In vitro and in vivo effect of flutamide on steroid hormone secretion in canine and human inflammatory breast cancer cell lines

Abstract

The aim was to study the effects of flutamide on cell proliferation, in vivo tumour growth andsteroid production in canine and human IBC cell lines. IPC-366 and SUM149 cell cultures wereexposed to flutamide concentrations for 72 hours. Additionally, IPC-366 and SUM149 xeno-transplanted mice were treated subcutaneously with flutamide 3 times a week for 2 weeks.Steroid hormones determination in culture media, serum and tumour homogenates (pregneno-lone, progesterone, androstenedione, testosterone, dihydrotestosterone, 17β-oestradiol andoestrone sulphate) were assayed by EIA. in vitro cell proliferation percentages showed adecrease in all flutamide dosages in IPC-366 and SUM149. in vivo flutamide reduced tumoursize by 55% to 65%, and metastasis rates decreased. In treated groups, androgen levels in cul-ture media, serum and tumour homogenates were increased as oestrogen levels decreased. These results suggest that flutamide treatment inhibits cell proliferation and promotes tumourreduction by increasing androgen levels and also support future therapy approaches