Target-based anticancer indole derivatives and insight into structure‒activity relationship: A mechanistic review update (2018–2021)

Targeting anti-apoptotic mechanisms in tumour cells: Strategies for enhancing Cancer therapy

Anti-cancer drug's cytotoxicity is determined by their ability to induce predetermined cell demise, commonly called apoptosis. The cancer-causing cells are able to evade cell death, which has been affiliated with both malignancy as well as resistance to cancer treatments. In order to avoid cell death, cancerous tumour cells often produce an abundance of anti-apoptotic proteins, becoming "dependent" on them. Consequently, protein inhibitors of cell death may prove to be beneficial as pharmacological targets for the future creation of cancer therapies. This article examines the molecular routes of apoptosis, its clinical manifestations, anti-cancer therapy options that target the intrinsic mechanism of apoptosis, proteins that prevent cell death, and members of the B-lymphoma-2 subset. In addition, novel approaches to cell death are highlighted, including how curcumin mitigates chemotherapy-induced apoptosis in healthy tissues and the various ways melatonin modifies apoptosis to improve cancer treatment efficacy, particularly through the TNF superfamily. Cancer treatment-induced increases in anti-apoptotic proteins lead to drug resistance; yet, ligands that trigger cell death by inhibiting these proteins are expected to improve chemotherapy's efficacy. The potential of frequency-modulated dietary phytochemicals as a cancer therapeutic pathway, including autophagy and apoptosis, is also explored. This approach may be more efficient than inhibition alone in overcoming drug resistance. Consequently, this method has the potential to allow for lower medication concentrations, reducing cytotoxicity and unwanted side effects.

Predicting the anticancer activity of indole derivatives: A novel GP-tree-based QSAR model optimized by ALO with insights from molecular docking and decision-making methods

Indole derivatives have demonstrated significant potential as anticancer agents; however, the complexity of their structure-activity relationships and the high dimensionality of molecular descriptors present challenges in the drug discovery process. This study addresses these challenges by introducing a modified GP-Tree feature selection algorithm specifically designed for regression tasks and high-dimensional feature spaces. The algorithm effectively identifies relevant descriptors for predicting LogIC50 values, the target variable. Furthermore, the GP-Tree method adeptly balances the selection of both positively and negatively contributing descriptors, enhancing the performance of DT, k-NN, and RF models. Additionally, the SMOGN technique was employed to address class imbalances, expanding the dataset to 1381 instances and enhancing the accuracy of IC50 predictions. Various machine learning models were optimized using probabilistic and nature-inspired algorithms, with the Ant Lion Optimizer (ALO) demonstrating the highest efficacy. The AdaBoost-ALO (ADB-ALO) model outperformed all other models, such as MLR, SVR, ANN, k-NN, DT, XGBoost, and RF, achieving an R2 of 0.9852 across the entire dataset, an RMSE of 0.1470, and a high CCC of 0.9925. SHAP analysis revealed critical descriptors, such as TopoPSA and electronic properties, which are essential for potent anticancer activity. Furthermore, molecular docking, in conjunction with the Weighted Sum Method (WSM), identified promising candidates, particularly N-amide derivatives of indole-benzimidazole-isoxazoles, which exhibit dual inhibition against topoisomerase I and topoisomerase II enzymes. Consequently, this research integrates computational predictions with experimental insights to accelerate the discovery of novel anticancer therapies through the accurate prediction and interpretation of the anti-prostate cancer activity of indole derivatives.

Exploring β-carboline hybrids and their derivatives: A review on synthesis and anticancer efficiency

β-Carboline is a crucial compound in medicinal chemistry known for its versatile pharmacological activities. Recent research has focused on hybrid molecules incorporating a β-carboline scaffold linked to other pharmacophore moieties. These hybrid compounds have demonstrated diverse therapeutic properties, including anticancer, antianxiety, antimalarial, antidepressant, anti-inflammatory, antileishmanial, and antioxidant effects. This review highlights studies conducted from 2014 to the present with a particular emphasis on the development of β-carboline hybrid compounds and their derivatives as potent anticancer agents. The structure-activity relationship (SAR) analysis reveals that these hybrids exhibit significant cytotoxicity against various cancer cell lines. This review aims to inspire further research into the novel synthesis and evolution of β-carboline hybrids and their derivatives, potentially leading to new therapeutic advancements.

Development of indole hybrids for potential lung cancer treatment - part II

Lung cancer has become the most prevalent cancer for the past three decades, and the 5-years survival rate of lung cancer is only ~20% nowadays. Chemotherapy is the mainstay of lung cancer therapy, especially for non-small cell lung cancer. However, drug resistance represents a principal cause of therapeutic failure in non-small cell lung cancer leading to therapeutic insensitivity, tumor recurrence, and disease progression. Indole hybrids have the potential to conquer drug resistance, enhance efficacy, reduce adverse events, and improve pharmacokinetic properties due to their capacity to inhibit multiple targets simultaneously. Moreover, indole hybrids osimertinib, mobocertinib, cediranib, and vizimpro are currently applied in clinics for lung cancer therapy, demonstrating that indole hybrids are valuable scaffolds in the treatment and eradication of lung cancer. This review provides a comprehensive overview of the evolving landscape of indole hybrids with the in vitro and in vivo efficacy against lung cancer, and the structure-activity relationships as well as mechanisms of action are also discussed, covering articles published from 2021 onward.

Development of indole hybrids for potential lung cancer treatment-part I: nitrogen-containing six-membered aromatic heterocycles

Lung cancer is the most prevalent invasive malignancy and the leading cause of cancer-related death. Chemotherapy is vital for lung cancer therapy, but multidrug resistance is responsible for the majority of lung cancer fatalities, creating an imperative demand to develop novel chemotherapeutics. Indole is a valuable anti-lung cancer pharmacophore since its derivatives could act on lung cancer cells through various mechanisms. Notably, indole hybrids could inhibit multiple targets simultaneously and have the potential to overcome the shortcomings of traditional chemotherapeutics. Moreover, many indole hybrids such as the indole-pyrimidine hybrid osimertinib and the indole-hydroxamic acid hybrid panobinostat, are either under clinical evaluations or have already been approved for lung cancer therapy. This indicates that the rational design of indole hybrids represents a highly prospective approach for the development of new anti-lung cancer chemotherapeutic agents. This review focuses on exploring the anti-lung cancer therapeutic potential of indole hybrids and delves into their action mechanisms as well as structure-activity correlations, covering articles published between 2021 and present. The ultimate goal is to offer a foundation for the rational design of indole hybrids in the future.

Copper-catalyzed chemoselective C-H functionalization/dearomatization sequence: direct access to indole-based spirocyclic scaffolds

Herein, a copper-catalyzed intermolecular [4+1] spiroannulation of indoles with alkynyldiazoketones affording various indole-based spirocyclic molecules via a chemoselective C-H functionalization/dearomatization sequence was developed.

Indole-Boron-Difluoride Complexes with Anticancer and Fluorescence Properties

Eight indole-boron-difluoride complexes were synthesized from 2,3-arylpyridylindole derivatives via Sonogashira coupling and Larock heteroannulation. These complexes exhibited distinct photophysical properties. Solvent polarity influenced their spectral behavior showing hypsochromic absorption, bathochromic emission shifts, and aggregation-induced emission (AIE) in mixed solvents. The ¹⁹F NMR shifts and photophysical properties, including excitation, emission maxima, and Stokes shift, correlated with Hammett substituent constants highlighting electronic effects on molecular properties. The synthesized complexes exhibited a range of intramolecular charge transfer (ICT) behaviors, as evidenced by their Lippert-Mataga parameters. TD-DFT calculations aligned with experimental data, offering insight into spectroscopic behavior. Notably, the indole-boron-difluoride complex bearing a methyl ester group exhibited significant anticancer activity against HeLa cells and potential for fluorescence imaging, indicating its promise for biomedical applications in cell imaging and therapy.

Discovery of novel thienopyridine indole derivatives as inhibitors of tubulin polymerization targeting the colchicine-binding site with potent anticancer activities

Based on the molecular hybridization strategy, novel thienopyridine indole derivatives were designed and synthesized as tubulin polymerization inhibitors, and the in vitro antiproliferative potency on MGC-803, KYSE450 and HCT-116 cells was evaluated. Among them, compound 20b showed a broad-spectrum antiproliferative activity against 11 cancer cell lines, with IC50 values below 4 nmol/L. Notably, it demonstrated exceptional efficacy against MGC-803 (IC50 = 1.61 nmol/L) and HGC-27 (IC50 = 1.82 nmol/L) cells. Further mechanism explorations suggested that compound 20b could inhibit tubulin polymerization (IC50 = 2.505 μmol/L) by acting on the colchicine binding site, thereby disrupting intracellular microtubule networks and interfering with cell mitosis. In addition, compound 20b effectively inhibited the colony formation and cell migration activities, and induced G2/M phase cycle arrest and apoptosis in MGC-803 and HGC-27 cells. Besides, compound 20b also displayed potent anti-angiogenesis effects on HUVECs. Importantly, compound 20b demonstrated oral efficacy in inhibiting tumor growth with a TGI of 45.8 % (5 mg/kg/qod) in the mouse xenograft model bearing MGC-803 cells, surpassing that of CA-4 (TGI of 27.1 % at 20 mg/kg/qod), as well as also exhibited a good safety profile. Therefore, these results suggested that the thienopyridine indole derivative 20b represents a novel tubulin inhibitor with potent anticancer efficacy that inhibits gastric cancers.

Protein profiling uncovers IGF-1R inhibition potential of 3-(2-furoyl)-indole scaffolds in hepatocellular carcinoma

AIM

This study investigates the anti-proliferative potential and possible molecular mechanisms of 3-(2-furoyl)-indole derivatives against HepG2.

METHOD

Identified hit compounds (4a, 4b, 4c) using MTT screening, were further investigated for their efficacy and mechanism of action through FACS studies, in-silico molecular docking, molecular dynamics (MD) simulations, and label-free quantitative proteome and ADMET prediction.

RESULTS

Lead compound 4a, showed IC50 of 27 µM against HepG2 cells and a binding score of -8.077 kcal/mol against IGF-1 R (PDB ID: 5XFS) and formed a stable complex 100 ns. Proteomic study revealed significant downregulation of the IGF-1 R downstream signaling molecules and showed minimal toxicity and favorable drug-like properties.

CONCLUSION

These findings suggest that 4a is a promising IGF-1 R inhibitor and potential drug candidate against drug resistance hepatocellular carcinoma (HCC).

Design, synthesis, and biological evaluation of steroidal indole derivatives as membrane-targeting antibacterial candidates

Rational modification of natural products plays a key role in drug discovery. Herein, a series of steroidal indole derivatives containing various substituents and steroidal skeletons were designed and synthesized with classical Fischer indole synthesis as a key step in an efficient synthetic route for the first time. The in vitro antibacterial activity of all the synthesized derivatives was evaluated against four Gram-positive strains including three Methicillin-Resistant Staphylococcus aureus. Compound 11e displayed the most potent antibacterial activity (MIC = 1-2 μg/mL) with low cytotoxicity and hemolytic activity. Derivative 11e displayed more rapid bactericidal kinetic than vancomycin in the time-kill study and was less likely to induce bacterial resistance. Moreover, the preliminary antibacterial mechanism explorations indicated that compound 11e could effectively inhibit biofilm formation, promote the accumulation of reactive oxygen species, decrease bacterial metabolism, and destroy bacterial cell membranes to exert its antibacterial effects. The study of in vivo antibacterial activity suggested that compound 11e could significantly reduce the bacteria counts in a mouse subcutaneous infection model. These findings provided a bright hope for steroidal indole derivatives as promising antibacterial candidates to settle drug resistance.

Natural and synthetic 5-(3'-indolyl)oxazoles: Biological activity, chemical synthesis and advanced molecules

5-(3'-Indolyl)oxazole moiety is a privileged heterocyclic scaffold, embedded in many biologically interesting natural products and potential therapeutic agents. Compounds containing this scaffold, whether from natural sources or synthesized, have demonstrated a wide array of biological activities. This has piqued the interest of synthetic chemists, leading to a large number of reported synthetic approaches to 5-(3'-indolyl)oxazole scaffold in recent years. In this review, we comprehensively overviewed the different biological activities and chemical synthetic methods for the 5-(3'-indolyl)oxazole scaffold reported in the literatures from 1963 to 2024. The focus of this study is to highlight the significance of 5-(3'-indolyl)oxazole derivatives as the lead compounds for the lead discovery of anticancer, pesticidal, antimicrobial, antiviral, antioxidant and anti-inflammatory agents, to summarize the synthetic methods for the 5-(3'-indolyl)oxazole scaffold. In addition, the reported mechanism of action of 5-(3'-indolyl)oxazoles and advanced molecules studied in animal models are also reviewed. Furthermore, this review offers perspectives on how 5-(3'-indolyl)oxazole scaffold as a privileged structure might be exploited in the future.

Probing the Biomolecular Interactions of DNA/HSA with the New Sn(IV) Complex and Computational Perspectives: Design, Synthesis, Characterization, Anticancer Activity, and Molecular Modeling Approach

The ligands 2,2'-bipyridyl and indole-3-carboxylic acid were used to create a Sn(IV) complex, which was then synthesized and carefully characterized using elemental analysis and spectroscopic techniques (UV-vis, IR, 1H, 13C, and 119Sn NMR, and ESI-MS) and RXPD. Utilizing biophysical techniques such as UV-vis, fluorescence titrations, circular dichroism, FTIR (for HSA), and cleavage activity (for DNA), in vitro binding studies of Sn(IV) complex and DNA/HSA were satisfied with the strong electrostatic binding interaction of the Sn(IV) complex via the phosphate backbone of the DNA helix as well as in the subdomain IIA of HSA. The observed trend in the binding interactions and computational studies of the Sn(IV) complex was attributed to the nature of the ligands bound to the Sn(IV) center that influences their in vitro activities. The Sn(IV) complex showed sufficient effectiveness to be considered a viable candidate for the creation of anticancer medications.

Neuroprotective Potential of Indole-Based Compounds: A Biochemical Study on Antioxidant Properties and Amyloid Disaggregation in Neuroblastoma Cells

Based on the established neuroprotective properties of indole-based compounds and their significant potential as multi-targeted therapeutic agents, a series of synthetic indole-phenolic compounds was evaluated as multifunctional neuroprotectors. Each compound demonstrated metal-chelating properties, particularly in sequestering copper ions, with quantitative analysis revealing approximately 40% chelating activity across all the compounds. In cellular models, these hybrid compounds exhibited strong antioxidant and cytoprotective effects, countering reactive oxygen species (ROS) generated by the Aβ(25-35) peptide and its oxidative byproduct, hydrogen peroxide, as demonstrated by quantitative analysis showing on average a 25% increase in cell viability and a reduction in ROS levels to basal states. Further analysis using thioflavin T fluorescence assays, circular dichroism, and computational studies indicated that the synthesized derivatives effectively promoted the self-disaggregation of the Aβ(25-35) fragment. Taken together, these findings suggest a unique profile of neuroprotective actions for indole-phenolic derivatives, combining chelating, antioxidant, and anti-aggregation properties, which position them as promising compounds for the development of multifunctional agents in Alzheimer's disease therapy. The methods used provide reliable in vitro data, although further in vivo validation and assessment of blood-brain barrier penetration are needed to confirm therapeutic efficacy and safety.

Bisindole Compounds-Synthesis and Medicinal Properties

The indole nucleus stands out as a pharmacophore, among other aromatic heterocyclic compounds with remarkable therapeutic properties, such as benzimidazole, pyridine, quinoline, benzothiazole, and others. Moreover, a series of recent studies refer to strategies for the synthesis of bisindole derivatives, with various medicinal properties, such as antimicrobial, antiviral, anticancer, anti-Alzheimer, anti-inflammatory, antioxidant, antidiabetic, etc. Also, a series of natural bisindole compounds are mentioned in the literature for their various biological properties and as a starting point in the synthesis of other related bisindoles. Drawing from these data, we have proposed in this review to provide an overview of the synthesis techniques and medicinal qualities of the bisindolic compounds that have been mentioned in recent literature from 2010 to 2024 as well as their numerous uses in the chemistry of materials, nanomaterials, dyes, polymers, and corrosion inhibitors.

Adipose-derived stem cells exosomal circHIPK3 protects ovarian function by regulating MAPK signaling

BACKGROUND

Exosomes derived from adipose-derived stem cells (ADSCs) have garnered significant attention for their therapeutic potential in various diseases. These vesicles are capable of transporting bioactive molecules such as noncoding RNAs and proteins. Among these noncoding RNAs, circular RNAs (circRNAs) are characterized as end-to-end circular structures, which are notably enriched within exosomes.

OBJECTIVE

This study aims to investigate the impact of the circHIPK3 delivered via ADSC-derived exosomes on ovarian aging.

MATERIALS AND METHODS

ADSCs were isolated, and exosomes were obtained from a cell culture medium. The exosomes were labeled with PKH26, and uptake by primary granulosa cells (pGCs) was detected. ADSCs were transfected with circHIPK3 siRNAs, and the exosomes were isolated for the treatment of aging female mice. Ovary weight was recorded, and HE staining, Masson's trichrome, and TUNEL staining were performed to detect tissue morphology and apoptosis in ovary tissues. In addition, the senescence and apoptosis of pGCs were evaluated using the S-β-gal staining kit and Annexin V/PI detection kit. Further experiments included immunoprecipitation and RNA pulldown, determined the ubiquitination of p38 protein under circHIPK3 alteration.

RESULTS

Results showed that ADSC-derived exosomes effectively delivered circHIPK3 to pGCs. Treatment with these exosomes significantly increased ovary weight and enhanced follicular development in aged mice. Conversely, the depletion of circHIPK3 reversed these effects, promoting cell apoptosis. ADSC-derived exosomes also mitigated senescence and apoptosis in pGCs, while circHIPK3 depletion hindered these benefits.

CONCLUSION

Exosomal circHIPK3 modulated the ubiquitination of p38 in pGCs to improve ovarian function in aging mice and to promote pGC cell viability.

ARG2 knockdown promotes G0/G1 cell cycle arrest and mitochondrial dysfunction in adenomyosis via regulation NF-κB and Wnt/Β-catenin signaling cascades

BACKGROUND

Adenomyosis is a common gynecological disease, characterized by overgrowth of endometrial glands and stroma in the myometrium, however its exact pathophysiology still remains uncertain. Emerging evidence has demonstrated the elevated level of arginase 2 (ARG2) in endometriosis and adenomyosis. This study aimed to determine whether ARG2 involved in mitochondrial function and epithelial to mesenchymal transition (EMT) in adenomyosis and its potential underlying mechanisms.

MATERIALS AND METHODS

RNA interference was used to inhibit ARG2 gene, and then Cell Counting Kit (CCK-8) assay and flow cytometery were performed to detect the cell proliferation capacity, cell cycle, and apoptosis progression, respectively. The mouse adenomyosis model was established and RT-PCR, Western blot analysis, mitochondrial membrane potential (Δψm) detection and mPTP opening evaluation were conducted.

RESULTS

Silencing ARG2 effectively down-regulated its expression at the mRNA and protein levels in endometrial cells, leading to decreased enzyme activity and inhibition of cell viability. Additionally, ARG2 knockdown induced G0/G1 cell cycle arrest, promoted apoptosis, and modulated the expression of cell cycle- and apoptosis-related regulators. Notably, the interference with ARG2 induces apoptosis by mitochondrial dysfunction, ROS production, ATP depletion, decreasing the Bcl-2/Bax ratio, releasing Cytochrome c, and increasing the expression of Caspase-9/-3 and PARP. In vivo study in a mouse model of adenomyosis demonstrated also elevated levels of ARG2 and EMT markers, while siARG2 treatment reversed EMT and modulated inflammatory cytokines. Furthermore, ARG2 knockdown was found to modulate the NF-κB and Wnt/β-catenin signaling pathways in mouse adenomyosis.

CONCLUSION

Consequently, ARG2 silencing could induce apoptosis through a mitochondria-dependent pathway mediated by ROS, and G0/G1 cell cycle arrest via suppressing NF-κB and Wnt/β-catenin signaling pathways in Ishikawa cells. These findings collectively suggest that ARG2 plays a crucial role in the pathogenesis of adenomyosis and may serve as a potential target for therapeutic intervention.

A Metal-Free Direct Decarboxylative Fluoroacylation of Indole Carboxylic Acids with Fluorinated Acids

A straightforward preparation of diversified fluorinated indol-3-yl ketones was developed by the direct decarboxylative fluoroacylation of indole carboxylic acids. The reaction could be performed on a gram scale under net conditions. Neither a metal catalyst nor an additive was employed. This methodology featured simple reaction conditions, high efficiency, exclusive selectivity, a broad substrate scope, and easy operation, which allowed it to meet the green chemistry requirement of the modern pharmaceutical industry. Control experiments confirmed that a radical process might be involved in the tandem decarboxylative fluoroacylation sequence.

Assessment of the Lipophilicity of Indole Derivatives of Betulin and Their Toxicity in a Zebrafish Model

There are scientific studies indicating that the attachment of an indole moiety to the triterpene scaffold can lead to increased anticancer potential. Lipophilicity is one of the factors that may influence biological properties and is therefore an important parameter to determine for newly obtained compounds as drug candidates. In the present study, previously synthesized 3 and/or 28-indole-betulin derivatives were evaluated for lipophilicity by reversed-phase thin-layer chromatography. The experimental values of lipophilicity (logPTLC) were then subjected to correlation analysis with theoretical values of logP, as well as for selected physicochemical and pharmacokinetic parameters and anticancer activity. A toxicity test using zebrafish embryos and larvae was also conducted. High correlation was observed between the experimental and theoretical values of lipophilicity. We presented correlation equations and statistical parameters describing the relationships between logPTLC and several physicochemical and ADME parameters. We also revealed the lack of correlation between the experimental values of lipophilicity and anticancer activity. Moreover, experiments on zebrafish have confirmed no toxicity of the tested compounds, which was consistent with the results of the in silico toxicity analysis. The results demonstrated, using the example of indole derivatives of betulin, the utility of lipophilicity values in the context of predicting the biological activity of new compounds.

Discovery of Indole-Thiourea Derivatives as Tyrosinase Inhibitors: Synthesis, Biological Evaluation, Kinetic Studies, and In Silico Analysis

Tyrosinase, a key enzyme in melanin synthesis, represents a crucial therapeutic target for hyperpigmentation disorders due to excessive melanin production. This study aimed to design and evaluate a series of indole-thiourea derivatives by conjugating thiosemicarbazones with strong tyrosinase inhibitory activity to indole. Among these derivatives, compound 4b demonstrated tyrosinase inhibitory activity with an IC50 of 5.9 ± 2.47 μM, outperforming kojic acid (IC50 = 16.4 ± 3.53 μM). Kinetic studies using Lineweaver-Burk plots confirmed competitive inhibition by compound 4b. Its favorable ADMET and drug-likeness properties make compound 4b a promising therapeutic candidate with a reduced risk of toxicity. Molecular docking revealed that the compounds bind strongly to mushroom tyrosinase (mTYR) and human tyrosinase-related protein 1 (TYRP1), with compound 4b showing superior binding energies of -7.0 kcal/mol (mTYR) and -6.5 kcal/mol (TYRP1), surpassing both kojic acid and tropolone. Molecular dynamics simulations demonstrated the stability of the mTYR-4b complex with low RMSD and RMSF and consistent Rg and SASA values. Persistent strong hydrogen bonds with mTYR, along with favorable Gibbs free energy and MM/PBSA calculations (-19.37 kcal/mol), further support stable protein-ligand interactions. Overall, compound 4b demonstrated strong tyrosinase inhibition and favorable pharmacokinetics, highlighting its potential for treating pigmentary disorders.

Comparison of esophageal cancer survival after neoadjuvant chemoradiotherapy plus surgery versus definitive chemoradiotherapy: A systematic review and meta-analysis

Surgery after neoadjuvant chemoradiotherapy remains the gold standard for the treatment of resectable esophageal cancer (EC); however, chemoradiotherapy without surgery has been recommended in specific cases. The aim of this meta-analysis is to analyse the survival between surgeries after neoadjuvant chemoradiotherapy compared with definitive chemoradiotherapy in order to provide a theoretical basis for clinically individualised differential treatment. We conducted an initial search of MEDLINE (PubMed), the Cochrane Library, and Embase for English-only articles that compared treatment regimens and provided survival data. According to the final I2 value of the two survival indicators, the random effect model or fixed effect model was used to calculate the overall hazard ratio (HR) and 95% confidence intervals (CI). Cochrane's Q test was used to judge the heterogeneity of the studies, and a funnel plot was used to evaluate for publication bias. A sensitivity analysis was performed to verify the stability of the included studies. A total of 38 studies involving 29161 patients (neoadjuvant therapy: 15401, definitive chemoradiotherapy: 13760) were included in the analysis. The final pooled results (HR = 0.74, 95% CI: 0.67-0.82) showed a statistically significant increase in overall survival with neoadjuvant chemoradiotherapy plus surgery compared with definitive chemoradiotherapy. Subgroup analyses were performed to determine the effects of heterogeneity, additional treatment regimens, study types, and geographic regions, as well as histologic differences, complications, and recurrence, on the overall results. For people with esophageal cancer that can be removed, neoadjuvant chemoradiotherapy combined with surgery improves survival compared to definitive chemoradiotherapy. However, more research is needed to confirm these results and help doctors make decisions about treatment.

Pd(II)-Catalyzed C4-Selective Alkynylation of Indoles by a Transient Directing Group

With alanine as a transient directing group, Pd-catalyzed regioselective alkynylation at the indole C4-position was successfully established in a good yield. The total synthesis of the PAF antagonist demonstrated the synthetic utility of this protocol. The regioselectivity was explicitly proven by the prepared C4-selective palladacycle intermediate in the catalytic process and the DFT calculation of the energy barriers of C4- and C2-site-selective C-H activation of indole.

Palladium-Catalyzed Regioselective Monofluoroallylation of Indoles with gem-Difluorocyclopropanes

We present a palladium-catalyzed ring-opening reaction that induces indoles to cross-couple with gem-difluorocyclopropanes. The reaction proceeds through a domino process of C-C bond activation and C-F bond elimination, followed by C-C(sp2) coupling to produce various 2-fluoroallylindoles. This method is characterized by its high functional group tolerance, good yields and high regioselectivity, under base-free conditions. The synthetic utility of the products is illustrated by the functionalization of the NH and C2 positions of the indole scaffold.

Antitumor activity of anlotinib in malignant melanoma: modulation of angiogenesis and vasculogenic mimicry

Malignant melanoma presents a formidable challenge due to its aggressive metastatic behavior and limited response to current treatments. To address this, our study delves into the impact of anlotinib on angiogenesis and vasculogenic mimicry using malignant melanoma cells and human umbilical vein endothelial cells. Evaluating tubular structure formation, cell proliferation, migration, invasion, and key signaling molecules in angiogenesis, we demonstrated that anlotinib exerts a dose-dependent inhibition on tubular structures and effectively suppresses cell growth and invasion in both cell types. Furthermore, in a mouse xenograft model, anlotinib treatment resulted in reduced tumor growth and vascular density. Notably, the downregulation of VEGFR-2, FGFR-1, PDGFR-β, and PI3K underscored the multitargeted antitumor activity of anlotinib. Our findings emphasize the therapeutic potential of anlotinib in targeting angiogenesis and vasculogenic mimicry, contributing to the development of novel strategies for combating malignant melanoma.

Anti-proliferation evaluation of new derivatives of indole-6-carboxylate ester as receptor tyrosine kinase inhibitors

Aim: The main goal was to create two new groups of indole derivatives, hydrazine-1-carbothioamide (4a and 4b) and oxadiazole (5, and 6a-e) that target EGFR (4a, 4b, 5) or VEGFR-2 (6a-e). Materials & methods: The new derivatives were characterized using various spectroscopic techniques. Docking studies were used to investigate the binding patterns to EGFR/VEGFR-2, and the anti-proliferative properties were tested in vitro. Results: Compounds 4a (targeting EGFR) and 6c (targeting VEGFR-2) were the most effective cytotoxic agents, arresting cancer cells in the G2/M phase and inducing the extrinsic apoptosis pathway. Conclusion: The results of this study show that compounds 4a and 6c are promising cytotoxic compounds that inhibit the tyrosine kinase activity of EGFR and VEGFR-2, respectively.

Indole-Based Compounds in the Development of Anti-Neurodegenerative Agents

Neurodegeneration is a gradual decay process leading to the depletion of neurons in both the central and peripheral nervous systems, ultimately resulting in cognitive dysfunctions and the deterioration of brain functions, alongside a decline in motor skills and behavioral capabilities. Neurodegenerative disorders (NDs) impose a substantial socio-economic strain on society, aggravated by the advancing age of the world population and the absence of effective remedies, predicting a negative future. In this context, the urgency of discovering viable therapies is critical and, despite significant efforts by medicinal chemists in developing potential drug candidates and exploring various small molecules as therapeutics, regrettably, a truly effective treatment is yet to be found. Nitrogen heterocyclic compounds, and particularly those containing the indole nucleus, which has emerged as privileged scaffold, have attracted particular attention for a variety of pharmacological applications. This review analyzes the rational design strategy adopted by different research groups for the development of anti-neurodegenerative indole-based compounds which have the potential to modulate various molecular targets involved in NDs, with reference to the most recent advances between 2018 and 2023.

Design, synthesis, and anticancer evaluation of 1-benzo[1,3]dioxol-5-yl-3-N-fused heteroaryl indoles

A series of 1-benzo[1,3]dioxol-5-yl-indoles bearing 3-N-fused heteroaryl moieties have been designed based on literature reports of the activity of indoles against various cancer cell lines, synthesized via a Pd-catalyzed C-N cross-coupling, and evaluated for their anticancer activity against prostate (LNCaP), pancreatic (MIA PaCa-2), and acute lymphoblastic leukemia (CCRF-CEM) cancer cell lines. A detailed structure-activity relationship study culminated in the identification of 3-N-benzo[1,2,5]oxadiazole 17 and 3-N-2-methylquinoline 20, whose IC50 values ranged from 328 to 644 nM against CCRF-CEM and MIA PaCa-2. Further mechanistic studies revealed that 20 caused cell cycle arrest at the S phase and induced apoptosis in CCRF-CEM cancer cells. These 1-benzo[1,3]dioxol-5-yl-3-N-fused heteroaryl indoles may serve as a template for further optimization to afford more active analogs and develop a comprehensive understanding of the structure-activity relationships of indole anticancer molecules.

LL-37 improves sepsis-induced acute lung injury by suppressing pyroptosis in alveolar epithelial cells

BACKGROUND

LL-37 (also known as murine CRAMP) is a human antimicrobial peptide that plays a crucial role in innate immune defence against sepsis through various mechanisms. However, its involvement in sepsis-induced lung injury remains unclear.

OBJECTIVES

This work investigates the impact of LL-37 on pyroptosis generated by LPS in alveolar epithelial cells. The research utilizes both in vivo and in vitro sepsis-associated acute lung injury (ALI) models to understand the underlying molecular pathways.

METHODS

In vivo, an acute lung injury model induced by sepsis was established by intratracheal administration of LPS in C57BL/6J mice, which were subsequently treated with low-dose CRAMP (recombinant murine cathelicidin, 2.5 mg.kg-1) and high-dose CRAMP (5.0 mg.kg-1). In vitro, pyroptosis was induced in a human alveolar epithelial cell line (A549) by stimulation with LPS and ATP. Treatment was carried out with recombinant human LL-37, or LL-37 was knocked out in A549 cells using small interfering RNA (siRNA). Subsequently, haematoxylin and eosin staining was performed to observe the histopathological changes in lung tissues in the control group and sepsis-induced lung injury group. TUNEL and PI staining were used to observe DNA fragmentation and pyroptosis in mouse lung tissues and cells in the different groups. An lactate dehydrogenase (LDH) assay was performed to measure the cell death rate. The expression levels of NLRP3, caspase1, caspase 1 p20, GSDMD, NT-GSDMD, and CRAMP were detected in mice and cells using Western blotting, qPCR, and immunohistochemistry. ELISA was used to assess the levels of interleukin (IL)-1β and IL-18 in mouse serum, bronchoalveolar lavage fluid (BALF) and lung tissue and cell culture supernatants.

RESULTS

The expression of NLRP3, caspase1 p20, NT-GSDMD, IL 18 and IL1β in the lung tissue of mice with septic lung injury was increased, which indicated activation of the canonical pyroptosis pathway and coincided with an increase in CRAMP expression. Treatment with recombinant CRAMP improved pyroptosis in mice with lung injury. In vitro, treatment with LPS and ATP upregulated these classic pyroptosis molecules, LL-37 knockdown exacerbated pyroptosis, and recombinant human LL-37 treatment alleviated pyroptosis in alveolar epithelial cells.

CONCLUSION

These findings indicate that LL-37 protects against septic lung injury by modulating the expression of classic pyroptotic pathway components, including NLRP3, caspase1, and GSDMD and downstream inflammatory factors in alveolar epithelial cells.

Demethoxymurrapanine, an indole-naphthoquinone alkaloid, inhibits the proliferation of oral cancer cells without major side effects on normal cells

Antioral cancer drugs need a greater antiproliferative impact on cancer than on normal cells. Demethoxymurrapanine (DEMU) inhibits proliferation in several cancer cells, but an in-depth investigation was necessary. This study evaluated the proliferation-modulating effects of DEMU, focusing on oral cancer and normal cells. DEMU (0, 2, 3, and 4 μg/mL) at 48 h treatments inhibited the proliferation of oral cancer cells (the cell viability (%) for Ca9-22 cells was 100.0 ± 2.2, 75.4 ± 5.6, 26.0 ± 3.8, and 15.4 ± 1.4, and for CAL 27 cells was 100.0 ± 9.4, 77.2 ± 5.9, 57.4 ± 10.7, and 27.1 ± 1.1) more strongly than that of normal cells (the cell viability (%) for S-G cells was 100.0 ± 6.6, 91.0 ± 4.6, 95.0 ± 2.6, and 95.8 ± 5.5), although this was blocked by the antioxidant N-acetylcysteine. The presence of oxidative stress was evidenced by the increase of reactive oxygen species and mitochondrial superoxide and the downregulation of the cellular antioxidant glutathione in oral cancer cells, but these changes were minor in normal cells. DEMU also caused greater induction of the subG1 phase, extrinsic and intrinsic apoptosis (annexin V and caspases 3, 8, and 9), and DNA damage (γH2AX and 8-hydroxy-2-deoxyguanosine) in oral cancer than in normal cells. N-acetylcysteine attenuated all these DEMU-induced changes. Together, these data demonstrate the preferential antiproliferative function of DEMU in oral cancer cells, with the preferential induction of oxidative stress, apoptosis, and DNA damage in these cancer cells, and low cytotoxicity toward normal cells.

Platinum(IV) Prodrugs Incorporating an Indole-Based Derivative, 5-Benzyloxyindole-3-Acetic Acid in the Axial Position Exhibit Prominent Anticancer Activity

Kinetically inert platinum(IV) complexes are a chemical strategy to overcome the impediments of standard platinum(II) antineoplastic drugs like cisplatin, oxaliplatin and carboplatin. In this study, we reported the syntheses and structural characterisation of three platinum(IV) complexes that incorporate 5-benzyloxyindole-3-acetic acid, a bioactive ligand that integrates an indole pharmacophore. The purity and chemical structures of the resultant complexes, P-5B3A, 5-5B3A and 56-5B3A were confirmed via spectroscopic means. The complexes were evaluated for anticancer activity against multiple human cell lines. All complexes proved to be considerably more active than cisplatin, oxaliplatin and carboplatin in most cell lines tested. Remarkably, 56-5B3A demonstrated the greatest anticancer activity, displaying GI50 values between 1.2 and 150 nM. Enhanced production of reactive oxygen species paired with the decline in mitochondrial activity as well as inhibition of histone deacetylase were also demonstrated by the complexes in HT29 colon cells.

Rhodium-catalyzed annulation of hydrazines with vinylene carbonate to synthesize unsubstituted 1-aminoindole derivatives

Herein, we describe rhodium-catalysed C-H bond activation for [3 + 2] annulation using hydrazide and vinylene carbonate, providing an efficient method for synthesising unsubstituted 1-aminoindole compounds. Characterised by high yields, mild reaction conditions, and no need for external oxidants, this transformation demonstrates excellent regioselectivity and a wide tolerance for various functional groups.

Over-expression of microRNA-145 Elevating Autophagy Activities via Downregulating FRS2 Expression

OBJECTIVES

Osteoarthritis (OA) is one of the most common chronic and progressive joint diseases characterized by cartilage degeneration and chondrocyte death. In this study, we aimed to identify the modulation effect of miR-145 on chondrocytes' autophagy during the development of OA.

BACKGROUND

Osteoarthritis (OA) is one of the most prevalent types of chronic and progressive joint disorder with the symptoms of joint pain and stiffness, and it leads to disability at the end stage. In recent years, microRNA-145 (miR-145) has been found to activate autophagy in various cell types, including mesenchymal stem cells, cardiomyocytes, and osteosarcoma cells. However, it is unknown whether miR-145 regulates the progression of OA by influencing chondrocyte autophagy.

METHODS

Before investigating the regulatory effect of miR-145 on the autophagic activity of chondrocytes, the expression of miR-145 in human joint samples was analyzed. The targeting relationship between miR-145 and FRS2 was detected by dual luciferase assay. The effect of FRS2 and miR-145 on the autophagic activity of chondrocytes was observed by bidirectional expression of FRS2 and miR-145.

RESULTS

The miR-145 expression and LC3-II/LC3-I ratio were significantly decreased and the SQSTM1 expression was increased in OA patients. The miR-145 overexpression in C20A4 cells increased LC3-II/LC3-I ratio, decreased SQSTM1 expression, and was positively correlated with autophagic activity. Under oxidative stress, miR-145 overexpression significantly improved chondrocyte viability through autophagy stimulation. FRS2 is a potential target of miR-145 via a binding sequence within its 3' UTR. FRS2 acts as the downstream mediator of miR-145 to suppress autophagy through activating PI3K/Akt/mTOR pathways.

CONCLUSION

The miR-145 acts as a protective factor against chondrocytes by regulating miRFRS2- autophagy axis. The decrease of miR-145 in articular synovial fluid may turn out to be an important marker for early diagnosis of OA, and modulation of miR-145 may represent a promising therapeutic strategy for OA.

Metformin Preserves Insulin Secretion in Pancreatic β-cells through FGF21/Akt Pathway In vitro and In vivo

BACKGROUND

In our previous studies, it was found that metformin can elevate the expression of FGF21 in the peripheral blood of type 2 diabetic rats and improve insulin sensitivity in diabetic rats. However, whether this effect is mediated by increased FGF21 expression in pancreatic islet β-cells is still unknown. Therefore, this study focuses on the effect of metformin on insulin secretion in pancreatic β-cells.

AIMS

Metformin can effectivly improve insulin resistance. Metformin influencing pancreatic β- cell function is inclusive. In this study, we sought to analyze possible variations in insulin secretion and possible signaling mechanisms after metformin intervention.

METHODS

The study employed an in vivo model of a high-fat diet in streptozocin-induced diabetic rats and an in vitro model of rat pancreatic β-cells (INS-1 cells) that were subjected to damage caused by hyperglycemia and hyperlipidemia. After treating INS-1 cells in normal, high-glucose, and high-glucose+metformin, we measured insulin secretion by glucose-stimulated insulin secretion (GSIS). Insulin was measured using an enzyme-linked immunosorbent assay. FGF21 expression was detected by RT-PCR and Western blot, as well as that p-Akt and t-Akt expression were detected by Western blot in INS-1 cells and diabetic rat islets. Finally, to verify the regulation of the FGF21 /Akt axis in metformin administration, additional experiments were carried out in metformin-stimulated INS-1 cells.

RESULTS

High-glucose could significantly stimulate insulin secretion while metformin preserved insulin secretion. Expression of FGF21 and p-Akt was decreased in high-glucose, however, metformin could reverse this effect in INS-1 cells and diabetic rat islets.

CONCLUSION

Our results demonstrate a protective role of metformin in preserving insulin secretion through FGF21/Akt signaling in T2DM.

The Protective Effect of Sanggenol L Against DMBA-induced Hamster Buccal Pouch Carcinogenesis Induces Apoptosis and Inhibits Cell Proliferative Signalling Pathway

BACKGROUND

Oral squamous cell carcinoma (OSCC) has a poor prognosis when treated with surgery and chemotherapy. Therefore, a new therapy and preventative strategy for OSCC and its underlying mechanisms are desperately needed. The purpose of this study was to examine the chemopreventive effects of sanggenol L on oral squamous cell carcinoma (OSCC). The research focused on molecular signalling pathways in 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.

AIM

The purpose of this study was to look at the biochemical and chemopreventive effects of sanggenol L on 7,12-dimethylbenz(a)anthracene (DMBA)-induced HBP (hamster buccal pouch) carcinogenesis via cell proliferation and the apoptotic pathway.

METHODS

After developing squamous cell carcinoma, oral tumours continued to progress leftward into the pouch 3 times per week for 10 weeks while being exposed to 0.5 % reactive DMBA three times per week. Tumour growth was caused by biochemical abnormalities that induced inflammation, increased cell proliferation, and decreased apoptosis.

RESULTS

Oral sanggenol L (10 mg/kg bw) supplementation with cancer-induced model DMBApainted hamsters prevented tumour occurrences, improved biochemistry, inhibited inflammatory markers, decreased cell proliferation marker expression of tumour necrosis factor-alpha (TNF- α), nuclear factor (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and induced apoptosis.

CONCLUSION

Sanggenol L could be developed into a new medicine for the treatment of oral carcinogenesis.

Neuritin Alleviates Diabetic Retinopathy by Regulating Endoplasmic Reticulum Stress in Rats

BACKGROUND

Neuritin, a small-molecule neurotrophic factor, maintains neuronal cell activity, inhibits apoptosis, promotes process growth, and regulates neural progenitor cell differentiation, migration, and synaptic maturation. Neuritin helps retinal ganglion cells (RGCs) survive optic nerve injury in rats and regenerate axons. However, the role of Neuritin in Diabetic retinopathy (DR) is unclear.

OBJECTIVE

This study is intended to investigate the effect and mechanism of Neuritin in DR. For this purpose, we established DR rat models and injected Neuritin into them. This study provides a potential treatment for diabetic retinopathy.

METHODS

The rat model of DR was established by streptozotocin (STZ) injection, and the effect of Neuritin on DR was detected by intravitreal injection. Histological analysis was performed by H&E and TUNEL methods. The mRNA and protein expressions of endoplasmic reticulum stress (ERS) pathway-related transcription factors were detected by qRT-PCR and western blot. The blood-retinal barrier (BRB) function was assessed using the patch-clamp technique and Evans blue leakage assay.

RESULTS

Neuritin significantly improved the retinal structure, restrained the apoptosis of retinal cells, and protected the normal function of BRB in DR model rats. Mechanistically, Neuritin may function by inhibiting the expression of GRP78, ASK1, Caspase-12, VEGF, and so on.

CONCLUSION

Our results indicate that Neuritin alleviates retinal damage in DR rats via the inactive endoplasmic reticulum pathway. Our study provides a potential treatment for DR.

A Review on Indole-triazole Molecular Hybrids as a Leading Edge in Drug Discovery: Current Landscape and Future Perspectives

Molecular hybridization is a rational design strategy used to create new ligands or prototypes by identifying and combining specific pharmacophoric subunits from the molecular structures of two or more known bioactive derivatives. Molecular hybridization is a valuable technique in drug discovery, enabling the modulation of unwanted side effects and the creation of potential dual-acting drugs that combine the effects of multiple therapeutic agents. Indole-triazole conjugates have emerged as promising candidates for new drug development. The indole and triazole moieties can be linked through various synthetic strategies, such as click chemistry or other coupling reactions, to generate a library of diverse compounds for biological screening. The achievable structural diversity with indole-triazole conjugates offers avenues to optimize their pharmacokinetic and pharmacodynamic attributes, amplifying their therapeutic efficacy. Researchers have extensively tailored both indole and triazole frameworks with diverse modifications to comprehend their impact on the drug's pharmacokinetic and pharmacodynamic characteristics. The current review article endeavours to explore and discuss various research strategies to design indoletriazole hybrids and elucidate their significance in a variety of pathological conditions. The insights provided herein are anticipated to be beneficial for the researchers and will likely encourage further exploration in this field.

Anti-Angiogenic Agents Combined with Immunotherapy for Advanced Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Anti-angiogenic agents could enhance tumor immunity response, and anti- angiogenesis plus immunotherapy has become a novel treatment option for advanced non-small cell lung cancer (NSCLC). The efficacy of this combination therapy remains controversial and obscure.

AIM

We conducted a meta-analysis to evaluate the clinical efficacy and safety of this therapeutic strategy in patients with advanced NSCLC and provide more guidance for treating NSCLC clinically.

METHODS

A systematic literature search was performed in PubMed, Embase, Web of Science, CNKI, and Wanfang databases to identify relevant studies published up to December 2021. The primary endpoint was the objective response rate (ORR). Second endpoints were progression-free survival (PFS), overall survival (OS), and grade ≥3 AEs adverse events (AEs). The sensitivity analysis was conducted to confirm the stability of the results. STATA 15.0 was utilized for all pooled analyses.

RESULTS

Eleven studies were eventually included in the meta-analysis, involving 533 patients with advanced NSCLC. The pooled ORR rate was 27% (95% CI 18% to 35%; I2 =84.2%; p<0.001), while the pooled median PFS and OS was 5.84 months (95% CI 4.66 to 7.03 months; I2=78.4%; p<0.001) and 14.20 months (95% CI 11.08 to 17.32 months; I2=82.2%; p=0.001), respectively. Most common grade ≥3 AEs included hypertension, hand-foot syndrome, diarrhea, adrenal insufficiency, hyponatremia, proteinuria, rash, thrombocytopenia, and fatigue.

CONCLUSION

Anti-angiogenesis combined with immunotherapy demonstrated satisfactory antitumor activity and an acceptable toxicity profile in patients with advanced NSCLC. The pooled results of our meta-analysis provided further evidence supporting the favorable efficacy and safety of this therapeutic strategy.

Atorvastatin Calcium Ameliorates Cognitive Deficits Through the AMPK/Mtor Pathway in Rats with Vascular Dementia

AIM

In this study, the protective effects of atorvastatin calcium (AC) on nerve cells and cognitive improvement in vivo and in vitro were investigated by establishing cell models and vascular dementia (VD) rat models.

BACKGROUND

VD is a neurodegenerative disease characterized by cognitive deficits caused by chronic cerebral hypoperfusion. AC has been studied for its potential to cure VD but its efficacy and underlying mechanism are still unclear.

OBJECTIVE

The mechanism of action of AC on cognitive deficits in the early stages of VD is unclear. Here, the 2-vessel occlusion (2-VO) model in vivo and the hypoxia/reoxygenation (H/R) cell model in vitro was established to investigate the function of AC in VD.

METHODS

The spatial learning and memory abilities of rats were detected by the Morris method. The IL-6, tumour necrosis factor-α (TNF-α), malondialdehyde (MDA) and superoxide dismutase (SOD) in cell supernatant was tested by ELISA kits. After behavioural experiments, rats were anaesthetized and sacrificed, and their brains were extracted. One part was immediately fixed in 4% paraformaldehyde for H&E, Nissl, and immunohistochemical analyses, and the other was stored in liquid nitrogen. All data were shown as mean ± SD. Statistical comparison between the two groups was performed by Student's t-test. A two-way ANOVA test using GraphPad Prism 7 was applied for escape latency analysis and the swimming speed test. The difference was considered statistically significant at p < 0.05.

RESULTS

AC decreased apoptosis, increased autophagy, and alleviated oxidative stress in primary hippocampal neurons. AC regulated autophagy-related proteins in vitro by western blotting. VD mice improved cognitively in the Morris water maze. Spatial probing tests showed that VD animals administered AC had considerably longer swimming times to the platform than VD rats. H&E and Nissl staining showed that AC reduces neuronal damage in VD rats. Western blot and qRT-PCR indicated that AC in VD rats inhibited Bax and promoted LC3-II, Beclin-1, and Bcl-2 in the hippocampus region. AC also improves cognition via the AMPK/mTOR pathway.

CONCLUSION

This study found that AC may relieve learning and memory deficits as well as neuronal damage in VD rats by changing the expression of apoptosis/autophagy-related genes and activating the AMPK/mTOR signalling pathway in neurons.

Sequential virtual screening collaborated with machine-learning strategies for the discovery of precise medicine against non-small cell lung cancer

Dysregulation of MAPK pathway receptors are crucial in causing uncontrolled cell proliferation in many cancer types including non-small cell lung cancer. Due to the complications in targeting the upstream components, MEK is an appealing target to diminish this pathway activity. Hence, we have aimed to discover potent MEK inhibitors by integrating virtual screening and machine learning-based strategies. Preliminary screening was conducted on 11,808 compounds using the cavity-based pharmacophore model AADDRRR. Further, seven ML models were accessed to predict the MEK active compounds using six molecular representations. The LGB model with morgan2 fingerprints surpasses other models ensuing 0.92 accuracy and 0.83 MCC value versus test set and 0.85 accuracy and 0.70 MCC value with external set. Further, the binding ability of screened hits were examined using glide XP docking and prime-MM/GBSA calculations. Note that we have utilized three ML-based scoring functions to predict the various biological properties of the compounds. The two hit compounds such as DB06920 and DB08010 resulted excellent binding mechanism with acceptable toxicity properties against MEK. Further, 200 ns of MD simulation combined with MM-GBSA/PBSA calculations confirms that DB06920 may have stable binding conformations with MEK thus step forwarded to the experimental studies in the near future.Communicated by Ramaswamy H. Sarma.

Recent Development in the Search for Epidermal Growth Factor Receptor (EGFR) Inhibitors based on the Indole Pharmacophore

The signal transduction and cell proliferation are regulated by the epidermal growth factor receptor. The proliferation of tumor cells, apoptosis, invasion, and angiogenesis is inhibited by the epidermal growth factor receptor. Thus, breast cancer, non-small cell lung cancer, cervical cancer, glioma, and bladder cancer can be treated by targeting the epidermal growth factor receptor. Although third-generation epidermal growth factor receptor inhibitors are potent drugs, patients exhibit drug resistance after treatment. Thus, the search for new drugs is being continued. Among the different potent epidermal growth factor receptor inhibitors, we have reviewed the indole-based inhibitors. We have discussed the structure-activity relationship of the compounds with the active sites of the epidermal growth factor receptor receptors, their synthesis, and molecular docking studies.

Alleviation of Angiotensin II-Induced Vascular Endothelial Cell Injury Through Long Non-coding RNA TUG1 Inhibition

BACKGROUND

Hypertension damages endothelial cells, causing vascular remodelling. It is caused by Ang II-induced endothelial cell (EC) destruction. The long noncoding RNA (lncRNAs) are emerging regulators of endothelium homeostasis. Injured endothelium expresses lncRNA taurine-upregulated gene 1 (TUG1), which may mediate endothelial cell damage, proliferation, apoptosis, and autophagy and contribute to cardiovascular disease. However, uncertainty surrounds the function of lncRNA TUG1, on arterial endothelium cell damage.

OBJECTIVE

This research aimed to investigate the role and mechanism of lncRNA TUG1 in vascular endothelial cell injury.

METHOD

A microarray analysis of lncRNA human gene expression was used to identify differentially expressed lncRNAs in human umbilical vein endothelial cell (HUVEC) cultures. The viability, apoptosis, and migration of Ang II-treated HUVECs were then evaluated. In order to investigate the role of lncRNA TUG1 in hypertension, qRT-PCR, western blotting, and RNA-FISH were used to examine the expression of TUG1 in SHR mice.

RESULTS

Ang II-activated HUVECs and SHR rats' abdominal aortas highly express the lncRNA TUG1. LncRNA TUG1 knockdown in HUVECs could increase cell viability, reduce apoptosis, and produce inflammatory factors. In SHR rat abdominal aortas, lncRNA TUG1 knockdown promoted proliferation and inhibited apoptosis. HE spotting showed that lncRNA TUG1 knockdown improved SHR rats' abdominal aorta shape. lncRNA TUG1 knockdown promotes miR-9- 5p, which inhibits CXCR4 following transcription. The lncRNA TUG1/miR-9-5p/CXCR4 axis and vascular cell injury were also examined. MiR-9-5p silencing or CXCR4 overexpression lowered cell survival, apoptosis, and lncRNA TUG1-induced IL-6 and NO expression.

CONCLUSION

lncRNA TUG1 suppression could reduce Ang II-induced endothelial cell damage by regulating and targeting miR-9-5p to limit CXCR4 expression and open new vascular disease research pathways.

Gut Metabolite Indoxyl Sulfate Has Selective Deleterious and Anticancer Effect on Colon Cancer Cells

There are a number of reports about anticancer activity of indole derivatives. In this study, we investigated the role of indoxyl sulfate (IS) for its selective anticancer activity on colon cancer cells. IS treatment on HCT-116 and HT-29 human epithelial adenocarcinoma cells led to a decrease in cell proliferation, cell viability, and ATP content. Colon cancer cells showed a 10% increase in cell apoptosis in comparison to control. Due to IS treatment, cell morphology got distorted, cell number found decreased, intracellular vesicles formed, and cells were found floating in the media. Cells also showed a loss in membrane integrity and a decrease in colony-forming ability and ceased at the G2/M phase of the cell cycle. No significant change was noted in the level of inflammatory cytokines IL-17A, IL-1β, and TNF-α, histology, length of intestine, and spleen after 100 mM IS treatment to balb/c mice. These observations indicate the selective anticancer effect of IS on colon cancer cells.

Research status of indole-modified natural products

Indole is a heterocyclic compound formed by the fusion of a benzene ring and pyrrole ring, which has rich biological activity. Many indole-containing compounds have been sold on the market due to their excellent pharmacological activity. For example, vincristine and reserpine have been widely used in clinical practice. The diverse structures and biological activities of natural products provide abundant resources for the development of new drugs. Therefore, this review classifies natural products by structure, and summarizes the research progress of indole-containing natural product derivatives, their biological activities, structure-activity relationship and research mechanism which has been studied in the past 13 years, so as to provide a basis for the development of new drug development.

Designing of efficient two-armed colorimetric and fluorescent indole appended organosilicon sensors for the detection of Al(III) ions: Implication as paper-based sensor

Metal ions have significant roles in diagnosis, industry, human health, and the environment. To design and develop new lucid molecular receptors for the selective detection of metal ions is important for environmental and medical applications. In the present work, two-armed indole appended Schiff bases conjoined with 1,2,3-Triazole bis-organosilane and bis-organosilatrane skelton sensors for naked eye colorimetric and fluorescent detection sensors for Al(III) are developed. The introduction of Al(III) in sensor 4 and 5 show red shift in UV-visible spectra, changes in fluorescence spectra and immediate color change from colorless to dark yellow. Furthermore, the pH and time response studies were explored for both sensors 4 & 5. The sensors 4 and 5 exhibited significantly low detection limit (LOD) in nano-molar range 1.41 × 10-9 M and 0.17 × 10-9 M respectively from emission titration. The LOD form absorption titration was found to be 0.6 × 10-7 M for sensor 4 and 0.22 × 10-7 M for sensor 5. In addition, the sensing model is developed as paper based sensor for its practical applicability. The theoretical calculations were performed on Gaussian 03 program by relaxing the structures using Density functional theory.

Novel 2-substituted-quinoxaline analogs with potential antiproliferative activity against breast cancer: insights into cell cycle arrest, topoisomerase II, and EGFR activity

Breast cancer is a global health concern, with increasing disease burden and disparities in access to healthcare. Late diagnosis and limited treatment options in underserved areas contribute to poor outcomes. In response to this challenge, we developed a novel family of 2-substituted-quinoxaline analogues, combining coumarin and quinoxaline scaffolds known for their anticancer properties. Through a versatile synthetic approach, we designed, synthesized, and characterized a set of 2-substituted quinoxaline derivatives. The antiproliferative activity of the synthesized compounds was assessed toward the MCF-7 breast cancer cells. Our investigations showed that the synthesized compounds exhibit considerable antiproliferative activity toward MCF-7 cells. Notably, compound 3b, among examined compounds, displayed a superior inhibitory effect (IC50 = 1.85 ± 0.11 μM) toward the growth of MCF-7 cells compared to the conventional anticancer drug staurosporine (IC50 = 6.77 ± 0.41 μM) and showed minimal impact on normal cells (MCF-10A cell lines, IC50 = 33.7 ± 2.04 μM). Mechanistic studies revealed that compound 3b induced cell cycle arrest at the G1 transition and triggered apoptosis in MCF-7 cells, as evidenced by increasing the percentage of cells arrested in the G2/M and pre-G1 phases utilizing flow cytometric analysis and Annexin V-FITC/PI analysis. Moreover, compound 3b was found to substantially suppress topoisomerase enzyme activity in MCF-7 cells. Molecular modeling studies further supported the potential of compound 3b as a therapeutic candidate by demonstrating significant binding affinity to the active sites of both topoisomerase II and EGFR proteins. Taken together, the presented 2-substituted-quinoxaline analogues, especially compound 3b, show promise as potential candidates for the development of effective anti-breast cancer drugs.

In Situ Cocktail Nanovaccine for Cancer Immunotherapy

In situ vaccination is a desirable strategy for cancer immunotherapy due to its convenience and capacity to target tumor antigens. Here, an in situ nanovaccine based on a cationic peptide with cholesterol-modified, DP7-C, for cancer immunotherapy is rationally designed, and developed a cancer nanovaccine that is easy to preparate. The nanovaccine includes cocktail small interfering RNAs (siRNAs) and immunologic adjuvant CpG ODNs, has synergistic effect in the cancer treatment. This nanovaccine can induce tumor cell death, promote antigen presentation and relieve immune suppression in the tumor microenvironment (TME). Moreover, this nanovaccine is administered to CT26 (hot) and B16F10 (cold) tumor model mice, in which it targeted the primary tumors and induced systemic antitumor immunity to inhibit metastasis. It is validated that the nanovaccine can convert cold tumors into hot tumors. Furthermore, the nanovaccine increased the immune response to anti-PD-1 therapy by modulating the TME in both CT26- and B16F10-tumor-bearing mice. The siRNA cocktail/CpG ODN/self-assembling peptide nanovaccine is a simple and universal tool that can effectively generate specific tumor cell antigens and can be combined with immuno-oncology agents to enhance antitumor immune activity. The versatile methodology provides an alternative approach for developing cancer nanovaccines.

Novel Acrylate-Based Derivatives: Design, Synthesis, Antiproliferative Screening, and Docking Study as Potential Combretastatin Analogues

A variety of 3-(4-chlorophenyl) acrylic acids 4a,b and 3-(4-chlorophenyl)acrylate esters 5a-i were synthesized and structurally proven by spectroscopic studies such as IR, 1H NMR, and 13C NMR as well as mass spectrometry. All substances were investigated for their antiproliferative efficacy against the MDA-MB-231 cell line. Among these, acrylic acid compound 4b demonstrated the most potent cytotoxic effect with an IC50 value of 3.24 ± 0.13 μM, as compared to CA-4 (IC50 = 1.27 ± 09 μM). Additionally, acrylic acid molecule 4b displayed an inhibitory effect against β-tubulin polymerization with a percentage inhibition of 80.07%. Furthermore, compound 4b was found to produce considerable cell cycle arrest at the G2/M stage and cellular death, as demonstrated by FACS analysis. In addition, the in vivo antitumor screening of the sodium salt of acrylic acid 4b was carried out, and the results have shown that the tested molecule showed a significant decrease in viable EAC count and EAC volume, accompanied by a considerable increase in the life span prolongation, if compared to the positive control group. Furthermore, molecular modeling studies were performed to understand how the highly efficient chemicals 4b and 5e interact with the colchicine-binding region on tubulin. This work aims to shed light on the reasons behind their exceptional cytotoxicity and their better capacity to inhibit tubulin in comparison to CA-4.

Indole derivatives targeting colchicine binding site as potential anticancer agents

Microtubules are appealing as intracellular targets for anticancer activity due to their importance in cell division. Three important binding sites are present on the tubulin protein: taxane, vinca, and colchicine binding sites (CBS). Many USFDA-approved drugs such as paclitaxel, ixabepilone, vinblastine, and combretastatin act by altering the dynamics of the microtubules. Additionally, a large number of compounds have been synthesized by medicinal chemists around the globe that target different tubulin binding sites. Although CBS inhibitors have proved their cytotoxic potential, no CBS-targeting drug had been able to reach the market. Several studies have reported design, synthesis, and biological evaluation of indole derivatives as potential anticancer agents. These compounds have been shown to inhibit cancer cell proliferation, induce apoptosis, and disrupt microtubule formation. Moreover, the binding affinity of these compounds to the CBS has been demonstrated using molecular docking studies and competitive binding assays. The present work has reviewed indole derivatives as potential colchicine-binding site inhibitors. The structure-activity relationship studies have revealed the crucial pharmacophoric features required for the potent and selective binding of indole derivatives to the CBS. The development of these compounds with improved efficacy and reduced toxicity could potentially lead to the development of novel and effective cancer therapies.

Discovery, Synthesis, and Evaluation of Novel Dual Inhibitors of a Vascular Endothelial Growth Factor Receptor and Poly(ADP-Ribose) Polymerase for BRCA Wild-Type Breast Cancer Therapy

Poly(ADP-ribose) polymerase (PARP) inhibitors have been approved for the treatment of breast cancer (BC) with breast cancer susceptibility (BRCA) gene mutation. Leveraging new synthetic lethal interactions may be an effective way to broaden the indication of PARP inhibitors for BC patients with wild-type BRCA. Vascular endothelial growth factor receptor (VEGFR)-mediated suppression of angiogenesis has been reported to improve the sensitivity of wild-type BRCA cells to PARP inhibitors through synthetic lethality. Herein, we reported the conjugation of a PARP inhibitor with a VEGFR inhibitor pharmacophore to construct dual VEGFR and PARP inhibitors. The most potent compound 14b is identified to exert promising activities against VEGFR and PARP in the nanomolar range and possesses significant in vitro and in vivo antitumor and antimetastasis features. It also presented a favorable pharmacokinetic characteristics in rats with an oral bioavailability of 60.1%. Collectively, 14b may be a promising therapeutic agent of BRCA wild-type BC.

OSGIN1 is a novel TUBB3 regulator that promotes tumor progression and gefitinib resistance in non-small cell lung cancer

BACKGROUND

Oxidative stress induced growth inhibitor 1 (OSGIN1) regulates cell death. The role and underlying molecular mechanism of OSGIN1 in non-small cell lung cancer (NSCLC) are uncharacterized.

METHODS

OSGIN1 expression in NSCLC samples was detected using immunohistochemistry and Western blotting. Growth of NSCLC cells and gefitinib-resistant cells expressing OSGIN1 or TUBB3 knockdown was determined by MTT, soft agar, and foci formation assays. The effect of OSGIN1 knockdown on in vivo tumor growth was assessed using NSCLC patient-derived xenograft models and gefitinib-resistant patient-derived xenograft models. Potentially interacting protein partners of OSGIN1 were identified using IP-MS/MS, immunoprecipitation, PLA, and Western blotting assays. Microtubule dynamics were explored by tubulin polymerization assay and immunofluorescence. Differential expression of signaling molecules in OSGIN1 knockdown cells was investigated using phospho-proteomics, KEGG analysis, and Western blotting.

RESULTS

We found that OSGIN1 is highly expressed in NSCLC tissues and is positively correlated with low survival rates and tumor size in lung cancer patients. OSGIN1 knockdown inhibited NSCLC cell growth and patient-derived NSCLC tumor growth in vivo. Knockdown of OSGIN1 strongly increased tubulin polymerization and re-established gefitinib sensitivity in vitro and in vivo. Additionally, knockdown of TUBB3 strongly inhibited NSCLC cell proliferation. Mechanistically, we found that OSGIN1 enhances DYRK1A-mediated TUBB3 phosphorylation, which is critical for inducing tubulin depolymerization. The results of phospho-proteomics and ontology analysis indicated that knockdown of OSGIN1 led to reduced propagation of the MKK3/6-p38 signaling axis.

CONCLUSIONS

We propose that OSGIN1 modulates microtubule dynamics by enhancing DYRK1A-mediated phosphorylation of TUBB3 at serine 172. Moreover, elevated OSGIN1 expression promotes NSCLC tumor growth and gefitinib resistance through the MKK3/6-p38 signaling pathway. Our findings unveil a new mechanism of OSGIN1 and provide a promising therapeutic target for NSCLC treatment in the clinic.