Knock-out of 5-lipoxygenase in overexpressing tumor cells – consequences on gene expression and cellular function

In healthy human beings expression of 5-lipoxygenase (5-LO), the central enzyme in the biosynthesis of leukotrienes (LT) and 5-oxo-ETE, is restricted to leukocytes where 5-LO-derived lipid mediators shape the immune response upon an acute inflammation. Even though solid tissues do not express 5-LO under physiological conditions, 5-LO expression has been frequently found in many solid malignancies. There is still little knowledge on the functional consequences of 5-LO overexpression in solid tumor cells. We established a complete knock-out (KO) of 5-LO in HCT-116 and HT-29 colon cancer cells as well as the osteosarcoma cell line U2OS using the CRISPR/Cas technology. Consequences on global gene expression in the three cell lines were studied employing next generation sequencing followed by pathway enrichment analysis and expression of the differentially expressed genes was verified using qPCR. mRNA profiling of wildtype (WT) HCT-116, HT-29 and U2OS cells as well as several 5-Lipoxygenase knockout cell clones (5-LO KO) derived from these cell lines and the corresponding vector controls (VC). Knockout of 5-Lipoxygenase was established using CRISPRCas technology. Three independent replicates from each cell line were measured.