Aromatase Enzyme Research Articles

Cellulose nanocrystals derived from chicory plant: an un-competitive inhibitor of aromatase in breast cancer cells via PI3K/AKT/mTOP signalling pathway

A significant contributing factor in the development of breast cancer is the estrogens. The synthesis of estrogens is primarily facilitated by aromatase (CYP19), a cytochrome P450 enzyme. Notably, aromatase is expressed at a higher level in human breast cancer tissue compared with the normal breast tissue. Therefore, inhibiting aromatase activity is a potential strategy in hormone receptor-positive breast cancer treatment. In this study, Cellulose Nanocrystals (CNCs) were obtained from Chicory plant waste through a sulfuric acid hydrolysis method with the objective of investigating that whether the obtained CNCs could act as an inhibitor of aromatase enzyme, and prevent the conversion of androgens to estrogens. Structural analysis of CNCs was carried out using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), while morphological results were obtained using AFM, TEM, and FE-SEM. Furthermore, the nano-particles were found to be spherical in shape with a diameter range of 35-37 nm and displayed a reasonable negative surface charge. Stable transfection of MCF-7 cells with CYP19 has demonstrated the ability of CNCs to inhibit aromatase activities and prevent cell growth by interfering with the enzyme activities. Spectroscopic results revealed the binding constant of CYP19-CNCs and (CYP19-Androstenedione)-CNCs complexes to be 2.07 × 103 L/gr and 2.06 × 104 L/gr, respectively. Conductometry and CD data reported different interaction behaviors among CYP19 and CYP19-Androstenedione complexes at the presence of CNCs in the system. Moreover, the addition of CNCs to the solution in a successive manner resulted in the enhancement of the secondary structure of the CYP19-androstenedione complex. Additionally, CNCs showed a marked reduction in the viability of cancer cells compared to normal cells by enhancing the expression of Bax and p53 at protein and mRNA levels, and by decreasing mRNA levels of PI3K, AKT, and mTOP, as well as protein levels of PI3Kg-P110 and P-mTOP, in MCF-7 cells after incubation with CNCs at IC50 concentration. These findings confirm the decrease in proliferation of breast cancer cells associated with induction of apoptosis through down-regulation of the PI3K/AKT/mTOP signaling pathway. According to the provided data, the obtained CNCs are capable of inhibiting aromatase enzyme activity, which has significant implications for the treatment of cancer. Communicated by Ramaswamy H. Sarma

Inhibition of phosphodiesterase PDE8B reduces activation of primordial follicles in mouse ovaries.

In the ovaries, cyclic adenosine 3',5'-monophosphate (cAMP) is a second messenger supporting the generation of steroids. Phosphodiesterases (PDEs) are regulators of intracellular cAMP, and therefore, potential regulators of ovarian function. Interestingly, the family of PDE genes are differentially expressed in human oocytes and granulosa cells from primordial and primary follicles, suggesting diverse roles. In this study, we addressed the functions of PDE3B and PDE8B in primordial follicle regulation using inhibitors of PDE3B and PDE8B in murine ovary primary in vitro cultures. Inhibition of PDE8B in ovarian cultures prevented primordial follicle activation, while inhibition of PDE3B had no effect on follicle distribution in the ovary, under the tested conditions. As cAMP levels may increase steroid levels, we assessed the protein levels of the steroidogenic acute regulatory protein (StAR) and aromatase enzymes, and found that inhibition of PDE3B reduced StAR protein levels, whereas inhibition of PDE8 did not alter StAR expression in our murine ovary culture system conditions. Our results showed that ketotifen-induced inhibition of PDE8B can decrease primordial follicle activation, whereas we observed no effect of follicle distribution, when PDE3B was inhibited. Expression of the StaR enzyme was not altered when PDE8B was inhibited, which might reflect not sufficient inhibition by ketotifen to induce StAR alterations, or redundant mechanisms.

Androgen receptor signaling regulates follicular growth and steroidogenesis in interaction with gonadotropins in the ovary during mini-puberty in mice.

In females, androgens contribute to ovarian diseases such as polycystic ovarian syndrome (PCOS), but their action is also crucial for ovarian physiology, i.e., follicular growth and estradiol (E2) synthesis during reproductive life, in interaction with the gonadotropins LH and FSH. However, it is unclear whether androgens already play a role in the ovary at mini-puberty, a phase of postnatal development with active follicular growth and high E2 levels. Therefore, we analyzed the potential actions of androgens on the ovary and their possible interaction with gonadotropins during this period in mice. We used molecular-based studies and pharmacological approaches in vivo and on cultured ovaries. We found that mini-pubertal ovaries produce significant amounts of testosterone and display androgen receptor (AR) expression in growing follicles, both under the control of LH. By blocking AR signaling either in vivo or in ovarian cultures, we found that this pathway may participate in the regulation of prepubertal E2 synthesis and follicular growth, possibly by regulating the expression of a number of key intra-ovarian regulators, including FSH receptor (Fshr), the aromatase enzyme converting androgens into estrogens (Cyp19a1) and the cell cycle inhibitor p27KIP1 (Cdkn1b). We further showed that AR may stimulate FSH-mediated regulation of Cyp19a1 through its action on Fshr mRNA abundance. Overall, this work supports the idea that AR signaling is already activated in mini-pubertal ovaries to regulate E2 synthesis and follicular growth, at the interplay with LH and FSH signaling. Its early action may, thus, contribute to the implementation of early ovarian function with possible impacts on reproductive function.

Rosetta Stone for Cancer Cure: Comparison of the Anticancer Capacity of Endogenous Estrogens, Synthetic Estrogens and Antiestrogens.

This work presents the history of the recognition of principal regulatory capacities of estrogen hormones having been mistakenly regarded as breast cancer promoting agents for more than 120years. Comprehensive analysis of the results of clinical, epidemiological, immunological and molecular studies justified that endogenous estrogens are the principal regulators of embryonic development, survival and reproduction via orchestrating appropriate expression and even edition of all genes in mammalians. Medical use of chemically modified synthetic estrogens caused toxic complications; thromboembolic events and increased cancer risk in female organs as they proved to be endocrine disruptors deregulating estrogen receptors (ERs) rather than their activators. Synthetic estrogen treatment exhibits ambiguous correlations with cancer risk at different sites, which may be attributed to an inhibition of the unliganded activation of estrogen receptors (ERs) coupled with compensatory liganded activation. The principle of estrogen induced breast cancer led to the introduction of antiestrogen therapies against this tumor; inhibition of the liganded activation of estrogen receptors and aromatase enzyme activity. The initial enthusiasm turned into disappointment as the majority of breast cancers proved to be primarily resistant to antiestrogens. In addition, nearly all patients showing earlier good tumor responses to endocrine therapy, later experienced secondary resistance leading to metastatic disease and fatal outcome. Studying the molecular events in tumors responsive and unresponsive to antiestrogen therapy, it was illuminated that a complete inhibition of liganded ER activation stimulates the growth of cancers, while a successful compensatory upregulation of estrogen signal may achieve DNA restoration, tumor regression and patient's survival. Recognition of the principal role of endogenous estrogens in gene expression, gene edition and DNA repair, estrogen treatment and stimulation of ER expression in patients may bring about a great turn in medical practice.

Switching from Aromatase Inhibitors to Dual Targeting Flavonoid-Based Compounds for Breast Cancer Treatment

Despite the significant outcomes attained by scientific research, breast cancer (BC) still represents the second leading cause of death in women. Estrogen receptor-positive (ER+) BC accounts for the majority of diagnosed BCs, highlighting the disruption of estrogenic signalling as target for first-line treatment. This goal is presently pursued by inhibiting aromatase (AR) enzyme or by modulating Estrogen Receptor (ER) α. An appealing strategy for fighting BC and reducing side effects and resistance issues may lie in the design of multifunctional compounds able to simultaneously target AR and ER. In this paper, previously reported flavonoid-related potent AR inhibitors were suitably modified with the aim of also targeting ERα. As a result, homoisoflavone derivatives 3b and 4a emerged as well-balanced submicromolar dual acting compounds. An extensive computational study was then performed to gain insights into the interactions the best compounds established with the two targets. This study highlighted the feasibility of switching from single-target compounds to balanced dual-acting agents, confirming that a multi-target approach may represent a valid therapeutic option to counteract ER+ BC. The homoisoflavone core emerged as a valuable natural-inspired scaffold for the design of multifunctional compounds.

Computational method for aromatase-related proteins using machine learning approach.

Human aromatase enzyme is a microsomal cytochrome P450 and catalyzes aromatization of androgens into estrogens during steroidogenesis. For breast cancer therapy, third-generation aromatase inhibitors (AIs) have proven to be effective; however patients acquire resistance to current AIs. Thus there is a need to predict aromatase-related proteins to develop efficacious AIs. A machine learning method was established to identify aromatase-related proteins using a five-fold cross validation technique. In this study, different SVM approach-based models were built using the following approaches like amino acid, dipeptide composition, hybrid and evolutionary profiles in the form of position-specific scoring matrix (PSSM); with maximum accuracy of 87.42%, 84.05%, 85.12%, and 92.02% respectively. Based on the primary sequence, the developed method is highly accurate to predict the aromatase-related proteins. Prediction scores graphs were developed using the known dataset to check the performance of the method. Based on the approach described above, a webserver for predicting aromatase-related proteins from primary sequence data was developed and implemented at https://bioinfo.imtech.res.in/servers/muthu/aromatase/home.html. We hope that the developed method will be useful for aromatase protein related research.

Virtual Screening for Identification of Dual Inhibitors against CDK4/6 and Aromatase Enzyme.

CDK4/6 and aromatase are prominent targets for breast cancer drug discovery and are involved in abnormal cell proliferation and growth. Although aromatase inhibitors have proven to be effective (for example exemestane, anastrozole, letrozole), resistance to treatment eventually occurs through the activation of alternative signaling pathways, thus evading the antiproliferative effects of aromatase inhibitors. One of the evasion pathways is Cylin D-CDK4/6-Rb signaling that promotes tumor proliferation and resistance to aromatase inhibitors. There is significant evidence that the sequential inhibition of both proteins provides therapeutic benefits over the inhibition of one target. The basis of this study objective is the identification of molecules that are likely to inhibit both CDK4/6 and aromatase by computational chemistry techniques, which need further biochemical studies to confirm. Initially, a structure-based pharmacophore model was constructed for each target to screen the sc-PDB database. Consequently, pharmacophore screening and molecular docking were performed to evaluate the potential lead candidates that effectively mapped both of the target pharmacophore models. Considering abemaciclib (CDK4/6 inhibitor) and exemestane (aromatase inhibitor) as reference drugs, four potential virtual hit candidates (1, 2, 3, and 4) were selected based on their fit values and binding interaction after screening a sc-PDB database. Further, molecular dynamics simulation studies solidify the stability of the lead candidate complexes. In addition, ADMET and DFT calculations bolster the lead candidates. Hence, these combined computational approaches will provide a better therapeutic potential for developing CDK4/6-aromatase dual inhibitors for HR+ breast cancer therapy.

Synthesis, In Vitro Biological Evaluation of Antiproliferative and Neuroprotective Effects and In Silico Studies of Novel 16E-Arylidene-5α,6α-epoxyepiandrosterone Derivatives

Steroids constitute an important class of pharmacologically active molecules, playing key roles in human physiology. Within this group, 16E-arylideneandrostane derivatives have been reported as potent anti-cancer agents for the treatment of leukemia, breast and prostate cancers, and brain tumors. Additionally, 5α,6α-epoxycholesterol is an oxysterol with several biological activities, including regulation of cell proliferation and cholesterol homeostasis. Interestingly, pregnenolone derivatives combining these two modifications were described as potential neuroprotective agents. In this research, novel 16E-arylidene-5α,6α-epoxyepiandrosterone derivatives were synthesized from dehydroepiandrosterone by aldol condensation with different aldehydes followed by a diastereoselective 5α,6α-epoxidation. Their cytotoxicity was evaluated on tumoral and non-tumoral cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Furthermore, the assessment of the neuroprotective activity of these derivatives was performed in a dopaminergic neuronal cell line (N27), at basal conditions, and in the presence of the neurotoxin 6-hydroxydopamine (6-OHDA). Interestingly, some of these steroids had selective cytotoxic effects in tumoral cell lines, with an IC50 of 3.47 µM for the 2,3-dichlorophenyl derivative in the breast cancer cell line (MCF-7). The effects of this functionalized epoxide on cell proliferation (Ki67 staining), cell necrosis (propidium iodide staining), as well as the analysis of the nuclear area and near neighbor distance in MCF-7 cells, were analyzed. From this set of biological studies, strong evidence of the activation of apoptosis was found. In contrast, no significant neuroprotection against 6-OHDA-induced neurotoxicity was observed for the less cytotoxic steroids in N27 cells. Lastly, molecular docking simulations were achieved to verify the potential affinity of these compounds against important targets of steroidal drugs (androgen receptor, estrogen receptor α, and 5α-reductase type 2, 17α-hydroxylase-17,20-lyase and aromatase enzymes). This in silico study predicted a strong affinity between most novel steroidal derivatives and 5α-reductase and 17α-hydroxylase-17,20-lyase enzymes.

Aromatase Enzyme Activity and Liver Receptor Homolog-1 Levels in Gestational Diabetes Mellitus

Background: Gestational diabetes mellitus (GDM) is one of the prediabetes conditions in which high blood sugar levels and body weight increase during pregnancy. The underlying molecular and biochemical mechanisms of GDM are poorly defined. Introduction: Aromatase enzyme activity is responsible for the conversion of androgens to estrogens and has a share in the regulation of body fat distribution and liver receptor homolog-1 (LRH-1), which plays a critical role in cholesterol transport, acid homeostasis, and steroidogenesis in GDM patients. This study aims to determine the levels of aromatase enzyme and LRH-1 in GDM patients and to investigate the relationship between the levels of aromatase enzyme and LRH-1 and the levels of insulin, HbA 1c and total cholesterol. Method: This prospective cross-sectional study was conducted over eleven months (September 2020 to July 2021). The study population was selected at Harran University Teaching and Research Hospital. The study included 32 GDM patients and 32 healthy pregnants. The automated assay measured serum fasting blood glucose, HbA1c, and insulin levels (AVIDA 1800 Chemistry System; Siemens). Aromatase enzyme activity and LRH-1 levels were determined by using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Result: Aromatase activity decreased in GDM patients while LRH1 increased. Significant differences in means levels of fasting blood glucose (p=0.11), insulin (p= 0.001) and HbA1c (p= 0.001) between the patients and control groups. There was a significant negative correlation between the levels of aromatase and insulin (r=-370, p =0.037). In addition, a positive significant correlation coefficient (r=0.645, p=0.001) was found between HbA1c and total cholesterol among the patients' group. Conclusion: Our findings indicate that there is a negative relationship between aromatase activity and insulin levels. Aromatase and LRH 1 may play a role in the pathogenesis of GDM, and the use of LRH-1 agonists in treating the disease may be considered an alternative treatment in the future. However, additional studies are required to reveal the possible functions of these two proteins in GDM with their mechanisms.

Growth, pectoralis muscle performance, and testis of pelung cockerels (Gallus gallus gallus [Linnaeus, 1758]) supplemented with blood clam shell powder (Anadara granosa [Linnaeus, 1758]).

Pelung cockerels (Gallus gallus gallus [Linnaeus, 1758]) are different from other native cockerels in that they have a long and unique voice, in addition to their tall, large, and sturdy body with a relatively heavy body weight (BW). The sound quality of pelung cockerels is affected by the structure of the syrinx and their large and strong chest muscles. The performance of the chest muscles, and subsequently its voice, is influenced by the hormone testosterone. The shell of blood clams (Anadara granosa Linnaeus, 1758), a saltwater bivalve is known to contain a natural aromatase blocker (NAB) capable of blocking the aromatase enzyme from converting testosterone to estradiol. This generates consistently high levels of testosterone. This study aimed to determine the effect of blood clam shell powder (BCSP) as an NAB on the growth, pectoralis muscle performance, and testes of pelung cockerels. The study design was a completely randomized design, with 16 pelung cockerels aged 40-56 weeks divided into four treatment groups: T0 (control); T1 (BCSP [A. granosa] 0.9 mg/kg BW); T2 (zinc sulfate [ZnSO4] 0.9 mg/kg BW); and T3 (testosterone 3 mg/day). The animals were acclimatized for 7 days and then given dietary treatments for 56 days. The measurement of the comb, wattle, and chest circumference (CC) of pelung cockerels was performed on days 0, 14, 28, 42, and 56. At the end of the treatment, the pelung cockerels were sacrificed and the data of the pectoralis muscle weight (PMW), testis weight (TW), and area of the pectoralis muscle (APM) were measured. Samples of pectoralis muscle and testes were taken and fixed in 10% neutral buffer formalin for histology. The proliferating cell nuclear antigen (PCNA) was identified by immunohistochemical staining. To measure fascicle area (FA), myofiber area (MA), and enumerate, the fascicle myofibers (NM) histology preparations were stained with hematoxylin and eosin (H and E). Testicular preparations were stained with H and E to measure the diameter of the seminiferous tubules (DST) using ImageJ software. The growth performance on day 56 showed significantly (p < 0.05) higher differences of CC in T1 compared to T2 and T0, in T1 and T3 compared to T0, and in T3 and T2 compared to T0. Pectoralis muscle results, that is, FA, NM, MA, and PCNA-positive cells, showed that cockerels on treatment T3 had significantly higher results than other treatments, T1 was significantly different from T2 and T0, and T2 was significantly different from T0. In addition, the TW and DST measurement of cockerels on treatment T3 were significantly reduced (p < 0.05) than the other treatment groups. The oral administration of BCSP in the role of a NAB at a dose of 0.9 mg/kg BW for 56 days improved the growth performance and pectoralis muscle, especially the CC, FA, NM, MA, and PCNA-positive cells parameters, but did not affect the PMW, APM, and testis of pelung cockerels. The administration of testosterone at 3 mg/day for 56 days contributed to the decrease in TW and DST, as well as atrophy of the seminiferous tubules of pelung cockerels.

Radiation-Induced Localized Bullous Pemphigoid.

Radiation-Induced Localized Bullous Pemphigoid.

Rational Drug Design and In vitro Cell Line Studies of Some N-(4-(1Hbenzo[ d]imidazol-2-yl)phenyl)arylamine Derivatives as Aromatase Inhibitors for the Treatment of Cancer

Background: Aromatase is a catalytic enzyme involved in the biosynthesis of estrogen from androgen. It catalyzes the last rate-limiting/crucial critical step in estrogen biosynthesis. Following the success of the aromatase inhibitor, researchers are working on developing a small physiologically active molecule with fewer side effects and improved tolerance. Objectives: Inhibition of the aromatase enzyme, which plays a major role in the rate-limiting phase, is one strategy to prevent estrogen synthesis. After knowing the importance of nitrogen atom containing moieties in the treatment of breast cancer, we have designed some N-(4-(1H-benzo[d]imidazol-2-yl)phenyl)arylamine derivatives through in silico screening such as ADMET analysis and molecular docking studies. From the present investigation we aimed for the synthesis and biological evaluation of the most potent derivatives obtained in this study. Methods: The selected derivatives were synthesized and confirmed by spectral analysis (FTIR, 1H NMR, and Mass). Cytotoxic activity of the compounds was evaluated by colorimetric MTT assay on MDA-MB-231 (breast adenocarcinoma), MCF-7(breast adenocarcinoma), A549 (lung adenocarcinoma) NCI-H23 (Lung carcinoma) and A-498 (Renal carcinoma) cell line using Doxorubicin hydrochloride as positive control. Results: From present investigation, we have concluded that compound 10 [N-(4-(1H-benzo[d]imidazol-2-yl)phenyl)-1H-benzo[d]imidazol-5-amine) is most potent and exhibited -9.5 kcal/mol binding affinity. It has formed conventional hydrogen bonds with ALA306 and THR310. It displayed most promising activity with GI50 value 0.796±0.06 µM, 0.695±0.05 µM, 1.14±0.06 µM, 2.15±0.04 µM, and 0.987±0.07 µM against MDAMB-231, MCF-7, A-549, NCI-H23, and A-498, respectively when compared with Doxorubicin (0.306±0.04 µM, 0.270±0.02 µM, 0.297±0.04 µM, 0.305±0.04 µM, and 0.345±0.09 µM). Conclusion: From present investigation it is concluded that the designed molecules had potential to be developed as broad spectrum anticancer agents.

Buchholzia coriacea seed induce antifertility by interfering with steroidogenic enzymes and inflammatory cytokines in rat testis

Buchholzia coriacea has been reported to possess antifertility activities but little is known of the mechanisms responsible. This study was therefore designed to examine the mechanism responsible for the action of Buchholzia coriacea. Eighteen male Wistar rats (180–200 g) were used for this study. They were grouped into 3 (n = 6) namely, Control, Methanolic fraction of Buchholzia coriacea (MFBC) 50 mg/kg, and MFBC 100 mg/kg administered orally with respective dosage. After 6 weeks of administration, rats were euthanized, serum collected, while testes, epididymis and prostate were excised and homogenized. Testicular protein and testosterone, aromatase and 5α-reductase enzyme, 3β hydroxysteroid dehydrogenase (HSD), 17β-HSD, interleukin (IL) 1β, IL-10 and Prostatic specific enzyme antigen (PSA) were assessed and data analyzed with ANOVA. There were significant increases in 3β-HSD and 17β-HSD levels in the MFBC 50 mg/kg with corresponding decreases in MFBC 100 mg/kg when compared to control. IL-1 was decreased in both doses while IL-10 increased in both doses compared to control. 5-α reductase enzyme was significantly decreased in the MFBC 100 mg/kg relative to the control. Testicular protein, testosterone and aromatase enzyme were not significantly different at both doses compared to control. PSA was significantly increased in the MFBC 100 mg/kg but not the 50 mg/kg relative to control. MFBC exhibits antifertility properties by interfering with testicular enzymes and inflammatory cytokines.

Design, synthesis, modeling studies and biological evaluation of pyrazole derivatives linked to oxime and nitrate moieties as nitric oxide donor selective COX-2 and aromatase inhibitors with dual anti-inflammatory and anti-neoplastic activities

Two new series of pyrazole derivatives 10a-f and 11a-f with selective COX-2 inhibition pharmacophore and oxime/nitrate moieties as NO donor moiety were designed, synthesized and tested for anti-inflammatory, cytotoxic activities and NO release. Compounds 10c, 11a, 11e were more selective for COX-2 isozyme (S.I. = 25.95, 22.52 and 21.54 respectively) in comparison to celecoxib (S.I. = 21.41). Regarding anti-cancer activity, all synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compounds 10c, 11a, 11e were found to be the most potent inhibitors on breast, ovarian and melanoma cell lines (MCF-7, IGROV1 and SK-MEL-5), compound 11a causing 79 % inhibition in case of MCF-7, 78.80 % inhibition in case of SK-MEL-5 and unexpected cell growth −26.22 % inhibition in case of IGROV1 (IC50 = 3.12, 4.28, 4.13 μM respectively). On the other hand, compounds 10c and 11e showed lower inhibition on the same cell lines with IC50 = 3.58, 4.58, 4.28 μM respectively for 10c, IC50 = 3.43, 4.73, 4.43 μM respectively for 11e. Furthermore, DNA-flow cytometric analysis showed that compound 11a induces cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Additionally, these derivatives examined against F180 fibroblasts to investigate their selectivity indexes. The pyrazole derivative with internal oxime 11a was the most potent compound against most used cell lines especially MCF-7, IGROV1 and SK-MEL-5 (IC50 = 3.12, 4.28, 4.13 μM respectively) with 4.82-fold selectivity towards MCF-7 than F180 fibroblasts. Moreover, oxime derivative 11a showed potent aromatase inhibitory activity (IC50 16.50 μM) when compared with reference compound letrozole (IC50 15.60 μM). All compounds 10a-f and 11a-f released NO in a slow rate (0.73–3.88 %) and the six derivatives 10c, 10e, 11a, 11b, 11c and 11e were the highest NO releasers (3.88, 2.15, 3.27, 2.27, 2.55 and 3.74 % respectively). Herein structure based and ligand based studies were implemented to under stand and evaluate the compounds activity for further in vivo and preclinical studies. Docking mode of final designed compounds with celecoxib (ID: 3LN1) represented that their triazole ring adopted as the core aryl in Y shaped structure. Regarding aromatase enzyme inhibition, docking was carried out with ID: 1 M17. The internal oxime series was more active as anticancer because of their ability to form extra HBs with receptor cleft.

A KNIME Workflow to Assist the Analogue Identification for Read-Across, Applied to Aromatase Activity.

The reduction and replacement of in vivo tests have become crucial in terms of resources and animal benefits. The read-across approach reduces the number of substances to be tested, exploiting existing experimental data to predict the properties of untested substances. Currently, several tools have been developed to perform read-across, but other approaches, such as computational workflows, can offer a more flexible and less prescriptive approach. In this paper, we are introducing a workflow to support analogue identification for read-across. The implementation of the workflow was performed using a database of azole chemicals with in vitro toxicity data for human aromatase enzymes. The workflow identified analogues based on three similarities: structural similarity (StrS), metabolic similarity (MtS), and mechanistic similarity (McS). Our results showed how multiple similarity metrics can be combined within a read-across assessment. The use of the similarity based on metabolism and toxicological mechanism improved the predictions in particular for sensitivity. Beyond the results predicting a large population of substances, practical examples illustrate the advantages of the proposed approach.

Testolactone: The Rise and Fall of a Drug

Testolactone is structurally related to testosterone and belongs to the first generation of aromatase inhibitors. It is a non-selective irreversible aromatase enzyme inhibitor that was one of the first steroids used in the clinical treatment of breast cancer. The use of testolactone in the treatment of breast cancer started in 1970, although its ability to inhibit aromatase was not discovered until 1975. Its use was primarily based on the inhibition of estrogen synthesis, which was applied in the treatment of estrogen-dependent breast cancers, in the treatment of disorders of sex steroid excess, familial male-limited precocious puberty, or in the treatment of patients with McCune–Albright syndrome, etc. The weak inhibitory activity of testolactone, and the moderate clinical response, prevented its widespread use, which ultimately resulted in withdrawal from the drug market in 2008. This review paper is dedicated to testolactone, its rise in the second half of the 20th century, and its fall in the first decade of the 21st century. Regardless of withdrawal from the market, for many years testolactone was a drug that improved the quality of life of patients facing one of the most serious diseases today, and for this reason, this paper describes medicinal application, synthesis, and modifications of testolactone.

Effects of Ventromedial Hypothalamic Nucleus (VMN) Aromatase Gene Knockdown on VMN Glycogen Metabolism and Glucoregulatory Neurotransmission

The enzyme aromatase is expressed at high levels in the ventromedial hypothalamic nucleus (VMN), a principal component of the brain gluco-regulatory network. Current research utilized selective gene knockdown tools to investigate the premise that VMN neuroestradiol controls glucostasis. Intra-VMN aromatase siRNA administration decreased baseline aromatase protein expression and tissue estradiol concentrations and either reversed or attenuated the hypoglycemic regulation of these profiles in a VMN segment-specific manner. Aromatase gene repression down-regulated protein biomarkers for gluco-stimulatory (nitric oxide; NO) and -inhibitory (gamma-aminobutyric acid; GABA) neurochemical transmitters. Insulin-induced hypoglycemia (IIH) up- or down-regulated neuronal nitric oxide synthase (nNOS) and glutamate decarboxylase65/67 (GAD), respectively, throughout the VMN. Interestingly, IIH caused divergent changes in tissue aromatase and estradiol levels in rostral (diminished) versus middle and caudal (elevated) VMN. Aromatase knockdown prevented hypoglycemic nNOS augmentation in VMN middle and caudal segments, but abolished the GAD inhibitory response to IIH throughout this nucleus. VMN nitrergic and GABAergic neurons monitor stimulus-specific glycogen breakdown. Here, glycogen synthase (GS) and phosphorylase brain- (GPbb; AMP-sensitive) and muscle- (GPmm; noradrenergic -responsive) type isoform responses to aromatase siRNA were evaluated. Aromatase repression reduced GPbb and GPmm content in euglycemic controls and prevented hypoglycemic regulation of GPmm but not GPbb expression while reversing glycogen accumulation. Aromatase siRNA elevated baseline glucagon and corticosterone secretion and abolished hypoglycemic hyperglucagonemia and hypercorticosteronemia. Outcomes document the involvement of VMN neuroestradiol signaling in brain control of glucose homeostasis. Aromatase regulation of VMN gluco-regulatory signaling of hypoglycemia-associated energy imbalance may entail, in part, control of GP variant-mediated glycogen disassembly.

New tamoxifen analogs for breast cancer therapy: synthesis, aromatase inhibition and in silico studies

A new class of tamoxifen analogues, using McMurry reaction conditions, is described. The scheme involved the conversion of ketoprofen (6) into amide derivatives 7 and 8, by coupling with N1,N1 -substituted propan-1,3-diamine derivatives in the presence DIC and HOB. Treatment of 7 and 8 with various ketones under McMurry reaction conditions afforded the tamoxifen analogues 9–16. All the analogues were screened in vitro for their aromatase inhibitory and antiproliferative activity against MCF-7 breast cancer cells. Compounds 10, 11 and 12 showed a potent activity against MCF-7 cell lines breast cancer with IC50 values of 0.070, 0.042 and 0.077 µM of selectivity index (SI) 3.0, 2.5 and 2.6, respectively. Further, 12 exhibited potent activity against estrogen receptor (14.7 ± 2.4 nM), while compound 10 was the most active analogues against aromatase with IC50 of (0.070 nM). Furthermore, all new compounds were docked into human placental aromatase enzyme and estrogen receptor and showed very good correlations with experimental IC50. Therefore, we can consider these designed compounds as starting scaffold to design an efficient drug against estrogen receptor and aromatase. Communicated by Ramaswamy H. Sarma

Synthesis of new 1,2,3-triazole-based compounds of potential anti-breast cancer activity targeting aromatase enzyme inhibition

Synthesis of new 1,2,3-triazole-based compounds of potential anti-breast cancer activity targeting aromatase enzyme inhibition

The physiological effect of breast cancer on activity of aromatase enzyme and some concentrations of hormones and biochemical in the women in Baghdad city

This study was conducted to investigate the effect of women breast cancer on some hormones (Estrogen, Testosterone, prolactin) and biochemical parameters (Glucose, Cholesterol, Aromatase). The study is done in Medical City Teaching Hospital in Baghdad to show the effect of age, body weight and type of feeding for women with breast cancer and compared with healthy women. Their age ranged between (24-70) years for both groups. The results showing high significant effects of all parameters study in cancer disease women compared with healthy. All Study parameters increased with the advance of age and with the increased in body mass index. The breast cancer was spread in women artificial infant feeding compared with natural feeding .The conclusion suggested that the increase in estrogen, testosterone, prolactin, aromatase, cholesterol and glucose when the women have breast cancer.