RT Journal Article T1 The inhibition of steroid hormones determines the fate of IPC-366 tumor cells, highlighting the crucial role of androgen production in tumor processes A1 Crespo, Belen A1 Cáceres Ramos, Sara Cristina A1 Silván Granado, Gema A1 Illera Del Portal, Josefina María A1 Illera Del Portal, Juan Carlos AB Inflammatory mammary cancer (IMC) is a disease that affects female dogs. It is characterized by poor treatment options and no efficient targets. However, anti-androgenic and anti-estrogenic therapies could be effectivebecause IMC has a great endocrine influence, affecting tumor progression. IPC-366 is a triple negative IMC cell line that has been postulated as a useful model to study this disease. Therefore, the aim of this study was toinhibit steroid hormones production at different points of the steroid pathway in order to determine its effect in cell viability and migration in vitro and tumor growth in vivo. For this purpose, Dutasteride (anti-5αReductase),Anastrozole (anti-aromatase) and ASP9521 (anti-17βHSD) and their combinations have been used. Results revealed that this cell line is positive to estrogen receptor β (ERβ) and androgen receptor (AR) and endocrinetherapies reduce cell viability. Our results enforced the hypothesis that estrogens promote cell viability and migration in vitro due to the function of E1SO4 as an estrogen reservoir for E2 production that promotes the IMCcells proliferation. Also, an increase in androgen secretion was associated with a reduction in cell viability.Finally, in vivo assays showed large tumor reduction. Hormone assays determined that high estrogen levels and the reduction of androgen levels promote tumor growth in Balb/SCID IMC mice. In conclusion, estrogen levels reduction may be associated with a good prognosis. Also, activation of AR by increasing androgen production could result in effective therapy for IMC because their anti-proliferative effect. PB Elsevier SN 0034-5288 YR 2023 FD 2023-06-01 LK https://hdl.handle.net/20.500.14352/96857 UL https://hdl.handle.net/20.500.14352/96857 LA eng NO Crespo, B., Caceres, S., Silvan, G., Illera, M. J., & Illera, J. C. (2023). The inhibition of steroid hormones determines the fate of IPC-366 tumor cells, highlighting the crucial role of androgen production in tumor processes. Research in veterinary science, 161, 1–14. https://doi.org/10.1016/j.rvsc.2023.05.014 NO CRediT authorship contribution statementBelen Crespo: Conceptualization, Methodology, Writing – original draft, Writing – review & editing. Sara Caceres: Conceptualization, Methodology, Writing – original draft, Writing – review & editing. Gema Silvan: Methodology, Writing – review & editing. Maria Jose Illera: Methodology, Writing – review & editing. J.C. Illera: Conceptualization, Methodology, Writing – original draft, Writing – review & editing. NO Ministerio de Ciencia, Inovacion y Universidades NO Instituto de Salud Carlos III DS Docta Complutense RD 31 ago 2024