DEFB123 is differentially expressed in metastasis to lymph nodes in human breast cancer.
Metastasis to the brain is a clinical problem in patients with breast cancer (1-3). Between the brain and the breast resides the secondary lymphoid organ, the lymph nodes. We mined published microarray data (4, 5) to compare primary and metastatic tumor transcriptomes for the discovery of genes associated with metastasis to the lymph nodes in human breast cancer. We found that the defensin beta 123, encoded by DEFB123, was among the genes whose expression was most different in the lymph nodes metastases of patients with metastatic breast cancer as compared to primary tumors of the breast (4). DEFB123 was also differentially expressed in the primary tumors of the breast when compared to normal mammary epithelium (5). DEFB123 mRNA was present at increased quantities in lymph node metastatic tissues as compared to primary tumors of the breast. Importantly, expression of DEFB123 in primary tumors was significantly correlated with patient overall survival in patients with lymph node negative breast cancer. Modulation of DEFB123 expression may be relevant to the biology by which tumor cells metastasize from the breast to the lymph nodes in humans with metastatic breast cancer.