ATP7B is a differentially expressed gene in brain metastatic human 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 for the discovery of genes associated with brain metastasis in humans with metastatic breast cancer. We found that the ATPase copper transporting beta, also known as Wilson disease protein, encoded by ATP7B, was among the genes whose expression was most different in the brain metastases of patients with metastatic breast cancer as compared to primary tumors of the breast. ATP7B mRNA was present at increased quantities in brain metastatic tissues as compared to primary tumors of the breast. Expression of ATP7B in primary tumors was significantly correlated with patient overall survival. Modulation of ATP7B expression may be relevant to the biology by which tumor cells metastasize from the breast to the brain in humans with metastatic breast cancer.