Fibroblasts transcriptome altered by breast cell lines

Interactions between epithelial cells and their associated stroma, mainly the fibroblasts therein have been implicated in breast malignancy. Our aim was to verify the effect of soluble factors resulting from the co-culture of normal (NAF) or associated breast cancer fibroblasts (CAF) with a normal (MCF-10A) or a metastatic (MDA-MB231) breast epithelial cell line on fibroblast gene expression profiles. Fibroblast primary cultures were established and co-culture of these cell types separated by inserts, which allow the passage of soluble factors, was performed. Total RNA was extracted, amplified and subjected to microarray gene expression profiling using microarrays in which 4,608 ORESTES (open reading frame expressed sequence tags) were spotted. Differentially expressed genes, at a False Discovery Ratio (FDR) less then 0.01 and fold variation greater than 2, were selected. CAF molecular signature was characterized by down regulation of 62% (29/47) of genes as compared to NAF, represented mainly by those related to vesicular transport, cytoskeleton plasticity and cell motility. CAF responded to co-culture with MCF-10A cells by up regulation of 63.5% (89/140) of genes, including those involved with cytoskeleton remodelling, lipid synthesis and members of the PI3K pathway. Contrarywise, MDA-MB231 cells affected the gene expression profile of CAF by down regulation of 65% (102/156) of genes, including those associated to tumor suppression and antiangiogenic potential. Up regulated genes, were mainly implicated with cell cycle progression and proliferation. NAF signature was altered by MDA-MB231 presence resulting in down regulation of suppressor genes, integrins and angiogenic factors, but it was modestly affected by MCF-10A. Keywords: Fibroblasts transcriptome altered by breast cell lines 4 samples of CAF and 3 samples of NAF were analyzed. HB4A cells were used as reference, all samples were performed with dye-swaps.