TOR2A 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 torsin family 2, member A, encoded by TOR2A, 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 breast4, as well as in primary tumors of the breast when compared to normal breast tissue5. TOR2A mRNA was present at increased quantities in brain metastatic tissues as compared to primary tumors of the breast. Importantly, expression of TOR2A in primary tumors was significantly correlated with patient recurrence-free survival. Modulation of TOR2A expression may be relevant to the biology by which tumor cells metastasize from the breast to the brain in humans with metastatic breast cancer.