We examined the expression of major inflammatory genes,
cyclooxygenase-1 and 2 (COX1, COX2) and
arachidonate 5-lipoxygenase (ALOX5) in 1090
tumor samples of invasive
breast cancer from The
Cancer Genome Atlas (TCGA). Mean
cyclooxygenase expression (COX1 + COX2) ranked in the upper 99th percentile of all 20,531 genes and surprisingly, the mean expression of COX1 was more than tenfold higher than COX2. Highly significant correlations were observed between COX2 with eight
tumor-promoting genes (EGR2,
IL6, RGS2, B3GNT5, SGK1, SLC2A3, SFRP1 and ETS2) and between ALOX5 and ten
tumor promoter genes (CD33, MYOF1, NLRP1, GAB3, CD4, IFR8, CYTH4, BTK, FGR, CD37). Expression of CYP19A1 (
aromatase) was significantly correlated with COX2, but only in
tumors positive for ER, PR and HER2.
Tumor-promoting genes correlated with the expression of COX1, COX2, and ALOX5 are known to effectively increase mitogenesis, mutagenesis, angiogenesis, cell survival, immunosuppression and
metastasis in the pathogenesis of
breast cancer.