Expression of 5-Lipoxygenase in human colorectal cancer

AIM： To evaluate the 5-lipoxygenases （Loxs） expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis.METHODS： The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase （Cox）-2 proteins was also examined using immunohistochemical staining methods.RESULTS： There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples （P 〈 0.0001）. Sixty six （72.5%） tumors showed high 5-Lox mRNA levels, The positivity rate of 5-Lox and Cox-2 protein expression was 68,7% and 79,1% respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size （Rho = 0.392, P = 0.0002）, depth or vessel invasion.CONCLUSION： These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.