Laboratory of Biochemistry, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal; UCIBIO.REQUIMTE, Laboratory of Biochemistry, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal.
Laboratory of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal; CIEPQPF Centre for Chemical Processes Engineering and Forest Products, University of Coimbra, 3030-790 Coimbra, Portugal.
J Steroid Biochem Mol Biol. 2019 Dec;195:105486. doi: 10.1016/j.jsbmb.2019.105486. Epub 2019 Sep 23.
Estrogen receptor-positive (ER) breast cancers require estrogens for their growth. Aromatase inhibitors (AIs) are considered the first-line therapy for this type of tumours. Despite the well-established clinical benefit of this therapy, the search for novel potent AIs that present higher efficacy and fewer side effects is still demanded. Thus, taking into account the known interactions of the natural substrate, androstenedione, within the aromatase active-site, a range of new steroidal compounds have been designed, synthesized and studied by our group. In this work, it was evaluated in MCF-7aro, an ER breast cancer cell line that overexpress aromatase, the anti-aromatase efficacy and the biological effects of eight new AIs: 6α-methyl-5α-androst-3-en-17-one (1a), 6α-methyl-3α,4α-epoxy-5α-androstan-17-one (3a), 6α-methylandrost-4-ene-3,17-dione (9), 6α-allylandrosta-1,4-diene-3,17-dione (13), 6α-allylandrost-4-ene-3,17-dione (15), 6α-allylandrost-4-en-17-one (17), 6β-hydroxyandrost-4-ene-3,17-dione (19) and 6α-hydroxyandrost-4-ene-3,17-dione (20). Their anti-cancer properties were elucidated, as well as, the dependence of their mechanism of action on aromatase inhibition and/or on steroid receptors modulation, such as estrogen and androgen receptors, which are key targets for this type of cancer. Results demonstrate that the studied AIs present high anti-aromatase activity, disrupt MCF-7aro cell cycle progression and induce apoptosis, through the mitochondrial pathway. Compounds 1a, 3a, 9, 13, 15 and 17 exhibited an aromatase-dependent effect on cells and, interestingly, steroids 9 and 13 displayed the ability to decrease aromatase protein levels without affecting CYP19A1 mRNA levels. Furthermore, the effects of compounds 1a, 3a and 15 were dependent on ER and on AR modulation, whereas compounds 9 and 19 were only dependent on AR modulation. From a clinical point of view, these actions can be considered as a therapeutic advantage for this type of tumours. Thus, new promising AIs that impair ER breast cancer cell growth, by acting on aromatase, and even, on ER and AR were discovered. Furthermore, new insights on the most favourable structural modifications in the steroidal core structure were provided, helping to a more rational drug design of new and potent AIs.
雌激素受体阳性（ER）乳腺癌的生长需要雌激素。芳香酶抑制剂（AIs）被认为是此类肿瘤的一线治疗药物。尽管这种治疗方法具有良好的临床疗效，但仍需要寻找具有更高疗效和更少副作用的新型强效 AI。因此，考虑到天然底物雄烯二酮在芳香酶活性部位的已知相互作用，我们小组设计、合成并研究了一系列新的甾体化合物。在这项工作中，评估了 MCF-7aro，一种过表达芳香酶的 ER 乳腺癌细胞系，对八种新型 AI 的抗芳香酶功效和生物学效应：6α-甲基-5α-雄甾-3-烯-17-酮（1a）、6α-甲基-3α,4α-环氧-5α-雄甾烷-17-酮（3a）、6α-甲基雄甾-4-烯-3,17-二酮（9）、6α-丙烯基雄甾-1,4-二烯-3,17-二酮（13）、6α-丙烯基雄甾-4-烯-3,17-二酮（15）、6α-丙烯基雄甾-4-烯-17-酮（17）、6β-羟基雄甾-4-烯-3,17-二酮（19）和 6α-羟基雄甾-4-烯-3,17-二酮（20）。阐明了它们的抗癌特性，以及它们的作用机制对芳香酶抑制和/或甾体受体调节的依赖性，如雌激素和雄激素受体，这是此类癌症的关键靶点。结果表明，所研究的 AIs 具有很高的抗芳香酶活性，通过线粒体途径破坏 MCF-7aro 细胞周期进展并诱导细胞凋亡。化合物 1a、3a、9、13、15 和 17 对细胞表现出芳香酶依赖性作用，有趣的是，甾体化合物 9 和 13 具有降低芳香酶蛋白水平而不影响 CYP19A1 mRNA 水平的能力。此外，化合物 1a、3a 和 15 的作用取决于 ER 和 AR 的调节，而化合物 9 和 19 仅取决于 AR 的调节。从临床角度来看，这些作用可被视为此类肿瘤的治疗优势。因此，发现了通过作用于芳香酶甚至 ER 和 AR 来损害 ER 乳腺癌细胞生长的新型有前途的 AI。此外，还提供了甾体核心结构中最有利的结构修饰的新见解，有助于设计新型强效 AI。
