Differential expression of solute carrier family 29 member 4 in cancers of the breast.
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 solute carrier family 29 member 4, SLC29A4, when comparing primary tumors of the breast to the tissue of origin, the normal breast. SLC29A4 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 SLC29A4 in primary tumors of the breast was correlated with overall survival in patients with luminal B subtype cancer and in patients with normal-like subtype cancer, demonstrating a relationship between primary tumor expression of a differentially expressed gene and patient survival outcomes influenced by PAM50 molecular subtype. SLC29A4 may be of relevance to initiation, maintenance or progression of cancers of the female breast.