Modelling neoplastic progression in epithelial ovarian
Doctoral thesis, UCL (University College London).
A national screening programme could significantly reduce mortality from epithelial ovarian cancer (EOC). The biological events that occur in the early stages of development of EOCs remain poorly understood, thus hindering the discovery of biomarkers of early disease. This thesis describes the development of a three-dimensional heterotypic genetic model of neoplastic transformation of normal ovarian surface epithelial (NOSE) cells. hTERT, C-MYC, KRAS and BRAF are genes that are commonly mutated or overexpressed in EOCs. Ectopic expression of hTERT increased in vitro lifespan of NOSE cells without inducing neoplastic transformation. Subsequent overexpression of CMYC +/- KRASG12V /BRAFV 600E in immortalised NOSE (IOSE) cells induced a significant increase in anchorage-independent growth and invasive ability. In in vitro assays and gene expression microarrays, phenotypic and molecular heterogeneity was associated with differential oncogene expression. Physiological and biological features of NOSE cells grown in 3D more closely resembled characteristics of NOSE cells in vivo than when grown by classical two-dimensional (2D) approaches. 3D models of oncogene-expressing clones revealed characteristics of malignant cells in vivo that could not be detected in 2D monolayer cultures. Gene expression microarrrays profiles of ~25,000 genes were generated to identify novel genes that are altered synergistically with the oncogenes that were introduced. A panel of genes has been identified that provides novel candidates for detecting ovarian carcinomas at the earliest, most treatable, stages of disease. Finally, a role for ageing fibroblasts in the initiation of EOC development was explored. In 2D and 3D in vitro co-culture assays, pre-senescent and senescent ovarian fibroblasts differentially affected proliferation, anchorage-independent growth, migration and invasion of IOSECMYC cell lines but not of IOSE cells. These data provide in vitro evidence that the ageing microenvironment can promote transformation of ovarian epithelial cells, and that this is conditional upon mutation in the OSE.
|Title:||Modelling neoplastic progression in epithelial ovarian cancer|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute for Women's Health|
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