Postnatal exposure to flutamide affects CDH1 and CTNNB1 gene expression in adult pig epididymis and prostate and alters metabolism of testosterone

In both epididymis and prostate the dynamic cross-talk between the cells is hormonally regulated and, in part, through direct cell-to-cell interactions. Functionality of the male reproductive organs may be affected by exposure to specific chemicals, so-called reprotoxicants'. In this study we tested whether early postnatal and prepubertal exposure to anti-androgen flutamide altered the expression of adherens junction genes encoding E-cadherin (CDH1) and -catenin (CTNNB1) in adult pig epididymis and prostate. In addition, the expression of mRNAs and proteins for 5-reductase (ST5AR2) and aromatase (CYP19A1) were examined to show whether flutamide alters metabolism of testosterone. Thus, flutamide was injected into male piglets between Days 2 and 10 and between Days 90 and 98 postnatally (PD2 and PD90; 50mg/kg bw), tissues that were obtained on postnatal Day 270. To assess the expression of the genes and proteins, real-time RT-PCR and Western blot were performed respectively. Moreover, adherens junction proteins were localized by immunohistochemistry. In response to flutamide, CDH1 and CTNNB1 expressions were down-regulated along the epididymis, mostly in PD2 group (p<0.001, p<0.01). In the prostate, CDH1 mRNA and protein expressions were significantly down-regulated (p<0.01), whereas CTNNB1 mRNA was slightly up-regulated in both flutamide-treated groups. CTNNB1 protein level was markedly elevated in both PD2 (p<0.001) and PD90 (p<0.01) groups. In the epididymis, the expression of ST5AR2 and CYP19A1 was down- and up-regulated, respectively (p<0.05), whereas in the prostate evident decrease in CYP19A1 expression (p<0.001, p<0.01, p<0.05) was demonstrated. In both tissues, membranous immunolocalization of CTNNB1 suggests its involvement in cell-cell adhesion. Overall, flutamide administration resulted in suppression of androgen action in the epididymis and prostate leading to deregulation of CDH1 and CTNNB1 gene expressions which is probably caused by the alterations in the expression of ST5AR2 and CYP19A1 in both reproductive organs.