Differential expression of spexin hormone 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 spexin hormone, SPX, when comparing primary tumors of the breast to the tissue of origin, the normal breast. SPX 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 SPX in primary tumors of the breast was correlated with distant metastasis-free survival in patients with basal-like subtype cancer, demonstrating a relationship between primary tumor expression of a differentially expressed gene and patient survival outcomes influenced by PAM50 molecular subtype. SPX may be of relevance to initiation, maintenance or progression of cancers of the female breast.