Biological characterization of a novel and potent gonadotropin releasing hormone （GnRH） antagonist LXT-101

AIM The biological characterization of LXT-101 was investigated in vivo using intact male rats and nude mice bearing xenografts of LNCaP prostate cancer. The effect of LXT-101 on the proliferation of androgen -sensitive prostate cancer cell LNCaP and androgen-insensitive DU145 and PC-3M in vitro was also determined. METHODS Rats were injected subcutaneously with LXT-101 while control animals received only vehicle (5% mannitol). Blood samples were collected at different time after adminis-tration of LXT-101. The androgen-dependent LNCaP prostate cancer cells were grown, mixed with Matrigel and injected subcutaneously into nude mice. Experimental group received LXT-101 injectionfor up to 4 weeks. At the end point, blood samples were drawn and the excised tumors and sex organswere weighted. The serum testosterone was determined by specific immunochemiluminescence assay using kits produced by Beckman-Counter Co. The mRNA expressions of the genes of hormone receptor related to the gonadal axis were investigated by real-time RT-PCR technique. Cell viability was determined by MTT method.