Tyrosine kinase BMX is differentially expressed in the brain metastases of patients with metastatic breast cancer.
Metastasis to the brain is a clinical problem in patients with breast cancer (1-3). We mined published microarray data (4, 5) to compare primary and metastatic tumor transcriptomes to discover genes associated with brain metastasis in patients with metastatic breast cancer. We found that tyrosine kinase BMX was among the genes whose expression was most different in the brain metastases of patients with metastatic breast cancer as compared to normal and transformed breast tissues. BMX mRNA was present at significantly reduced quantities in brain metastatic tissues as compared to normal breast tissues. Down-regulation of signals transduced by BMX may be an important event for metastasis of primary tumor-derived cancer cells to the brain in humans with metastatic breast cancer.