Endocrine disruptors are exogenous chemicals that their endocrine disrupting effects mediated by androgenic signaling plays crucial roles in the control of development and several androgen-related diseases. However, there are no authorized in vitro screening and testing methods to evaluation of (anti-)androgenic activity. To find out a better in vitro cell line model, we have previously reported that 22Rv1 cells, a human prostate cancer cells contained functional Androgen Receptor (AR), might be an appropriate model for the evaluation of (anti-)androgenic endocrine disruptors. Based on this result, we developed a stable 22Rv1/mouse mammary tumor virus (MMTV) cell line to test AR-mediated transcriptional activation (TA). Using 22Rv1/MMTV cells, we established the test protocol and optimized the testing condition for AR-TA assay. In this study, we performed the inter-validation assay by four different laboratories to evaluate the 20 coded chemicals which were selected from the ICCVAM list (ICCVAM, 2003) or academic articles that exhibited exact (anti-) androgenic activity. The statistical analysis of the results of the inter-laboratory validation study revealed that there was reproducibility between the four participating laboratories. In conclusion, 22Rv1/MMTV AR-TA assay might be a quick and relatively inexpensive method, which can be used to screen large numbers of chemicals for their potential to activate or inhibit AR-mediated gene transcription. Furthermore, it will provide mechanistic data relevant to understanding adverse reactions observed in intact organisms.

• Hee-Seok Lee(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Eun-Jung Park(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Songyi Han(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Gyeong-Yong Oh(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Min-Hee Kim(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Kwang-Soo Lee(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Myung-Sil Hwang(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• Guiim Moon(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)
• In-Gyun Hwang(Food Safety Risk Assessment Division, National Institute of Food and Drug Safety Evaluation)