SPRY2 is differentially expressed in both lymph node and brain metastases in 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 sprouty homolog 2, encoded by SPRY2, was among the genes whose expression was most quantitatively different in the brain metastases of patients with metastatic breast cancer. SPRY2 mRNA was present at decreased quantities in brain metastatic tissues as compared to primary tumors of the breast. Importantly, expression of SPRY2 in primary tumors was significantly correlated with patient recurrence-free survival in patients with breast cancer. Modulation of SPRY2 expression may be relevant to the biology by which tumor cells metastasize from the breast to the brain.