Proteomic and transcriptomic study on the action of a cytotoxic saponin (Polyphyllin D): induction of endoplasmic reticulum stress and mitochondria-mediated apoptotic pathways

Systematic computational strategies for identifying protein targets and lead discovery

Computational algorithms and tools have retrenched the drug discovery and development timeline. The applicability of computational approaches has gained immense relevance owing to the dramatic surge in the structural information of biomacromolecules and their heteromolecular complexes. Computational methods are now extensively used in identifying new protein targets, druggability assessment, pharmacophore mapping, molecular docking, the virtual screening of lead molecules, bioactivity prediction, molecular dynamics of protein-ligand complexes, affinity prediction, and for designing better ligands. Herein, we provide an overview of salient components of recently reported computational drug-discovery workflows that includes algorithms, tools, and databases for protein target identification and optimized ligand selection.

Proteomics Analysis of Polyphyllin D-Treated Triple-Negative Breast Cancer Cells Reveal the Anticancer Mechanisms of Polyphyllin D

Polyphyllin D (PD), one of the important steroid saponins in traditional medicinal herb Paris polyphylla, has been demonstrated to have anticancer activity both in vitro and in vivo. However, the mechanisms through which PD exerts its anticancer effects in triple-negative breast cancer (TNBC) remain unclear. Our study was presented to evaluate the anticancer effect and the potential mechanisms of PD in two TNBC cell lines, BT-549 and MDA-MB-231. Through comprehensively comparing the liquid chromatography-tandem mass spectrometry (LC-MS/MS) data of PD-treated and untreated BT-549 and MDA-MB-231 cells, we found that PD could induce apoptosis of TNBC cells by activating oxidative phosphorylation pathway in BT-549 cells, as well as inhibiting spliceosome function alteration in MDA-MB-231 cells. These results suggested that the mechanisms underlying the pro-apoptotic effect of PD on TNBC may be cell type-specificity-dependent. Moreover, we found that nodal modulator 2/3 (NOMO2/3) were downregulated both in PD-treated BT-549 and MDA-MB-231 cells, suggesting that NOMO2/3 may be the potential target of PD. Verification experiments revealed that PD deceased NOMO2/3 expression at protein level, rather than mRNA level. Whether NOMO2/3 are the upstream modulators of oxidative phosphorylation pathway and spliceosome needs further validation. In conclusion, a comprehensive proteomics study was performed on PD-treated or untreated TNBC cells, revealing the anticancer mechanisms of PD.

Research trends and hotspots of polyphyllin in high-incidence cancers: A bibliometric analysis

Background

Polyphyllin, a natural compound derived primarily from the Paris genus, manifests its anticancer properties. Extensive research on its therapeutic potential in cancers has been reported. However, there is no systematical analysis of the general aspects of research on polyphyllin by bibliometric analysis. The aim of this study is to visualize emerging trends and hotspots and predict potential research directions in this field.

Methods

In this study, we collected relevant research articles from the Web of Science Core Collection Bibliometrics. Using R-bibliometrix, we analyzed the research status, hotspots, frontiers, and development trends of polyphyllin in high-incidence cancers. To conduct a comprehensive visual analysis, CiteSpace and VOSviewer were used for visual analysis of authors, countries, institutions, keywords, and co-cited references within the published articles.

Results

A total of 257 articles focusing on the research of polyphyllin in high-incidence cancers were retrieved from the WOSCC database, covering the period from 2005 to 2023. The analysis revealed a consistent increasing trend in annual publications during this timeframe. Notably, China emerged as the most productive country, with Tianjin University leading the institutions. The Journal of Ethnopharmacology stood out as the most prominent journal in this field, while Gao WY emerged as the most prolific author. Polyphyllin VI, polyphyllin II, and polyphyllin VII have emerged as the latest research hotspots. Additionally, the investigation of autophagy and its associated mechanisms has gained significant attention as a novel research direction.

Conclusion

This study presents a novel visualization of the research on polyphyllin saponins in the field of highly prevalent cancers using bibliometric analysis. The investigation of polyphyllin D has emerged as a primary focus in this field, with lung cancer, breast cancer, and liver cancer being the key areas of current research. Lastly, polyphyllin saponins show potential application in the field of cancer.

Polyphyllin D-Loaded Solid Lipid Nanoparticles for Breast Cancer: Synthesis, Characterization, In Vitro, and in Vivo Studies

Polyphyllin D (PD), a steroidal saponin in Paris polyphylla, induces apoptosis via the intrinsic apoptotic pathway in different cancer types. However, emerging evidence has shown that the primary issue with PD is its structure's hemolysis and cytotoxicity. This study aimed to develop and optimize PD-loaded SLN formulation and evaluate its efficacy in breast cancer cell lines. Apoptosis, as the mechanism of cell death, was confirmed by flow cytometry following Annexin V/propidium iodide staining and western blot analysis. In in vivo studies, tumor inhibitory efficacy was compared with different doses of PD-loaded SLN on 4T1-implanted BALB/c mice. The half-maximal inhibitory concentration (IC₅₀) of PD- loaded SLN was calculated to be 33.25 and 35.74 μg/mL for MCF7 and MDA-MB-231 cells, respectively. Flow cytometry analysis further confirmed a significant increase in apoptosis after treatment with PD- loaded SLN. When both cell lines were treated with PD-loaded SLN, Bcl2 and HSP70 proteins were down regulated, while Bax, Bad, P53, Apaf-1, p-p53 and Noxa proteins were upregulated. This effect was also confirmed by test performed on BALB/c mice in vivo. Based on results, PD-loaded SLN may be a promising breast cancer treatment, without recognizable side effects.

6-Shogaol Overcomes Gefitinib Resistance via ER Stress in Ovarian Cancer Cells

In women, ovary cancer is already the fifth leading cause of mortality worldwide. The use of cancer therapies, such as surgery, radiotherapy, and chemotherapy, may be a powerful anti-cancer therapeutic strategy; however, these therapies still have many problems, including resistance, toxicity, and side effects. Therefore, natural herbal medicine has the potential to be used for cancer therapy because of its low toxicity, fewer side effects, and high success. This study aimed to investigate the anti-cancer effect of 6-shogaol in ovarian cancer cells. 6-shogaol induces ER stress and cell death via the reduction in cell viability, the increase in LDH cytotoxicity, caspase-3 activity, and Ca²⁺ release, and the upregulation of GRP78, p-PERK, p-eIF2α, ATF-4, CHOP, and DR5. Moreover, 6-shogaol treatment medicates endoplasmic reticulum (ER) stress and cell death by upregulating Nox4 and releasing ROS. The knockdown of Nox4 in ovarian cancer cells inhibits ER stress and cell death by blocking the reduction in cell viability and the enhancement of LDH cytotoxicity, caspase-3 activity, Ca²⁺, and ROS release. In gefitinib-resistant ovarian cancer cells, A2780R and OVCAR-3R, 6-shogaol/gefitinib overcomes gefitinib resistance by inhibiting EMT phenomena such as the reduction in E-cadherin, and the increase in N-cadherin, vimentin, Slug, and Snail. Therefore, our results suggest that 6-shogaol exerts a potential anti-cancer effect in ovarian cancer and combination treatment with 6-shogaol and gefitinib may provide a novel anti-tumor therapeutic strategy in gefitinib-resistant ovarian cancer.

Therapeutic effects on cancer of the active ingredients in rhizoma paridis

Cancer is a major threat to human health, with high mortality and a low cure rate, continuously challenging public health worldwide. Extensive clinical application of traditional Chinese medicine (TCM) for patients with poor outcomes of radiotherapy and chemotherapy provides a new direction in anticancer therapy. Anticancer mechanisms of the active ingredients in TCM have also been extensively studied in the medical field. As a type of TCM against cancer, Rhizoma Paridis (Chinese name: Chonglou) has important antitumor effects in clinical application. The main active ingredients of Rhizoma Paridis (e.g., total saponins, polyphyllin I, polyphyllin II, polyphyllin VI, and polyphyllin VII) have shown strong antitumor activities in various cancers, such as breast cancer, lung cancer, colorectal cancer, hepatocellular carcinoma (HCC), and gastric cancer. Rhizoma Paridis also has low concentrations of certain other active ingredients with antitumor effects, such as saponins polyphyllin E, polyphyllin H, Paris polyphylla-22, gracillin, and formosanin-C. Many researchers have studied the anticancer mechanism of Rhizoma Paridis and its active ingredients. This review article describes research progress regarding the molecular mechanism and antitumor effects of the active ingredients in Rhizoma Paridis, suggesting that various active ingredients in Rhizoma Paridis may be potentially therapeutic against cancer.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Yamogenin-Induced Cell Cycle Arrest, Oxidative Stress, and Apoptosis in Human Ovarian Cancer Cell Line

Steroidal saponins are a group of compounds with complex structures and biological activities. They have anti-inflammatory, antimicrobial, fungicidal, and antitumor properties. Yamogenin is one of the spirostane saponins and occurs in Trigonella foenum-graecum, Asparagus officinalis, and Dioscorea collettii. It is a stereoisomer of diosgenin-a well-known compound whose activity and mechanisms of action in cancer cells are determined. However, the antitumor effect of yamogenin is still little known, and the mechanism of action has not been determined. In this study, we evaluated the effect of yamogenin on human ovarian cancer SKOV-3 cells in vitro by determining the cellular factors that trigger cell death. The viability of the cells was assessed with a Real-Time xCELLigence system and the cell cycle arrest with flow cytometry. The activity of initiator and executioner caspases (-8, -9, and -3/7) was estimated with luminometry and flow cytometry, respectively. The mitochondrial membrane depolarization, the level of oxidative stress, and DNA damage in the yamogenin-treated cells were also evaluated by flow cytometry. Genes expression analysis at the mRNA level was conducted with Real-Time PCR. Bid activation and chromatin condensation were estimated with fluorescent microscopy. The obtained results indicate that yamogenin has cytotoxic activity in SKOV-3 cells with an IC₅₀ value of 23.90 ± 1.48 µg/mL and strongly inhibits the cell cycle in the sub-G1 phase. The compound also triggers cell death with a significant decrease in mitochondrial membrane potential, an increase in the level of oxidative stress (over two times higher in comparison to the control), and activation of caspase-8, -9, -3/7, as well as Bid. The results of genes expression indicate that the Tumor Necrosis Factor (TNF) Receptor Superfamily Members (TNF, TNFRSF10, TNFRSF10B, TNFRSF1B, and TNFRSF25), Fas Associated via Death Domain (FADD), and Death Effector Domain Containing 2 (DEDD2) were significantly upregulated and their relative expression was at least two times higher than in the control. Our work shows that yamogenin induces apoptosis in ovarian cancer cells, and both the extrinsic and mitochondrial-intrinsic pathways are involved in this process.

Breast Cancer: A Global Concern, Diagnostic and Therapeutic Perspectives, Mechanistic Targets in Drug Development

Cancer is a complex multifactorial process, unchecked and abrupt division, and cell growth—conventional chemotherapy, along with radiotherapy, is used to treat breast cancer. Due to reduce efficacy and less survival rate, there is a particular need for the discovery of new active anticancer agents. Natural resources such as terrestrial/marine plants or organisms are a promising source for the generation of new therapeutics with improving efficacy. The screening of natural plant extracts and fractions, isolations of phytochemicals, and mechanistic study of those potential compounds play a remarkable role in the development of new therapeutic drugs with increased efficacy. Cancer is a multistage disease with complex signaling cascades. The initial study of screening whole extracts or fractions and later the isolation of secondary compounds and their mechanism of action study gives a clue of potential therapeutic agents for future drug development. The phytochemicals present in extracts/fractions produce remarkable effects due to synergistically targeting multiple signals. In this review, the molecular targets of extracts/ fractions and isolated compounds highlighted. The therapeutic agent's mechanistic targets in drug development focused involves; i) Induction of Apoptosis, ii) modulating cell cycle arrest, iii) Inhibition or suppression of invasion and metastasis and iv) various other pro-survival signaling pathways. The phytochemicals and their modified analogs identified as future potential candidates for anticancer chemotherapy.

Plant-Derived Saponins: A Review of Their Surfactant Properties and Applications

In response to increasing natural surfactant demand and environmental concerns, natural plant-based surfactants have been replacing synthetic ones. Saponins belong to a class of plant metabolites with surfactant properties that are widely distributed in nature. They are eco-friendly because of their natural origin and biodegradable. To date, many plant-based saponins have been investigated for their surface activity. An overview of saponins with a particular focus on their surface-active properties is presented in this article. For this purpose, works published in the past few decades, which report better surfactant relevant properties of saponins than synthetic ones, were extensively studied. The investigations on the potential surfactant application of saponins are also documented. Moreover, some biological activities of saponins such as antimicrobial activity, antidiabetic activity, adjuvant potentials, anticancer activity, and others are reported. Plants rich in saponins are widely distributed in nature, offering great potential for the replacement of toxic synthetic surfactants in a variety of modern commercial products and these saponins exhibit excellent surface and biological activities. New opportunities and challenges associated with the development of saponin-based commercial formulations in the future are also discussed in detail.

JI017, a Complex Herbal Medication, Induces Apoptosis via the Nox4-PERK-CHOP Axis in Ovarian Cancer Cells

Many anti-cancer drugs, including paclitaxel and etoposide, have originated and been developed from natural products, and traditional herbal medicines have fewer adverse effects and lesser toxicity than anti-tumor reagents. Therefore, we developed a novel complex herbal medicine, JI017, which mediates endoplasmic reticulum (ER) stress and apoptosis through the Nox4-PERK-CHOP signaling pathway in ovarian cancer cells. JI017 treatment increases the expression of GRP78, ATF4, and CHOP and the phosphorylation of PERK and eIF2α via the upregulation of Nox4. Furthermore, it increases the release of intracellular reactive oxygen species (ROS), the production of intracellular Ca2+, and the activation of exosomal GRP78 and cell lysate GRP78. Combination treatment using the sarco/endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin (TG) and JI017 reportedly induces increased ER stress and cell death in comparison to the control; however, knockdown experiments of PERK and CHOP indicated suppressed apoptosis and ER stress in JI017-treated ovarian cancer cells. Furthermore, targeting Nox4 using specific siRNA and pharmacological ROS inhibitors, including N-acetylcystein and diphenylene iodonium, blocked apoptosis and ER stress in JI017-treated ovarian cancer cells. In the radioresistant ovarian cancer model, when compared to JI017 alone, JI017 co-treatment with radiation induced greater cell death and resulted in overcoming radioresistance by inhibiting epithelial-mesenchymal-transition-related phenomena such as the reduction of E-cadherin and the increase of N-cadherin, vimentin, Slug, and Snail. These findings suggest that JI017 is a powerful anti-cancer drug for ovarian cancer treatment and that its combination treatment with radiation may be a novel therapeutic strategy for radioresistant ovarian cancer.

Saponins in Cancer Treatment: Current Progress and Future Prospects

Saponins are steroidal or triterpenoid glycoside that is distinguished by the soap-forming nature. Different saponins have been characterized and purified and are gaining attention in cancer chemotherapy. Saponins possess high structural diversity, which is linked to the anticancer activities. Several studies have reported the role of saponins in cancer and the mechanism of actions, including cell-cycle arrest, antioxidant activity, cellular invasion inhibition, induction of apoptosis and autophagy. Despite the extensive research and significant anticancer effects of saponins, there are currently no known FDA-approved saponin-based anticancer drugs. This can be attributed to a number of limitations, including toxicities and drug-likeness properties. Recent studies have explored options such as combination therapy and drug delivery systems to ensure increased efficacy and decreased toxicity in saponin. This review discusses the current knowledge on different saponins, their anticancer activity and mechanisms of action, as well as promising research within the last two decades and recommendations for future studies.

The comparison analysis of polyphyllin I and its analogues induced apoptosis of colon and lung cancer cells via mitochondrial dysfunction

Polyphyllin I (PPI) and its analogues, including polyphyllin II (PPII), polyphyllin VI (PPVI) and polyphyllin VII (PPVII), are major bioactive compounds isolated from the Chinese herb Chonglou. However, the susceptibilities of PPI and its analogues towards the different cell lines are diversified and the mechanisms are not fully clarified. Thus, the present study aimed to investigate the cytotoxicity of PPI and its analogues on two different cell lines, as well as to explore the underlying mechanisms of these agents via inducing mitochondrial dysfunction. The results showed that PPI and its analogues were cytotoxic agents towards both A549 and HT-29 cells, with IC₅₀ values ranged from 1.0 to 4.5 μmol/L. Further investigations demonstrated that they decreased the mitochondrial membrane potentials of both A549 and HT-29 cells in a dose-dependent manner. Among all tested compounds, PPVI and PPI induced the most obvious changes in Ca²⁺ haemostasis in these two cell lines. In addition, they could induce the accumulation of ROS in cells and down-regulated the Bcl-2 expression, up-regulated the Bax expression and induced the activity of cleaved caspase-3 in cells. Collectively, our findings clearly demonstrated the cytotoxic differences and mechanisms of PPI and its analogues induced cell apoptosis and could partially explain the anticancer effects of these natural constituents in Chonglou.

Natural products: A lead for drug discovery and development

Natural products are used since ancient times in folklore for the treatment of various ailments. Plant-derived products have been recognized for many years as a source of therapeutic agents and structural diversity. A literature survey has been carried out to determine the utility of natural molecules and their modified analogs or derivatives as pharmacological active entities. This review presents a study on the importance of natural products in terms of drug discovery and development. It describes how the natural components can be utilized after small modifications in new perspectives. Various new modifications in structure offer a unique opportunity to establish a new molecular entity with better pharmacological potential. It was concluded that in this current era, new attempts are taken to utilize the compounds derived from natural sources as novel drug candidates, with a focus to find and discover new effective molecules that were referred to as "new entities of natural product drug discovery."

Polyphyllin I promotes cell death via suppressing UPR-mediated CHOP ubiquitination and degradation in non-small cell lung cancer

Polyphyllin I (PPI) purified from Polyphyllarhizomes displays puissant cytotoxicity in many kinds of cancers. Several researches investigated its anti-cancer activity. But novel mechanisms are still worth investigation. This study aimed to explore PPI-induced endoplasmic reticulum (ER) stress as well as the underlying mechanism in non-small cell lung cancer (NSCLC). Cell viability or colony-forming was detected by MTT or crystal violet respectively. Cell cycle, apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential were assessed by flow cytometry. Gene and protein levels were evaluated by qRT-PCR and immunoblotting respectively. Protein interaction was determined by immunoprecipitation or immunofluorescence assay. Gene overexpression or silencing was carried out by transient transfection with plasmids or small interfering RNAs. The Cancer Genome Atlas (TCGA) database was used for Gene Set Enrichment Analysis (GSEA), survival analysis, gene expression statistics or pathway enrichment assay. PPI inhibited the propagation of NSCLC cells, increased non-viable apoptotic cells, arrested cell cycle at G2/M phase, induced ROS levels but failed to decrease mitochondrial membrane potential. High levels of GRP78 indicates poor prognosis in NSCLC patients. PPI selectively suppressed unfolded protein response (UPR)-induced GRP78 expression, subsequently protected CHOP from GRP78-mediated ubiquitination and degradation. We demonstrated that the natural product PPI, obtained from traditional herbal medicine, deserves for further study as a valuable candidate for lead compound in the chemotherapy of NSCLC.

An Integrative Transcriptome-Wide Analysis of Amyotrophic Lateral Sclerosis for the Identification of Potential Genetic Markers and Drug Candidates

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative neuromuscular disease. Although genome-wide association studies (GWAS) have successfully identified many variants significantly associated with ALS, it is still difficult to characterize the underlying biological mechanisms inducing ALS. In this study, we performed a transcriptome-wide association study (TWAS) to identify disease-specific genes in ALS. Using the largest ALS GWAS summary statistic (n = 80,610), we identified seven novel genes using 19 tissue reference panels. We conducted a conditional analysis to verify the genes’ independence and to confirm that they are driven by genetically regulated expressions. Furthermore, we performed a TWAS-based enrichment analysis to highlight the association of important biological pathways, one in each of the four tissue reference panels. Finally, utilizing a connectivity map, a database of human cell expression profiles cultured with bioactive small molecules, we discovered functional associations between genes and drugs to identify 15 bioactive small molecules as potential drug candidates for ALS. We believe that, by integrating the largest ALS GWAS summary statistic with gene expression to identify new risk loci and causal genes, our study provides strong candidates for molecular basis experiments in ALS.

Natural Polyphyllins (I, II, D, VI, VII) Reverses Cancer Through Apoptosis, Autophagy, Mitophagy, Inflammation, and Necroptosis

Cancer is the second leading cause of mortality worldwide. Conventional therapies, including surgery, radiation, and chemotherapy, have limited success because of secondary resistance. Therefore, safe, non-resistant, less toxic, and convenient drugs are urgently required. Natural products (NPs), primarily sourced from medicinal plants, are ideal for cancer treatment because of their low toxicity and high success. NPs cure cancer by regulating different pathways, such as PI3K/AKT/mTOR, ER stress, JNK, Wnt, STAT3, MAPKs, NF-kB, MEK-ERK, inflammation, oxidative stress, apoptosis, autophagy, mitophagy, and necroptosis. Among the NPs, steroid saponins, including polyphyllins (I, II, D, VI, and VII), have potent pharmacological, analgesic, and anticancer activities for the induction of cytotoxicity. Recent research has demonstrated that polyphyllins (PPs) possess potent effects against different cancers through apoptosis, autophagy, inflammation, and necroptosis. This review summarizes the available studies on PPs against cancer to provide a basis for future research.

Lymecycline reverses acquired EGFR-TKI resistance in non-small-cell lung cancer by targeting GRB2

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) were first-line treatments for NSCLC patients with EGFR-mutations. However, about 30 % of responders relapsed within six months because of acquired resistance. In this study, we used Connectivity Map (CMap) to discover a drug capable of reversing acquired EGFR-TKIs resistance. To investigate Lymecycline's ability to reverse acquired EGFR-TKIs resistance, two Icotinib resistant cell lines were constructed. Lymecycline's ability to suppress the proliferation of Icotinib resistant cells in vitro and in vivo was then evaluated. Molecular targets were predicted using network pharmacology and used to identify the molecular mechanism. Growth factor receptor-bound protein 2 (GRB2) is an EGFR-binding adaptor protein essential for EGFR phosphorylation and regulation of AKT/ERK/STAT3 signaling pathways. Lymecycline targeted GRB2 and inhibited the resistance of the cell cycle to EGFR-TKI, arresting disease progression and inducing apoptosis in cancer cells. Combined Lymecycline and Icotinib treatment produced a synergistic effect and induced apoptosis in HCC827R5 and PC9R10 cells. Cell proliferation in resistant cancer cells was significantly inhibited by the combined Lymecycline and Icotinib treatment in mouse models. Lymecycline inhibited the resistance of the cell cycle to EGFR-TKI and induced apoptosis in NSCLC by inhibiting EGFR phosphorylation and GRB2-mediated AKT/ERK/STAT3 signaling pathways. This provided strong support that Lymecycline when combined with EGFR targeting drugs, enhanced the efficacy of treatments for drug-resistant NSCLC.

Identification of Key Pro-Survival Proteins in Isolated Colonic Goblet Cells of Winnie, a Murine Model of Spontaneous Colitis

BACKGROUND

Accumulating evidence suggests that the goblet cell-derived mucin-2 (Muc2) is a major component of the immune system and that perturbations in Muc2 lead to an ulcerative colitis-like phenotype. The animal model Winnie carries a missense mutation in Muc2 that causes Muc2 misfolding, accumulation in goblet cells, and ER stress. Excessive ER stress is a hallmark of many diseases, including ulcerative colitis, cancer, diabetes and Parkinson's disease. However, rather than committing to cell death, which is the typical outcome of unresolved ER stress, Winnie goblet cells are characterized by hyperproliferation, suggesting additional regulation of this cellular stress response.

METHODS

To elucidate the molecular mechanisms underlying ulcerative colitis in the Winnie model, we isolated goblet cells from Winnie and wild-type mice and used label-free quantitative proteomics and bioinformatics to understand the functional consequences of Muc2 misfolding and accumulation.

RESULTS

A large number of changes were identified that highlight a dramatic reprogramming of energy production, including enhanced utilization of butyrate, a key energy source of colonic cells. A major finding was the marked upregulation of the coiled-coil-helix-coiled-coil-helix domain proteins Chchd2, Chchd3, and Chchd6. In particular, we identified and confirmed the upregulation and nuclear translocation of Chchd2, a protein known to inhibit oxidative stress induced apoptosis.

CONCLUSIONS

This study is the first to apply proteome-level analysis to the preclinical Winnie model of ulcerative colitis. Identification of proteins and pathways affected in isolated Winnie goblet cells provides evidence for novel adaptive mechanisms underlying cell survival under conditions of chronic ER stress.

Rapid Discovery of Potential Drugs for Osteonecrosis of Femoral Head Based on Gene Expression Omnibus Database and Connectivity Map

Objective

To use Gene Expression Omnibus (GEO) database coupled with Connectivity Map (CMap) databases to screen potential therapeutic drugs for osteonecrosis of femoral head (ONFH) rapidly.

Methods

Raw genetic data with accession number GSE74089 that contained eight hip articular cartilage specimens from four ONFH patients and four healthy controls were obtained from the Gene Expression Omnibus (GEO) database and were then integrated using R to identify differentially expressed genes (DEGs). Subsequently, to identify several potential small molecular compounds that were most strongly negatively correlated with ONFH, a search query of DEGs was explored by using CMap.

Results

Filtering revealed 1937 DEGs with log (fold‐change) ≥1 and adjust P value < 0.001. Finally, a network of candidate targets for ONFH with 135 nodes and 660 edges was constructed through network topology analysis, including 96 up‐regulated genes and 39 down‐regulated genes. Several significant gene functions and signaling pathways associated with pathological processes of ONFH were identified via gene enrichment analysis. Based on the CMap database, some potential small molecular components that may be possible to counteract the effects of molecular signal imbalance for ONFH were identified. Neostigmine bromide with low CMap score and P value and specificity score was predicted to be the most candidate compound, involved in the “positive regulation of stem cell proliferation,” “regulation of protein autophosphorylation,” “VEGF signaling pathway,” and “ECM‐receptor interaction.”

Conclusions

The GEO and CMap databases can be effectively used in understanding the molecular changes in ONFH and provide a systematic manner to identify potential drugs for ONFH prevention and treatment. However, additional clinical and experimental research of the candidate compound is warranted.

Hepatocellular Toxicity of Paris Saponins I, II, VI and VII on Two Kinds of Hepatocytes-HL-7702 and HepaRG Cells, and the Underlying Mechanisms

Rhizoma paridis is a popularly-used Chinese medicine in clinics, based on the pharmacodynamic properties of its saponin components. The four main saponins in Rhizoma paridis are designated saponins I, II, VI, and VII. At present, much attention is focused on the anticancer effect of Rhizoma paridis which is manifested in its cytotoxicity to various cancer cells. The purpose of this study was to investigate the hepatocellular toxicities of the four saponins in Rhizoma paridis and the relative intensities of their cytotoxic effects. It was found that the four saponins were cytotoxic to two types of hepatocytes-HL-7702 and HepaRG cells. The cytotoxicities of the four saponins to the two cell models were compared. One of the most cytotoxic saponins was Rhizoma paridis saponin I (PSI). This was used to determine the mechanism of hepatocellular toxicity. Results from MTT assays demonstrated that the four saponins induced apoptosis of the two hepatocyte models in a dose-dependent and time-dependent manner. In addition, fluorescent 4′,6-diamidino-2-phenylindole (DAPI) staining was used to observe the morphological changes of HepaRG cells after saponin administration. Further, as the concentration increased, PSI-induced lactate dehydrogenase (LDH) release from HepaRG cells increased gradually. In addition, PSI enhanced the levels of reactive oxygen species (ROS) and blocked the S and G2 phases of the cell cycle in HepaRG cells. A western blot indicated that PSI upregulated the protein expression levels of p53, p21, and Fas. Furthermore, the PSI-induced changes in the p53 protein increased the Bax/bcl-2 ratio, resulting in enhancement of the release of mitochondrial cytochrome c, activation of caspases-3, -8, and -9, poly-ADP ribose polymerase (PARP), and ultimately apoptosis. Increased Fas protein activated caspase-8, which led to the activation of caspase-3 and its downstream PARP protein, resulting in cell apoptosis. These results indicate that PSI induced apoptosis in HepaRG cells through activation of ROS and death receptor pathways. The results obtained in this study suggest that the hepatocellular toxicity of saponins in Rhizoma paridis should be considered during the clinical application of this drug. In addition, they provide a reference for future anti-cancer studies on Rhizoma paridis.

Natural Products and Acute Myeloid Leukemia: A Review Highlighting Mechanisms of Action

Recent findings have shown great potential of alternative interventions such as immunotherapy and natural products for acute myeloid leukemia (AML). This study aims to review the anti-AML effect of various natural compounds. Natural compounds were classified into five groups: alkaloids, carotenoids, nitrogen-containing compounds, organosulfur compounds or phenolics based on each compound’s chemical properties. Fifty-eight studies were collected and reviewed in this article. Phenolics are the most abundant group to have an apoptotic effect over AML cells, while other groups have also shown significant apoptotic effects. Some compounds induced apoptosis by regulating unique mechanism like human telomerase reverse transcriptase (hTERT) or laminin receptor (67LR), while others modified caspases, poly (adp-ribose) polymerase (PARP) and p53. Further study is required to identify side-effects of potent compounds and the synergistic effects of combination of two or more natural compounds or existing conventional anti-AML drugs to treat this dreadful disease.

LSCDFS-MKL: A multiple kernel based method for lung squamous cell carcinomas disease-free survival prediction with pathological and genomic data

Lung squamous cell carcinoma (SCC) is a fatal disease in both male and female, for which current treatments are inadequate. Surgical resection is regarded as the cornerstone of treatment for patients with lung SCC, but even for the same stage patients, the wide spectrum of disease-free survival (DFS) times exits. Therefore, how to improve the DFS prediction performance of lung SCC becomes one major research area. In this study, we proposed a novel method called LSCDFS-MKL, which was on the basis of multiple kernel learning to predict DFS of lung SCC. In LSCDFS-MKL, we first efficiently integrated pathological images and genomic data (copy number aberration, gene expression, protein expression) from lung SCC. The results of LSCDFS-MKL between different types of data show that the features extracted from pathological images play an important role in DFS prediction of lung SCC. Then we compared our method LSCDFS-MKL with other existing methods and performance analysis indicates that LSCDFS-MKL has a significantly better performance than other prediction methods. After that, we applied the proposed method on different stage stratums and the performance demonstrates that LSCDFS-MKL remains efficient in DFS prediction of lung SCC patients. Finally, we performed LSCDFS-MKL on an independent validation dataset and the accuracy of DFS prediction achieves 100%, which is promising.

The Role of the ER-Induced UPR Pathway and the Efficacy of Its Inhibitors and Inducers in the Inhibition of Tumor Progression

Cancer is the second most frequent cause of death worldwide. It is considered to be one of the most dangerous diseases, and there is still no effective treatment for many types of cancer. Since cancerous cells have a high proliferation rate, it is pivotal for their proper functioning to have the well-functioning protein machinery. Correct protein processing and folding are crucial to maintain tumor homeostasis. Endoplasmic reticulum (ER) stress is one of the leading factors that cause disturbances in these processes. It is induced by impaired function of the ER and accumulation of unfolded proteins. Induction of ER stress affects many molecular pathways that cause the unfolded protein response (UPR). This is the way in which cells can adapt to the new conditions, but when ER stress cannot be resolved, the UPR induces cell death. The molecular mechanisms of this double-edged sword process are involved in the transition of the UPR either in a cell protection mechanism or in apoptosis. However, this process remains poorly understood but seems to be crucial in the treatment of many diseases that are related to ER stress. Hence, understanding the ER stress response, especially in the aspect of pathological consequences of UPR, has the potential to allow us to develop novel therapies and new diagnostic and prognostic markers for cancer.

Gene expression profile-based drug screen identifies SAHA as a novel treatment for NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide.

Role of the Death Receptor and Endoplasmic Reticulum Stress Signaling Pathways in Polyphyllin I-Regulated Apoptosis of Human Hepatocellular Carcinoma HepG2 Cells

Polyphyllin has been reported to exhibit anticancer effects against various types of cancer via the proapoptotic signaling pathway. The aim of the present study was to investigate the role of the endoplasmic reticulum stress and death receptor signaling pathways in PPI-induced apoptosis of human hepatocellular carcinoma HepG2 cells. Analysis demonstrated that PPI could significantly inhibit the proliferation and induce apoptosis of HepG2 cells in a dose- and time-dependent manner. Investigation into the molecular mechanism of PPI indicated that PPI notably mediated ER stress activation via IRE-1 overexpression and activation of the caspase-12 to protect HepG2 cells against apoptosis. In addition, PPI markedly induced the expression of death receptors signaling pathways-associated factors, including tumor necrosis factor (TNF) receptor 1/TNF-α and FAS/FASL. Additionally, suppression of the death receptor signaling pathways with a caspase-8 inhibitor, Z-IETD-FMK, revealed an increase in the death rate and apoptotic rate of HepG2 cells. Collectively, the findings of the present study suggested that the ER stress and death receptor signaling pathways were associated with PPI-induced HepG2 cell apoptosis; however, endoplasmic reticulum stress may serve a protective role in this process. The combination of PPI and Z-IETD-FMK may activate necroptosis, which enhances apoptosis. Therefore, the results of the present study may improve understanding regarding the roles of signaling pathways in PPI regulated apoptosis and contribute to the development of novel therapies for the treatment of HCC.

The synergistic anticancer effect of formosanin C and polyphyllin VII based on caspase-mediated cleavage of Beclin1 inhibiting autophagy and promoting apoptosis

OBJECTIVES

Drug combination has a promising and potential development prospect in the treatment of various cancers. The objective of this study is to investigate the synergistic mechanisms of polyphyllin VII (PVII) and formosanin C (FC) in lung cancer.

MATERIALS AND METHODS

The combination of FC and PVII influenced on the apoptosis, autophagy, and the relative signalling pathways were analysed in lung cancer cells.

RESULTS

The combination of FC and PVII demonstrated a concentration- dependent growth inhibition in human lung cancer cells. The combination index (CI) obtained from four lung cancer cells was smaller than 1. This synergistic antitumour effect was based on the increase of their single proapoptotic effect but inhibiting FC-induced autophagy in NCI-H460 cells. FC and PVII activated proapoptotic elements like cleaved-caspase-3, -8, and -9 to induce Beclin1 cleaved into Beclin1-C which suppressed FC-triggered autophagy and enhanced apoptosis.

CONCLUSIONS

Formosanin C and PVII showed a synergistic antitumour effect on lung cancer cells. The findings would provide the foundation for the use of combination drugs in the future.

Anti-Cancer Natural Products and Their Bioactive Compounds Inducing ER Stress-Mediated Apoptosis: A Review

Cancer is the second biggest cause of death worldwide. Despite a number of studies being conducted, the effective mechanism for treating cancer has not yet been fully understood. The tumor-microenvironment such as hypoxia, low nutrients could disturb function of endoplasmic reticulum (ER) to maintain cellular homeostasis, ultimately leading to the accumulation of unfolded proteins in ER, so-called ER stress. The ER stress has a close relation with cancer. ER stress initiates unfolded protein response (UPR) to re-establish ER homeostasis as an adaptive pathway in cancer. However, persistent ER stress triggers the apoptotic pathway. Therefore, blocking the adaptive pathway of ER stress or facilitating the apoptotic pathway could be an anti-cancer strategy. Recently, natural products and their derivatives have been reported to have anti-cancer effects via ER stress. Here, we address mechanisms of ER stress-mediated apoptosis and highlight strategies for cancer therapy by utilizing ER stress. Furthermore, we summarize anti-cancer activity of the natural products via ER stress in six major types of cancers globally (lung, breast, colorectal, gastric, prostate and liver cancer). This review deepens the understanding of ER stress mechanisms in major cancers as well as the suppressive impact of natural products against cancers via ER stress.

A review of connectivity map and computational approaches in pharmacogenomics

Large-scale perturbation databases, such as Connectivity Map (CMap) or Library of Integrated Network-based Cellular Signatures (LINCS), provide enormous opportunities for computational pharmacogenomics and drug design. A reason for this is that in contrast to classical pharmacology focusing at one target at a time, the transcriptomics profiles provided by CMap and LINCS open the door for systems biology approaches on the pathway and network level. In this article, we provide a review of recent developments in computational pharmacogenomics with respect to CMap and LINCS and related applications.

Saponins from Chinese Medicines as Anticancer Agents

Saponins are glycosides with triterpenoid or spirostane aglycones that demonstrate various pharmacological effects against mammalian diseases. To promote the research and development of anticancer agents from saponins, this review focuses on the anticancer properties of several typical naturally derived triterpenoid saponins (ginsenosides and saikosaponins) and steroid saponins (dioscin, polyphyllin, and timosaponin) isolated from Chinese medicines. These saponins exhibit in vitro and in vivo anticancer effects, such as anti-proliferation, anti-metastasis, anti-angiogenesis, anti-multidrug resistance, and autophagy regulation actions. In addition, related signaling pathways and target proteins involved in the anticancer effects of saponins are also summarized in this work.

Chemosensitizing effect of Paris Saponin I on Camptothecin and 10-hydroxycamptothecin in lung cancer cells via p38 MAPK, ERK, and Akt signaling pathways

Paris Saponin I (PSI), a steroidal sponins isolated from plant, has been exhibited antitumor and many other biological activities. In this study, we investigated the role and underlying mechanisms of PSI in the synergistic regulation of antitumor activity of Camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) in four types of lung cancer cells. The inhibitory evaluation showed that PSI could significantly reduce the CPT/HCPT-mediated cell proliferation and enhance the sensitivities of H1299, H460 and H446 lung cancer cells to CPT/HCPT. Mechanism study indicated that PSI improved the CPT/HCPT induced apoptosis in lung cancer cells through mitochondria pathway including cytochrome C release and activation of caspase-9 and -3 cascades. Furthermore, PSI plus CPT/HCPT also increased the up-regulation of Bax and down-regulation of Bcl-2 and Bcl-XL in H460 and H446 cells. Moreover, PSI enhanced CPT/HCPT-mediated inhibition of p38 MAPK and activation of phosphorylation of p38 MAPK in H1299 cells, and suppression of Akt and ERK pathways activation in H460 cells as well as in H446 cells. Collectively, our results demonstrated that PSI functions as a chemosensitizer by enhancing apoptosis through influencing p38 MAPK, ERK, and Akt pathways in lung cancer cells, and the combination with CPT/HCPT might be a promising strategy for the development of new therapeutic agents.

A synergistic antitumor effect of polyphyllin I and formosanin C on hepatocarcinoma cells

Polyphyllin I (PPI) and formosanin C (FC) were regarded as effective and imperative components isolated from Rhizoma Paridis saponins (RPS) and exhibited strong anti-tumor effects on a variety of cancers. With the wide application of complex mixtures in clinics, synergistic interactions are of vital importance in phytomedicine. Therefore, it is of inherent importance to study whether there is a synergistic anti-tumor effect on PPI and FC from one herb. In this study, the viability was detected by MTT assay. The combination index (CI) analysis was used to assess their synergistic effect. Consequently, there was a synergistic anti-tumor effect between PPI and FC at a ratio of 1:1. The CI value was less than 1.0. Their combination significantly increased their single G1 phase arrest and mitochondria-dependent apoptotic pathway. Meanwhile, PPI and FC reduced the ability of cell migration. In conclusion, polyphyllin I and formosanin C showed a synergistic anti-tumor effect on hepatocarcinoma cells. The findings would provide the foundation for the use of RPS in the future.

The Natural Occurring Compounds Targeting Endoplasmic Reticulum Stress

ER stress has been implicated in pathophysiological development of many diseases. Persistent overwhelming stimuli trigger ER stress to initiate apoptosis, autophagy, and cell death. IRE1-JNK and eIF2α-CHOP signaling pathways are the two important players of ER stress, which is also modulated by ROS production, calcium disturbance, and inflammatory factors. ER stress has been developed as a novel strategy for diseases management. Recently, a vast of research focuses on the natural occurring compounds targeting ER stress, which results in medical benefits to human diseases. These small reported molecules mainly include polyphenols, alkaloids, and saponins. Many of them have been developed for use in clinical applications. To better understand the pharmacological mechanism of these molecules in ER stress in diseases, efforts have been made to discover and deliver medical merits. In this paper, we will summarize the natural occurring compounds targeting ER stress.

Polyphyllin D induces apoptosis and differentiation in K562 human leukemia cells

Polyphyllin D, a compound derived from Paris polyphylla rhizoma, demonstrated strong anticancer activities in a previous study. Our results demonstrated that polyphyllin D exerts a growth inhibitory effect by inducing apoptosis and differentiation in the human erythroleukemia cell line K562. Polyphyllin D induced apoptosis via the mitochondrial apoptotic pathway, as evidenced by the decreased Bcl-2 and Bcr/Abl expression levels, the disruption of MMP and increased Bax, cytochrome c and cleaved-caspase-3 levels. At a low dose, polyphyllin D increased CD14 expression on the surface of K562 cells and induced cells to differentiate into monocytes or mature macrophages. These data suggest that polyphyllin D has the potential to be a potent therapeutic agent for treating human chronic myelogenous leukemia.

Paris saponin I inhibits proliferation and promotes apoptosis through down-regulating AKT activity in human non-small-cell lung cancer cells and inhibiting ERK expression in human small-cell lung cancer cells

PSI regulated AKT activity in NSCLC and inhibited ERK expression in SCLC.

Complexation of phospholipids and cholesterol by triterpenic saponins in bulk and in monolayers

The interactions between three triterpene saponins: α-hederin, hederacoside C and ammonium glycyrrhizate with model lipids: cholesterol and dipalmitoylphosphatidylcholine (DPPC) are described. The oleanolic acid-type saponins (α-hederin and hederacoside C) were shown to form 1:1 complexes with lipids in bulk, characterized by stability constants in the range (4.0±0.2)·10(3)-(5.0±0.4)·10(4) M(-1). The complexes with cholesterol are generally stronger than those with DPPC. On the contrary, ammonium glycyrrhizate does not form complexes with any of the lipids in solution. The saponin-lipid interactions were also studied in a confined environment of Langmuir monolayers of DPPC and DPPC/cholesterol with the saponins present in the subphase. A combined monolayer relaxation, surface dilational rheology, fluorescence microscopy and neutron reflectivity (NR) study showed that all three saponins are able to penetrate pure DPPC and mixed DPPC/cholesterol monolayers. Overall, the effect of the saponins on the model lipid monolayers does not fully correlate with the lipid-saponin complex formation in the homogeneous solution. The best correlation was found for α-hederin, for which even the preference for cholesterol over DPPC observed in bulk is well reflected in the monolayer studies and the literature data on its membranolytic activity. Similarly, the lack of interaction of ammonium glycyrrhizate with both lipids is evident equally in bulk and monolayer experiments, as well as in its weak membranolytic activity. The combined bulk and monolayer results are discussed in view of the role of confinement in modulating the saponin-lipid interactions and possible mechanism of membranolytic activity of saponins.

Anti-lung Cancer Effects of Polyphyllin VI and VII Potentially Correlate with Apoptosis In Vitro and In Vivo

Polyphyllin VI (PVI) and polyphyllin VII (PVII) derived from Paris polyphylla possess anti-cancer activities. However, the mechanisms for the anti-lung cancer effects of PVI and PVII remain poorly understood. In this study, PVI and PVII exhibited inhibitory effects on the proliferation of A549 and NCI-H1299 cells. PVI and PVII induced G2/M cell cycle arrest and triggered apoptosis. PVI and PVII upregulated the tumor suppressor protein p53 and downregulated cyclin B1. The two treatments significantly increased the expression levels of death receptor 3, death receptor 5, Fas, cleaved PARP, and cleaved caspase-3. Furthermore, PVI and PVII significantly inhibited the growth of A549 cells in vivo. The tumor inhibitory rates of PVI were 25.74%, 34.62%, and 40.43% at 2, 3, and 4 mg/kg, respectively, and those of PVII were 25.63%, 41.71%, and 40.41% at 1, 2, and 3 mg/kg, respectively. Finally, PVI and PVII regulated the expression of proteins related to the apoptotic pathway in A549 xenografts. In summary, PVI and PVII exhibited strong inhibitory effects on lung cancer cell growth in vitro and in vivo by inducing G2/M cell cycle arrest and triggering apoptosis.

Inhibition of cell proliferation by mild hyperthermia at 43˚C with Paris Saponin I in the lung adenocarcinoma cell line PC-9

Rhizoma paridis is widely used for cancer therapy due to its potential involvement in the suppression of tumor growth. However, at present there is no clear explanation for the mechanism underlying the inhibitory effects of Rhizoma paridis combined with hyperthermia on tumor growth. The aim of the present study was to evaluate the effects of Paris saponin I (PSI) combined with hyperthermia on a variety of non-small cell lung cancer (NSCLC) cell lines. An MTT assay was used to determine the levels of growth inhibition. The cell cycle was analyzed using flow cytometry and cell apoptosis was analyzed with Annexin V/propidium iodide staining and the Hoechst assay. The morphology of cells during apoptosis was determined using a transmission electron microscope. The expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase-3 proteins were detected using western blotting. The inhibition rates significantly increased with PSI in combination with hyperthermia at 43˚C. PSI with hyperthermia at 43˚C caused G2/M phase arrest and significantly induced apoptosis. The expression level of Bcl-2 decreased, while Bax expression increased following treatment with PSI with hyperthermia at 43˚C. In addition, the protein expression of caspase-3 was significantly enhanced. PSI combined with hyperthermia is a potent antitumor treatment through the inhibition of proliferation of NSCLC cells and may be developed as a new antitumor therapy. PSI combined with hyperthermia significantly induced apoptosis through a multi regulatory process involving G2/M arrest and regulation of Bax, Bcl-2 and caspase-3 expression, resulting in cell death and tumor inhibition.

Chinese medicines induce cell death: the molecular and cellular mechanisms for cancer therapy

Chinese medicines have long history in treating cancer. With the growing scientific evidence of biomedical researches and clinical trials in cancer therapy, they are increasingly accepted as a complementary and alternative treatment. One of the mechanisms is to induce cancer cell death. Aim. To comprehensively review the publications concerning cancer cell death induced by Chinese medicines in recent years and provide insights on anticancer drug discovery from Chinese medicines. Materials and Methods. Chinese medicines (including Chinese medicinal herbs, animal parts, and minerals) were used in the study. The key words including “cancer”, “cell death”, “apoptosis”, “autophagy,” “necrosis,” and “Chinese medicine” were used in retrieval of related information from PubMed and other databases. Results. The cell death induced by Chinese medicines is described as apoptotic, autophagic, or necrotic cell death and other types with an emphasis on their mechanisms of anticancer action. The relationship among different types of cell death induced by Chinese medicines is critically reviewed and discussed. Conclusions. This review summarizes that CMs treatment could induce multiple pathways leading to cancer cell death, in which apoptosis is the dominant type. To apply these preclinical researches to clinic application will be a key issue in the future.