Differential expression of cancer-related genes by single and permanent exposure to bone morphogenetic protein 2.
OBJECTIVE
Bone morphogenetic proteins (BMPs) are multifunctional regulators of various cell functions. The BMP-signalling network plays a pivotal role during embryogenesis and tumorigenesis. BMPs, e.g. BMP-2 exert their biological function in a time and concentration-dependent manner but also modulated by the context of the cellular microenvironment. In this study, we investigated the effect of a steady high level of BMP-2 versus a single application of BMP-2 on the breast cancer cell line MCF-7.


METHODS
The effect of the incubation regimes was analysed by DNA microarray expression profiling. Data were verified by real-time PCR. The protein expression of apoptosis-related genes was studied by western blot analysis.


RESULTS
We found a clear difference in the altered gene expression between the constant high level and the single application of BMP-2. After grouping the genes of interest into the biological processes of Gene Ontology, the group of apoptosis-related genes like BAX, BAG5 or PKR, was predominantly affected under the single-application regime of BMP-2. Among these protein kinase R was the most prominently regulated. Further studies on the protein level showed activation of PKR after 4 h with a subsequent enhanced phosphorylation of the PKR substrate eIF2alpha for several hours.


CONCLUSIONS
The duration of treatment and the concentration of BMP-2 affect the global expression pattern of MCF-7 cells. Among the regulated cancer-related genes, the cohort of the apoptosis-related genes showed the pronounced alterations. Our data point to a novel role of BMP-2 in the regulation of the PKR pathway in tumorigenesis.
Steinert
Susanne
S
Clinic for Internal Medicine II, Friedrich-Schiller-University Jena, Erlanger Allee 101, 07740, Jena, Germany.
Kroll
Torsten C
TC
Taubert
Isabel
I
Pusch
Larissa
L
Hortschansky
Peter
P
Höffken
Klaus
K
Wölfl
Stefan
S
Clement
Joachim H
JH
D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000235:genetics*; D045744:Cell Line, Tumor; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics; D009369:Neoplasms / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D018075:RNA, Complementary / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D017931:DNA Primers; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D018075:RNA, Complementary