MicroRNAs in extracellular vesicles as biomarkers for pancreaticobiliary cancers
File(s)
Author(s)
Liu, Daniel
Type
Thesis
Abstract
Pancreaticobiliary cancers including pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA) have an extremely poor prognosis. MicroRNAs (miRNAs) are small non-coding RNAs that have been found to be commonly deregulated in cancer, found in plasma and bile and can be encapsulated in extracellular vesicles (EVs). EVs are nanosized particles with a lipid bilayer that are secreted by cells and have been found to play a role both locally within the tumour microenvironment and on distant organs to promote the premetastatic niche.
The MIRABILE (MIcroRNAs as BILE-based biomarkers in Pancreaticobiliary Cancers) study was a prospectively recruited study at Hammersmith Hospital (2017-2020) which collected samples from patients presenting with obstruction of the bile duct leading to jaundice. Our aim was to determine novel miRNAs for the diagnosis of PDAC and CCA.
We detected miR-182-5p and miR-340-5p in our cell-free RNA from bile that generated an AUC value of 0.85 in the detection of malignancy. For the first time, we investigated EV miRNAs using a size-exclusion chromatography protocol comparing this with other methods to evaluate optimum EV isolation in bile
and plasma. RNA-Sequencing of bile EVs detected the presence of let-7a and miR-21 as upregulated in patients with PDAC. Furthermore, validated differential expression of miR-200a and miR-429 (p<0.0001) was found in both PDAC and CCA bile EVs compared with controls. Four candidates (let-7a-5p, miR-21-5p, miR-200a-3p, and miR-429) were combined to form a subset of EV-miRNAs which could detect PDAC with an AUC of 0.96. Plasma EVs were also shown to be present in greater concentrations and upregulated in miR-200a/miR-200b/miR-200c/miR-141/miR-429. Together these 5 members of the miR-200 family were combined to exhibit a validated AUC of 0.82 which in combination with CA 19-9 generated an AUC of 0.96. In conclusion, these markers have the potential to diagnose patients with PDAC and CCA.
The MIRABILE (MIcroRNAs as BILE-based biomarkers in Pancreaticobiliary Cancers) study was a prospectively recruited study at Hammersmith Hospital (2017-2020) which collected samples from patients presenting with obstruction of the bile duct leading to jaundice. Our aim was to determine novel miRNAs for the diagnosis of PDAC and CCA.
We detected miR-182-5p and miR-340-5p in our cell-free RNA from bile that generated an AUC value of 0.85 in the detection of malignancy. For the first time, we investigated EV miRNAs using a size-exclusion chromatography protocol comparing this with other methods to evaluate optimum EV isolation in bile
and plasma. RNA-Sequencing of bile EVs detected the presence of let-7a and miR-21 as upregulated in patients with PDAC. Furthermore, validated differential expression of miR-200a and miR-429 (p<0.0001) was found in both PDAC and CCA bile EVs compared with controls. Four candidates (let-7a-5p, miR-21-5p, miR-200a-3p, and miR-429) were combined to form a subset of EV-miRNAs which could detect PDAC with an AUC of 0.96. Plasma EVs were also shown to be present in greater concentrations and upregulated in miR-200a/miR-200b/miR-200c/miR-141/miR-429. Together these 5 members of the miR-200 family were combined to exhibit a validated AUC of 0.82 which in combination with CA 19-9 generated an AUC of 0.96. In conclusion, these markers have the potential to diagnose patients with PDAC and CCA.
Version
Open Access
Date Issued
2023-01-01
Date Awarded
16/01/2024
License URL
Advisor
Krell, Jonathan
Frampton, Adam
Jiao, Long
Sponsor
Royal College of Surgeons of England
Moulton Charitable Foundation
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)