Naphthazarin suppresses cell proliferation and induces apoptosis in human colorectal cancer cells via the B-cell lymphoma 2/B-cell associated X protein signaling pathway

Unlocking the potential of 1,4-naphthoquinones: A comprehensive review of their anticancer properties

Cancer encompasses a group of pathologies with common characteristics, high incidence, and prevalence in all countries. Although there are treatments available for this disease, they are not always effective or safe, often failing to achieve the desired results. This is why it is necessary to continue the search for new therapies. One of the strategies for obtaining new antitumor drugs is the use of 1,4-naphthoquinone as a scaffold in synthetic or natural products with antitumor activity. This review focuses on compiling studies related to the antitumor activity of 1,4-naphthoquinone and its natural and synthetic derivatives over the last 10 years. The work describes the main natural naphthoquinones with antitumor activity and classifies the synthetic naphthoquinones based on the structural modifications made to the scaffold. Additionally, the formation of metal complexes using naphthoquinones as a ligand is considered. After a thorough review, 197 synthetic compounds with potent biological activity against cancer have been classified according to their chemical structures and their mechanisms of action have been described.

2'-Fucosyllactose Suppresses Angiogenesis and Alleviates Toxic Effects of 5-Fu in a HCT116 Colon Tumor-Bearing Model

The present study was aimed at examining the anti-tumor effects and molecular mechanisms of 2'-fucosyllactose (2'-FL). At the beginning, the viabilities of four types of colon cancer cells were analyzed after exposure to increasing concentrations of 2'-FL, and HCT116 cells were selected as the sensitive ones, which were applied in the further experiments; then, interestingly, 2'-FL (102.35 µM) was found to induce apoptosis of HCT116 cells, which coincides with significant changes in VEGFA/VEGFR2/p-PI3K/p-Akt/cleaved Caspase3 proteins. Next, in a tumor-bearing nude mouse model, HCT116 was chosen as the sensitive cell line, and 5-fluorouracil (5-Fu) was chosen as the positive medicine. It was noteworthy that both 2'-FL group (2.41 ± 0.57 g) and 2'FL/5-Fu group (1.22 ± 0.35 g) had a significantly lower tumor weight compared with the control (3.87 ± 0.79 g), suggesting 2'-FL could inhibit colon cancer. Since 2'-FL reduced the number of new blood vessels and the malignancy of tumors, we confirmed that 2'-FL effectively inhibited HCT116 tumors, and its mechanism was achieved by regulating the VEGFA/VEGFR2/PI3K/Akt/Caspase3 pathway. Moreover, though HE staining and organ index measurement, 2'-FL was validated to alleviate toxic effects on liver and kidney tissue when combining with 5-Fu. In conclusion, 2'-FL had certain anti-tumor and detoxification effects.

Synthesis of thia-Michael-Type Adducts between Naphthoquinones and N-Acetyl-L-Cysteine and Their Biological Activity

A series of naphthoquinones, namely, 1,4-naphthoquinone, menadione, plumbagin, juglone, naphthazarin, and lawsone, were reacted with N-acetyl-L-cysteine, and except for lawsone, which did not react, the related adducts were obtained. After the tuning of the solvent and reaction conditions, the reaction products were isolated as almost pure from the complex reaction mixture via simple filtration and were fully characterized. Therefore, the aim of this work was to evaluate whether the antitumor activity of new compounds of 1,4-naphthoquinone derivatives leads to an increase in ROS in tumor cell lines of cervical carcinoma (HeLa), neuroblastoma (SH-SY5Y), and osteosarcoma (SaOS2, U2OS) and in normal dermal fibroblast (HDFa). The MTT assay was used to assay cell viability, the DCF-DA fluorescent probe to evaluate ROS induction, and cell-cycle analysis to measure the antiproliferative effect. Compounds 8, 9, and 12 showed a certain degree of cytotoxicity towards all the malignant cell lines tested, while compound 11 showed biological activity at higher IC₅₀ values. Compounds 8 and 11 induced increases in ROS generation after 1 h of exposure, while after 48 h of treatment, only 8 induced an increase in ROS formation in HeLa cells. Cell-cycle analysis showed that compound 8 caused an increase in the number of G0/G1-phase cells in the HeLa experiment, while for the U2OS and SH-SY5Y cell lines, it led to an accumulation of S-phase cells. Therefore, these novel 1,4-naphthoquinone derivatives may be useful as antitumoral agents in the treatment of different cancers.

Identification and Characterization of Natural and Semisynthetic Quinones as Aurora Kinase Inhibitors

Aurora kinases (Aurora A, B, and C) are a family of serine/threonine kinases that play critical roles during mitotic initiation and progression. Aurora A and B kinases are ubiquitously expressed, and their overexpression and/or amplification in many cancers have been associated with poor prognosis. Several inhibitors that target Aurora kinases A, B, or both have been developed during the past decade with efficacy in different in vitro and in vivo models for a variety of cancers. Recent studies have also identified Aurora A as a synthetic lethal target for different tumor suppressors, including RB1, SMARCA4, and ARID1A, which signifies the need for Aurora-A-selective inhibitors. Here, we report the screening of a small library of quinones (nine naphthoquinones, one orthoquinone, and one anthraquinone) in a biochemical assay for Aurora A kinase that resulted in the identification of several quinones as inhibitors. IC₅₀ determination against Aurora A and B kinases revealed the inhibition of both kinases with selectivity toward Aurora A. Two of the compounds, natural quinone naphthazarin (1) and a pseudo anthraquinone, 2-(chloromethyl)quinizarin (11), potently inhibited the proliferation of various cancer cell lines with IC₅₀ values ranging from 0.16 ± 0.15 to 1.7 ± 0.06 and 0.15 ± 0.04 to 6.3 ± 1.8 μM, respectively. Treatment of cancer cells with these compounds for 24 h resulted in abrogated mitosis and apoptotic cell death. Direct binding of both the compounds with Aurora A kinase was also confirmed through STD NMR analysis. Docking studies predicted the binding of both compounds to the ATP binding pocket of Aurora A kinase. We have, therefore, identified quinones as Aurora kinase inhibitors that can serve as a lead for future drug discovery endeavors.

ROS -mediated p53 activation by juglone enhances apoptosis and autophagy in vivo and in vitro

Juglone (JG) exhibits a broad-spectrum of cytotoxicity against some cancer cells. However, its molecular mechanisms have not been investigated well. Here, the present results showed that JG significantly inhibited tumor growth in vivo. CCK-8 assays, flow cytometric analysis, western blotting and immunohistochemistry revealed that JG effectively inhibited cell proliferation and induced apoptosis through extrinsic pathways. We also observed that JG treatment induced autophagy flux via activiting the AMPK-mTOR signaling pathway. In addition, we found that JG enhanced p53 activation by increasing down-regulation of ubiquitin-mediated degradation. Inhibition of p53 by siRNA attenuated JG-induced cell death and autophagy. Moreover, JG enhanced the generation of hydrogen peroxide (H₂O₂) and superoxide anion radical (O₂^{• -}). Further experiments proved that H₂O₂ was a major factor since the H₂O₂ scavenger catalase (CAT) reduced both autophagy and cell death to a greater extent than the O₂^{• -} scavenger SOD. Overall, our results illustrated that JG caused apoptosis and autophagy via activating the ROS-mediated p53 pathway in human liver cancer cells in vitro and in vivo, which provided basic scientific evidence that JG serves as a potential anti-cancer agent.

Quinalizarin Induces Apoptosis through Reactive Oxygen Species (ROS)-Mediated Mitogen-Activated Protein Kinase (MAPK) and Signal Transducer and Activator of Transcription 3 (STAT3) Signaling Pathways in Colorectal Cancer Cells

BACKGROUND Quinalizarin (1,2,5,8-tetrahydroxyanthraquinone) exhibits potentially useful anticancer effects by inducing apoptosis in several types of cancer, but its underlying mechanism of action remains unknown. The present study examined the effects of quinalizarin on the induction of cell cycle arrest, apoptosis, the generation of reactive oxygen species (ROS), other underlying mechanisms, and its role in modifying colorectal cancer cell lines. MATERIAL AND METHODS The MTT assay was used to evaluate the viability of SW480 and HCT-116 cells that had been treated with quinalizarin and 5-fluorouracil (5-FU). Cell cycle arrest and apoptosis were analyzed by flow cytometry. Western blotting was used to investigate the mitochondrial pathway; Akt, MAPK, and STAT3 signaling pathways were also investigated. The relationship between ROS generation and apoptosis was analyzed by flow cytometry and western blotting. RESULTS The results indicated that quinalizarin significantly inhibits the viability of SW480 and HCT-116 cells in a dose-dependent manner. Quinalizarin induced SW480 cell cycle arrest at G2/M by regulating cyclin B1 and CDK1/2. The apoptosis-related protein expression levels of p-p53, Bad, cleaved caspase-3, cleaved PARP and p-JNK were increased in quinalizarin-treated cells, while protein expression levels Bcl-2, p-Akt, p-ERK, and p-STAT3 were decreased. Quinalizarin induced apoptosis in colorectal cancer cells by regulating MAPK and STAT3 signaling pathways via ROS generation. CONCLUSIONS Quinalizarin induces apoptosis via ROS-mediated MAPK/STAT3 signaling pathways.