Identification of polypharmacological anticancerous molecules against Aurora kinase family of proteins

Mitotic kinases are emerging therapeutic targets against metastatic breast cancer

This review aims to outline mitotic kinase inhibitors' roles as potential therapeutic targets and assess their suitability as a stand-alone clinical therapy or in combination with standard treatments for advanced-stage solid tumors, including triple-negative breast cancer (TNBC). Breast cancer poses a significant global health risk, with TNBC standing out as the most aggressive subtype. Comprehending the role of mitosis is crucial for understanding how TNBC advances from a solid tumor to metastasis. Chemotherapy is the primary treatment used to treat TNBC. Some types of chemotherapeutic agents target cells in mitosis, thus highlighting the need to comprehend the molecular mechanisms governing mitosis in cancer. This understanding is essential for devising targeted therapies to disrupt these mitotic processes, prevent or treat metastasis, and improve patient outcomes. Mitotic kinases like Aurora kinase A, Aurora Kinase B, never in mitosis gene A-related kinase 2, Threonine-Tyrosine kinase, and Polo-kinase 1 significantly impact cell cycle progression by contributing to chromosome separation and centrosome homeostasis. When these kinases go awry, they can trigger chromosome instability, increase cell proliferation, and activate different molecular pathways that culminate in a transition from epithelial to mesenchymal cells. Ongoing clinical trials investigate various mitotic kinase inhibitors as potential biological treatments against advanced solid tumors. While clinical trials against mitotic kinases have shown some promise in the clinic, more investigation is necessary, since they induce severe adverse effects, particularly affecting the hematopoietic system.

Structure-based virtual screening methods for the identification of novel phytochemical inhibitors targeting furin protease for the management of COVID-19

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is a highly contagious respiratory disease with widespread societal impact. The symptoms range from cough, fever, and pneumonia to complications affecting various organs, including the heart, kidneys, and nervous system. Despite various ongoing efforts, no effective drug has been developed to stop the spread of the virus. Although various types of medications used to treat bacterial and viral diseases have previously been employed to treat COVID-19 patients, their side effects have also been observed. The way SARS-CoV-2 infects the human body is very specific, as its spike protein plays an important role. The S subunit of virus spike protein cleaved by human proteases, such as furin protein, is an initial and important step for its internalization into a human host. Keeping this context, we attempted to inhibit the furin using phytochemicals that could produce minimal side effects. For this, we screened 408 natural phytochemicals from various plants having antiviral properties, against furin protein, and molecular docking and dynamics simulations were performed. Based on the binding score, the top three compounds (robustaflavone, withanolide, and amentoflavone) were selected for further validation. MM/GBSA energy calculations revealed that withanolide has the lowest binding energy of -57.2 kcal/mol followed by robustaflavone and amentoflavone with a binding energy of -45.2 kcal/mol and -39.68 kcal/mol, respectively. Additionally, ADME analysis showed drug-like properties for these three lead compounds. Hence, these natural compounds robustaflavone, withanolide, and amentoflavone, may have therapeutic potential for the management of SARS-CoV-2 by targeting furin.

Identification of small molecule inhibitors of RAD52 for breast cancer therapy: in silico approach

The breast cancer susceptibility gene 1/2 (BRCA1/2) are the key regulators in maintaining the genomic integrity and mutations in these genes have been associated with development of breast and ovarian cancers. Also, synthetic lethality has been shown in BRCA1/2 deficient cancers, when the RAD52 gene is silenced by shRNA or small molecules aptamers, suggesting a role for RAD52 in the breast cancers pathogenesis. Thus, to find the potential inhibitors of RAD52, a collection of 21,000 compounds from the ChemBridge screening library was screened to conduct molecular docking and molecular dynamics simulation (MD) against RAD52. Further, the results were validated by a density functional theory (DFT) analysis and using post-dynamics free energy calculations. Out of all screened molecules, the docking study revealed five compounds were found to have promising activities against RAD52. Moreover, the catalytic amino acid residues of RAD52 developed stable contacts with compound 8758 and 10593, as anticipated by DFT calculation, MD simulation, and post dynamics MM-GBSA energy calculation. It appears that compound 8758 is the best inhibitor against RAD52 followed by 10593 compared to the other top hits, in terms of the HOMO orbital energy (-1.0966 eV and -1.2136 eV) from DFT and the post dynamics binding free energy calculation (-54.71 and -52.43 Kcal/mol). Furthermore, a drug-like properties of lead molecules (8758 and 10593) were also seen via ADMET analysis. Based on our computational analysis, we hypothesize that a small molecule 8758 and 10593 possess the therapeutic potential in the management for breast cancer patients with a BRCA mutation via targeting RAD52.Communicated by Ramaswamy H. Sarma.

Natural sapogenins as potential inhibitors of aquaporins for targeted cancer therapy: computational insights into binding and inhibition mechanism

Aquaporins (AQPs) are membrane proteins that facilitate the transport of water and other small molecules across biological membranes. AQPs are involved in various physiological processes and pathological conditions, including cancer, making them as potential targets for anticancer therapy. However, the development of selective and effective inhibitors of AQPs remains a challenge. In this study, we explored the possibility of using natural sapogenins, a class of plant-derived aglycones of saponins with diverse biological activities, as potential inhibitors of AQPs. We performed molecular docking, dynamics simulation and binding energy calculation to investigate the binding and inhibition mechanism of 19 sapogenins against 13 AQPs (AQP0-AQP13) that are overexpressed in various cancers. Our results showed that out of 19 sapogenins, 8 (Diosgenin, Gitogenin, Tigogenin, Ruscogenin, Yamogenin, Hecogenin, Sarsasapogenin and Smilagenin) exhibited acceptable drug-like characteristics. These sapogenin also exhibited favourable binding affinities in the range of -7.6 to -13.4 kcal/mol, and interactions within the AQP binding sites. Furthermore, MD simulations provided insights into stability and dynamics of the sapogenin-AQP complexes. Most of the fluctuations in binding pocket were observed for AQP0-Gitogenin and AQP4-Diosgenin. However, remaining protein-ligand complex showed stable root mean square deviation (RMSD) plots, strong hydrogen bonding interactions, stable solvent-accessible surface area (SASA) values and minimum distance to the receptor. These observations suggest that natural sapogenin hold promise as novel inhibitors of AQPs, offering a basis for the development of innovative therapeutic agents for cancer treatment. However, further validation of the identified compounds through experiments is essential for translating these findings into therapeutic applications.Communicated by Ramaswamy H. Sarma.

Comparative clinical significance and biological roles of PFKFB family members in oral squamous cell carcinoma

BACKGROUND

Cancer cells promote glycolysis, which supports rapid cell growth and proliferation. Phosphofructokinase-fructose bisphosphatases (PFKFBs), a family of bidirectional glycolytic enzymes, play key roles in the regulation of glycolysis in many types of cancer. However, their roles in oral squamous cell carcinoma (OSCC), the most common type of oral cancer, are still unknown.

METHODS

We compared the gene expression levels of PFKFB family members and analyzed their clinical significance in oral cancer patients, whose clinical data were obtained the Cancer Genome Atlas database. Moreover, real-time quantitative polymerase chain reaction, western blotting, assays for cell viability, cell cycle, cell migration and viability of cell spheroid were performed in scramble and PFKFB-silenced cells.

RESULTS

We discovered that PFKFB3 expression in tumor tissues was slightly higher than that in tumor adjacent normal tissues but that PFKFB4 expression was significantly higher in the tumor tissues of oral cancer patients. High PFKFB3 and PFKFB4 expression had different effects on the prognosis of oral cancer patients with different clinicopathological outcomes. Our data showed that PFKFB3 and PFKFB4 play different roles; PFKFB3 is involved in cell viability, G2/M cell cycle progression, invasion, and migration, whereas PFKFB4 is involved in the drug resistance and cancer stemness of OSCC cells. Furthermore, oral cancer patients with co-expressions of PFKFB3/cell cycle or EMT markers and PFKFB4/stemness markers had poor prognosis.

CONCLUSIONS

PFKFB3 and PFKFB4 play different biological roles in OSCC cells, which implying that they might be potential prognostic biomarkers for OSCC patients with certain clinicopathological outcomes.

Antioxidative and ROS-dependent apoptotic effects of Cuscuta reflexa Roxb. stem against human lung cancer: network pharmacology and in vitro experimental validation

Lung cancer remains a formidable global health challenge, necessitating the exploration of novel therapeutic approaches. This study investigates the potential of Cuscuta reflexa Roxb. stem extract as an anticancer agent against human lung cancer, focusing on its antioxidative and ROS-dependent apoptotic effects. Utilizing a combination of network pharmacology and in-vitro experimental validation, we delineate the multifaceted molecular mechanisms underlying the observed effects. The antioxidant potential of C. reflexa stem extract was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS•+) and ferric reducing/antioxidant power (FRAP), hydroxyl free radical scavenging, reactive nitrogen oxide scavenging and super oxide anion radical scavenging assays. Furthermore, the antiproliferative and proapoptotic effect of C. reflexa stem extract was evaluated against A549 lung adenocarcinoma cell line using the consecrated sulforhodamine B (SBR) and Annexin V-PI assays. Additionally, the mitochondrial membrane potential (MMP) and the total reactive oxygen species (ROS) estimation assays were performed. As a result, network pharmacology analysis revealed a complex interaction network between the bioactive constituents of C. reflexa and key proteins implicated in lung cancer progression. The C. reflexa stem extract showed dose-dependent antioxidant activity against DPPH• (IC50 - 87.38 µg/mL), reactive nitrogen oxide (IC50 - 318.34 µg/mL), FRAP (IC50 - 359.96 µg/mL), hydroxy free radicals (IC50 - 526.12 µg/mL) than ABTS●+ (IC50 - 698.45 µg/mL) and super oxide anion (IC50 - 892.71 µg/mL) as well as cytotoxic activity against A549 cells (IC50 - 436.80 µg/mL). Observations of morphological features in treated cells have revealed hallmark of apoptosis properties. Furthermore, as a result of treatment with C. reflexa stem extract, ROS generation and mitochondrial depolarization were increased in A549 cells, suggesting that this treatment has significant apoptotic properties. . These findings highlight the potential utility of this natural extract as an innovative therapeutic strategy for lung cancer treatment. The integration of network pharmacology and experimental validation enhances our understanding of the underlying mechanisms and provide the way for further translational research.Communicated by Ramaswamy H. Sarma.

Myricetin 3-rhamnoside retards the proliferation of hormone-independent breast cancer cells by targeting hyaluronidase

Breast cancer is the second-leading cause of cancer-related death in women and the most often diagnosed malignancy. As the majority of chemotherapeutic medications are associated with recurrence, drug resistance, and side effects, scientists are shifting to beneficial agents for prevention and treatment, such as natural molecules. Myricetin 3-rhamnoside, a natural flavonol glycoside is known for diverse pharmacological activities but fewer reports describe the antiproliferative ability. The study aims to investigate the antiproliferative efficacy and target [hyaluronidase (HYAL) and ornithine decarboxylase (ODC), two poor breast cancer prognostic markers] modulatory potential of myricetin 3-rhamnoside on breast cancer cell lines using cytotoxicity assays and in silico docking, molecular dynamics analysis, cell-free and cell-based test methods. Myricetin 3-rhamnoside significantly retard the growth of MDA-MB-231 cells in SRB (IC50 88.64 ± 7.14 µM) and MTT (56.26 ± 8.50 µM) assay. It suppressed the transition of cells to the S-phase by inducing arrest in the G0/G1 phase with a fold change of 1.10. It shows robust binding interaction with ODC (-7.90 kcal/mol) and HYAL (-9.46 kcal/mol) and inhibits ODC (15.22 ± 2.61 µM) and HYAL (11.92 ± 2.89 µM) activity, but in a cell-based assay, the prominent response was observed against HYAL (21.46 ± 4.03 µM). Besides, it shows a 1.38 fold-down regulation of HYAL and forms a stable complex with HYAL. The binding pocket for myricetin 3-rhamnoside and the simulation pocket during the simulation are identical, indicating that myricetin 3-rhamnoside is actively blocking hyaluronidase. The computational prediction suggests it is a safe molecule. These observations imply that myricetin 3-rhamnoside could be used as a pharmacophore to design and synthesize a novel and safe agent for managing hormone-independent breast cancer.Communicated by Ramaswamy H. Sarma.

Overcoming translational barriers in H3K27-altered diffuse midline glioma: Increasing the drug-tumor residence time

Background

H3K27-altered diffuse midline glioma (DMG) is the deadliest pediatric brain tumor; despite intensive research efforts, every clinical trial to date has failed. Is this because we are choosing the wrong drugs? Or are drug delivery and other pharmacokinetic variables at play? We hypothesize that the answer is likely a combination, where optimization may result in a much needed novel therapeutic approach.

Methods

We used in vitro drug screening, patient samples, and shRNA knockdown models to identify an upregulated target in DMG. A single small molecule protein kinase inhibitor with translational potential was selected for systemic and direct, loco-regional delivery to patient-derived xenografts (PDX) and genetically engineered mouse models (GEMM). Pharmacokinetic studies were conducted in non-tumor bearing rats.

Results

Aurora kinase (AK) inhibitors demonstrated strong antitumor effects in DMG drug screens. Additional in vitro studies corroborated the importance of AK to DMG survival. Systemic delivery of alisertib showed promise in subcutaneous PDX but not intracranial GEMM and PDX models. Repeated loco-regional drug administration into the tumor through convection-enhanced delivery (CED) was equally inefficacious, and pharmacokinetic studies revealed rapid clearance of alisertib from the brain. In an effort to increase the drug to tumor residence time, continuous CED over 7 days improved drug retention in the rodent brainstem and significantly extended survival in both orthotopic PDXs and GEMMs.

Conclusions

These studies provide evidence for increasing drug-tumor residence time of promising targeted therapies via extended CED as a valuable treatment strategy for DMG.

Computational and Biophysical Characterization of Heterocyclic Derivatives of Anthraquinone against Human Aurora Kinase A

Human Aurora kinase A (AurA) has recently garnered the attention of researchers worldwide as a promising effective mitotic drug target for its involvement in cancer and related inflammatory anomalies. This study has explored the binding affinity of newly identified heteroarene-fused anthraquinone derivatives against AurA. Molecular docking analyses showed that all the heteroanthraquinone compounds bind to AurA with different affinities. Molecular dynamics simulation studies revealed that the compounds maintained relatively stable binding modes in the active site pocket while inducing minimal conformational changes in the AurA structure, interacting with key residues through several noncovalent interactions, including hydrogen bonds. Fluorescence spectroscopy and biolayer interferometry binding assays with synthesized compounds against recombinantly expressed AurA further verified their binding efficacy. Naphthoisatine 3 proved to be the best binder, with compounds anthraimidazole 5 and anthrathiophene 2 showing comparable results. Overall, this study indicates decent binding of heterocyclic derivatives of anthraquinone with the target AurA, which can further be assessed by performing enzymatic assays and cellular studies. The studies also highlight the applicability of the heteroarene-fused anthraquinone scaffold to construct selective and potent inhibitors of Aurora kinases after necessary structural modifications for the development of new anticancer drugs.