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 SP140 nuclear body protein like, encoded by SP140L, 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). SP140L was also differentially expressed in the tumor cells of patients with triple negative breast cancer (5). SP140L mRNA was present at increased quantities in lymph node metastatic tissues as compared to primary tumors of the breast. Importantly, expression of SP140L in primary tumors was significantly correlated with patient overall survival, in lymph node positive patients but not in lymph node negative patients. Modulation of SP140L expression may be relevant to the biology by which tumor cells metastasize from the breast to the lymph node and to the brain in humans with metastatic breast cancer.
Detection and quantification of circulating tumor cells in mouse models of human breast cancer using immunomagnetic enrichment and multiparameter flow cytometry