Role of 20-Hydroxyeicosatetraenoic Acid (20-HETE) in Androgen-Mediated Cell Viability in Prostate Cancer Cells

Abstract

20-Hydroxyeicosatetraenoic acid (20-HETE) is generated intracellularly through the ω-hydroxylation of arachidonic acid by the cytochrome P450 (in humans, CYP4A11 and CYP4F2). 20-HETE induces mitogenic responses in different cancer cells. The aim of this study was to analyze how 20-HETE impacts cell survival, proliferation, and apoptosis in prostate cancer cells. Incubation of the human androgen-sensitive cells (LNCaP) with 1-10 μM HET0016 (a selective inhibitor of 20-HETE synthesis) reduced cell viability by 49*-64%* (*p < 0.05 vs. control). This was explained by a reduction in cell proliferation (vehicle, 46 ± 3%; 1 μM, 23 ± 3%*; 10 μM, 28 ± 3%*) and by an increase in apoptosis (vehicle, 2.1 ± 0%; 1 μM, 16 ± 4%*; 10 μM, 31 ± 3%*). Furthermore, the increase in LNCaP cell viability induced by dihydrotestosterone (DHT, 0.1 nM) was abrogated by 30*-42%* by 1-10 μM HET0016. Incubation with 20-HETE (5-1000 nM) increased LNCaP cell viability up to 50%*, together with a 70%* reduction in apoptosis. PC-3 (androgen-insensitive) cell viability was not affected by either HET0016 or 20-HETE. In LNCaP cells, HET0016 (10 μM) diminished the expression of androgen receptors (AR): messenger RNA (mRNA) (40%*) and protein (50%*). DHT (10 nM) augmented CYP4F2 protein expression (1.9-fold*) and 20-HETE levels (50%*). Oppositely, enzalutamide (AR antagonist) reduced CYP4F2 mRNA and protein expressions by 30 and 25%, respectively. Thus, intracellular availability of 20-HETE is necessary to sustain LNCaP cell viability. 20-HETE may act as a signaling molecule in the pathways involved in LNCaP cell viability upon stimulation of the AR. This effect may be partially attributed to its role on securing normal AR expression levels that in turn contribute to maintain intracellular levels of 20-HETE.

GPR75 receptor mediates 20-HETE-signaling and metastatic features of androgen-insensitive prostate cancer cells

“…Our laboratory has reported that 20-HETE production is key to sustain cell viability in an androgen sensitive prostate cancer cell line, primarily by prevention of apoptosis. These findings support a role for 20-HETE as a mediator in androgen driven prostate cancer cell survival [13]. Although prostate cancer tumor growth is initially dependent on androgens as documented by Huggins as early as 1941 [14], many patients eventually develop an androgen-insensitive more aggressive phenotype of prostate cancer, termed castrationresistant prostate cancer (CRPC).…”

“…Cells were harvested in lysis buffer (Tris, 10 mM; NaCl, 150 mM; Triton X-100® 1%; EDTA, 1 mM; EGTA, 1 mM; Na 4 P 2 O 7 •10H 2 O, 10 mM; Na 3 VO 4 , 10 mM; and NaF, 100 mM) supplemented with a mix of protease inhibitors (cOmplete™ Mini EDTA-free, Roche Diagnostics, Mannheim Germany). Whole cell extracts for western blotting were prepared as described previously [13]. For subcellular fractionation, cell lysates were first centrifuged at 4°C for 7 min at 3100 xg.…”

“…Protein separation and blotting were performed as previously described [13]. Briefly, equal amounts of protein were separated by denaturing SDS-PAGE and transferred to polyvinylidene fluoride (PVDF) microporous membranes (Millipore, Boston, MA).…”

CYP4F2 and CYP3A5 gene polymorphisms and lung cancer in Chinese Han population

“…This is similar to the conclusion of the present study. In addition, many studies have confirmed that CYP4F2 was closely related to the metabolism of 20-hydroxyethyl hexadecanoic acid (20-HETE) [ 17 – 19 ]. In the past decade, 20-HETE has been recognized as a key conditioning agent of cancer progression, which can induce cell proliferation in vitro by stimulating the formation of reactive oxygen species and the production of vascular endothelial growth factor.…”

CYP4F2 And CYP3A5 Gene Polymorphisms And Lung Cancer In Chinese Han Population

“…This is similar to the conclusion of the present study. In addition, many studies have con rmed that CYP4F2 was closely related to the metabolism of 20hydroxyethylhexadecanoic acid (20-HETE) (Stec, Roman et al 2007, Colombero, Papademetrio et al 2017. In the past decade, 20-HETE has been recognized as a key conditioning agent of cancer progression, which can induce cell proliferation in vitro by stimulating the formation of reactive oxygen species and the production of vascular endothelial growth factor.…”