Differential expression of lamin B1 in triple negative breast cancer.
Women diagnosed with triple negative breast cancer can benefit neither from endocrine therapy nor from HER2-targeted therapies (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding lamin B1, LMNB1, when comparing the tumor cells of patients with triple negative breast cancer to normal mammary ductal cells (2). LMNB1 was also differentially expressed in bulk tumor in human breast cancer (3). LMNB1 mRNA was present at significantly increased quantities in TNBC tumor cells relative to normal mammary ductal cells. Analysis of human survival data revealed that expression of LMNB1 in primary tumors of the breast was correlated with overall survival in patients with basal-like and luminal A subtype cancer, while within triple negative breast cancer, primary tumor expression of LMNB1 was correlated with overall survival in patients with basal-like 2, immunomodulatory and mesenchymal subtype disease. LMNB1 may be of relevance to initiation, maintenance or progression of triple negative breast cancers.