The neuronal cell adhesion molecule L1CAM as a therapeutic targe in breast cancer.

e21138 Background: Brain metastases of breast cancer occurs in approximately one-third of metastatic triple negative and HER2+ breast cancer patients and contributes to patient morbidity and mortality. The identification and validation of molecular pathways underlying brain metastases of breast cancer may lead to the development of effective therapeutics. Methods: We have identified 23 sets of matched primary breast tumors and resected brain metastases, and determined their gene expression profiles using the DASL platform on formalin-fixed, paraffin embedded tumor sections. Multiple independent shRNAs to L1CAM or a control shRNA were transfected into a brain metastatic derivative (231-BR) of human MDA-MB-231 breast carcinoma cells. Brain metastases were quantified one month after intracardiac injection. Results: Patient characteristics: mean age at diagnosis of brain metastases: 48 years (range 29-68 years); 10 HER2+(3+)/ER- (43.5%), 1 HER2(2+)/ER- (4.4%), 2 HER2(2+)/ER+ (8.7%), 3 HER2-/ER+ (13%), 2 HER2(...