Relationship Between Cysteinyl-Leukotriene-1 Receptor and Human Transitional Cell Carcinoma in Bladder

ObjectivesTo investigate the leukotriene (LT) D4 (LTD4) receptor (cysteinyl-LT1 receptor [CysLT1R]) expression in transitional cell carcinoma (TCC) of the bladder, as well as the effects of the CysLT1R antagonist on cell proliferation in TCC cell lines. The metabolism of arachidonic acid by either cyclooxygenase or lipoxygenase is thought to play an important role in carcinogenesis. LTD4 is a pro-inflammatory mediator derived from arachidonic acid through various enzymatic steps, and 5-lipoxygenase is an important factor in generating LTD4.MethodsCysLT1R expression in TCC tissue and normal bladder tissue was examined. CysLT1R expression was detected using immunohistochemistry. The effects of the CysLT1R antagonist on TCC cell growth were examined by 3-(4,5-dimethylthiazol-2-thiazolyl)-2,5-diphenyltetrazolium bromide assay and reverse transcriptase-polymerase chain reaction. Flow cytometry was used to determine whether the CysLT1R antagonist induced apoptosis.ResultsInitially, only slight CysLT1R expression was detected in normal bladder tissues and marked CysLT1R expression was detected in the TCC tissues. CysLT1R expression was greater in high-grade cancer than in low-grade cancer. Furthermore, CysLT1R expression was also greater in advanced-stage cancer than in early-stage cancer. Finally, the CysLT1R antagonist caused marked inhibition of TCC cells by inducing early apoptosis.ConclusionsCysLT1R was induced in TCC. The results suggest that the CysLT1R antagonist might mediate potent antiproliferative effects on TCC cells. Thus, the target of the CysLT1R is potentially a new therapy in the treatment of TCC.