Taken together, our data suggest that BMP6 plays a critical role in breast cancer cell aberrant proliferation and chemoresistance and may serve as a novel diagnostic biomarker or therapeutic target for breast cancer.
Through detecting mRNA expression levels of PTHrP and BMP-6 in 35 breast cancer specimens, the two genes' expression were proved to be negatively correlated.
In 33 breast tumor specimens, promoter methylation of BMP-6 was detected by methylation-specific PCR, hypermethylation of BMP-6 was observed in ER negative cases (16 of 16 cases (100%)), while obviously lower methylation frequency were observed in ER positive cases (3 of 17 cases (18%)), indicating that BMP-6 promoter methylation status is correlated with ER status in breast cancer.
Consistent with the fact that higher level of deltaEF1 expression is associated with more invasive phenotype of breast cancer cells, our collective data suggests that deltaEF1 is likely the switch through which BMP-6 restores E-cadherin-mediated cell-to-cell adhesion and prevents breast cancer metastasis.