Directly established mammary tumour xenograft lines with the capacity to metastasize were not developed until the early 1990s [ 25], although prior and subsequent to this a number of established in vitro lines have been adapted to xenograft cultures.
To model anoikis resistance in vitro, cell lines are cultured in suspension rather than conventional monolayers.
Although thymic nurse cells are not easily studied in vitro, nurse cell lines are available by transforming nurse cells with the SV40 virus [ 49].
In vitro growing cell lines are the closest model systems available today for studying the biological features of body cavity lymphomas.
The relevance of studies using in vitro cell lines is always of debate, especially in the epigenetic field, as microenvironment and culture conditions differ dramatically from in vivo conditions and can modify the chromatin profile of cells.
In a previous study of 69 GEJ adenocarcinoma samples consisting of 54 primary tumours, four lymph node metastases, nine xenografts and two in vitro cell lines were investigated for β-catenin expression and β-catenin exon 3 mutations (Wijnhoven et al, 2000b).
Although thermal imaging and FDG/MRI scans are capable of capturing human BAT activity non-invasively, for in vitro research, human cell lines are still needed to uncover the genetic, pharmacological, and environmental determinants of BAT biological functions.
However, of course, in vitro studies in cell lines are not necessarily transferable to in vivo studies in organisms.
However, although in vitro experiments using cell lines are powerful techniques, the results that emerge from these studies should be viewed cautiously.
Established in vitro breast cancer cell lines are being extensively used by the research community to address various aspects of cancer biology [ 12, 38– 40].
