<p>Dihydrotestosterone Induces Proliferation, Migration, and Invasion of Human Glioblastoma Cell Lines</p>

Abstract

Introduction Glioblastomas (GBM) are the most frequent and aggressive human brain tumors due to their high capacity to migrate, invade healthy brain tissue, and resist anticancer therapies. It has been reported that testosterone (T) levels are higher in patients with GBM than in healthy controls. It has also been dem{}onstrated that T induces proliferation, migration, and invasion of human GBM cell lines. T is mainly metabolized to 5α-dihydrotestosterone (DHT) by the enzyme 5α-reductase (5αR), but the role of this metabolite in GBM cells is unknown. Methods The expression of 5αR isoenzymes and AR in biopsies of GBMs was determined by the analysis of TCGA. U87 and U251 GBM cell lines were grown in supplemented DMEM. For evaluating the expression of AR in U251 and U87 cells, a RT-qPCR was performed. The cells were treated with T, DHT, finasteride (FIN), dutasteride (D), and the combined treatments, FIN+T and D+T or vehicle. After treatments, the viability was quantified by the trypan blue exclusion assay, the proliferation was evaluated by BrdU incorporation, and migration and invasion were analyzed by the scratch-wound and the transwell assays, respectively. Results In a set of glioma biopsies from TCGA, we observed that SRD5A2 (5αR2) expression was higher in GBM and in low-grade gliomas than in normal brain tissue. We observed that DHT and T increased proliferation, migration, and invasion of human GBM cell lines: U87 and U251. F and D, drugs that inhibit 5αR activity, blocked the effects of T on GBM cells. Discussion These data suggest that T induces human GBM progression through its conversion into DHT. These results can be related to the chemical structure of DHT, which increases its affinity for AR and decreases five times the rate of dissociation compared to T. Also, it is possible that DHT mediates the effects of T on cell human GBM cells motility by changing the expression of genes involved in tumor infiltration.

Insights into the role of estrogens and androgens in glial tumorigenesis

“…recently showed that DHT had an independent and stronger effect than testosterone toward enhancing cell growth, proliferation, migration, and invasion in U87 and U251 cells in vitro . [ 30 ] These results were also confirmed by Orozco et al . wherein it was shown that DHT (not androstenedione) could independently increase cell viability, proliferation, and invasion in human U87 GBM cells in vitro in a more potent fashion than testosterone.…”

“…Apart from this, AR expression has been confirmed in various glioma cell lines (A172, LN18, LN229, M059, T98G, U87, U118MG, U138MG, and U251MG). [ 22 25 26 27 28 29 30 ]…”

“…also analyzed RNA-sequencing (RNA Seq) data retrieved from the TCGA database and found that one of the enzymes responsible for metabolizing testosterone to DHT (SRD5A2 or 5 alpha reductase 2) was upregulated in low grade glioma and GBM compared to normal brain tissue. [ 30 ] Regarding testosterone, an initial study had shown that exposure of human A172 GBM cell line to testosterone decreased cell viability at higher concentrations, but had no effect at lower concentrations. [ 32 ] In contrast, another study showed that testosterone increased proliferation, cell migration, and invasion at 100nM (not at 1nM or 1000nM) in three human GBM cell lines (D54, U87, U251) in vitro .…”

Astrocytoma: A Hormone-Sensitive Tumor?

“…Bunevicius and colleagues [84] suggested a greater prenatal testosterone and lower prenatal estrogen exposure in brain tumor patients [84,85]. Moreover, testosterone (100 nM) and DHT (10 nM) exposed U87, U251 and D54 GBM cells displayed enhanced proliferation, migration and invasion [86,87]. In rats xenografted with GBM, experimental castration reduced the incidence of tumor development and increased the time between implantation and death [88].…”

Impact of sex in the prevalence and progression of glioblastomas: the role of gonadal steroid hormones

“…In this study, the TCGA Data Analysis of mRNA expression of AR, 5αR1, and 5αR2 from 196 grade II, 223 grade III, and 139 grades IV were compared with 249 healthy brain cortex samples. This analysis showed that AR and 5αR2 expression was higher in all astrocytomas than the healthy brain; however, no statistically significant differences were observed between astrocytoma grades [ 110 ]. Werner and cols determined that AR expression at the transcript and protein levels in LN18, T98G glioblastoma cell lines, patient-derived xenografts (PDX), and human tumors overlapped with the expression of this receptor in primary prostate cancer.…”