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Ajeawung N.F.,Pediatrics Research Unit | Maltais R.,Endocrinology and Genomic Unit | Jones C.,Molecular Therapeutics | Poirier D.,Endocrinology and Genomic Unit | And 2 more authors.
Cancer Letters | Year: 2013

Pediatric low grade gliomas are the most common central nervous system tumors and are still incurable among a subset of patients despite current treatment modalities. Steroid biosynthesis occurs in a wide variety of organs including the brain, to mediate an assortment of functions, including a proposed role in the growth of gliomas. Hence, targeting steroid biosynthesis and/or their signaling pathways, is anticipated as an effective approach for treating gliomas. In this study, we investigated whether our chemical library of steroid inhibitors can modulate the growth of pediatric low grade glioma cell lines (Res186, Res259, R286), and subsequently identified a potent inhibitor of 17β-hydroxysteroid dehydrogenase type 3, referred to as DK16, which functions by attenuating cell viability, proliferation, migration/invasion and anchorage independent growth and conversely induces apoptosis and cell cycle arrest in a dose and duration dependent manner. Further investigations into the mechanisms of how DK16 functions showed that this drug increased the BAX/BCL2 expression ratio, induced phosphatidylserine externalization, and mitochondrial membrane depolarizations culminating to the release and nuclear translocation of AIF. In addition, treatments of low grade glioma cell lines with DK16 increased the expression of pro-apoptotic mediators including CDK2 and CTSL1, and with the converse diminished expression of pro-survival and migratory/invasion genes like PRKCA, TERT, MAPK8, MMP1 and MMP2. Our findings collectively demonstrate the potent anti-neoplastic properties of DK16, a steroid biosynthesis inhibitor, on the growth of pediatric low grade gliomas. © 2012 Elsevier Ireland Ltd.

Maltais R.,Endocrinology and Genomic Unit | Fournier M.-A.,Endocrinology and Genomic Unit | Poirier D.,Endocrinology and Genomic Unit | Poirier D.,Laval University
Bioorganic and Medicinal Chemistry | Year: 2011

17Beta-hydroxysteroid dehydrogenase type 3 (17β-HSD3) is a steroidogenic enzyme that catalyzes the transformation of 4-androstene-3,17- dione (Δ4-dione) into androgen testosterone (T). To provide effective inhibitors of androgen biosynthesis, we synthesized two different series (amines and carbamates) of 3β-substituted-androsterone derivatives and we tested their inhibitory activity on 17β-HSD3. From the results of our structure-activity relationship study, we identified a series of compounds producing a strong inhibition of 17β-HSD3 overexpressed in HEK-293 cells (homogenized cells). The most active compound when tested in intact HEK-293 transfected cells, namely (3α,5α)-3-{[trans-2,5-dimethyl-4-{[2- (trifluoromethyl)phenyl] sulfonyl}piperazin-1-yl]methyl}-3-hydroxyandrostan-17- one (15b), shows an IC50 value of 6 nM, this compound is thus eight times more active than our reference compound D-5-2 (IC50 = 51 nM). This new improved inhibitor did not stimulate the proliferation of androgen-sensitive Shionogi cells, suggesting a non-androgenic profile. Compound 15b is thus a good candidate for further in vivo studies on rodents. © 2011 Elsevier Ltd. All rights reserved.

Roy J.,Endocrinology and Genomic Unit | Roy J.,Laval University | Maltais R.,Endocrinology and Genomic Unit | Maltais R.,Laval University | And 4 more authors.
Molecular Diversity | Year: 2011

Libraries of steroid derivatives with two levels of molecular diversity were prepared to optimize the antiproliferative activity on leukemia HL-60 cells by first varying the amino acid (AA) at R1 (libraries A, B, C, and D: with 45, 45, 20, and 20 members, respectively) and, subsequently, the capping group at R2 (library E: 168 members). The screening of these aminosteroids revealed interesting structure-activity relationships. In library A, the compounds bearing a tetrahydroisoquinolone residue as the first element of diversity showed potent cytotoxicity, principally when isovaleric or cyclohexyl acetic acid was used as a capping group (>40% of cell growth inhibition at 1 μM).In library B,the phenylalanine (Phe) derivatives bearing a cyano group induced a higher growth inhibition than the other Phe derivatives. The screening of library C indicated the increase of hydrophobicity of proline (Pro) seems to preserve the cytotoxic effect achieved by the lead compound. However, the synthesis of structural Pro variants (library D) clearly shows weaker activities when compared to L-Pro building blocks. Finally, by incorporating some of the most active AA of libraries A-D in library E, we observed that the amide coupling functionality gave stronger cytotoxic activity compared to the corresponding sulfonamides or benzylamines. Six of the most active amide derivatives (E-37P, E-41P, E-42P, E-46P, E-48F, and E-12T) were selected and IC50 determined on HL-60 cells as well as on normal human lymphocytes. Among this series of new anticancer agents, good to high selectivity indices (SI =IC50 (lymphocytes)/IC50 (HL-60 cells)=5-55) were obtained. © Springer Science+Business Media B.V. 2010.

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