Analysis of breast cancer metastasis candidate genes from next generation-sequencing via systematic functional genomics

Monica Marie Blomstrøm

    Research output: ThesisPh.D. thesis

    Abstract

    Metastatic breast cancer remains an incurable disease accounting for the vast majority of deaths from breast cancer. Understanding the molecular mechanisms for metastatic spread is important to improve diagnosis and for generating starting points for novel treatment strategies. Inhibition of metastatic spread or targeted drugs causing synthetic lethality to metastatic cells are two conceivable approaches. Somatic mutations identified by next-generation sequencing offer a promising source for discovering so far unknown, new genes and mutations playing a role in metastasis formation. A great advantage of mutations is that they are most likely stable in the metastatic cancer cell population, whereas miRNA, mRNA and protein expression profiles may change substantially prior to, throughout, or after the complex metastatic process as well as between subpopulations such as cancer stem cells (CSCs) and non-CSCs.
    The main goal of this project was to functionally characterize a set of candidate genes recovered from next-generation sequencing analysis for their role in breast cancer metastasis formation. The starting gene set comprised 104 gene variants; i.e. 57 wildtype and 47 mutated variants. During the project, the aim was to generate a panel of genetically identical (“isogenic”) MCF7 breast cancer cell lines with inducible overexpression of the gene variants, and to analyze these for effects on breast cancer growth and invasion in vitro under standardized conditions. Moreover, it was aimed at acquiring insight into which gene variants may be involved in epithelial-mesenchymal-transition (EMT), by measuring CDH1 and CDH2 mRNA levels by quantitative RT-PCR, because EMT is generally considered as main driving mechanism for acquiring metastatic abilities and for the emergence of CSCs.
    At present state several growth modulators and invasion modulators were identified and independently validated. These candidates revealed a group of genes with metastasis-related functions in vitro that are involved in RNA-related processes, such as RNA-processing. Moreover, a general feature was that proliferation and invasion potential were inversely correlated. Opposed to this, a clear association of invasive potential with EMT could not be confirmed. Collectively, this points to that mechanisms other than EMT may play at least an equivalent role in acquisition of metastatic potential.
    Translated title of the contributionAnalyse af brystkræft metastase kandidat gener fra next generation-sequencing via systematisk funktionel genomics
    Original languageEnglish
    Publication statusPublished - 15. Mar 2016

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