DDX54 is a differentially expressed gene in human metastatic breast cancer, in the brain and in the lymph nodes.

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 for the discovery of genes associated with brain metastasis in humans with metastatic breast cancer. We found that the DEAD-box helicase 54, encoded by DDX54, was among the genes whose expression was most different in the brain and lymph node metastases of patients with metastatic breast cancer. DDX54 mRNA was present at increased quantities in brain metastatic tissues as compared to primary tumors of the breast. Importantly, expression of DDX54 in primary tumors was significantly correlated with patient recurrence-free survival in patients with breast cancer. Modulation of DDX54 expression may be relevant to the biology by which tumor cells metastasize from the breast to the brain while evading immune clearance in the lymph nodes in humans with metastatic breast cancer.