Activation of caspases and inhibition of ribosome biogenesis mediate antitumor activity of Chijongdan in A549 non-small lung cancer cells

Xanthine oxidase, a therapeutic target of realgar for non-small cell lung cancer

Background

The effects of realgar against non-small cell lung cancer (NSCLC) have been massively studied, but the direct therapeutic targets of realgar remain unclear. This study aimed to identify the molecular targets of realgar against NSCLC and explore their therapeutic mechanisms based on a network pharmacology approach and experimental validations.

Methods

The BATMAN-TCM and Digsee databases were used to predict realgar targets and NSCLC-related genes, respectively. A protein-protein interaction network was constructed for each gene set, and the overlapping genes were identified as potential targets of realgar against NSCLC. The correlation between potential targets and NSCLC was analyzed using The Cancer Genome Atlas and International Cancer Genome Consortium databases, and the key target was validated by in-silico and in-vitro experiments.

Results

Twenty-three overlapping genes, including xanthine oxidase (XO), were identified as potential targets of realgar against NSCLC. XO was selected as the key target for validation, as it was found to be upregulated in NSCLC tumor tissue, which correlated with poor overall survival. A possible interaction between realgar and XO was revealed by molecular docking which was further validated experimentally. Realgar treatment suppressed the activity of XO in NSCLC cells, as demonstrated by the unchanged XO protein levels. Finally, the mechanism of action of XO as a target against NSCLC through the cell-cell junction organization pathway was investigated.

Conclusions

Overall, this study proposes a potential molecular mechanism illustrating that XO is a target of realgar against NSCLC and highlights the usefulness of XO as a therapeutic target for NSCLC.

Apoptosis and its therapeutic implications in neurodegenerative diseases

Neurodegenerative disorders are characterized by progressive loss of particular populations of neurons. Apoptosis has been implicated in the pathogenesis of neurodegenerative diseases, including Parkinson disease, Alzheimer disease, Huntington disease, and amyotrophic lateral sclerosis. In this review, we focus on the existing notions relevant to comprehending the apoptotic death process, including the morphological features, mediators and regulators of cellular apoptosis. We also highlight the evidence of neuronal apoptotic death in Parkinson disease, Alzheimer disease, Huntington disease, and amyotrophic lateral sclerosis. Additionally, we present evidence of potential therapeutic agents that could modify the apoptotic pathway in the aforementioned neurodegenerative diseases and delay disease progression. Finally, we review the clinical trials that were conducted to evaluate the use of anti-apoptotic drugs in the treatment of the aforementioned neurodegenerative diseases, in order to highlight the essential need for early detection and intervention of neurodegenerative diseases in humans.

The Nucleolar Protein Nucleophosmin Is Physiologically Secreted by Endothelial Cells in Response to Stress Exerting Proangiogenic Activity Both In Vitro and In Vivo

Nucleophosmin (NPM), a nucleolar multifunctional phosphoprotein, acts as a stress sensor in different cell types. NPM can be actively secreted by inflammatory cells, however its biology on endothelium remains unexplored. In this study, we show for the first time that NPM is secreted by human vein endothelial cells (HUVEC) in the early response to serum deprivation and that NPM acts as a pro-inflammatory and angiogenic molecule both in vitro and in vivo. Accordingly, 24 h of serum starvation condition induced NPM relocalization from the nucleus to cytoplasm. Interestingly, NPM was increasingly excreted in HUVEC-derived conditioned media in a time dependent fashion upon stress conditions up to 24 h. The secretion of NPM was unrelated to cell necrosis within 24 h. The treatment with exogenous and recombinant NPM (rNPM) enhanced migration as well as the Intercellular Adhesion Molecule 1 (ICAM-1) but not Vascular cell adhesion protein 1 (VCAM-1) expression and it did not affect cell proliferation. Notably, in vitro tube formation by Matrigel assay was significantly increased in HUVEC treated with rNPM compared to controls. This result was confirmed by the in vivo injection of Matrigel plug assay upon stimulation with rNPM, displaying significant enhanced number of functional capillaries in the plugs. The stimulation with rNPM in HUVEC was also associated to the increased expression of master genes regulating angiogenesis and migration, including Vascular Endothelial Growth Factor-A (VEGF-A), Hepatocyte Growth Factor (HGF), Stromal derived factor-1 (SDF-1), Fibroblast growth factor-2 (FGF-2), Platelet Derived Growth Factor-B (PDGF-B), and Matrix metallopeptidase 9 (MMP9). Our study demonstrates for the first time that NPM is physiologically secreted by somatic cells under stress condition and in the absence of cell necrosis. The analysis of the biological effects induced by NPM mainly related to a pro-angiogenic and inflammatory activity might suggest an important autocrine/paracrine role for NPM in the regulation of both phenomena.

What Has Come out from Phytomedicines and Herbal Edibles for the Treatment of Cancer?

Several modern treatment strategies have been adopted to combat cancer with the aim of minimizing toxicity. Medicinal plant-based compounds with the potential to treat cancer have been widely studied in preclinical research and have elicited many innovations in cutting-edge clinical research. In parallel, researchers have eagerly tried to decrease the toxicity of current chemotherapeutic agents either by combining them with herbals or in using herbals alone. The aim of this article is to present an update of medicinal plants and their bioactive compounds, or mere changes in the bioactive compounds, along with herbal edibles, which display efficacy against diverse cancer cells and in anticancer therapy. It describes the basic mechanism(s) of action of phytochemicals used either alone or in combination therapy with other phytochemicals or herbal edibles. This review also highlights the remarkable synergistic effects that arise between certain herbals and chemotherapeutic agents used in oncology. The anticancer phytochemicals used in clinical research are also described; furthermore, we discuss our own experience related to semisynthetic derivatives, which are developed based on phytochemicals. Overall, this compilation is intended to facilitate research and development projects on phytopharmaceuticals for successful anticancer drug discovery.

Cytometrical analysis of the adverse effects of indican, indoxyl, indigo, and indirubin on rat thymic lymphocytes

Many businesses thrive by producing health supplements from agricultural products, as exemplified by the production of functional (or health) foods using plants traditionally cultivated in rural areas. Dyes, such as indican, indigo, indoxyl, and indirubin, present in dye plants, possess antibacterial, antifungal, and antiproliferative activities. However, these effects may also lead to cytotoxicity. Thus, studies on normal mammalian cells are necessary to identify cytotoxicity and prevent adverse effects of functional foods that contain these dyes. In this study, the effects of indican, indigo, indoxyl, and indirubin were evaluated by flow cytometry using appropriate fluorescent probes in rat thymic lymphocytes. Among the dyes analyzed, indirubin exerted distinct cellular activities. Treatment with indirubin (10-30 μM) increased the population of shrunken dead cells. The side scatter, but not forward scatter, increased in indirubin-treated living cells. It increased the population of annexin V-bound living and dead cells and that of dead cells without annexin V. Indirubin elevated intracellular Ca2+, but not Zn2+ levels. The cellular content of superoxide anions increased and that of glutathione decreased. Indirubin depolarized the cellular plasma and mitochondrial membranes. It did not potentiate or attenuate the cytotoxicity of A23187 (Ca2+ overload) and H2O2 (oxidative stress). The results suggested that indirubin induces both apoptotic and non-apoptotic cell death. It may be difficult to predict and prevent the adverse effects of indirubin due to its diverse activities on normal mammalian cells. Therefore, indirubin should be removed from products that contain dye plant extracts.

Prospective lncRNA-miRNA-mRNA regulatory network of long non-coding RNA LINC00968 in non-small cell lung cancer A549 cells: A miRNA microarray and bioinformatics investigation

Accumulating evidence suggests that the dysregulation of long non-coding RNAs (lncRNAs) serves vital roles in the incidence and progression of lung cancer. However, the molecular mechanisms of LINC00968, a recently identified lncRNA, remain unknown. The objective of present study was to investigate the role of a prospective lncRNA-miRNA‑mRNA network regulated by LINC00968 in non-small cell lung cancer cells. Following the transfection of lentiviruses carrying LINC00968 into A549 cells, the microRNA (miRNA) expression profile of the cells in response to the overexpression of LINC00968 was detected using an miRNA microarray. Five differentially expressed miRNAs (DEMs) with LINC00968 overexpression were obtained, including miR-9-3p, miR‑22-5p, miR-668-3p, miR‑3675-3p and miR-4536-3p. Five target prediction algorithms and three target validation algorithms were used to obtain 1,888 prospective target genes of the five DEMs. The result of Gene Ontology analysis suggested that these five DEMs were involved in complex cellular pathways, which included intracellular transport, organelle lumen and nucleotide binding. Furthermore, analysis of Kyoto Encyclopedia of Genes and Genomes pathways indicated that the five DEMs were important regulators in the adherens junction and focal adhesion. An lncRNA-miRNA-mRNA regulatory network and a protein-protein interaction network were then constructed. Eventually, a prospective lncRNA‑miRNA-mRNA regulatory network of LINC00968, three miRNAs (miR-9, miR-22 and miR-4536) and two genes (polo-like kinase 1 and exportin-1) was obtained following validation in the Cancer Genome Atlas database. These results may provide novel insights to support future research into lncRNA in lung cancer.

Properties of realgar bioleaching using an extremely acidophilic bacterium and its antitumor mechanism as an anticancer agent

Realgar is a naturally occurring arsenic sulfide (or Xionghuang, in Chinese). It contains over 90% tetra-arsenic tetra-sulfide (As4S4). Currently, realgar has been confirmed the antitumor activities, both in vitro and in vivo, of realgar extracted using Acidithiobacillus ferrooxidans (A. ferrooxidans). Bioleaching, a new technology to greatly improve the use rate of arsenic extraction from realgar using bacteria, is a novel methodology that addressed a limitation of the traditional method for realgar preparation. The present systematic review reports on the research progress in realgar bioleaching and its antitumor mechanism as an anticancer agent. A total of 93 research articles that report on the biological activity of extracts from realgar using bacteria and its preparation were presented in this review. The realgar bioleaching solution (RBS) works by inducing apoptosis when it is used to treat tumor cells in vitro and in vivo. When it is used to treat animal model organisms in vivo, such as mice and Caenorhabditis elegans, tumor tissues grew more slowly, with mass necrosis. Meanwhile, the agent also showed obvious inhibition of tumor cell growth. Bioleaching technology greatly improves the utilization of realgar and is a novel methodology to improve the traditional method.

Anti-proliferation effects, efficacy of cyasterone in vitro and in vivo and its mechanism

Cyasterone was demonstrated potential inhibition effect in mouse skin carcinoma cells in published report. However, the molecular mechanisms of the cyasterone on cells remain unknown. Herein, we investigated the effects of cyasterone-induced apoptosis in A549 and MGC823 cells in vitro. MTT assay showed that cyasterone caused a significantly decreasing of the proliferation of A549 and MGC823 cells in a time-and dose-dependent manner with IC₅₀ values of 38.50±3.73μg/mL on A549 cells and 32.96±1.24μg/mL on MGC823 cells at 48h, respectively. Hoechst staining and TUNEL staining results indicated the quintessential apoptosis features in immunofluorescence image. Apoptosis and cell cycle were determined by flow cytometry. Cyasterone treatment triggered inhibition of epidermal growth factor receptor- phosphatidylinositol 3 kinase/protein kinase B (EGFR-AKT) signaling pathways and activation of P38 pathways. Furthermore, cyasterone inhibited MGC823 cells xenografted tumor growth in vivo with few changes in body weights. In conclusion, our findings provide the evidence that cyasterone inhibits growth of A549 and MGC823 cells, via regulating EGFR signaling pathway. Our results indicated that cyasterone, a natural EGFR inhibitor, maybe a promising anti-cancer agent.

Sodium selenite (Na2SeO3) induces apoptosis through the mitochondrial pathway in CNE-2 nasopharyngeal carcinoma cells

This study investigated the effect of sodium selenite (Na2SeO3) on proliferation, cell cycle, apoptosis as well as the underlying mechanism in CNE-2 nasopharyngeal carcinoma (NPC) cells. The CNE-2 cell line was treated with different concentrations of Na2SeO3, and the effects of Na2SeO3 on cell viability and proliferation were evaluated using Cell Counting kit-8 (CCK-8) assay. Cellular apoptosis and cell cycle were evaluated by flow cytometry following Annexin V‑FITC/PI double staining and PI single staining respectively; nuclei morphology stained with DAPI and Hoechst 333258 was observed under a fluorescence microscope, while DNA fragmentation was detected by agarose gel electrophoresis. The mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were analyzed using fluorescent staining assays. Expression of Bcl-XL, Bax, Bak, and caspase-3 activation were examined by western blotting. The results showed that Na2SeO3 inhibited proliferation and induced apoptosis of CNE-2 cells in a dose- and time-dependent manner. Na2SeO3 at low concentrations induced cell cycle arrest at S phase, while high concentrations of Na2SeO3 induced cell cycle arrest at G0/G1 phase. Furthermore, Na2SeO3 increased ROS level and decreased MMP, upregulated caspase-3 activity and the expression of Bak and Bax but simultaneously downregulated Bcl-XL. In conclusion, our studies demonstrated that Na2SeO3 had significant anti-proliferative and apoptosis-inducing effects via arresting cell cycle and regulating mitochondria-mediated intrinsic caspase pathway in CNE-2 NPC cells, suggesting that Na2SeO3 might have therapeutic potentials in the treatment of NPC.

RNAi-mediated silencing of praline-rich gene causes growth reduction in human lung cancer cells

Lung cancer ranks among one of the most frequent causes of cancer death in the world. Here, we investigated PRR11, one novel gene, with no functional annotation, was found to be over-expressed in lung cancer patients suggesting its potential implication in tumorigenesis. Furthermore, high PRR11 levels predict shorter survival of lung cancer patients. In this study, we investigated the therapeutic potential of PRR11 in lung cancer using the technique of RNA silencing via small interfering RNA (siRNA). Synthetic siRNA duplexes against PRR11 were introduced into 3 lung cancer cell lines, which subsequently resulted in a significant depletion in PRR11 expression in the cells. We found that the targeted depletion of PRR11 caused a dramatic cell cycle arrest followed by massive apoptotic cell death, and eventually resulted in a significant decrease in growth and viability of all 2 lung cancer cell lines. In summary, our study strongly suggests that PRR11 may serve as a potential therapeutic target in human lung cancer.

Ubiquitin-specific protease 14 (USP14) regulates cellular proliferation and apoptosis in epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. Thus, there is an emergent need to invest a novel therapeutic for EOC. In this study, we defined ubiquitin-specific protease 14 (USP14) as a therapeutic target for EOC. Western blot was used to evaluate the expression of USP14 in nine fresh EOC tissues and three fresh normal ovarian tissues. The protein level of USP14 was higher in the cancer samples compared with that in the normal ovary tissues. Immunohistochemistry analysis was performed on formalin-fixed paraffin-embedded section of 116 cases of EOCs and indicated that USP14 was significantly associated with clinical pathologic variables. Kaplan-Meier curve showed that high expression of USP14 was related to poor prognosis of EOC patients. Starvation and re-feeding assay was used to imitate cell cycle, suggesting that USP14 played a critical role in SKOV3 cell proliferation. CCK-8 assay showed that SKOV3 cells treated with USP14-shRNA (shUSP14) grew more slowly than control group. Flow cytometry revealed that the reduced expression of USP14 induced the apoptosis of the SKOV3 EOC cells. In summary, our findings suggest that USP14 is involved in the progression of EOC and that it may be a useful target of therapy in EOC.