Identification of bone morphogenetic proteins and their receptors in humanbreast cancer cell lines: Importance of BMP2

The most frequent site of breast cancer metastasis is bone suggesting that some breast cancers express proteins that facilitate this process. We evalu ated whether a highly metastatic breast cancer cell line, MDA-MB-231, and a less metastatic breast cancer cell line, MCF-7, contain bone morphogenetic proteins (BMP), Semiquantitative reverse transcriptase-polymerase chain re action (RT-PCR) demonstrated that MDA and MCF-7 cells contain mRNAs for BMP receptors IA, IB and II. RT-PCR indicated the presence of mRNAs for BMPs 2 and 3 but not 4 and 7 in breast cells. Using a RT-PCR strategy with molecu lar beacons, we found that the mRNA for BMP2 in MDA cells was decreased by 75% after a sublethal dose of radiation. An ELISA using an antibody specifi c for BMP2 demonstrated that BMP2 protein was reduced after radiation of MD A cells. The mRNA for BMP2 was expressed to a lesser extent in MCF-7 cells than MDA cells and was not altered after radiation treatment of MCF-7 cells as demonstrated by molecular beacon RT-PCR, Recombinant human BMP2 decreas ed the proliferation of MDA cells to a greater extent than MCF-7 cells. The se results expand the number of tissues that contain BMPs and demonstrate t he effect of this signalling pathway of the growth state of these tissues. (C) 1999 Academic Press.