Expression of cysteinylLT1 receptor in human testicular cancer and growth reduction by its antagonist through apoptosis.

The metabolism of arachidonic acid by either cyclooxygenase or lipoxygenase is believed to play an important role in carcinogenesis. Leukotriene (LT) D4 is a pro-inflammatory mediator derived from arachidonic acid through various enzymatic steps, and 5-lipoxygenase is an important factor in generating LTD4. We investigated LTD4 receptor (cysteinylLT1 receptor; CysLT1R) expression in testicular cancer (TC), as well as the effects of the CysLT1R antagonist on cell proliferation in a TC cell line. CysLT1R expression in tissue from TC patients and normal testes (NTs) was detected using immunohistochemistry and RT-PCR. The effects of the CysLT1R antagonist on TC cell growth were examined using the MTT assay. Flow cytometry was used to determine whether or not the CysLT1R antagonist induces apoptosis. Immunohistochemistry indicated that CysLT1R expression was strong in all types of TC tissues, but very weak in NT tissues. The TC cell line expressed CysLT1R mRNA as detected by RT-PCR. MTT and flow cytometry revealed that the CysLT1R antagonist caused marked inhibition of TC cells through early apoptosis. In conclusion, CysLT1R was induced in TC. The results suggest that the CysLT1R antagonist may mediate potent anti-proliferative effects against TC cells. Thus, CysLT1R may become a new therapeutic target for the treatment of TC.