Samuriwo, Tendayi;
(2023)
Functional Characterisation of Copine III (CPNE3) in ERBB2 Overexpressing Breast Cancer.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Functional Characterisation of Copine III (CPNE3) in ERBB2 Overexpressing Breast Cancer.pdf - Accepted Version Download (12MB) | Preview |
Abstract
BACKGROUND: ERBB2/HER2 is amplified in a significant proportion of human breast cancers, where it is correlated to poor prognosis for the patient and therapeutic resistance. However, little is known about the underlying mechanisms and their effect on tumour progression. In the ongoing attempt to elucidate the downstream signalling mechanisms of ERBB2 overexpressing breast cancer, a poorly characterised calcium-binding protein called Copine III (CPNE3) has been identified as potentially associated with ERBB2-dependent transformation. METHODS: Two mass spectrometry-based proteomic methods, tandem mass tagging (TMT) LCMS/ MS and label-free LC-MS/IMS/MS were implemented to discover candidate biomarkers regulated by siRNA-mediated gene knockdown of CPNE3 in ERBB2 overexpressing HMLECs. A combination of real-time cell adhesion assays, mass spectrometry based proteomic workflows, statistical analysis, biological network construction, causal and functional enrichment analysis revealed the functional role of these CPNE3 regulated candidate biomarkers. Novel clinical biomarkers of HER2-positive status were confirmed by mapping candidate biomarkers to data from two breast cancer patient cohorts using Pearson correlation and potential signalling mechanisms were identified by evaluating phosphopeptide enrichment. RESULTS: The downregulation of adhesion related proteins ITGA6 and ITGB4 was shown to correlate with the overexpression of CPNE3 in ERBB2 over-expressing HMLECs. However, the knockdown of both CPNE3 and ERBB2 did not reverse the expression pattern. Cell adhesion assays demonstrated that ERBB2 over-expressing HMLECs adhere to an adherent surface more readily than parental HMLECs and mass spectrometry-based proteomic profiling, PCA and k-means clustering revealed a link between CPNE3 and components of ribonucleoprotein complexes that form in the early stages of cell spreading. In addition, CPNE3 expression regulates several proteins such as CANX, CS, HIST1H4A and PYGM that are downstream effectors or targets of OXPHOS. CONCLUSION: CPNE3 is proposed as a marker for adaptive mechanosensing related metabolic reprogramming. Moreover, suggesting a role for CPNE3 in glucose homeostasis of breast cancer during malignant transformation.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Functional Characterisation of Copine III (CPNE3) in ERBB2 Overexpressing Breast Cancer |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2023. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > UCL EGA Institute for Womens Health UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > UCL EGA Institute for Womens Health > Womens Cancer UCL |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10170883 |
Archive Staff Only
 |
View Item |
