Bone morphogenetic proteins (BMPs) are members of the transforming growth factor beta superfamily of growth factors. They are well-known for their key roles in the regulation of various developmental processes and bone formation, but in recent years, evidence has also accumulated of their crucial contribution in tumor biology. In particular, BMP4 and BMP7 have been implicated in breast cancer pathogenesis. However, little is known about BMP target genes in the context of tumor cells. Here, we used whole-genome microarrays to explore the effects of BMP4 and BMP7 treatment on global gene expression levels in seven breast cancer cell lines during a 6-point time series. Several complementary methods, including hierarchical clustering of differentially expressed genes, gene ontology enrichment analyses and model based clustering of temporal data, were used for data analysis. Both BMP ligands had a strong influence on gene expression levels, although the response to BMP4 treatment was more pronounced as compared to BMP7. As might have been expected, the cellular functions most strongly affected by the stimulation of BMP signaling were regulation of transcription and development. The observed transcriptional response, as well as its functional outcome, followed a temporal sequence, where the regulation of gene expression and signal transduction was followed by changes in transcripts involved in metabolism and cell proliferation. Hierarchical clustering analysis revealed distinct differences in the response of individual cell lines to BMPs, but also underlined a common synexpression group of genes for both ligands. Remarkably, the majority of the genes within these synexpression groups were shared by the two ligands, and thus these genes are likely to represent the core molecular responses common to BMP4 and BMP7 signaling pathways. Taken together, our data demonstrate that BMP signaling has a substantial effect on gene transcription in breast cancer cells and that the cellular functions affected follow a logical temporal pattern. Our results also reveal components of the cellular transcriptional response that are common to BMP4 and BMP7. Finally, our study provides a list of putative novel BMP target genes relevant in breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5089. doi:1538-7445.AM2012-5089