Synthesis of hydrocortisone esters targeting androgen and glucocorticoid receptors in prostate cancer in vitro.

Androgen and glucocorticoid receptors have been recently described as key players in processes related to prostate cancer and mainly androgen receptor's inactivation was shown as an effective way for the prostate cancer treatment. Unfortunately, androgen deprivation therapy usually loses its effectivity and the disease frequently progresses into castration-resistant prostate cancer with poor prognosis. The role of the glucocorticoid receptor is associated with the mechanism of resistance; therefore, pharmacological targeting of glucocorticoid receptor in combination with antiandrogen treatment was shown as an alternative approach in the prostate cancer treatment. We introduce here the synthesis of novel 17α- and/or 21-ester or carbamate derivatives of hydrocortisone and evaluation of their biological activity towards androgen and glucocorticoid receptors in different prostate cancer cell lines. A 17α-butyryloxy-21-(alkyl)carbamoyloxy derivative 14 was found to diminish the transcriptional activity of both receptors (in single-digit micromolar range), with comparable potency to enzalutamide towards the androgen receptor, but weaker potency compared to mifepristone towards the glucocorticoid receptor. Lead compound inhibited proliferation and the formation of cell colonies in both androgen and glucocortiocid receptors-positive prostate cancer cell lines in low micromolar concentrations. Candidate compound 14 showed to interact with both receptors in cells and inhibited the translocation of receptors to nucleus and their activation phoshorylation. Moreover, binding to receptor's ligand binding domains was assessed by molecular modelling. Lead compound also induced the accumulation of cells in G1 phase and its combination with enzalutamide was shown to be more effective than enzalutamide alone.

A-ring-fused pyrazoles of dihydrotestosterone targeting prostate cancer cells via the downregulation of the androgen receptor.

High expression of the androgen receptor (AR) and the disruption of its regulation are strongly responsible for the development of prostate cancer (PCa). Therapeutically relevant non-steroidal or steroidal antiandrogens are able to block the AR effect by eliminating AR-mediated signalling. Herein we report the synthesis of novel steroidal pyrazoles derived from the natural sex hormone 5α-dihydrotestosterone (DHT). 2-Ethylidene or 2-(hetero)arylidene derivatives of DHT obtained by regioselective Claisen-Schmidt condensation with acetaldehyde or (hetero)aromatic aldehydes in alkaline ethanol were reacted with monosubstituted hydrazines to give A-ring-fused 1,5-disubstituted pyrazoles as main or exclusive products, depending on the reaction conditions applied. Spontaneous or 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ)-induced oxidation of the primarily formed pyrazolines resulted in the desired products in moderate to good yields, while 17-oxidation also occurred by using the Jones reagent as a strong oxidant. Transcriptional activity of the AR in a reporter cell line was examined for all novel compounds, and several previously synthesized similar DHT-based pyrazoles with differently substituted heteroring were also included to obtain information about the structure-activity relationship. Two specific regioisomeric groups of derivatives significantly diminished the transcriptional activity of the AR in reporter cell line in 10 µM concentration, and displayed reasonable antiproliferative activity in AR-positive PCa cell lines. Lead compound (3d) was found to be a potent AR antagonist (IC50 = 1.18 µM), it generally suppressed AR signalling in time and dose dependent manner, moreover, it also led to a sharp decrease in wt-AR protein level probably caused by proteasomal degradation. We confirmed the antiproliferative activity of 3d in AR-positive PCa cell lines (with GI50 in low micromolar ranges), and its cellular, biochemical and in silico binding in AR ligand-binding domain. Moreover, compound 3d was shown to be potent even ex vivo in patient-derived tissues, which highlights the therapeutic potential of A-ring-fused pyrazoles.

Synthesis and Biological Evaluation of New Isoxazolyl Steroids as Anti-Prostate Cancer Agents.

Steroids with a nitrogen-containing heterocycle in the side chain are known as effective inhibitors of androgen signaling and/or testosterone biosynthesis, thus showing beneficial effects for the treatment of prostate cancer. In this work, a series of 3ß-hydroxy-5-ene steroids, containing an isoxazole fragment in their side chain, was synthesized. The key steps included the preparation of Weinreb amide, its conversion to acetylenic ketones, and the 1,2- or 1,4-addition of hydroxylamine, depending on the solvent used. The biological activity of the obtained compounds was studied in a number of tests, including their effects on 17α-hydroxylase and 17,20-lyase activity of human CYP17A1 and the ability of selected compounds to affect the downstream androgen receptor signaling. Three derivatives diminished the transcriptional activity of androgen receptor and displayed reasonable antiproliferative activity. The candidate compound, 24j (17R)-17-((3-(2-hydroxypropan-2-yl)isoxazol-5-yl)methyl)-androst-5-en-3ß-ol, suppressed the androgen receptor signaling and decreased its protein level in two prostate cancer cell lines, LNCaP and LAPC-4. Interaction of compounds with CYP17A1 and the androgen receptor was confirmed and described by molecular docking.