Breast cancer affects women at relatively high frequency (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 sodium voltage-gated channel beta subunit 4, SCN4B, when comparing primary tumors of the breast to the tissue of origin, the normal breast. SCN4B was also differentially expressed in the tumor cells of patients with triple negative breast cancer. SCN4B mRNA was present at significantly lower quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of SCN4B in primary tumors of the breast was correlated with overall survival in patients with basal and luminal A subtype cancers but in a contrary manner, demonstrating a complex relationship between primary tumor expression of a differentially expressed gene and patient survival outcomes influenced by molecular subtype. SCN4B may be of relevance to initiation, maintenance or progression of cancers of the female breast.
Differential expression of the sodium voltage-gated channel beta subunit 4 in cancers of the breast.
