Palladin 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 palladin, encoded by PALLD, was among the genes whose expression was most quantitatively different in the brain metastases of patients with metastatic breast cancer. PALLD mRNA was present at decreased quantities in brain metastatic tissues as compared to primary tumors of the breast. Importantly, expression of PALLD in primary tumors was significantly correlated with patient overall survival in patients with breast cancer. Modulation of PALLD expression may be relevant to the biology by which tumor cells metastasize from the breast to the brain.