Iminoenamine based novel androgen receptor antagonist exhibited anti-prostate cancer activity in androgen independent prostate cancer cells through inhibition of AKT pathway

Ligandrol Ameliorates High-Fat Diet- and Streptozotocin-Induced Type 2 Diabetes Mellitus and Prevents Pancreatic Islets Degeneration

Androgen therapy has been shown to alleviate type 2 diabetes mellitus (T2DM) but is also associated with severe side effects such as prostate cancer. The present study aims to identify the best hit selective androgen receptor (AR) modulator by in silico studies and then investigates its antidiabetic effects in high-fat diet- and streptozotocin (STZ)-induced T2DM male rat model. Molecular docking and molecular dynamics (MD) studies were carried out using Maestro 13.1 and Desmond (2023-2024). Cytotoxicity and insulin secretion were measured in MIN6 cell lines. T2DM was induced using high-fat diet (HFD) for 4 weeks, followed by single STZ (40 mg/kg, intraperitoneally). OneTouch Ultra glucometer was used to measure fasting blood glucose. Gene expression was determined using reverse transcription polymerase chain reaction. Histopathology was carried out using hematoxylin and eosin stain. Through molecular docking, we identify ligandrol as a potential hit. Ligandrol showed a good binding affinity (-10.74 kcal/mol). MD showed that ligandrol is stable during the 100 ns simulation. Ligandrol increases insulin secretion in a dose-dependent manner in vitro in 2 h. Ligandrol (0.3 and 1 mg/kg, orally) significantly decreased the body weight and fasting blood glucose levels compared with the HFD and STZ group. Gene expression showed that ligandrol significantly increased the AR-targeted gene, neurogenic differentiation 1, compared with the HFD and STZ group. Histopathological staining studies showed that ligandrol prevents pancreatic islet degeneration compared with the HFD and STZ group. Our findings suggest that ligandrol's protective effect on pancreatic islets leading to its antidiabetic effect occurs through the activation of AR.

Synthesis and photophysical investigations of pyridine-pyrazolate bound boron(III) diaryl complexes

This study presents the design and synthetic pathway of unsymmetric ligands based on pyridine-pyrazolate scaffold with Donor-Acceptor (D-A) molecular arrays and their boron complexes to achieve a large Stokes shift. Intermolecular charge transfer (ICT) triggered by the uneven molecular charge distribution from electronically dense pyrazolate (donor) part of the ligands to electron-deficient boron centre (acceptor) resulted in a mega Stokes shift up to 263 nm for selected compounds while retaining the characteristic quantum efficiency and chemical stability. The photophysical properties of derivatization of pyrazolate group in the pyridine-pyrazolate scaffold of diaryl boron complexes were explored based on UV-Visible, steady-state and time-resolved fluorescence spectroscopy. An interesting dual emission along with quenching behaviour was also observed for 2-(6-methoxynaphthelene) 5-(2-pyridyl) pyrazolate boron complex (P₅) due to the formation of a twisted intermolecular charge transfer (TICT) state from a locally excited (LE) state rendering it a potential candidate for sensing applications based on H-Bond quenching. In addition, the extended excited state lifetime of the reported compounds compared to classical boron-dipyrromethene (BODIPY) makes them suitable as potential probes for analytical applications requiring a longer excited state lifetime.

Citrus Flavone Tangeretin Inhibits CRPC Cell Proliferation by Regulating Cx26, AKT, and AR Signaling

Prostate cancer (PCa) progression depends on the action of androgen receptors (AR). Therefore, preventing ligand-mediated activation of AR is the first-line treatment strategy for metastatic PCa. Androgen deprivation therapy (ADT) can inhibit ligand binding to AR and alleviate PCa progression initially. However, due to the adaptation of PCa and recovery of AR signaling, castration-resistant prostate cancer (CRPC) eventually develops. Exploring novel dietary compounds that can target AR signaling appears to be a viable alternative therapeutic option for CRPC. In the present study, compounds from the citrus fruits were focused upon, which contain various flavonoid ingredients. Key components contained within orange peel, which is frequently used in traditional Chinese medicine, and downstream targets were first analyzed using network pharmacology approach. Notably, it was found that tangeretin, an active ingredient from orange peel, can significantly inhibit CRPC cell (C4-2 and Du145 cells) proliferation and migration whilst also synergistically increasing the sensitivity of CRPC cells to anti-tumor drugs sorafenib or cisplatin. Tangeretin also significantly reduced AR and AKT expressions in C4-2 cells and signal transducer and activator of transcription 3 expression in the androgen-insensitive cell line Du145. In addition, tangeretin increased the expression of both connexin26 (Cx26) and gap junction function, which may mediate the bystander effects of cisplatin or sorafenib. Taken together, the present study revealed a novel molecular mechanism by which tangeretin may inhibit the proliferation of CRPC cells, by affecting the Cx26/AKT/AR pathway, to synergistically increase the sensitivity of CRPC cells to sorafenib and cisplatin.

High Content Screening Using New U2OS Reporter Cell Models Identifies Harmol Hydrochloride as a Selective and Competitive Antagonist of the Androgen Receptor

Prostate cancer is the most commonly diagnosed malignancy in men. Its growth mainly relies on the activity of the androgen receptor (AR), justifying the use of androgen deprivation therapy as a gold standard treatment for the metastatic disease. Inhibition of the androgen axis using second generation antagonists has improved patients’ survival, but is systematically confronted to resistance mechanisms, leading to a median survival that does not exceed 5 years. Counteracting this resistance has been the object of a large number of investigations, with a particular emphasis towards the identification of new AR inhibitors, whether they antagonize the receptor by a competitive or a non-competitive binding. To this end, many high content screens have been performed, to identify new non-steroidal AR antagonists, using a variety of approaches, but reported somewhat controversial results, depending on the approach and on the cell model that was used for screening. In our study, we used the U2OS osteosarcoma cells stably transfected with AR or ARv7 and a luciferase reporter as a previously validated model to screen the Prestwick Phytochemical library. The results of our screen identified ellipticine, harmol, and harmine hydrochloride as confirmed hits. Surprisingly, we could demonstrate that harmol hydrochloride, previously identified as a non-competitive inhibitor of AR or a weak inhibitor of androgen signaling, was actually a competitive antagonist of AR, which inhibits the growth of VCaP prostate cancer line, at concentrations for which it did not affect the growth of the AR negative DU145 and PC3 cells. Interestingly, we also report for the first time that harmol hydrochloride was selective for AR, as it could not alter the activity of other nuclear receptors, such as the glucocorticoid receptor (GR), the progesterone receptor (PR), or the mineralocorticoid receptor (MR). Additionally, we demonstrate that, conversely to enzalutamide, harmol hydrochloride did not show any agonistic activity towards the pregnane X receptor (PXR), a master regulator of drug metabolism. Together, our results shed light on the importance of the cellular context for the screening of new AR antagonists. They further indicate that some of the potential hits that were previously identified may have been overlooked.

Design, Synthesis, and Biological Evaluation of 2-(2-Bromo-3-nitrophenyl)-5-phenyl-1,3,4-oxadiazole Derivatives as Possible Anti-Breast Cancer Agents

Breast Cancer (BCa) is the most often diagnosed cancer among women who were in the late 1940's. Breast cancer growth is largely dependent on the expression of estrogen and progesterone receptor. Breast cancer cells may have one, both, or none of these receptors. The treatment for breast cancer may involve surgery, hormonal therapy (Tamoxifen, an aromatase inhibitor, etc.) and oral chemotherapeutic drugs. The molecular docking technique reported the findings on the potential binding modes of the 2-(2-bromo-3-nitrophenyl)-5-phenyl-1,3,4-oxadiazole derivatives with the estrogen receptor (PDB ID: 3ERT). The 1,3,4-oxadiazole derivatives 4a-4j have been synthesized and described by spectroscopic method. 2-(2-Bromo-6-nitrophenyl)-5-(4-bromophenyl)-1,3,4-oxadiazole (4c) was reconfirmed by single-crystal XRD. All the compounds have been tested in combination with generic Imatinib pharmaceutical drug against breast cancer cell lines isolated from Caucasian woman MCF-7, MDA-MB-453 and MCF-10A non-cancer cell lines. The compounds with the methoxy (in 4c) and methyl (in 4j) substitution were shown to have significant cytotoxicity, with 4c showing dose-dependent activation and decreased cell viability. The mechanism of action was reported by induced apoptosis and tested by a DNA enzyme inhibitor experiment (ELISA) for Methyl Transferase. Molecular dynamics simulations were made for hit molecule 4c to study the stability and interaction of the protein-ligand complex. The toxicity properties of ADME were calculated for all the compounds. All these results provide essential information for further clinical trials.

Syringaresinol as a novel androgen receptor antagonist against wild and mutant androgen receptors for the treatment of castration-resistant prostate cancer: molecular docking, in-vitro and molecular dynamics study

Phytoestrogens are dietary estrogens having similar structure as of estrogen. Some of these phytoestrogens are androgen receptor (AR) antagonists and exhibit preventive role in the prostate cancer. However, in androgen-independent prostate cancer (AIPC) the ARs were mutated (T877A, W741L, F876L, etc.) and these mutant ARs convert the antagonist to agonist. Our aim in this study is to find phytoestrogens that could function as an antagonist with wild and mutant ARs. The phytoestrogens were analyzed for binding affinity with wild and mutant ARs in agonist and antagonist conformations. The point mutations were carried out using Chimera. The antagonist AR conformation was modeled using Modeller. We hypothesize that the compounds having binding affinity with agonist AR conformation could not function as a full or pure antagonist. Most of the phytoestrogens have binding affinity with agonist AR conformation contradicting previous results. For example, genistein which is a widely studied isoflavone has known AR antagonist property. However, in our study, it had good binding affinity with agonist AR conformation. Hence, to confirm our hypothesis, we tested genistein in LNCaP (T877A mutant AR) cells by qPCR studies. The genistein functioned as an antagonist only in the presence of an androgen indicting a partial agonist type of activity. The in-vitro results supported our docking hypothesis. We applied this principle and found syringaresinol could function as an antagonist with wild and mutated ARs. Further, we carried out molecular dynamics for the hit molecule to confirm its antagonist binding mode with mutant AR.Communicated by Ramaswamy H. Sarma.

Design, Synthesis and Evaluation of Novel Substituted (5-methyl-1H-pyrazol-3-yl)- 1,3,4-oxadiazole as Potent Androgen Receptor Antagonist

BACKGROUND

Androgen Receptor (AR) is one of the highly explored targets for the treatment of prostate cancer. The emergence of point mutation in the Ligand Binding Domain (LBD) of AR has resulted in the development of resistance against AR antagonist. The point mutation T877A, W741L and F876L confer resistance to flutamide, bicalutamide and enzalutamide respectively. There is no AR antagonist in the present clinical set up without resistance. Hence, our aim in this study is to design a novel molecule to overcome the resistance caused by point mutation.

METHODS

Here, we developed novel AR antagonist bearing (5-methyl-1H-pyrazol-3-yl)-1, 3,4-oxadiazole core by rational drug design. The test molecules 8a-h were synthesized from the corresponding dihydrazide compounds 7a-h on treatment with phosphorous oxychloride on reflux conditions. The structure of the molecules was confirmed from spectral data such as IR, 1H-NMR, HRMS and 13C-NMR. The synthesized compounds were screened for cytotoxicity in prostate cancer cell lines LNCaP-FGC and PC3. The confirmation of AR mediated activity of the test compounds was confirmed by gene expression study. The interaction of the best active ligands with mutant AR was predicted and drug design was rationalized through docking studies.

RESULTS

The test compounds 8a-h were synthesized and the structures were conformed using suitable techniques like IR, 1H-NMR, HRMS and 13C-NMR. Among the tested compounds, 8b and 8d showed potent antiproliferative activity against mutant AR cell lines. Further, these compounds significantly decreased the gene expression of prostate cancer biomarkers.

CONCLUSION

In this study, we have identified a potential hit molecule for AR antagonism that could be further developed to obtain a potent clinical candidate.

Design, Synthesis, and Biological Evaluation of (E)-N'-((1-Chloro-3,4-Dihydronaphthalen-2-yl)Methylene)Benzohydrazide Derivatives as Anti-prostate Cancer Agents

Prostate Cancer (PCa) is the most frequently diagnosed cancer in men in their late '50s. PCa growth is mainly due to the activation of the androgen receptor by androgens. The treatment for PCa may involve surgery, hormonal therapy, and oral chemotherapeutic drugs. A structural based molecular docking approach revealed the findings of (E)-N'-((1-chloro-3,4-dihydronaphthalen-2-yl)methylene)benzohydrazide derivatives, where the possible binding modes of the compounds with protein (PDB ID: 3V49) are shown. The compounds (6a-k) were synthesized and characterized by using conventional methods. The compounds, 6g, 6j, and 6k were reconfirmed through single crystal X-ray diffraction (XRD). Further, the compounds (6a-k) and standard drug were evaluated against human prostate cancer cell lines, LNCaP and PC-3 and the non-cancerous cell line, 3T3. Among these compounds, 6g and 6j showed higher cytotoxicity, and 6g exhibited dose-dependent activity and reduced cell viability. The mechanism of action was observed through the induced apoptosis and was further confirmed by western blot and ELISA. Molecular dynamics simulation studies were carried out to calculate the interaction and the stability of the protein-ligand complex in motion. ADME properties were predicted for all the tested compounds. These findings may give vital information for further development.

In Silico Molecular Docking, Synthesis of 4-(4-benzoylaminophenoxy) Phenol Derivatives as Androgen Receptor Antagonists

AIM AND OBJECTIVE

To study the structural difference, optimization, molecular docking and development of new benzoyl amino phenoxy phenol derivatives as anti-prostate cancer agents.

MATERIALS AND METHODS

Strategies towards the identification of novel benzoyl amino phenoxy phenol (BAPP), molecular docking was performed with the designed Androgen Receptor (AR) blockers. Pharmacophore-based studies revealed that the nitro- or cyano-substituted anilide groups have influenced the activity profiles of non-steroidal AR antagonists, followed by the molecular docking studies with five AR receptors. Molecular docking studies were carried out using Maestro from Schrödinger. Absorption, Distribution, Metabolism, and Excretion (ADME) properties of the BAPP derivatives were evaluated for the predictive bioavailability/drug-likeness. These studies supported vital information for designing new anti-prostate cancer agents.

RESULTS AND DISCUSSION

There are 125 compounds were screened and best fit compounds (12 entries) were well-synthesized in good to excellent yields and anticancer activities were evaluated. The compounds, 6i showed the highest activities of this series (14.65 ± 1.35 µM).

CONCLUSION

The present approach is simple and efficient for the synthesis of BAPP derivatives and the observed IC50 values of BAPPs were in good agreement with the glide scores obtained from the molecular docking. We, further, intend to carry out in vitro and in vivo AR binding studies for the active compounds.

Fluorescent boron complexes based on new N,O-chelates as promising candidates for flow cytometry

This study presents the synthesis and optical properties of a new class of bright green-yellow fluorescent dyes with potential applications in bioimaging. A facile synthetic route via the chelation of aryl(hetaryl)aminoacryloylthiophene scaffolds with a BF2 fragment is presented. The photophysical properties of the dyes are attributed to the nature and position of electron-donating and electron-withdrawing substituents. Upon coordination to a BF2 fragment, characteristic emission was observed, with λem ranging from 503 to 543 nm and quantum yields of 0.14-0.42. Compared with parent aryl(hetaryl)aminoacryloylthiophenes, a significant red shift in absorption (up to 480 nm in solution) and emission (up to 543 nm in solution and 610 nm in the solid state) and high chemical stability and photostability were observed. The electron-accepting character of the substituents on the terminal aromatic ring or replacing this fragment with pyridine or pyrazine moieties resulted in increased quantum yields. To gain insight into the electronic structures and optical properties, quantum mechanical calculations were performed. The results of (TD-)DFT calculations supported the structural and spectroscopic data and showed the features of electronic distribution in the frontier molecular orbitals and active electrophilic and nucleophilic sites in the compounds investigated. Synthesized BF2 complexes are promising dyes for cell imaging and flow cytometry owing to their ready penetration and accumulation in cells.

In silico Molecular Modelling of Selected Natural Ligands and their Binding Features with Estrogen Receptor Alpha

Background:

Breast cancer is one of the most common cancers diagnosed among women. It is now recognized that two receptors mediate estrogen action and the presence of estrogen receptor alpha (ER&#945;) correlates with better prognosis and the likelihood of response to hormonal therapy. ER&#945; is an attractive target for the treatment of breast cancer. Most of the drugs currently used for the breast cancer treatment have numerous side effects and they are often unsuccessful in removing the tumour completely. Hence, we focused on natural compounds like flavonoids, polyphenols, etc. which do not exhibit any high toxic effects against normal cells. </P><P> Objectives: To identify the potential natural inhibitors for BCa through an optimised in silico approach. </P><P> Methods: Structural modification and molecular docking-based screening approaches were imposed to identify the novel natural compounds by using Schrödinger (Maestro 9.5). The Qikprop v3.5 was used for the evaluation of important ADME parameters and its permissible ranges. Cytotoxicity of the compounds was evaluated by MTT assay against MCF-7 Cell lines.

Results:

From the docking studies, we found that the compounds, Myricetin, Quercetin, Apigenin, Luteolin and Baicalein showed the highest Glide Scores -10.78, -9.48, -8.92, -8.87 and -8.82 kcal mol-1 respectively. Of these, Luteolin and Baicalein showed the significant IC50 values (25 &#177; 4.0 and 58.3 &#177; 4.4 &#181;M, respectively) against MCF-7 cell line. The ADME profiling of the test compounds was evaluated to find the drug-likeness and pharmacokinetic parameters.