CEDIE   05498
CENTRO DE INVESTIGACIONES ENDOCRINOLOGICAS "DR. CESAR BERGADA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
20-Hydroxyeicosatetraenoic Acid (20-HETE) Promotes Cell Viability in Androgen Responsive Prostate Cancer Cells
Autor/es:
COLOMBERO C; NOWICKI S; PAPADEMETRIO D; ALVAREZ E
Lugar:
Boston
Reunión:
Congreso; ENDO 2016: Endocrine Society, 100 years of hormone science to health; 2016
Institución organizadora:
The Endocrine Society
Resumen:
20-HETE is an intracellular signaling molecule generated by 20-hidroxylation of arachidonic acid through the Cytochrome P450 complex (CYP), mainly by CYP4A11 and CYP4F2. Recently, the expression of these isoforms has been shown to be higher in different tumors. The growth and function of prostate cancer is mainly under the control of androgenic stimulation, particularly in the early stages of the disease. Interestingly, urinary excretion of 20-HETE was found to be increased in patients with benign prostatic hyperplasia and prostate cancer. Yet, little is known as whether 20-HETE has a role in this neoplasia.  The aim of this study was to assess if 20-HETE affects the viability of prostate cancer cells. Two cancer cell lines were used, LNCaP (androgen sensitive) and PC-3 (androgen insensitive). They were grown in whole media (WM) or steroid stripped media (SSM), so that in the latter the only steroid present came from supplementing with dihydrotestosterone (DHT). Cells were daily treated with either 20-HETE or HET0016 (a specific inhibitor of 20-HETE synthesis). Cell viability was assessed by the MTT assay, and apoptosis by the TUNEL assay and Western Blot.  Treatment of LNCaP cells in WM with HET0016 (5 days) reduced cell viability in a dose-dependent manner (% of Control (C): C, 100±3; 0.1 uM 36±5*; 1uM, 30±3*; 10uM, 14±2*). This effect was in part mediated by an increase in apoptosis (TUNEL + cells:  C, 2.2±0.2%; 10uM, 26±5%*). Also, it was sustained by a diminished proliferation rate after 48 h (C, 46±3%; 10uM, 25±4%*). Contrarily, PC-3 cell viability was not affected by incubation with HET0016, 1 to 10uM up to 5 days.  In SSM, DHT (0.1nM, 5 days) significantly increased LNCaP cell viability; this response was inhibited by HET0016, with a maximum inhibition at 10uM (% of C; C, 100±4; DHT, 266±13*; HET0016 10uM 100±7, DHT+HET0016 10uM, 152±11#). TUNEL + cells remained at low values with DHT, yet addition of HET0016 increased apoptotic index (C, 23±4%; DHT, 3.5±0.9%*; HET0016 18±3%; DHT+HET0016, 13±3%#). Also in SSM, 20-HETE (5 days) increased cell viability reaching the highest effect at 50nM (% of C: C, 100±5; 20-HETE 50nM, 150±6*), and reduced TUNEL + cells (C, 22±8%; 20-HETE 50nM, 9±2%*). Also, the end point marker of apoptosis, PARP cleavage, was diminished by 20-HETE in SSM and it was markedly increased by HET0016 in WM.  On the contrary, in SSM PC-3 cell viability was not altered through a wide range of concentrations of 20-HETE for up to 5 days; accordingly, PC-3 cell viability was not affected by incubation with DHT and/or HET0016.  Our results show that 20-HETE production is key to sustain cell viability in an androgen-sensitive prostate cancer cell line, being the prevention of apoptosis one of the mechanisms involved. These findings support the role of 20-HETE as a mediator molecule in androgen-driven prostate cancer survival.  Statistically significant differences: * p≤0.05 vs. C; # p≤0.05 vs. DHT  Nothing to Disclose: CC, DP, EA, SN