Schizandrin A exhibits potent anticancer activity in colorectal cancer cells by inhibiting heat shock factor 1

Sishen Pill and its active phytochemicals in treating inflammatory bowel disease and colon cancer: an overview

The incidence of inflammatory bowel disease (IBD) and the associated risk of colon cancer are increasing globally. Traditional Chinese medicine (TCM) treatment has unique advantages. The Sishen Pill, a common Chinese patented drug used to treat abdominal pain and diarrhea, consists mainly of Psoraleae Fructus, Myristicae Semen, Euodiae Fructus, and Schisandra Chinensis. Modern research has confirmed that Sishen Pill and its active secondary metabolites, such as psoralen, myristicin, evodiamine, and schisandrin, can improve intestinal inflammation and exert antitumor pharmacological effects. Common mechanisms in treating IBD and colon cancer mainly include regulating inflammation-related signaling pathways such as nuclear factor-kappa B, mitogen-activated protein kinase, phosphatidylinositol 3-kinase, NOD-like receptor heat protein domain-related protein 3, and wingless-type MMTV integration site family; NF-E2-related factor 2 and hypoxia-inducible factor 1α to inhibit oxidative stress; mitochondrial autophagy and endoplasmic reticulum stress; intestinal immune cell differentiation and function through the Janus kinase/signal transducer and activator of transcription pathway; and improving the gut microbiota and intestinal barrier. Overall, existing evidence suggests the potential of the Sishen pill to improve IBD and suppress inflammation-to-cancer transformation. However, large-scale randomized controlled clinical studies and research on the safety of these clinical applications are urgently required.

Schizandrin A induces non-small cell lung cancer apoptosis by suppressing the epidermal growth factor receptor activation

OBJECTIVE

The purpose of this study is to explore the biological mechanism of Schizandrin A (SchA) inducing non-small cell lung cancer (NSCLC) apoptosis.

METHODS

The reverse molecular docking tool "Swiss Target Prediction" was used to predict the targets of SchA. Protein-protein interaction analysis was performed on potential targets using the String database. Functional enrichment analyses of potential targets were performed with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. The conformation of SchA binding to target was simulated by chemical-protein interactomics and molecular docking. The effect of SchA on the expression and phosphorylation level of EGFR was detected by Western blot. Lipofectamine 3000 and EGFR plasmids were used to overexpress EGFR. Apoptosis was tested with Annexin V-FITC and propidium iodide staining, and cell cycle was detected by propidium iodide staining.

RESULTS

The "Swiss Target Prediction" database predicted 112 and 111 targets based on the 2D and 3D structures of SchA, respectively, of which kinases accounted for the most, accounting for 24%. Protein interaction network analyses showed that molecular targets such as ERBB family and SRC were at the center of the network. Functional enrichment analyses indicated that ERBB-related signaling pathways were enriched. Compound-protein interactomics and molecular docking revealed that SchA could bind to the ATP-active pocket of the EGFR tyrosine kinase domain. Laboratory results showed that SchA inhibited the phosphorylation of EGFR. Insulin could counteract the cytotoxic effect of SchA. EGFR overexpression and excess EGF or IGF-1 had limited impacts on the cytotoxicity of SchA.

CONCLUSIONS

Network pharmacology analyses suggested that ERBB family members may be the targets of SchA. SchA can inhibit NSCLC at least in part by inhibiting EGFR phosphorylation, and activating the EGFR bypass can neutralize the cytotoxicity of SchA.

Synergistic effect of schizandrin A and DNase I knockdown on high glucose induced beta cell apoptosis by decreasing intracellular calcium concentration

OBJECTIVE

To explore the synergistic effect of deoxyribonuclease I (DNase I) knockdown combined with Schizandrin A (Sch A) in protecting islet beta-cells (β-cells) from apoptosis under high-glucose (HG) conditions.

METHODS

The concentration of Sch A was detected by Cell Counting Kit-8 (CCK-8). High glucose-cultured rat insulinoma beta cell line (RIN-M5F) cells were treated with Sch A and transfected with DNase I small interfering RNA (siRNA). Cell apoptosis rate and apoptosis-related protein level were examined by flow cytometry and Western blot method respectively. In addition, Na-K-adenosine triphosphatease (Na-K-ATPase) and Ca-Mg-ATPase activity, cell membrane potential, and intracellular Ca concentration was also examined respectively.

RESULTS

Our study revealed that HG stimulation can cause a significant increase in DNase I level and cell apoptosis rate. However, Sch A combined with DNase I knockdown can significantly decrease the cell apoptosis rate and apoptosis-related protein levels such as BAX ( 0.05) and Caspase-3 ( 0.01). In addition, we also found that the combination of Sch A and DNase I knockdown can dramatically increase cell membrane potential level, Na-K-ATPase, and Ca-Mg-ATPase activity. Meanwhile, intracellular Ca concentration was also found to be significantly decreased by the synergistic effect of Sch A and DNase I knockdown.

CONCLUSION

Overall, our study reveals a synergistic effect of Sch A and DNase I knockdown in protecting β-cells from HG-induced apoptosis.

Targeting HSF1 for cancer treatment: mechanisms and inhibitor development

Heat Shock Factor 1 (HSF1) is a master regulator of heat shock responsive signaling. In addition to playing critical roles in cellular heat shock response, emerging evidence suggests that HSF1 also regulates a non-heat shock responsive transcriptional network to handle metabolic, chemical, and genetic stress. The function of HSF1 in cellular transformation and cancer development has been extensively studied in recent years. Due to important roles for HSF1 for coping with various stressful cellular states, research on HSF1 has been very active. New functions and molecular mechanisms underlying these functions have been continuously discovered, providing new targets for novel cancer treatment strategies. In this article, we review the essential roles and mechanisms of HSF1 action in cancer cells, focusing more on recently discovered functions and their underlying mechanisms to reflect the new advances in cancer biology. In addition, we emphasize new advances with regard to HSF1 inhibitors for cancer drug development.

Schizandrin A enhances killing effect of oxaliplatin on colorectal cancer cells

BACKGROUND

Schizandrin A (SchA) has anticancer and multidrug resistance-reversing effects in a variety of tumors, but its effect on oxaliplatin (L-OHP) in colorectal cancer cells is not clear.

AIM

To investigate whether SchA can enhance the killing effect of L-OHP on colorectal cancer cells, and to analyze the possible mechanism involved.

METHODS

Colorectal cancer cells were divided into control group, SchA treatment group, L-OHP treatment group, and SchA + L-OHP treatment group. Cell viability was detected by MTT assay. Cell apoptosis was detected by flow cytometry. The contents of reactive oxygen species (ROS) in cells was detected using a ROS probe. Mitochondrial membrane potential was evaluated by using the 1,1',3,3'-tetraethyl-5,5',6,6'-tetrachloroimidacarbocyanine iodide (JC-1) probe. Western blot was used to detect the expression of B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cytochrome c (Cyt c), and cleaved cysteine proteinase-3 (caspase-3) in the cells.

RESULTS

Compared with the L-OHP treatment group, the viability of colorectal cancer cells in the SchA + L-OHP treatment group was significantly decreased, while apoptosis was significantly increased. SchA could enhance ROS accumulation, Bax and cleaved caspase-3 expression, and mitochondrial Cyt c release, and decrease Bcl-2 expression in colorectal cancer cells induced by L-OHP.

CONCLUSION

SchA enhances the killing effect of L-OHP on colorectal cancer cells, and the mechanism may be related to the enhancement of intracellular ROS accumulation and the expression of apoptosis-related proteins.

Deoxyschizandrin Inhibits the Proliferation, Migration, and Invasion of Bladder Cancer Cells through ALOX5 Regulating PI3K-AKT Signaling Pathway

Objective

Deoxyschizandrin has a significant inhibitory effect on a variety of tumor cells. However, the effect of Deoxyschizandrin on bladder cancer cells and its mechanism are still unclear.

Methods

Bladder cancer cells were treated with different concentrations of Deoxyschizandrin for 24 h, 48 h, and 72 h. The inhibition rate of cell proliferation was detected by CCK-8 assay. The changes of cell migration and invasion were detected by wound healing and Transwell assay. Based on the structure of Deoxyschizandrin, the protein targets of Deoxyschizandrin were predicted by bioinformatics database and verified by RNA and protein. Then, the expressions of ALOX5 and PI3K-AKT signaling pathway proteins were detected by Western blot in bladder cancer cells treated with Deoxyschizandrin.

Result

Deoxyschizandrin inhibited the proliferation, migration, and invasion of bladder cancer cells in a time- and concentration-dependent manner. Bioinformatics analysis showed that Deoxyschizandrin had 100 protein targets; among them, the score of ALOX5 was the highest, and the mRNA and protein levels of ALOX5 decreased after treatment with different concentrations of Deoxyschizandrin. Western blot results showed that compared with the control group, Deoxyschizandrin could significantly reduce the expression of p-PI3K and p-AKT, and overexpression of ALOX5 could significantly enhance the expression of p-PI3K and p-AKT. Compared with Deoxyschizandrin or overexpression of ALOX5, the expression of p-PI3K and p-AKT of Deoxyschizandrin combined with overexpression of ALOX5 recovered.

Conclusion

Deoxyschizandrin inhibits the proliferation, migration, and invasion of bladder cancer cells through ALOX5 regulating PI3K-AKT signaling pathway.

Heat Shock Proteins and HSF1 in Cancer

Fitness of cells is dependent on protein homeostasis which is maintained by cooperative activities of protein chaperones and proteolytic machinery. Upon encountering protein-damaging conditions, cells activate the heat-shock response (HSR) which involves HSF1-mediated transcriptional upregulation of a group of chaperones - the heat shock proteins (HSPs). Cancer cells experience high levels of proteotoxic stress due to the production of mutated proteins, aneuploidy-induced excess of components of multiprotein complexes, increased translation rates, and dysregulated metabolism. To cope with this chronic state of proteotoxic stress, cancers almost invariably upregulate major components of HSR, including HSF1 and individual HSPs. Some oncogenic programs show dependence or coupling with a particular HSR factor (such as frequent coamplification of HSF1 and MYC genes). Elevated levels of HSPs and HSF1 are typically associated with drug resistance and poor clinical outcomes in various malignancies. The non-oncogene dependence ("addiction") on protein quality controls represents a pancancer target in treating human malignancies, offering a potential to enhance efficacy of standard and targeted chemotherapy and immune checkpoint inhibitors. In cancers with specific dependencies, HSR components can serve as alternative targets to poorly druggable oncogenic drivers.

Schizandrin A can inhibit non‑small cell lung cancer cell proliferation by inducing cell cycle arrest, apoptosis and autophagy

Schizandrin A (SchA) can be extracted from the vine plant Schisandra chinensis and has been reported to confer various biologically active properties. However, its potential biological effects on non‑small cell lung cancer (NSCLC) remain unknown. Therefore, the present study aims to address this issue. NSCLC and normal lung epithelial cell lines were first treated with SchA. Cell viability and proliferation were measured using CellTiter‑Glo Assay and colony formation assays, respectively. PI staining was used to measure cell cycle distribution. Cell cycle‑related proteins p53, p21, cyclin D1, CDK4, CDK6, cyclin E1, cyclin E2, CDK2 and DNA damage‑related protein SOX4 were detected by western blot analysis. Annexin V‑FITC/PI staining, DNA electrophoresis and Hoechst 33342/PI dual staining were used to detect apoptosis. JC‑1 and DCFH‑DA fluorescent dyes were used to measure the mitochondrial membrane potential and reactive oxygen species concentrations, respectively. Apoptosis‑related proteins caspase‑3, cleaved caspase‑3, poly(ADP‑ribose) polymerase (PARP), cleaved PARP, BimEL, BimL, BimS, Bcl2, Bax, caspase‑9 and cleaved caspas‑9 were measured by western blot analysis. Dansylcadaverine was used to detect the presence of the acidic lysosomal vesicles. The expression levels of the autophagy‑related proteins LC3‑I/II, p62/SQSTM and AMPKα activation were measured using western blot analysis. In addition, the autophagy inhibitor 3‑methyladenine was used to inhibit autophagy. SchA treatment was found to reduce NSCLC cell viability whilst inhibiting cell proliferation. Low concentrations of SchA (10‑20 µM) mainly induced G₁/S‑phase cell cycle arrest. By contrast, as the concentration of SchA used increases (20‑50 µM), cells underwent apoptosis and G₂/M‑phase cell cycle a13rrest. As the treatment concentration of SchA increased from 0 to 50 µM, the expression of p53 and SOX4 protein also concomitantly increased, but the expression of p21 protein was increased by 10 µM SchA and decreased by higher concentrations (20‑50 µM). In addition, the mRNA and protein expression levels of Bcl‑like 11 (Bim)EL, BimL and BimS increased following SchA application. SchA induced the accumulation of acidic vesicles and induced a marked increase in the expression of LC3‑II protein, suggsting that SchA activated the autophagy pathway. However, the expression of the p62 protein was found to be increased by SchA, suggesting that p62 was not degraded during the autophagic flux. The 3‑methyladenine exerted no notable effects on SchA‑induced apoptosis. Taken together, results from the present study suggest that SchA exerted inhibitory effects on NSCLC physiology by inducing cell cycle arrest and apoptosis. In addition, SchA partially induced autophagy, which did not result in any cytoprotective effects.

Schizandrin A induces the apoptosis and suppresses the proliferation, invasion and migration of gastric cancer cells by activating endoplasmic reticulum stress

Apart from its basic antioxidant and anti-inflammatory properties, schizandrin A (SchA), which is isolated from Fructus schisandra, can exert anticancer effects on multiple cancer types. However, to the best of our knowledge, there has been no study identifying the impacts of SchA on gastric cancer (GC). Therefore, the aim of the present study was to identify how SchA functioned to affect the progression of GC. To investigate the role of SchA in GC development, Cell Counting Kit-8, colony formation, wound healing and Transwell assays were conducted to assess the viability, proliferation, migration and invasion of AGS cells, respectively. Then, the apoptosis rate and apoptosis- and endoplasmic reticulum (ER) stress-related protein expression levels in AGS cells exposed to SchA were detected via TUNEL assays and western blotting, respectively. Subsequently, the aforementioned functional assays were performed again in AGS cells exposed to both SchA and the ER stress inhibitor 4-phenylbutyric acid (4-PBA) for the confirmation of the effect of SchA on ER stress in GC. It was found that SchA markedly decreased the viability, proliferation, migration and invasion, while it induced the apoptosis of AGS cells. Moreover, the markers of ER stress were elevated by SchA treatment in AGS cells. Nevertheless, 4-PBA reversed the effects of SchA on the viability, proliferation, migration, invasion and apoptosis of AGS cells, accompanied by decreased expression of ER stress markers. In conclusion, the present study demonstrated that SchA induced the apoptosis and suppressed the proliferation, invasion and migration of GC cells by activating ER stress, which provides a theoretical basis for the use of SchA in the treatment of GC.

Regulation of Nuclear Factor-KappaB (NF-κB) signaling pathway by non-coding RNAs in cancer: Inhibiting or promoting carcinogenesis?

The nuclear factor-kappaB (NF-κB) signaling pathway is considered as a potential therapeutic target in cancer therapy. It has been well established that transcription factor NF-κB is involved in regulating physiological and pathological events including inflammation, immune response and differentiation. Increasing evidences suggest that deregulated NF-κB signaling can enhance cancer cell proliferation, metastasis and also mediate radio-as well as chemo-resistance. On the contrary, non-coding RNAs (ncRNAs) have been found to modulate NF-κB signaling pathway under different settings. MicroRNAs (miRNAs) can dually inhibit/induce NF-κB signaling thereby affecting the growth and migration of cancer cells. Furthermore, the response of cancer cells to radiotherapy and chemotherapy may also be regulated by miRNAs. Regulation of NF-κB by miRNAs may be mediated via binding to 3^/-UTR region. Interestingly, anti-tumor compounds can increase the expression of tumor-suppressor miRNAs in inhibiting NF-κB activation and the progression of cancers. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can also effectively modulate NF-κB signaling thus affecting tumorigenesis. It is noteworthy that several studies have demonstrated that lncRNAs and circRNAs can affect miRNAs in targeting NF-κB activation. They can act as competing endogenous RNA (ceRNA) thereby reducing miRNA expression to induce NF-κB activation that can in turn promote cancer progression and malignancy.

Schisandrol A Suppresses Catabolic Factor Expression by Blocking NF-κB Signaling in Osteoarthritis

Schisandrol A possesses pharmacological properties and is used to treat various diseases; however, its effects on osteoarthritis (OA) progression remain unclear. Here, we investigated Schisandrol A as a potential therapeutic agent for OA. In vitro, Schisandrol A effects were confirmed based on the levels of expression of catabolic factors (MMPs, ADAMTS5, and Cox2) induced by IL-1β or Schisandrol A treatment in chondrocytes. In vivo, experimental OA in mice was induced using a destabilized medial meniscus (DMM) surgical model or oral gavage of Schisandrol A in a dose-dependent manner, and demonstrated using histological analysis. In vitro and in vivo analyses demonstrated that Schisandrol A inhibition attenuated osteoarthritic cartilage destruction via the regulation of Mmp3, Mmp13, Adamts5, and Cox2 expression. In the NF-κB signaling pathway, Schisandrol A suppressed the degradation of IκB and the phosphorylation of p65 induced by IL-1β. Overall, and Schisandrol A reduced the expression of catabolic factors by blocking NF-κB signaling and prevented cartilage destruction. Therefore, Schisandrol A attenuated OA progression, and can be used to develop novel OA drug therapies.

Ellagic Acid and Schisandrins: Natural Biaryl Polyphenols with Therapeutic Potential to Overcome Multidrug Resistance in Cancer

Multidrug resistance (MDR) is one of the major clinical challenges in cancer treatment and compromises the effectiveness of conventional anticancer chemotherapeutics. Among known mechanisms of drug resistance, drug efflux via ATP binding cassette (ABC) transporters, namely P-glycoprotein (P-gp) has been characterized as a major mechanism of MDR. The primary function of ABC transporters is to regulate the transport of endogenous and exogenous small molecules across the membrane barrier in various tissues. P-gp and similar efflux pumps are associated with MDR because of their overexpression in many cancer types. One of the intensively studied approaches to overcome this mode of MDR involves development of small molecules to modulate P-gp activity. This strategy improves the sensitivity of cancer cells to anticancer drugs that are otherwise ineffective. Although multiple generations of P-gp inhibitors have been identified to date, reported compounds have demonstrated low clinical efficacy and adverse effects. More recently, natural polyphenols have emerged as a promising class of compounds to address P-gp linked MDR. This review highlights the chemical structure and anticancer activities of selected members of a structurally unique class of 'biaryl' polyphenols. The discussion focuses on the anticancer properties of ellagic acid, ellagic acid derivatives, and schisandrins. Research reports regarding their inherent anticancer activities and their ability to sensitize MDR cell lines towards conventional anticancer drugs are highlighted here. Additionally, a brief discussion about the axial chirality (i.e., atropisomerism) that may be introduced into these natural products for medicinal chemistry studies is also provided.