A highly oxidized germacranolide from elephantopus tomentosus inhibits the growth of hepatocellular carcinoma cells by targeting EGFR in vitro and in vivo

Natural products targeting RAS by multiple mechanisms and its therapeutic potential in cancer: An update since 2020

RAS proteins, as pivotal signal transduction molecules, are frequently mutated and hyperactivated in various human cancers, closely associated with tumor cell proliferation, survival, and metastasis. Despite extensive research on RAS targeted therapies, developing effective RAS inhibitors remains a significant challenge. Natural products, endowed with unique chemical structures and diverse biological activities through long-term natural selection, have emerged as a vital resource for discovering novel RAS-targeted therapeutic drugs. This review focuses on the latest advancements in targeting RAS with natural products and categorizes these natural products based on their mechanisms of action. Additionally, we discuss the challenges faced by these natural products during clinical translation, including issues related to pharmacokinetics. Strategies such as combination therapy, structural optimization, and drug delivery systems are anticipated to enhance efficacy and overcome these challenges. Natural products targeting RAS by multiple mechanisms.

Wheat germ agglutinin modified mixed micelles overcome the dual barrier of mucus/enterocytes for effective oral absorption of shikonin and gefitinib

The combination of shikonin (SKN) and gefitinib (GFB) can reverse the drug resistance of lung cancer cells by affecting energy metabolism. However, the poor solubility of SKN and GFB limits their clinical application because of low bioavailability. Wheat germ agglutinin (WGA) can selectively bind to sialic acid and N-acetylglucosamine on the surfaces of microfold cells and enterocytes, and is a targeted biocompatible material. Therefore, we created a co-delivery micelle system called SKN/GFB@WGA-micelles with the intestinal targeting functions to enhance the oral absorption of SKN and GFB by promoting mucus penetration for nanoparticles via oral administration. In this study, Caco-2/HT29-MTX-E12 co-cultured cells were used to simulate a mucus/enterocyte dual-barrier environment, and HCC827/GR cells were used as a model of drug-resistant lung cancer. We aimed to evaluate the oral bioavailability and anti-tumor effect of SKN and GFB using the SKN/GFB@WGA-micelles system. In vitro and in vivo experimental results showed that WGA promoted the mucus penetration ability of micelles, significantly enhanced the uptake efficiency of enterocytes, improved the oral bioavailability of SKN and GFB, and exhibited good anti-tumor effects by reversing drug resistance. The SKN/GFB@WGA-micelles were stable in the gastrointestinal tract and provided a novel safe and effective drug delivery strategy.

αO-Conotoxin GeXIVA[1,2] Suppresses In Vivo Tumor Growth of Triple-Negative Breast Cancer by Inhibiting AKT-mTOR, STAT3 and NF-κB Signaling Mediated Proliferation and Inducing Apoptosis

Breast cancer is one of the leading causes of cancer mortality worldwide, and triple-negative breast cancer (TNBC) is the most problematic subtype. There is an urgent need to develop novel drug candidates for TNBC. Marine toxins are a valuable source for drug discovery. We previously identified αO-conotoxin GeXIVA[1,2] from Conus generalis, which is a selective antagonist of α9 nicotinic acetylcholine receptors (nAChRs). Recent studies indicated that α9 nAChR expression is positively correlated with breast cancer development; thus, α9 nAChR could serve as a therapeutic target for breast cancer. In this study, we aimed to investigate the in vivo antitumor effects of GeXIVA[1,2] on TNBC and to elucidate its underlying anticancer mechanism. Our data showed that GeXIVA[1,2] effectively suppressed 4T1 tumor growth in vivo at a very low dose of 0.1 nmol per mouse. Our results uncovered that the antitumor mechanism of GeXIVA[1,2] simultaneously induced apoptosis and blocked proliferation. Further investigations revealed that GeXIVA[1,2]-induced Caspase-3-dependent apoptosis was achieved through regulating Bax/Bcl-2 balance, and GeXIVA[1,2]-inhibited proliferation was mediated by the downregulation of the AKT-mTOR, STAT3 and NF-κB signaling pathways. Our study provides valuable arguments to demonstrate the potential of GeXIVA[1,2] as a novel marine-derived anticancer drug candidate for the treatment of TNBC.

Discovery of novel octahydroquinazoline scaffolds endowed with dual inhibition of tubulin polymerization/Eg5 against HCC: Apoptotic and radio-chemotherapeutic studies

Mitotic kinesin Eg5 isozyme as a motor protein plays a critical role in cell division of tumor cells. Kinesin Eg5 selective inhibitors and Colchicine binding site suppressors are essential targets for many anticancer drugs and radio chemotherapies. On this work, a new series of octahydroquinazoline as anti-mitotic candidates 2-13 has been synthesized with dual inhibition of tubulin polymerization/Eg5 against HCC cell line. All octahydroquinazolines have been in vitro assayed against HepG-2 cytotoxicity, Eg5 inhibitory and anti-tubulin polymerization activities. The most active analogues 7, 8, 9, 10, and 12 against HepG-2 were further subjected to in vitro cytotoxic assay against HCT-116 and MCF-7 cell lines. Chalcones 9, 10, and 12 displayed the most cytotoxic potency and anti-tubulin aggregation in comparable with reference standard colchicine and potential anti-mitotic Eg5 inhibitory activity in comparison with Monastrol as well. Besides, they exhibited cell cycle arrest at the G2/M phase. Moreover, good convinced apoptotic activities have been concluded as overexpression of caspase-3 levels and tumor suppressive gene p53 in parallel with higher induction of Bax and inhibition of Bcl-2 biomarkers. Octahydroquinazoline 10 displayed an increase in caspase-3 by 1.12 folds compared to standard colchicine and induce apoptosis and demonstrated cell cycle arrest in G2/M phase arrest by targeting p53 pathway. Analogue 10 has considerably promoted cytotoxic radiation activity and boosted apoptotic induction in HepG-2 cells by 1.5 fold higher than standard colchicine.

Rational design and synthesis of triazene-amonafide derivatives as novel potential antitumor agents causing oxidative damage towards DNA through intercalation mode

In this work, we rationally designed and synthesized two novel triazene-amonafide derivatives 2-(2-(diisopropylamino)ethyl)-5-(3,3-dimethyltriaz-1-en-1-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (D-11) and 5-(3,3-diethyltriaz-1-en-1-yl)-2-(2-(diisopropylamino)ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (D-12) as potential antitumor agents. The DNA damage induced by the intercalation mode of D-11 (D-12) towards DNA was electrochemically detected through the construction of efficient biosensors. The consecutive processes of reversible redox of naphthylimide ring and irreversible oxidation of triazene moiety were elucidated on the surface of glassy carbon electrode (GCE) by CV, SWV, and DPV methods. Electrochemical biosensors were obtained through the immobilization of ctDNA, G-quadruplexes, poly(dG), and poly(dA), respectively, on the clean surface of GCE. After the incubation of biosensors with D-11 or D-12, the peaks of dGuo and dAdo decreased prominently, and the peak of 8-oxoGua appeared at +0.50 V, suggesting that the interaction between D-11 (D-12) and DNA could result in the oxidative damage of guanine. Unexpected, the as-prepared DNA biosensor possessed satisfactory anti-interference property and good practicability in real samples. UV-vis and fluorescence spectra, and gel electrophoresis assays were employed to further confirm the intercalation mode of D-11 (D-12) towards DNA base pairs. Moreover, D-11 was proved to exhibit stronger anti-proliferation activity than mitionafide and amonafide against both A549 and HeLa cell lines.