed a dynamic expression pattern that corresponded to the global APA changes. Together with the Cyrano-PABPN1 interaction in hiPSCs, these suggested that Cyrano may play a role in regulating APA in the early stages of cardiomyocyte differentiation. Further investigations are needed to elucidate the function and mechanisms of Cyrano in cardiomyocyte differentiation and cardiac development.
The use of anthracyclines such as doxorubicin (DOX) has improved mortality and morbidity in cancer patients, yet associated risks of cardiomyopathy have limited their clinical application. DOX-induced cardiomyopathy (DIC) is frequently irreversible and typically progresses to heart failure. However, little is known about the role of lncRNAs in the underlying mechanisms of DOX-induced cardiotoxicity.
RNA-sequencing analysis of a DIC rat model revealed that the highly conserved lncRNA Cyrano was significantly down-regulated by DOX. To evaluate the functions and mechanisms of Cyrano, the highly conserved region and the promoter site were deleted separately by genome editing. Transcriptomic profiling of the transgenic lines showed that gene regulation by Cyrano does not solely depend on its conserved site. Capture hybridisation analysis of RNA targets revealed that Cyrano interacts with 3’UTRs of mRNAs and PABPN1, a crucial component of the mRNA 3’-end processing machinery. The depletion of Cyrano led to widespread 3’UTR lengthening of mRNAs. We propose that Cyrano may contribute to the dysregulation of alternative polyadenylation (APA) induced by DOX through its interaction with PABPN1 in cardiomyocytes.
As genes and pathways important in cardiac development are often re-activated in heart failure, we hypothesised that Cyrano also regulates APA in cardiomyocyte differentiation. During the differentiation of cardiomyocytes from human induced pluripotent stem cells (hiPSCs), Cyrano showed a dynamic expression pattern that corresponded to the global APA changes. Together with the Cyrano-PABPN1 interaction in hiPSCs, these suggested that Cyrano may play a role in regulating APA in the early stages of cardiomyocyte differentiation. Further investigations are needed to elucidate the function and mechanisms of Cyrano in cardiomyocyte differentiation and cardiac development.
Version
Open Access
Date Issued
2019-09
Date Awarded
2020-02
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Castellano, Leandro
Lyon, Alexander
Stebbing, Justin
Sponsor
British Heart Foundation
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)