Sanguinarine induces apoptosis in human colorectal cancer HCT-116 cells through ROS-mediated Egr-1 activation and mitochondrial dysfunction

Insights into the potential of Sanguinarine as a promising therapeutic option for breast cancer

Breast cancer (BC) is one of the leading causes of cancer-related deaths in women worldwide. The tumor microenvironment (TME) plays a crucial role in the progression and metastasis of BC. A significant proportion of BC is characterized by a hypoxic TME, which contributes to the development of drug resistance and cancer recurrence. Sanguinarine (SAN), an isoquinoline alkaloid found in Papaver plants, has shown promise as an anticancer agent. The present review focuses on exploring the molecular mechanisms of hypoxic TME in BC and the potential of SAN as a therapeutic option. The review presents the current understanding of the hypoxic TME, its signaling pathways, and its impact on the progression of BC. Additionally, the review elaborates on the mechanisms of action of SAN in BC, including its effects on vital cellular processes such as proliferation, migration, drug resistance, and tumor-induced immune suppression. The review highlights the importance of addressing hypoxic TME in treating BC and the potential of SAN as a promising therapeutic option.

Natural Products as Anticancer Agents: Current Status and Future Perspectives

Natural products have been an invaluable and useful source of anticancer agents over the years. Several compounds have been synthesized from natural products by modifying their structures or by using naturally occurring compounds as building blocks in the synthesis of these compounds for various purposes in different fields, such as biology, medicine, and engineering. Multiple modern and costly treatments have been applied to combat cancer and limit its lethality, but the results are not significantly refreshing. Natural products, which are a significant source of new therapeutic drugs, are currently being investigated as potential cytotoxic agents and have shown a positive trend in preclinical research and have prompted numerous innovative strategies in order to combat cancer and expedite the clinical research. Natural products are becoming increasingly important for drug discovery due to their high molecular diversity and novel biofunctionality. Furthermore, natural products can provide superior efficacy and safety due to their unique molecular properties. The objective of the current review is to provide an overview of the emergence of natural products for the treatment and prevention of cancer, such as chemosensitizers, immunotherapeutics, combinatorial therapies with other anticancer drugs, novel formulations of natural products, and the molecular mechanisms underlying their anticancer properties.

Sanguinarine Induces H2O2-Dependent Apoptosis and Ferroptosis in Human Cervical Cancer

Sanguinarine (SNG) is a benzophenanthridine alkaloid isolated mainly from Sanguinaria canadensis, Chelidonium majus, and Macleaya cordata. SNG is considered an antineoplastic agent based on its cytotoxic activity against various tumors. However, the exact molecular mechanism through which SNG mediates this activity has not been elucidated. Here, we report that SNG induces death in human cervical cancer (HeLa) cells through activation of two interdependent cell death pathways—apoptosis and ferroptosis. SNG-induced apoptosis was characterized by caspase activation and PARP cleavage, while ferroptosis involved solute carrier family 7 member 11 (SLC7A11) down-regulation, glutathione (GSH) depletion, iron accumulation, and lipid peroxidation (LPO). Interestingly, incubation with caspase inhibitor z-VAD-fmk not only inhibited the features of apoptosis, but also negated markers of SNG-induced ferroptosis. Similarly, pretreatment with ferroptosis inhibitor ferrostatin-1 (Fer-1), apart from rescuing cells from SNG-induced ferroptosis, also curbed the features of SNG-induced apoptosis. Our study implies that, together, apoptosis and ferroptosis act as partners in the context of SNG mediated tumor suppression in HeLa cells. Importantly, SNG increased the generation of reactive oxygen species (ROS), and ROS inhibition blocks the induction of both apoptosis and ferroptosis. These findings highlight the value of continued investigation into the potential use of SNG as an antineoplastic agent.

Sanguinarine promotes healthspan and innate immunity through a conserved mechanism of ROS-mediated PMK-1/SKN-1 activation

The longevity of an organism is influenced by both genetic and environmental factors. With respect to genetic factors, a significant effort is being made to identify pharmacological agents that extend lifespan by targeting pathways with a defined role in the aging process. Sanguinarine (San) is a benzophenanthridine alkaloid that exerts a broad spectrum of properties. In this study, we utilized Caenorhabditis elegans to examine the mechanisms by which sanguinarine influences aging and innate immunity. We find that 0.2 μM sanguinarine extends healthspan in C. elegans. We further show that sanguinarine generates reactive oxygen species (ROS), which is followed by the activation of PMK-1/SKN-1pathway to extend healthspan. Intriguingly, sanguinarine increases resistance to pathogens by reducing the bacterial burden in the intestine. In addition, we also find that sanguinarine enhances innate immunity through PMK-1/SKN-1 pathway. Our data suggest that sanguinarine may be a viable candidate for the treatment of age-related disorders.

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Sanguinarine extends healthspan in C. elegans

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Sanguinarine-induced ROS activates the PMK-1/SKN-1 pathway to extend healthspan

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Sanguinarine increases resistance to pathogens by reducing the bacterial burden

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Sanguinarine enhances innate immunity through PMK-1/SKN-1 pathway

Natural compound library screening identifies Sanguinarine chloride for the treatment of SCLC by upregulating CDKN1A

OBJECTIVES

Small cell lung cancer (SCLC) is notorious for aggressive malignancy without effective treatment, and most patients eventually develop tumor progression with a poor prognosis. There is an urgent need for discovering novel antitumor agents or therapeutic strategies for SCLC.

MATERIALS AND METHODS

We performed a screening method based on CCK-8 assay to screen 640 natural compounds for SCLC. The effects of Sanguinarine chloride on SCLC cell proliferation, colony formation, cell cycle, apoptosis, migration and invasion were determined. RNA-seq and bioinformatics analysis was performed to investigate the anti-SCLC mechanism of Sanguinarine chloride. Publicly available datasets and samples were analyzed to investigate the expression level of CDKN1A and its clinical significance. Loss of functional cancer cell models were constructed by shRNA-mediated silencing. Quantitative RT-PCR and Western blot were used to measure gene and protein expression. Immunohistochemistry staining was performed to detect the expression of CDKN1A, Ki67, and Cleaved caspase 3 in xenograft tissues.

RESULTS

We identified Sanguinarine chloride as a potential inhibitor of SCLC, which inhibited cell proliferation, colony formation, cell cycle, cell migration and invasion, and promoted apoptosis of SCLC cells. Sanguinarine chloride played an important role in anti-SCLC by upregulating the expression of CDKN1A. Furthermore, Sanguinarine chloride in combination with panobinostat, or THZ1, or gemcitabine, or (+)-JQ-1 increased the anti-SCLC effect compared with either agent alone treatment.

CONCLUSIONS

Our findings identified Sanguinarine chloride as a potential inhibitor of SCLC by upregulating the expression of CDKN1A. Sanguinarine chloride in combination with chemotherapy compounds exhibited strong synergism anti-SCLC properties, which could be further clinically explored for the treatment of SCLC.

Sanguinarine represses the growth and metastasis of non-small cell lung cancer by facilitating ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Sanguinarine (SAG), a natural benzophenanthridine alkaloid derived from the root of Sanguinaria canadensis Linn. (Bloodroot), possesses a potential anticancer activity. Lung carcinoma is the chief cause of malignancy-related mortality in China. Non-small cell lung carcinoma (NSCLC) is the main subtype of lung carcinoma and accounts for about eighty-five percent of this disease. Current treatment in controlling and curing NSCLC remains deficient.

AIM OF THE STUDY

The role and underlying mechanism of SAG in repressing the growth and metastasis of NSCLC was explored.

MATERIALS AND METHODS

The role of SAG in regulating the proliferation and invasion of NSCLC cells was evaluated in vitro and in a xenograft model. After treatment with SAG, Fe2+ concentration, reactive oxygen species (ROS) levels, malondialdehyde (MDA), and glutathione (GSH) content in NSCLC cells were assessed to evaluate the effect of SAG on facilitating ferroptosis.

RESULTS

SAG exhibited a dose- and time- dependent cytotoxicity in A549 and H3122 cells. SAG treatment effectively repressed the growth and metastasis of NSCLC in a xenograft model. We for the first time verified that SAG triggered ferroptosis of NSCLC cells, as evidenced by increased Fe2+ concentration, ROS level, and MDA content, and decreased GSH content. Mechanistically, SAG decreased the protein stability of glutathione peroxide 4 (GPX4) through E3 ligase STUB1-mediated ubiquitination and degradation of endogenous GPX4. GPX4 overexpression restored the proliferation and invasion of NSCLC cells treated with SAG through inhibiting ferroptosis.

CONCLUSIONS

SAG inhibits the growth and metastasis of NSCLC by regulating STUB1/GPX4-dependent ferroptosis.

MICAL1 inhibits colorectal cancer cell migration and proliferation by regulating the EGR1/β-catenin signaling pathway

MICAL1 has been reported to be involved in the malignant processes of several types of cancer cells, however, the roles of MICAL1 in colorectal cancer (CRC) have not been well-characterized. This study aims to investigate the cellular functions and molecular mechanisms of MICAL1 in CRC cells. Here, we found that both mRNA and protein levels of MICAL1 were down-regulated in colorectal cancer tissues compared with matched adjacent non-tumor tissues, and the expression level of MICAL1 was correlated with the metastatic status of colorectal cancer. Importantly, overexpression of MICAL1 significantly inhibited colorectal cancer cell migration and growth, and increased the level of E-cadherin and Occludin, and suppressed the expression level of Vimentin and N-cadherin; while silencing of MICAL1 promoted CRC cell migration and enhanced EMT. In addition, MICAL1 overexpression significantly inhibited the proliferation and growth of CRC in vitro and in vivo. Moreover, RNA sequencing and bioinformatics analysis identified that MICAL1 was closely correlated with "cell migration", "cell cycle" and "β-catenin signaling" genesets. Mechanistically, overexpression of MICAL1 downregulated the mRNA level of EGR1 and β-catenin, decreased the protein level and nuclear translocation of β-catenin, and inhibited the transcriptions of β-catenin downstream targets, c-myc and cyclin D1. The ectopic expression of EGR1 or β-catenin can significantly block the MICAL1-mediated inhibitory effects. Collectively, MICAL1 is down-regulated in CRC, and plays an inhibitory role in the migration and growth of CRC cells by suppressing the ERG1/β-catenin signaling pathway.

Targeting the redox imbalance in mitochondria: A novel mode for cancer therapy

Changes in reactive oxygen species (ROS) levels affect many aspects of cell behavior. During carcinogenesis, moderate ROS production modifies gene expression to alter cell function, elevating metabolic activity and ROS. To avoid extreme ROS-activated death, cancer cells increase antioxidative capacity, regulating sustained ROS levels that promote growth. Anticancer therapies are exploring inducing supranormal, cytotoxic oxidative stress levels either inhibiting antioxidative capacity or promoting excess ROS to selectively destroy cancer cells, triggering mechanisms such as apoptosis, autophagy, necrosis, or ferroptosis. This review exemplifies pro-oxidants (natural/synthetic/repurposed drugs) and their clinical significance as cancer therapies providing revolutionary approaches.

Reactive oxygen species (ROS) in cancer pathogenesis and therapy: An update on the role of ROS in anticancer action of benzophenanthridine alkaloids

Reactive oxygen species play crucial role in biological homeostasis and pathogenesis of human diseases including cancer. In this line, now it has become evident that ROS level/concentration is a major factor in the growth, progression and stemness of cancer cells. Moreover, cancer cells maintain a delicate balance between ROS and antioxidants to promote pathogenesis and clinical challenges via targeting a battery of signaling pathways converging to cancer hallmarks. Recent findings also entail the therapeutic importance of ROS for the better clinical outcomes in cancer patients as they induce apoptosis and autophagy. Moreover, poor clinical outcomes associated with cancer therapies are the major challenge and use of natural products have been vital in attenuation of these challenges due to their multitargeting potential with less adverse effects. In fact, most available drugs are derived from natural resources, either directly or indirectly and available evidence show the clinical importance of natural products in the management of various diseases, including cancer. ROS play a critical role in the anticancer actions of natural products, particularly phytochemicals. Benzophenanthridine alkaloids of the benzyl isoquinoline family of alkaloids, such as sanguinarine, possess several pharmacological properties and are thus being studied for the treatment of different human diseases, including cancer. In this article, we review recent findings, on how benzophenanthridine alkaloid-induced ROS play a critical role in the attenuation of pathological changes and stemness features associated with human cancers. In addition, we highlight the role of ROS in benzophenanthridine alkaloid-mediated activation of the signaling pathway associated with cancer cell apoptosis and autophagy.

Epidemic dropsy toxin, sanguinarine chloride, stimulates sucrose-sensitive hemolysis and breakdown of membrane phospholipid asymmetry in human erythrocytes

Sanguinarine (SGN) is a benzophenathridine alkaloid extracted from Sanguinaria canadensis plant. SGN is incriminated in epidemic dropsy (ED) characterized by multiple-organ failure and anemia. Nevertheless, how SGN leads to anemia of ED remains poorly understood. This study was thus initiated to investigate the interaction of SGN with human red blood cells (RBCs) and to delineate associated molecular mechanisms. Heparin- and EDTA-anticoagulated blood was collected from healthy participants and whole blood was analyzed for a complete blood count, while isolated RBCs were examined for hemolytic and eryptotic markers following exposure to 1-100 μM SGN for 24 h at 37 °C. Calcium was measured by Fluo4/AM, hemolysis by hemoglobin leakage, membrane scrambling by Annexin V-FITC, cell size by forward scatter (FSC), cell granularity by side scatter (SSC), and oxidative stress by H₂DCFDA. SGN led to increased Fluo4 fluorescence and dose-dependent hemolysis which was not ameliorated by exclusion of extracellular Ca²⁺ but was nevertheless sensitive to hyperosmotic conditions and to the presence of aspirin. SGN also caused significant increase in Annexin V-positive cells, decreased FSC and SSC values, and elevated DCF fluorescence. Moreover, significantly reduced lymphocyte and basophil percentages along with selective toxicity to platelets was noted. Collectively, SGN possesses sucrose- and cyclooxygenase-sensitive hemolytic potential and elicits eryptosis characterized by Ca²⁺ accumulation, phosphatidylserine externalization, morphological alterations including cell shrinkage and loss of granularity, and oxidative stress. In conclusion, this report reveals a novel activity of SGN against human RBCs and informs prospective policies in ED prevention and management.

Ring finger protein 2 promotes colorectal cancer progression by suppressing early growth response 1

Ring finger protein 2 (RNF2) is an important component of polycomb repressive complex 1. RNF2 is upregulated in many kinds of tumors, and elevated RNF2 expression is associated with a poor prognosis in certain cancers. To assess the function of RNF2 in colorectal cancer, we examined RNF2 protein levels in 313 paired colorectal cancer tissues and adjacent normal tissues. We then analyzed the association of RNF2 expression with the patients’ clinicopathologic features and prognoses. RNF2 expression was upregulated in colorectal cancer tissues and was associated with the tumor differentiation status, tumor stage and prognosis. In colorectal cancer cell lines, downregulation of RNF2 inhibited cell proliferation and induced apoptosis. Gene microarray analysis revealed that early growth response 1 (EGR1) was upregulated in RNF2-knockdown cells. Knocking down EGR1 partially reversed the inhibition of cell proliferation and the induction of apoptosis in RNF2-knockdown cells. RNF2 was enriched at the EGR1 promoter, where it mono-ubiquitinated histone H2A, thereby inhibiting EGR1 expression. These results indicate that RNF2 is oncogenic in colorectal cancer and may promote disease progression by inhibiting EGR1 expression. RNF2 is thus a potential prognostic marker and therapeutic target in colorectal cancer.

The Role of Oxidative Stress and Its Counteractive Utility in Colorectal Cancer (CRC)

An altered redox status accompanied by an elevated generation of reactive oxygen/nitrogen species (ROS/RNS) has been implicated in a number of diseases including colorectal cancer (CRC). CRC, being one of the most common cancers worldwide, has been reported to be associated with multiple environmental and lifestyle factors (e.g., dietary habits, obesity, and physical inactivity) and harboring heightened oxidative stress that results in genomic instability. Although under normal condition ROS regulate many signal transduction pathways including cell proliferation and survival, overwhelming of the antioxidant capacity due to metabolic abnormalities and oncogenic signaling leads to a redox adaptation response that imparts drug resistance. Nevertheless, excessive reliance on elevated production of ROS makes the tumor cells increasingly vulnerable to further ROS insults, and the abolition of such drug resistance through redox perturbation could be instrumental to preferentially eliminate them. The goal of this review is to demonstrate the evidence that links redox stress to the development of CRC and assimilate the most up-to-date information that would facilitate future investigation on CRC-associated redox biology. Concomitantly, we argue that the exploitation of this distinct biochemical property of CRC cells might offer a fresh avenue to effectively eradicate these cells.

The Synergistic Effect of Piperlongumine and Sanguinarine on the Non-Small Lung Cancer

BACKGROUND

Cancers are one of the leading causes of deaths nowadays. The development of new treatment schemes for oncological diseases is an interesting direction in experimental medicine. Therefore, the evaluation of the influence of two alkaloids-piperlongumine (PL), sanguinarine (SAN) and their combination-on the basic life processes of the A549 cell line was considered reasonable.

METHODS

The aim was achieved by analyzing the cytotoxic effects of PL and SAN and their combination in the ratio of 4:1 on the induction of cell death, changes in the distribution of cell cycle phases, reorganization of cytoskeleton and metastatic potential of A549 cells. The versatility of the applied concentration ratio was evaluated in terms of other cancer cell lines: MCF-7, H1299 and HepG2.

RESULTS

The results obtained from the MTT assay indicated that the interaction between the alkaloids depends on the concentration and type of cells. Additionally, the compounds and their combination did not exhibit a cytotoxic effect against normal cells. The combined effects of PL and SAN increased apoptosis and favored metastasis inhibition.

CONCLUSION

Selected alkaloids exhibit a cytotoxic effect on A549 cells. In turn, treatment with the combination of PL and SAN in a 4:1 ratio indicates a synergistic effect and is associated with an increase in the level of reactive oxygen species (ROS).

Biogenic Silver Nanoparticles: Assessment of Their Cytotoxicity, Genotoxicity and Study of Capping Proteins

The development of nanotechnology in the last two decades has led to the use of silver nanoparticles (AgNPs) in various biomedical applications, including antimicrobial, anti-inflammatory, and anticancer therapies. However, the potential of the medical application of AgNPs depends on the safety of their use. In this work, we assessed the in vitro cytotoxicity and genotoxicity of silver nanoparticles and identified biomolecules covering AgNPs synthesized from actinobacterial strain SH11. The cytotoxicity of AgNPs against MCF-7 human breast cancer cell line and murine macrophage cell line RAW 264.7 was studied by MTT assay, cell LDH (lactate dehydrogenase) release, and the measurement of ROS (reactive oxygen species) level while genotoxicity in Salmonella typhimurium cells was testing using the Ames test. The in vitro analysis showed that the tested nanoparticles demonstrated dose-dependent cytotoxicity against RAW 264.6 macrophages and MCF-7 breast cancer cells. Moreover, biosynthesized AgNPs did not show a mutagenic effect of S. typhimurium. The analyses and identification of biomolecules present on the surface of silver nanoparticles showed that they were associated with proteins. The SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) analysis revealed the presence of 34 and 43 kDa protein bands. The identification of proteins performed by using LC-MS/MS (liquid chromatography with tandem mass spectrometry) demonstrated their highest homology to bacterial porins. Capping biomolecules of natural origin may be involved in the synthesis process of AgNPs or may be responsible for their stabilization. Moreover, the presence of natural proteins on the surface of bionanoparticles eliminates the postproduction steps of capping which is necessary for chemical synthesis to obtain the stable nanostructures required for application in medicine.

Friend or foe, the role of EGR-1 in cancer

Early growth response-1 (EGR-1), also termed NEFI-A and Krox-24, as a multi-domain protein is implicated in several vital physiological processes, including development, metabolism, cell growth and proliferation. Previous studies have implied that EGR-1 was producing in response to the tissue injury, immune response and fibrosis. Meanwhile, emerging studies stressed the pronounced correlation of EGR-1 and human cancers. Nevertheless, the intricate mechanisms of cancer-reduce EGR-1 alteration still poorly characterized. In the review, we evaluated the effects of EGR-1 in tumor cell proliferation, apoptosis, migration, invasion and tumor microenvironment, and then, we dwell on the intricate signaling pathways that EGR-1 involved in. The aberrantly expressed of EGR-1 in cancers are expected to provide a new cancer therapy strategy or a new marker for assessing treatment efficacy.

Potential proapoptotic phytochemical agents for the treatment and prevention of colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of mortality among men and women. Chemo-resistance, adverse effects and disease recurrence are major challenges in the development of effective cancer therapeutics. Substantial literature on this subject highlights that populations consuming diets rich in fibers, fruits and vegetables have a significantly reduced incidence rate of CRC. This chemo-preventive effect is primarily associated with the presence of phytochemicals in the dietary components. Plant-derived chemical agents act as a prominent source of novel compounds for drug discovery. Phytochemicals have been the focus of an increasing number of studies due to their ability to modulate carcinogenic processes through the alteration of multiple cancer cell survival pathways. Despite promising results from experimental studies, only a limited number of phytochemicals have entered into clinical trials. The purpose of the current review is to compile previously published pre-clinical and clinical evidence of phytochemicals in cases of CRC. A PubMed, Google Scholar and Science Direct search was performed for relevant articles published between 2008-2018 using the following key terms: 'Phytochemicals with colorectal cancers', 'apoptosis', 'cell cycle', 'reactive oxygen species' and 'clinical anticancer activities'. The present review may aid in identifying the most investigated phytochemicals in CRC cells, and due to the limited number of studies that make it from the laboratory bench to clinical trial stage, may provide a novel foundation for future research.

Regulation of TBBPA-induced oxidative stress on mitochondrial apoptosis in L02 cells through the Nrf2 signaling pathway

Tetrabromobisphenol A (TBBPA) is a commonly used brominated flame retardant, which has a wide range of toxic effects on organisms. This study investigated the cytotoxic effects on human hepatocytes (L02 cells) after treated with 0, 5, 10, 20, and 40 μM of TBBPA. Results showed that TBBPA significantly increased intracellular reactive oxygen species (ROS), malondialdehyde (MDA) and the ratio of oxidized/reduced glutathione (GSSG/GSH) dose-dependently. TBBPA also decreased the cell mitochondrial membrane potential (MMP), caused the release of cytochrome C (Cyt C) to cytoplasm and promoted the expression of caspase-9 and caspase-3, and finally increased the level of apoptosis. The ROS inhibitor N-acetyl-L-cysteine (NAC) relieved the oxidative stress responses, and prevented the decrease of MMP and increase of apoptosis. In addition, TBBPA promoted the expression of antioxidant genes related to Nrf2, such as quinone oxidoreductase 1 (NQO1), catalase (CAT), and heme oxygenase 1 (HO-1). Oxidative stress initiated by TBBPA, activated mitochondrial apoptosis and Nrf2 pathway, and increased the degree of apoptosis in L02 cells.

Sanguinarine inhibits the proliferation of BGC-823 gastric cancer cells via regulating miR-96-5p/miR-29c-3p and the MAPK/JNK signaling pathway

Sanguinarine (SAN), a quaternary benzophenanthridine alkaloid extracted from the root of Papaveraceae plants, has shown antitumour effects in multiple cancer cells. However, the therapeutic effects and the underlying mechanisms of SAN in gastric cancer (GC) remain elusive. In this study, the in vitro proliferation inhibition effect of SAN in GC cells was determined using CCK-8 assay, the in vivo antitumor effect of SAN was evaluated in mice with xenotransplanted tumor. The mechanism underlying the antitumor activity of SAN was explored by gene microarray assay and bioinformatics analysis. The levels of differentially expressed miRNAs and target genes were verified by real-time RT-PCR and immunohistochemistry. SAN inhibited the proliferation of BGC-823 cells in a concentration-dependent manner in vitro and in vivo. The miR-96-5p and miR-29c-3p were significantly upregulated in untreated BGC-823 cells and significantly downregulated in SAN treated cells. The mRNA and protein expression of their target gene MAP4K4 were upregulated in SAN treated xenotransplanted tumors, and pMEK4 and pJNK1 proteins in the MAPK/JNK signaling pathway were also upregulated by SAN. These indicate that SAN may inhibit the proliferation of BGC-823 cells through the inhibition of miR-96-5p and miR-29c-3p expression, and subsequent activation of the MAPK/JNK signaling pathway.

Critical role of H2O2 in mediating sanguinarine-induced apoptosis in prostate cancer cells via facilitating ceramide generation, ERK1/2 phosphorylation, and Par-4 cleavage

Natural products are a major source of potential anticancer agents, and in order to develop improved and more effective cancer treatments, there is an immense need in exploring and elucidating their mechanism of action. Sanguinarine (SNG), a quaternary benzophenanthridine alkaloid, has been shown to induce cytotoxicity in various human cancers and suppresses various pro-tumorigenic processes such as invasion, angiogenesis, and metastasis in different cancers. Lack of understanding the anticancer mechanism(s) of SNG has impeded the development of this molecule as a potential anticancer agent. Earlier, we have reported that SNG induces reactive oxygen species (ROS)-dependent ceramide (Cer) generation and Akt dephosphorylation, leading to the induction of apoptosis in human leukemic cells. In the present study, we demonstrate that SNG has potent anti-proliferative activity against prostate cancer cells. Our data suggest that SNG induces Cer generation via inhibiting acid ceramidase and glucosylceramide synthase, two important enzymes involved in Cer metabolism. Furthermore, we demonstrate that SNG induces ROS-depended extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation, and prostate apoptosis response-4 (Par-4) cleavage, leading to the induction of apoptosis in human prostate cancer cells. Overall, our findings provide molecular insight into the role of ROS signaling in the anticancer mechanism(s) of SNG. This may provide the basis for its use as a nontoxic and an effective therapeutic agent in the treatment of prostate cancer.

Prostate cancer promotes a vicious cycle of bone metastasis progression through inducing osteocytes to secrete GDF15 that stimulates prostate cancer growth and invasion

Bone is the most frequent site of prostate cancer (PCa) metastasis; however, little is known about the role of the most common cell in bone, the osteocyte (OCy), in cancer biology. In this study we explored the crosstalk between PCa cells and OCys to determine if it contributes to PCa progression. PCa cells induced OCys to promote PCa proliferation, migration and invasion. A chemokine screen revealed that PCa cell induced OCys to produce growth-derived factor 15 (GDF15). Knockdown of GDF15 in OCys demonstrated that PCa cells conferred the ability on OCys to promote PCa proliferation, migration and invasion through GDF15. Consistent with this finding was the observation that the GDF15 receptor, GFRAL, was expressed on multiple PCa cell lines. Transcription factor array screening of PCa cells exposed to OCys with or without knockdown of GDF15 revealed that GDF15 in OCys promoted early growth response 1 (EGR1) expression in the PCa cells. Knockdown of EGR1 expression in PCa cells revealed it was required for the OCy-derived GDF15-mediated induction of in vitro PCa cell proliferation, migration and invasion. Subcutaneous co-injection of PCa cells and OCys into mice revealed that OCys promoted tumor growth in vivo, which was diminished by knockdown of GDF15 in the OCys. Knockdown of GDF15 in the tibiae diminished growth of PCa cancer cells injected into the tibiae, which was accompanied by decreased tumor cell proliferation and EGR1 expression. These results shed light on a novel mechanism through which PCa cells educate OCys to promote progression of PCa bone metastasis. They also suggest that targeting of GDF15-based and EGR1-based signaling pathways should be further explored for their potential to diminish progression of PCa bone metastasis.

Sanguinarine triggers intrinsic apoptosis to suppress colorectal cancer growth through disassociation between STRAP and MELK

Background

Previous studies showed sanguinarine induced apoptosis in CRC cells but did not define the underlying mechanisms. The purpose of this work was to determine the in vivo and in vitro effects of sanguinarine on CRC tumors and to elucidate the mechanism in regulating the intrinsic apoptosis.

Methods

Cell viability of CRC cell lines treated with sanguinarine was measured by MTT assay. Apoptotic cells stained with Annexin V and 7-AAD were detected by flow cytometry. Mitochondrial membrane potential and reactive oxygen species (ROS) were analyzed by JC-1 and DCFH-DA staining, respectively. The in vitro kinase activity of MELK was analyzed by using HTRF^® KinEASE™-STK kit. The expression of proteins were determined using Western blotting and immunohistochemistry. Co-immunoprecipitation and immunofluorecence were used to study the interaction between STRAP and MELK. The anti-neoplastic effect of sanguinarine was observed in vivo in an orthotopic CRC model.

Results

Sanguinarine decreased the tumor size in a dose-dependent manner in orthotopical colorectal carcinomas through intrinsic apoptosis pathway in BALB/c-nu mice. It significantly increased cleavage of caspase 3 and PARP in implanted colorectal tissues. Sanguinarine increased mitochondrial ROS and triggered mitochondrial outer membrane permeabilization in multiple colorectal cancer (CRC) cell lines. NAC pretreatment lowered ROS level and downregulated apoptosis induced by sanguinarine. The intrinsic apoptosis induced by sanguinarine was Bax-dependent. The elevated expression and association between serine-threonine kinase receptor-associated protein (STRAP) and maternal embryonic leucine zipper kinase (MELK) were observed in Bax positive cells but not in Bax negative cells. Sanguinarine dephosphorylated STRAP and MELK and disrupted the association between them in HCT116 and SW480 cells. The expression and association between STRAP and MELK were also attenuated by sanguinarine in the tumor tissues. Importantly, we found that STRAP and MELK were overexpressed and highly phosphorylated in colorectal adenocarcinomas and their expression were significantly correlated with tumor stages. Furthermore, the expression of MELK, but not STRAP, was associated with lymph node metastasis.

Conclusions

Sanguinarine dephosphorelates STRAP and MELK and disassociates the interaction between them to trigger intrinsic apoptosis. Overexpression of STRAP and MELK may be markers of CRC and their disassociation may be a determinant of therapeutic efficacy.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4463-x) contains supplementary material, which is available to authorized users.

Nickel Oxide Nanoparticles Induced Transcriptomic Alterations in HEPG2 Cells

Nickel oxide nanoparticles (NiO-NPs) are increasingly used and concerns have been raised on its toxicity. Although a few studies have reported the toxicity of NiO-NPs, a comprehensive understanding of NiO-NPs toxicity in human cells is still lagging. In this study, we integrated transcriptomic approach and genotoxic evidence to depict the mechanism of NiO-NPs toxicity in human hepatocellular carcinoma (HepG2) cells. DNA damage analysis was done using comet assay, which showed 26-fold greater tail moment in HepG2 cells at the highest concentration of 100 μg/ml. Flow cytometric analysis showed concentration dependent enhancement in intracellular reactive oxygen species (ROS). Real-time PCR analysis of apoptotic (p53, bax, bcl2) and oxidative stress (SOD1) genes showed transcriptional upregulation. Transcriptome analysis using qPCR array showed over expression of mRNA transcripts related to six different cellular pathways. Our data unequivocally suggests that NiO-NPs induces oxidative stress, DNA damage, apoptosis and transcriptome alterations in HepG2 cells.

Noninvasive bioluminescence imaging of the dynamics of sanguinarine induced apoptosis via activation of reactive oxygen species

Most chemotherapeutic drugs exert their anti-tumor effects primarily by triggering a final pathway leading to apoptosis. Noninvasive imaging of apoptotic events in preclinical models would greatly facilitate the development of apoptosis-inducing compounds and evaluation of their therapeutic efficacy. Here we employed a cyclic firefly luciferase (cFluc) reporter to screen potential pro-apoptotic compounds from a number of natural agents. We demonstrated that sanguinarine (SANG) could induce apoptosis in a dose- and time-dependent manner in UM-SCC-22B head and neck cancer cells. Moreover, SANG-induced apoptosis was associated with the generation of reactive oxygen species (ROS) and activation of c-Jun-N-terminal kinase (JNK) and nuclear factor-kappaB (NF-κB) signal pathways. After intravenous administration with SANG in 22B-cFluc xenograft models, a dramatic increase of luminescence signal can be detected as early as 48 h post-treatment, as revealed by longitudinal bioluminescence imaging in vivo. Remarkable apoptotic cells reflected from ex vivo TUNEL staining confirmed the imaging results. Importantly, SANG treatment caused distinct tumor growth retardation in mice compared with the vehicle-treated group. Taken together, our results showed that SANG is a candidate anti-tumor drug and noninvasive imaging of apoptosis using cFluc reporter could provide a valuable tool for drug development and therapeutic efficacy evaluation.

Molecular targets and anticancer potential of sanguinarine-a benzophenanthridine alkaloid

BACKGROUND

Cancer is an enormous global health burden, and should be effectively addressed with better therapeutic strategies. Currently, over 60% of the clinically approved anticancer agents are either directly isolated from natural sources or are modified from natural lead molecules. Sanguinarine (SNG), a quaternary benzophenanthridine alkaloid has gained increasing attention in recent years as a potential anticancer agent.

PURPOSE

There is a large untapped source of phytochemical-based anticancer agents remaining to be explored. This review article aims to recapitulate different anticancer properties of SNG, and describes some of the molecular targets involved in exerting its effect. It also depicts the pharmacokinetic and toxicological properties of SNG, two parameters important in determining the druggability of a molecule.

METHODS

Numerous in vivo and in vitro published studies have signified the anticancer properties of SNG. In order to collate and decipher these properties, an extensive literature search was conducted in PubMed, ScienceDirect, and Scopus using keywords followed by the evaluation of the relevant articles where the relevant reports are integrated and analyzed.

RESULTS

Apart from inducing cell death, SNG inhibits pro-tumorigenic processes such as invasion, angiogenesis, and metastasis in different cancers. Moreover, SNG has been shown to synergistically enhance the sensitivity of several chemotherapeutic agents and is effective against a variety of multi-drug resistant cancers.

Upregulation of CISD2 augments ROS homeostasis and contributes to tumorigenesis and poor prognosis of lung adenocarcinoma

CISD2 is a redox-sensitive gene critical for normal development and mitochondrial integrity. CISD2 was known to have aberrant expression in several types of human cancers. However, its relation with lung cancer is still not clear. In this study we found CISD2 mRNA was significantly upregulated in lung adenocarcinoma (ADC) samples, compared with their adjacent normal counterparts, and was correlated with tumor stage, grade, and prognosis based on analysis of clinical specimens-derived expression data in public domain and our validation assay. Cell based assay indicated that CISD2 expression regulated accumulation of reactive oxygen species (ROS), polarization of mitochondrial membrane potential, as well as cell viability, apoptosis, invasiveness, and tumorigenicity. In addition, CISD2 expression was found significantly correlated with stress response/redox signaling genes such as EGR1 and GPX3, while such correlations were also found valid in many public domain data. Taken together, upregulation of CISD2 is involved in an increased antioxidant capacity in response to elevated ROS levels during the formation and progression of lung ADC. The molecular mechanism underlying how CISD2 regulates ROS homeostasis and augments malignancy of lung cancer warrants further investigations.

Sanguinarine and Its Role in Chronic Diseases

The use of natural products derived from plants as medicines precedes even the recorded human history. In the past few years there were renewed interests in developing natural compounds and understanding their target specificity for drug development for many devastating human diseases. This has been possible due to remarkable advancements in the development of sensitive chemistry and biology tools. Sanguinarine is a benzophenanthridine alkaloid derived from rhizomes of the plant species Sanguinaria canadensis. The alkaloid can exist in the cationic iminium and neutral alkanolamine forms. Sanguinarine is an excellent DNA and RNA intercalator where only the iminium ion binds. Both forms of the alkaloid, however, shows binding to functional proteins like serum albumins, lysozyme and hemoglobin. The molecule is endowed with remarkable biological activities and large number of studies on its various activities has been published potentiating its development as a therapeutic agent particularly for chronic human diseases like cancer, asthma, etc. In this article, we review the properties of this natural alkaloid, and its diverse medicinal applications in relation to how it modulates cell death signaling pathways and induce apoptosis through different ways, its utility as a therapeutic agent for chronic diseases and its biological effects in animal and human models. These data may be useful to understand the therapeutic potential of this important and highly abundant alkaloid that may aid in the development of sanguinarine-based therapeutic agents with high efficacy and specificity.

Anticancer potential of sanguinarine for various human malignancies

Sanguinarine (Sang) - a benzophenanthridine alkaloid extracted from Sanguinaria canadensis - exhibits antioxidant, anti-inflammatory, proapoptotic and growth inhibitory activities on tumor cells of various cancer types as established by in vivo and in vitro studies. Although the underlying mechanism of Sang antitumor activity is yet to be fully elucidated, Sang has displayed multiple biological effects, which remain to suggest its possible use in plant-derived treatments of human malignancies. This review covers the anticancer abilities of Sang including inhibition of aberrantly activated signal transduction pathways, induction of cell death and inhibition of cancer cell proliferation. It also highlights Sang-mediated inhibition of angiogenesis, inducing the expression of tumor suppressors, sensitization of cancer cells to standard chemotherapeutics to enhance their cytotoxic effects, while addressing the present need for further pharmacokinetic-based studies.

IL-22 Impedes the Proliferation of Schwann cells: Transcriptome Sequencing and Bioinformatics Analysis

Schwann cells (SCs) proliferation is crucial for nerve regeneration following nerve injury. This study aims to investigate effects of interleukin-22 (IL-22) on SCs proliferation in vitro, as well as the corresponding mechanism. Rat SCs were treated with 100 ng/ml rat IL-22 for 48 h, and cell proliferation and apoptosis were detected using fluorescent staining and flow cytometry. After transcriptome sequencing, raw reads were filtered and mapped to reference genome rn5. Then, differentially expressed genes (DEGs) and long non-coding RNAs (DElncRNAs) between IL-22 and control groups were identified (tool: Cuffdiff). Functional and pathway enrichment analyses were performed (tool: GOFunction), and protein-protein interaction (PPI) network was constructed (tool: STRING and Cytoscape). Furthermore, Pearson's correlations between DEGs and DElncRNAs were analyzed, and regulatory network of DEGs, DElncRNAs, and transcription factors (TFs) was constructed. IL-22 significantly inhibited proliferation (p value < 0.05) and promoted apoptosis of Schwann cells. Totally, 932 DEGs and 118 DElncRNAs were identified, among which Ccl2 and Ccna2 were hub genes in PPI network. Up-regulated DEGs were enriched in apoptosis related terms, whereas down-regulated DEGs were enriched in proliferation related terms. DElncRNAs like NONRATT023505, NONRATG020400, and NONRATT022748 were correlated with multiple DEGs enriched in cell cycle and division. Moreover, up-regulated TFs Egr1, Cebpd, and Atf4 play crucial roles in regulatory network, and NONRATG020400-Cebpd-Ccl2, NONRATT023505/NONRATT022748-Atf4-Ccna2, and NONRATT022748-Egr1-Id1/Aldoc/Eno2/F3/Serpine1 regulatory pathways were identified in SCs after IL-22 treatment. IL-22 might influence SCs proliferation and apoptosis via regulating lncRNA-TF-gene pathways in SCs. However, more studies are required to confirm these results.

Coptisine-induced cell cycle arrest at G2/M phase and reactive oxygen species-dependent mitochondria-mediated apoptosis in non-small-cell lung cancer A549 cells

This study aimed to explore the effect of coptisine on non-small-cell lung cancer and its mechanism through various in vitro cellular models (A549). Results claimed significant inhibition of proliferation by coptisine against A549, H460, and H2170 cells with IC₅₀ values of 18.09, 29.50, and 21.60 µM, respectively. Also, coptisine exhibited upregulation of pH2AX, cell cycle arrest at G2/M phase, and downregulation of the expression of cyclin B1, cdc2, and cdc25C and upregulation of p21 dose dependently. Furthermore, induction of apoptosis in A549 cells by coptisine was characterized by the activation of caspase 9, caspase 8, and caspase 3, and cleavage of poly adenosine diphosphate ribose polymerase. In addition, coptisine was found to increase reactive oxygen species generation, upregulate Bax/Bcl-2 ratio, disrupt mitochondrial membrane potential, and cause cytochrome c release into the cytosol. Besides, treatment with a reactive oxygen species inhibitor (N-acetyl cysteine) abrogated coptisine-induced growth inhibition, apoptosis, reactive oxygen species generation, and mitochondrial dysfunction. Thus, the mediation of reactive oxygen species in the apoptosis-induced effect of coptisine in A549 cells was corroborated. These findings have offered new insights into the effect and mechanisms of action of coptisine against non-small-cell lung cancer.

Sanguinarine-induced oxidative stress and apoptosis-like programmed cell death(AL-PCD) in root meristem cells of Allium cepa

A vast number of studies on plant cell systems clearly indicate that various biotic and abiotic stresses give rise to the uncontrolled increase in the level of reactive oxygen species (ROS). Excess concentrations of ROS result in damage to proteins, lipids, carbohydrates, and DNA, which may lead, in consequence, to the apoptotic cell death. The current study investigates the effects of sanguinarine (SAN), a natural alkaloid derived from the roots of Sanguinaria canadensis, on root apical meristem cells of Allium cepa. It is shown that SAN treatment generated large amounts of hydrogen peroxide (H₂O₂) and superoxide anion (O₂·-). Oxidative stress induced in SAN-treated cells was correlated with DNA fragmentation, formation of micronuclei (MN), altered and 'degenerated' chromatin structures characteristic of apoptosis-like programmed cell death (AL-PCD). The experiments with SAN + MG132 (a proteasome inhibitor engaged in Topo II-mediated formation of cleavable complexes) and SAN + ascorbic acid (AA; H₂O₂ scavenger) seem to suggest, however, that the high level of H₂O₂ is not the only factor responsible for changes observed at the chromatin level and for the consequent cell death. Our findings imply that Topo II-DNA covalent complexes and 26S proteasomes are also involved in SAN-induced DNA damage.

Sanguinarine inhibits growth and invasion of gastric cancer cells via regulation of the DUSP4/ERK pathway

Sanguinarine, a bioactive benzophenanthridine alkaloid extracted from plants of the Papaveraceae family, has shown antitumour effects in multiple cancer cells. But the therapeutic effects and regulatory mechanisms of sanguinatine in gastric cancer (GC) remain elusive. This study was aimed to investigate the correlation of dual‐specificity phosphatase 4 (DUSP4) expression with clinicopathologic features and overall survival in patients with GC and explore the effects of sanguinarine on tumour growth and invasion in GC cells (SGC‐7901 and HGC‐27) and underlying molecular mechanisms. Immunohistochemical analysis showed that decreased DUSP4 expression was associated with the sex, tumour size, depth of invasion and distant metastasis in patients with GC. Functional experiments including CCK‐8, Transwell and flow cytometry analysis indicated that sanguinarine or DUSP4 overexpression inhibited GC cell viability and invasive potential, and induced cell apoptosis and cycle arrest in S phase, but DUSP4 knockdown attenuated the antitumour activity of sanguinarine. Further observation demonstrated that sanguinarine up‐regulated the expression of DUSP4 and Bcl‐2‐associated X protein (Bax), but down‐regulated phosphorylated extracellular signal‐regulated kinase (p‐ERK), proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP‐2) and B‐cell lymphoma 2 (Bcl‐2) expression. Taken together, our findings indicate that sanguinarine inhibits growth and invasion of GC cells through regulation of the DUSP4/ERK pathway, suggesting that sanguinarine may have potential for use in GC treatment.

Krüppel-Like Factor 12 Promotes Colorectal Cancer Growth through Early Growth Response Protein 1

Krüppel-like factor 12 (KLF12) is a transcription factor that plays a role in normal kidney development and repression of decidualization. KLF12 is frequently elevated in esophageal adenocarcinoma and has been reported to promote gastric cancer progression. Here, we examined the role of KLF12 in colorectal cancer (CRC). Indeed, KLF12 promotes tumor growth by directly activating early growth response protein 1 (EGR1). The levels of KLF12 and EGR1 correlate synergistically with a poor prognosis. These results indicate that KLF12 likely plays an important role in CRC and could serve as a potential prognostic marker and therapeutic target.

Molecular signatures of sanguinarine in human pancreatic cancer cells: A large scale label-free comparative proteomics approach

Pancreatic cancer remains one of the most lethal of all human malignancies with its incidence nearly equaling its mortality rate. Therefore, it's crucial to identify newer mechanism-based agents and targets to effectively manage pancreatic cancer. Plant-derived agents/drugs have historically been useful in cancer therapeutics. Sanguinarine is a plant alkaloid with anti-proliferative effects against cancers, including pancreatic cancer. This study was designed to determine the mechanism of sanguinarine's effects in pancreatic cancer with a hope to obtain useful information to improve the therapeutic options for the management of this neoplasm. We employed a quantitative proteomics approach to define the mechanism of sanguinarine's effects in human pancreatic cancer cells. Proteins from control and sanguinarine-treated pancreatic cancer cells were digested with trypsin, run by nano-LC/MS/MS, and identified with the help of Swiss-Prot database. Results from replicate injections were processed with the SIEVE software to identify proteins with differential expression. We identified 37 differentially expressed proteins (from a total of 3107), which are known to be involved in variety of cellular processes. Four of these proteins (IL33, CUL5, GPS1 and DUSP4) appear to occupy regulatory nodes in key pathways. Further validation by qRT-PCR and immunoblot analyses demonstrated that the dual specificity phosphatase-4 (DUSP4) was significantly upregulated by sanguinarine in BxPC-3 and MIA PaCa-2 cells. Sanguinarine treatment also caused down-regulation of HIF1α and PCNA, and increased cleavage of PARP and Caspase-7. Taken together, sanguinarine appears to have pleotropic effects, as it modulates multiple key signaling pathways, supporting the potential usefulness of sanguinarine against pancreatic cancer.

Antitumor effects of the benzophenanthridine alkaloid sanguinarine: Evidence and perspectives

Historically, natural products have represented a significant source of anticancer agents, with plant-derived drugs becoming increasingly explored. In particular, sanguinarine is a benzophenanthridine alkaloid obtained from the root of Sanguinaria canadensis, and from other poppy Fumaria species, with recognized anti-microbial, anti-oxidant and anti-inflammatory properties. Recently, increasing evidence that sanguinarine exibits anticancer potential through its capability of inducing apoptosis and/or antiproliferative effects on tumor cells, has been proved. Moreover, its antitumor seems to be due not only to its pro-apoptotic and inhibitory effects on tumor growth, but also to its antiangiogenic and anti-invasive properties. Although the precise mechanisms underlying the antitumor activity of this compound remain not fully understood, in this review we will focus on the most recent findings about the cellular and molecular pathways affected by sanguinarine, together with the rationale of its potential application in clinic. The complex of data currently available suggest the potential application of sanguinarine as an adjuvant in the therapy of cancer, but further pre-clinical studies are needed before such an antitumor strategy can be effectively translated in the clinical practice.

N-n-butyl Haloperidol Iodide Protects against Hypoxia/Reoxygenation Injury in Cardiac Microvascular Endothelial Cells by Regulating the ROS/MAPK/Egr-1 Pathway

Endothelium dysfunction induced by reactive oxygen species (ROS) is an important initial event at the onset of myocardial ischemia/reperfusion in which the Egr-1 transcription factor often serves as a master switch for various damage pathways following reperfusion injury. We hypothesized that an intracellular ROS/MAPK/Egr-1 signaling pathway is activated in cardiac microvascular endothelial cells (CMECs) following hypoxia/reoxygenation (H/R). ROS generation, by either H/R or the ROS donor xanthine oxidase-hypoxanthine (XO/HX) activated all three MAPKs (ERK1/2, JNK, p38), and induced Egr-1 expression and Egr-1 DNA-binding activity in CMECs, whereas ROS scavengers (EDA and NAC) had the opposite effect following H/R. Inhibitors of all three MAPKs individually inhibited induction of Egr-1 expression by H/R in CMECs. Moreover, N-n-butyl haloperidol (F₂), previously shown to protect cardiomyocytes subjected to I/R, dose-dependently downregulated H/R-induced ROS generation, MAPK activation, and Egr-1 expression and activity in CMECs, whereas XO/HX and MAPK activators (EGF, anisomycin) antagonized the effects of F₂. Inhibition of the ROS/MAPK/Egr-1 signaling pathway, by either F₂, NAC, or inhibition of MAPK, increased CMEC viability and the GSH/GSSG ratio, and decreased Egr-1 nuclear translocation. These results show that the ROS/MAPK/Egr-1 signaling pathway mediates H/R injury in CMECs, and F₂ blocks this pathway to protect against H/R injury and further alleviate myocardial I/R injury.

Promoting effects of sanguinarine on apoptotic gene expression in human neuroblastoma cells

Neuroblastoma is the most common extracranial solid tumor in children. Approximately half of the affected patients are diagnosed with high-risk poor prognosis disease, and novel therapies are needed. Sanguinarine is a benzophenanthridine alkaloid which has anti-microbial, anti-oxidant and anti-inflammatory properties. The aim of this study is whether sanguinarine has in vitro apoptotic effects and which apoptotic genes might be affected in the human neuroblastoma cell lines SH-SY5Y (N-myc negative), Kelly (N-myc positive, ALK positive), and SK- N-BE(2). Cell viability was analysed with WST-1 and apoptotic cell death rates were determined using TUNEL. After RNA isolation and cDNA conversion, expression of 84 custom array genes of apoptosis was determined. Sanguinarine caused cell death in a dose dependent manner in all neuroblastoma cell lines except SK-N-BE(2) with rates of 18% in SH-SY5Y and 21% in Kelly human neuroblastoma cells. Cisplatin caused similar apoptotic cell death rates of 16% in SH-SY5Y and 23% in Kelly cells and sanguinarine-cisplatin combinations caused the same rates (18% and 20%). Sanguinarine treatment did not affect apoptototic gene expression but decreased levels of anti-apoptotic genes NOL3 and BCL2L2 in SH-SY5Y cells. Caspase and TNF related gene expression was affected by the sanguinarine-cisplatin combination in SH-SY5Y cells. The expression of regulation of apoptotic genes were increased with sanguinarine treatment in Kelly cells. From these results, we conclude that sanguinarine is a candidate agent against neuroblastoma.

Hyperosmotic stress activates the expression of members of the miR-15/107 family and induces downregulation of anti-apoptotic genes in rat liver

microRNAs are an abundant class of small non-coding RNAs that negatively regulate gene expression. Importantly, microRNA activity has been linked to the control of cellular stress response. In the present study, we investigated whether the expression of hepatic microRNAs is affected by changes in ambient osmolarity. It is shown that hyperosmotic exposure of perfused rat liver induces a rapid upregulation of miR-15a, miR-15b and miR-16, which are members of the miR-15/107 microRNAs superfamily. It was also identified that hyperosmolarity significantly reduces the expression of anti-apoptotic genes including Bcl2, Ccnd1, Mcl1, Faim, Aatf, Bfar and Ikbkb, which are either validated or predicted targets of these microRNAs. Moreover, through the application of NOX and JNK inhibitors as well as benzylamine it is shown that the observed response is mediated by reactive oxygen species (ROS), suggesting that miR-15a, miR-15b and miR-16 are novel redoximiRs. It is concluded that the response of these three microRNAs to osmotic stress is ROS-mediated and that it might contribute to the development of a proapoptotic phenotype.

Effect of N-n-butyl haloperidol iodide on ROS/JNK/Egr-1 signaling in H9c2 cells after hypoxia/reoxygenation

Reactive oxygen species (ROS)-induced oxidative stress in cells is an important pathophysiological process during myocardial ischemia/reperfusion (I/R) injury, and the transcription factor Egr-1 is a master switch for various damage pathways during reperfusion injury. An in vitro model of myocardial I/R injury and H9c2 cardiomyoblast cells hypoxia/reoxygenation (H/R) was used to assess whether there is abnormal intracellular ROS/JNK/Egr-1 signaling. We also assessed whether N-n-butyl haloperidol (F2), which exerts protective effects during myocardial I/R injury, can modulate this pathway. H/R induced ROS generation, JNK activation, and increased the expression of Egr-1 protein in H9c2 cells. The ROS scavengers edaravone (EDA) and N-acetyl-L-cysteine (NAC) reduced ROS level, downregulated JNK activation, and Egr-1 expression in H9c2 cells after H/R. The JNK inhibitor SP600125 inhibited Egr-1 overexpression in H9c2 cells caused by H/R. F2 could downregulate H/R-induced ROS level, JNK activation, and Egr-1 expression in H9c2 cells in a dose-dependent manner. The ROS donor hypoxanthine-xanthine oxidase (XO/HX) and the JNK activator ANISO antagonized the effects of F2. Therefore, H/R activates ROS/Egr-1 signaling pathway in H9c2 cells, and JNK activation plays an important role in this pathway. F2 regulates H/R-induced ROS/JNK/Egr-1 signaling, which might be an important mechanism by which it antagonizes myocardial I/R injury.

Sanguinarine-induced apoptosis in lung adenocarcinoma cells is dependent on reactive oxygen species production and endoplasmic reticulum stress

Sanguinarine (SAN), an alkaloid isolated from plants of the Papaveraceae family, is a compound with multiple biological activities. In the present study, we explored the anticancer properties of SAN in lung cancer using the human lung adenocarcinoma cell line SPC-A1. Our results revealed that SAN inhibited SPC-A1 cell growth and induced apoptosis in a dose-dependent manner. We found that SAN triggered reactive oxygen species (ROS) production, while elimination of ROS by N-acetylcysteine (NAC) reversed the growth inhibition and apoptosis induced by SAN. SAN-induced endoplasmic reticulum (ER) stress resulted in the upregulation of many genes and proteins involved in the unfolded protein response (UPR) pathway, including glucose-regulated protein 78 (GRP78), p-protein kinase R (PKR)-like ER kinase (PERK), p-eukaryotic translation initiation factor 2α (eIF2α), activating transcription factor 4 (ATF4) and CCAAT/enhancer binding protein homologous protein (CHOP). Blocking ER stress with tauroursodeoxycholic acid (TUDCA) markedly reduced SAN-induced inhibition of growth and apoptosis. Furthermore, TUDCA decreased SAN-induced ROS production, and NAC attenuated SAN-induced GRP78 and CHOP expression. Overall, our data indicate that the anticancer effects of SAN in lung cancer cells depend on ROS production and ER stress and that SAN may be a potential agent against lung cancer.

Sanguinarine inhibits Rac1b-rendered cell survival enhancement by promoting apoptosis and blocking proliferation

AIM

Small GTPase Rac1 is a member of the Ras superfamily, which plays important roles in regulation of cytoskeleton reorganization, cell growth, proliferation, migration, etc. The aim of this study was to determine how a constitutively active Rac1b regulated cell proliferation and to investigate the effects of the Rac1b inhibitor sanguinarine.

METHODS

Three HEK293T cell lines stably overexpressing GFP, Rac1-GFP or Rac1b-GFP were constructed by lentiviral infection. The cells were treated with sanguinarine (1 μmol/L) or its analogue berberine (1 μmol/L) for 4 d. Cell proliferation was evaluated by counting cell numbers and with a BrdU incorporation assay. The levels of cleaved PARP-89 (an apoptosis marker) and cyclin-D1 (a proliferative index) were measured using Western blotting.

RESULTS

In 10% serum-containing media, overexpressing either Rac1 or Rac1b did not significantly change the cell proliferation. In the serum-starved media, however, the survival rate of Rac1b cells was significantly increased, whereas that of Rac1 cells was moderately increased. The level of cleaved PARP-89 was significantly increased in serum-starved Rac1 cells, but markedly reduced in serum-starved Rac1b cells. The level of cyclin-D1 was significantly increased in both serum-starved Rac1 and Rac1b cells. Treatment with sanguinarine, but not berberine, inhibited the proliferation of Rac1b cells, which was accompanied by significantly increased the level of PARP-89, and decreased both the level of cyclin-D1 and the percentage of BrdU positive cells.

CONCLUSION

Rac1b enhances the cell proliferation under a growth-limiting condition via both anti-apoptotic and pro-proliferative mechanisms. Sanguinarine, as the specific inhibitor of Rac1b, is a potential therapeutic agent for malignant tumors with up-regulated Rac1b.

Physicochemical properties of inclusion complexes of sanguinarine with natural cyclodextrins: spectroscopy, calorimetry and NMR studies

The study addresses interpretation of the various physicochemical properties of inclusion complexes of the anticancer plant alkaloid sanguinarine with natural cyclodextrins.

Involvement of heme oxygenase-1 in neuroprotection by sanguinarine against glutamate-triggered apoptosis in HT22 neuronal cells

Sanguinarine is a natural compound isolated from the roots of Macleaya cordata and M. microcarpa, has been reported to possess several biological activities such as anti-inflammatory and anti-oxidant effects. In the present study, we demonstrated that sanguinarine markedly induces the expression of HO-1 which leads to a neuroprotective response in mouse hippocampus-derived neuronal HT22 cells from apoptotic cell death induced by glutamate. Sanguinarine significantly attenuated the loss of mitochondrial function and membrane integrity associated with glutamate-induced neurotoxicity. Sanguinarine protected against glutamate-induced neurotoxicity through inhibition of HT22 cell apoptosis. JC-1 staining, which is a well-established measure of mitochondrial damage, was decreased after treatment with sanguinarine in glutamate-challenged HT22cells. In addition, sanguinarine diminished the intracellular accumulation of ROS and Ca(2+). Sanguinarine also induced HO-1, NQO-1 expression via activation of Nrf2. Additionally, we found that si RNA mediated knock-down of Nrf2 or HO-1 significantly inhibited sanguinarine-induced neuroprotective response. These findings revealed the therapeutic potential of sanguinarine in preventing the neurodegenerative diseases.

Induction of ROS-independent JNK-activation-mediated apoptosis by a novel coumarin-derivative, DMAC, in human colon cancer cells

In this study, we investigated the antitumor activity of a novel coumarin derivative, 5,7-dihydroxy-4-methyl-6-(3-methylbutanoyl)-coumarin (DMAC), on colorectal carcinoma. DMAC treatment resulted in substantial proapoptotic activity against colon cancer HCT116 and LoVo cells. Induction of apoptotic characteristics, including cellular shrinkage, chromatin condensation, and Annexin V detection, was observed following DMAC treatment. Mechanistically, we observed that DMAC elicited induction of proteolytic cascade activation including cleavage of caspase-3 and poly ADP-ribose polymerase (PARP) expression and loss of the antiapoptotic proteins, Mcl-1 and Bcl-XL, accompanied by an increase in expression of the proapoptotic protein, Bak. In addition, suppressing c-Jun N-terminal protein kinase (JNK), but not extracellular-regulated protein kinase (ERK) or p38, substantially diminished DMAC-induced cell death and caspase-3 and PARP cleavage. However, pretreatment with antioxidants, including N-acetyl-l-cysteine (NAC) and diphenylene iodonium (DPI), failed to protect against DMAC-elicited apoptosis. Pretreatment with the JNK inhibitor, SP600125, suppressed DMAC-induced JNK phosphorylation, which was accompanied by a reversal of Bcl-XL expression. Moreover, combining DMAC treatment with the conventional anticancer drugs, 5-FU and CPT-11, considerably enhanced their therapeutic efficacies. Structural-activity relationship analyses further revealed that an alkylation substitution at position 6 of the coumarin ring was critical for inducing apoptosis, and the phenyl group at position 4 might have enhanced its bioactivity. Our data showed that DMAC can be used as part of a promising strategy to enhance therapeutic efficacies, and could be used to develop an approach for structure-based drug design for cancer treatment.

NQO1 involves in the imine bond reduction of sanguinarine and recombinant adeno-associated virus mediated NQO1 overexpression decreases sanguinarine-induced cytotoxicity in rat BRL cells

Although sanguinarine (SANG) can be transformed to dihydrosanguinarine (DHSA) in human and animals, the enzyme involved in the imine bond reduction of SANG is still unknown. In this study, we found that rat

NAD(P)H

quinone oxidoreductase 1 expressed by prokaryotic system can transform SANG to DHSA in an NADPH dependent manner. We also found out that there was more DHSA in rAAV-NQO1 infected than rAAV-CYP1A1 and rAAV-control infected BRL cells. SANG decreased rat BRL cell proliferation and augmented cell apoptosis in a time and dose dependent manner. However, the influence of DHSA to BRL cells is not significant difference than SANG. SANG-induced apoptosis was correlated with the up-regulation of Bax/Bcl2 ratio and the down-regulation of Bcl2. SANG can also dose dependently down regulate NQO1 expression, but CYP1A1 expression was a little up regulated. Since CYP1A1 involving in SANG oxidative reactions and NQO1 involving in the transform of SANG to DHSA, we hypothesized that up regulation of NQO1 could reduce SANG cytotoxicity and up regulation of CYP1A1 could increase SANG cytotoxitity. Our further study showed that recombinant adeno-associated virus (rAAV) mediated overexpression of NQO1 significantly increased cell proliferation and decreased Bax/Bcl2 ratio, apoptosis, and cytotoxicity, whereas rAAV mediated CYP1A1 overexpression had opposite effects. These data illustrated that NQO1 involved in the imine bond reduction of sanguinarine and this was a less toxic metabolizing pathway than CYP1A1-metabolizing pathway.