The stellate cancer-associated fibroblast in pancreatic ductal adenocarcinoma; its role in chemoresistance
File(s)
Author(s)
Johnson, Natalie Georgette
Type
Thesis
Abstract
Introduction: The tumour microenvironment has been found to contribute to cancer
survival and progression, and more specifically, the stromal microenvironment has
been implicated in the drug resistant nature of cancers such as pancreatic cancer.
This microenvironment consists of fibroblasts, pericytes, endothelial cells and the
extracellular matrix, with the stellate cancer-associated fibroblast (CAF) being the
most predominant cell type present. The aim of this study was to investigate the role
of the cancer associated fibroblast in tumourigenesis in Pancreatic Ductal
Adenocarcinoma (PDA) with specific reference to the mechanisms involved in
chemoresistance via the stellate cancer associated fibroblast.
Methods: I investigated the molecular pathogenesis of PDA assessing DNA copy
number alterations (CNA) in selection of clinically relevant PDA cell lines (PANC-1,
MiaPaCa-2, ASPC-1, SU86.86, HPAC, HS776T, PL5 and PL45), seven primary
resected, non immortalised samples (PF3, PF7, PF8, PF9, PF16, PF18 and PF20)
and an immortalised stellate cell line using array comparative genomic hybridization
(aCGH). All cultures and cell lines were then screened in order to determine their
sensitivity to currently used therapeutic compounds. Analysis was done using R
software and Graph Pad Prism 5.
Results: The non-immortalised stellate CAFs and formalin fixed paraffin embedded
stromal fibroblast samples showed no homozygous genomic CNAs. The stellate
cancer associated fibroblasts both primary and immortalised appear more
responsive to the chemotherapeutic drugs in the compound library compared to the
PDA cell lines.
Conclusions: This study suggests the absence of homozygous deletions that may
lead to a change in phenotype in the stellate CAF. However, the presence of
heterozygous deletions and epigenetic changes has not yet been excluded. Further
experiments such as micro RNA and epigenetic studies, such as SNP arrays, may
identify the presence of aberrations that have aetiological significance in
carcinogenesis even if they do not result in CNVs. This higher sensitivity of the
stellate CAF to the drugs in the chemotherapy library may favour them as potential
targets for management of this hard to street subtype of disease.
survival and progression, and more specifically, the stromal microenvironment has
been implicated in the drug resistant nature of cancers such as pancreatic cancer.
This microenvironment consists of fibroblasts, pericytes, endothelial cells and the
extracellular matrix, with the stellate cancer-associated fibroblast (CAF) being the
most predominant cell type present. The aim of this study was to investigate the role
of the cancer associated fibroblast in tumourigenesis in Pancreatic Ductal
Adenocarcinoma (PDA) with specific reference to the mechanisms involved in
chemoresistance via the stellate cancer associated fibroblast.
Methods: I investigated the molecular pathogenesis of PDA assessing DNA copy
number alterations (CNA) in selection of clinically relevant PDA cell lines (PANC-1,
MiaPaCa-2, ASPC-1, SU86.86, HPAC, HS776T, PL5 and PL45), seven primary
resected, non immortalised samples (PF3, PF7, PF8, PF9, PF16, PF18 and PF20)
and an immortalised stellate cell line using array comparative genomic hybridization
(aCGH). All cultures and cell lines were then screened in order to determine their
sensitivity to currently used therapeutic compounds. Analysis was done using R
software and Graph Pad Prism 5.
Results: The non-immortalised stellate CAFs and formalin fixed paraffin embedded
stromal fibroblast samples showed no homozygous genomic CNAs. The stellate
cancer associated fibroblasts both primary and immortalised appear more
responsive to the chemotherapeutic drugs in the compound library compared to the
PDA cell lines.
Conclusions: This study suggests the absence of homozygous deletions that may
lead to a change in phenotype in the stellate CAF. However, the presence of
heterozygous deletions and epigenetic changes has not yet been excluded. Further
experiments such as micro RNA and epigenetic studies, such as SNP arrays, may
identify the presence of aberrations that have aetiological significance in
carcinogenesis even if they do not result in CNVs. This higher sensitivity of the
stellate CAF to the drugs in the chemotherapy library may favour them as potential
targets for management of this hard to street subtype of disease.
Version
Imperial Users Only
Date Issued
2012-12
Date Awarded
2014-03
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Stamp, Gordon
Thillainayagam, Andrew
Spalding, Duncan
Sponsor
Institute of Cancer Research
The London Clinic
Publisher Department
Medicine
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)