Sulforaphane-induced apoptosis in human leukemia HL-60 cells through extrinsic and intrinsic signal pathways and altering associated genes expression assayed by cDNA microarray

Sulforaphane and Benzyl Isothiocyanate Suppress Cell Proliferation and Trigger Cell Cycle Arrest, Autophagy, and Apoptosis in Human AML Cell Line

Isothiocyanates (ITCs) are naturally occurring sulfur-containing compounds with diverse biological effects. This study investigated the effects of sulforaphane (SFN, an aliphatic ITC) and benzyl isothiocyanate (BITC, an aromatic ITC) on human acute myeloid leukemia SKM-1 cells, focusing on cell proliferation, cell death, and drug resistance. Both drug-sensitive SKM-1 cells and their drug-resistant SKM/VCR variant, which overexpresses the drug transporter P-glycoprotein, were used. SFN and BITC reduced cell viability in a dose-dependent manner, with BITC showing greater potency. IC50 values ranged from 7.0-8.0 µM for SFN and 4.0-5.0 µM for BITC in both cell types, with only slight differences between the variants. Both ITCs induced autophagy as evidenced by increased LC3-II production and caused a significant increase in the sub-G0/G1 cell population, especially with BITC. Apoptosis was more pronounced after BITC treatment, whereas SFN had a weaker effect. These results suggest that autophagy may act as a defense mechanism in response to ITC-induced apoptosis in human AML cells.

Combined sulforaphane and β-sitosterol mitigate olanzapine-induced metabolic disorders in rats: Insights on FOXO, PI3K/AKT, JAK/STAT3, and MAPK signaling pathways

One of the best antipsychotics for treating schizophrenia and bipolar disorders is olanzapine (OLA). However, its use is restricted owing to unfavorable adverse effects as liver damage, dyslipidemia, and weight gain. The primary objective of the present investigation was to examine the signaling mechanisms that underlie the metabolic disruption generated by OLA. Besides, the potential protective effect of sulforaphane (SFN) and β-sitosterol (βSS) against obesity and metabolic toxicity induced by OLA were inspected as well. A total of five groups of male Wistar rats were established, including the control, OLA, SFN+OLA, βSS+OLA, and the combination + OLA groups. Hepatic histopathology, biochemical analyses, ultimate body weights, liver function, oxidative stress, and pro-inflammatory cytokines were evaluated. In addition to the relative expression of FOXO, the signaling pathways for PI3K/AKT, JAK/STAT3, and MAPK were assessed as well. All biochemical and hepatic histopathological abnormalities caused by OLA were alleviated by SFN and/or βSS. A substantial decrease in systolic blood pressure (SBP), proinflammatory cytokines, serum lipid profile parameters, hepatic MDA, TBIL, AST, and ALT were reduced through SFN or/and βSS. To sum up, the detrimental effects of OLA are mediated by alterations in the Akt/FOXO3a/ATG12, Ras/SOS2/Raf-1/MEK/ERK1/2, and Smad3,4/TGF-β signaling pathways. The administration of SFN and/or βSS has the potential to mitigate the metabolic deficit, biochemical imbalances, hepatic histological abnormalities, and the overall unfavorable consequences induced by OLA by modulating the abovementioned signaling pathways.

Single-cell transcriptome and chromatin accessibility mapping of upper lip and primary palate fusion

Cleft lip and/or primary palate (CL/P) represent a prevalent congenital malformation, the aetiology of which is highly intricate. Although it is generally accepted that the condition arises from failed fusion between the upper lip and primary palate, the precise mechanism underlying this fusion process remains enigmatic. In this study, we utilized transposase-accessible chromatin sequencing (scATAC-seq) and single-cell RNA sequencing (scRNA-seq) to interrogate lambdoidal junction tissue derived from C57BL/6J mouse embryos at critical stages of embryogenesis (10.5, 11.5 and 12.5 embryonic days). We successfully identified distinct subgroups of mesenchymal and ectodermal cells involved in the fusion process and characterized their unique transcriptional profiles. Furthermore, we conducted cell differentiation trajectory analysis, revealing a dynamic repertoire of genes that are sequentially activated or repressed during pseudotime, facilitating the transition of relevant cell types. Additionally, we employed scATAC data to identify key genes associated with the fusion process and demonstrated differential chromatin accessibility across major cell types. Finally, we constructed a dynamic intercellular communication network and predicted upstream transcriptional regulators of critical genes involved in important signalling pathways. Our findings provide a valuable resource for future studies on upper lip and primary palate development, as well as congenital defects.

TRIP13 Plays an Important Role in the Sensitivity of Leukemia Cell Response to Sulforaphane Therapy

Sulforaphane is one of the most characterized isothiocyanate compounds in cruciferous vegetables and shows anticancer effects, especially antileukemia properties. However, the molecular mechanism of the growth inhibition effect of sulforaphane in acute myeloid leukemia (AML) has not been fully explored. In the present study, a proteomic analysis was performed on the AML cell line U937 responding to sulforaphane treatment to identify novel and efficient therapeutic targets of sulforaphane on AML cells. Key driver analysis was run on the leukemia network, and TRIP13 was identified as a key regulatory factor in sulforaphane-induced growth inhibition in U937 cells. Pretreatment with DCZ0415, an inhibitor of TRIP13, could significantly attenuate sulforaphane-induced cell apoptosis and cell cycle arrest in vitro through the PI3K/Akt/mTOR signaling pathway. In addition, the inhibitory effect of sulforaphane on the tumor volume could also be obviously attenuated by the pretreatment of DCZ0415 in vivo. These results indicate that TRIP13 plays an important role in the sensitivity of leukemia cell response to sulforaphane treatment, and these findings expand the understanding of the mechanism of the antileukemic effect of sulforaphane and provide a new target for the treatment of AML.

Natural products targeting autophagy and apoptosis in NSCLC: a novel therapeutic strategy

Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) being the predominant type. The roles of autophagy and apoptosis in NSCLC present a dual and intricate nature. Additionally, autophagy and apoptosis interconnect through diverse crosstalk molecules. Owing to their multitargeting nature, safety, and efficacy, natural products have emerged as principal sources for NSCLC therapeutic candidates. This review begins with an exploration of the mechanisms of autophagy and apoptosis, proceeds to examine the crosstalk molecules between these processes, and outlines their implications and interactions in NSCLC. Finally, the paper reviews natural products that have been intensively studied against NSCLC targeting autophagy and apoptosis, and summarizes in detail the four most retrieved representative drugs. This paper clarifies good therapeutic effects of natural products in NSCLC by targeting autophagy and apoptosis and aims to promote greater consideration by researchers of natural products as candidates for anti-NSCLC drug discovery.

Telomerase Inhibition in the Treatment of Leukemia: A Comprehensive Review

Leukemia, characterized by the uncontrolled proliferation and differentiation blockage of myeloid or lymphoid precursor cells, presents significant therapeutic challenges despite current treatment modalities like chemotherapy and stem cell transplantation. Pursuing novel therapeutic strategies that selectively target leukemic cells is critical for improving patient outcomes. Natural products offer a promising avenue for developing effective chemotherapy and preventive measures against leukemia, providing a rich source of biologically active compounds. Telomerase, a key enzyme involved in chromosome stabilization and mainly active in cancer cells, presents an attractive target for intervention. In this review article, we focus on the anti-leukemic potential of natural substances, emphasizing vitamins (such as A, D, and E) and polyphenols (including curcumin and indole-3-carbinol), which, in combination with telomerase inhibition, demonstrate reduced cytotoxicity compared to conventional chemotherapies. We discuss the role of human telomerase reverse transcriptase (hTERT), particularly its mRNA expression, as a potential therapeutic target, highlighting the promise of natural compounds in leukemia treatment and prevention.

Modulating Effects of Cancer-Derived Exosomal miRNAs and Exosomal Processing by Natural Products

Cancer-derived exosomes exhibit sophisticated functions, such as proliferation, apoptosis, migration, resistance, and tumor microenvironment changes. Several clinical drugs modulate these exosome functions, but the impacts of natural products are not well understood. Exosome functions are regulated by exosome processing, such as secretion and assembly. The modulation of these exosome-processing genes can exert the anticancer and precancer effects of cancer-derived exosomes. This review focuses on the cancer-derived exosomal miRNAs that regulate exosome processing, acting on the natural-product-modulating cell functions of cancer cells. However, the role of exosomal processing has been overlooked in several studies of exosomal miRNAs and natural products. In this study, utilizing the bioinformatics database (miRDB), the exosome-processing genes of natural-product-modulated exosomal miRNAs were predicted. Consequently, several natural drugs that modulate exosome processing and exosomal miRNAs and regulate cancer cell functions are described here. This review sheds light on and improves our understanding of the modulating effects of exosomal miRNAs and their potential exosomal processing targets on anticancer treatments based on the use of natural products.

Anti-Leukemic Activity of Brassica-Derived Bioactive Compounds in HL-60 Myeloid Leukemia Cells

Acute myeloid leukemia (AML) is a cancer of the myeloid blood cells mainly treated with chemotherapy for cancer remission, but this non-selective treatment also induces numerous side effects. Investigations with bioactive compounds from plant-derived foods against cancer have increased in the last years because there is an urgent need to search for new anti-leukemic agents possessing higher efficacy and selectivity for AML cells and fewer negative side effects. In this study, we analyzed the anti-leukemic activity of several phytochemicals that are representative of the major classes of compounds present in cruciferous foods (glucosinolates, isothiocyanates, hydroxycinnamic acids, flavonols, and anthocyanins) in the human acute myeloid leukemia cell line HL-60. Our results revealed that among the different Brassica-derived compounds assayed, sulforaphane (SFN) (an aliphatic isothiocyanate) showed the most potent anti-leukemic activity with an IC50 value of 6 µM in dose-response MTT assays after 48 h of treatment. On the other hand, chlorogenic acid (a hydroxycinnamic acid) and cyanidin-3-glucoside (an anthocyanin) also displayed anti-leukemic potential, with IC50 values of 7 µM and 17 µM after 48 h of incubation, respectively. Importantly, these compounds did not show significant cell toxicity in macrophages-like differentiated cells at 10 and 25 µM, indicating that their cytotoxic effects were specific to AML cancer cells. Finally, we found that these three compounds were able to induce the NRF2/KEAP1 signaling pathway in a dose-dependent manner, highlighting SFN as the most potent NRF2 activator. Overall, the present evidence shed light on the potential for using foods and ingredients rich in anticancer bioactive phytochemicals from Brassica spp.

Eugenol Attenuates Transmissible Gastroenteritis Virus-Induced Oxidative Stress and Apoptosis Via ROS-NRF2-ARE Signaling

Transmissible gastroenteritis virus (TGEV), a coronavirus that causes severe diarrhea due to oxidative stress in the piglet intestine, is a major cause of economic loss in the livestock industry. However, limited interventions have been shown to be effective in the treatment of TGEV. Here, we demonstrate the therapeutic activity of eugenol in TGEV-induced intestinal oxidative stress and apoptosis. Our data show that eugenol supplementation protects intestine and IPEC-J2 cells from TGEV-induced damage. Mechanistically, eugenol reduces TGEV-induced oxidative stress in intestinal epithelial cells by reducing reactive oxygen species levels. Interestingly, eugenol also inhibits TGEV-induced intestinal cell apoptosis in vitro and in vivo. In conclusion, our data suggest that eugenol prevents TGEV-induced intestinal oxidative stress by reducing ROS-mediated damage to antioxidant signaling pathways. Therefore, eugenol may be a promising therapeutic strategy for TGEV infection.

Critical Role of Aquaporins in Cancer: Focus on Hematological Malignancies

Simple Summary

Aquaporins are proteins able to regulate the transfer of water and other small substances such as ions, glycerol, urea, and hydrogen peroxide across cellular membranes. AQPs provide for a huge variety of physiological phenomena; their alteration provokes several types of pathologies including cancer and hematological malignancies. Our review presents data revealing the possibility of employing aquaporins as biomarkers in patients with hematological malignancies and evaluates the possibility that interfering with the expression of aquaporins could represent an effective treatment for hematological malignancies.

Abstract

Aquaporins are transmembrane molecules regulating the transfer of water and other compounds such as ions, glycerol, urea, and hydrogen peroxide. Their alteration has been reported in several conditions such as cancer. Tumor progression might be enhanced by aquaporins in modifying tumor angiogenesis, cell volume adaptation, proteases activity, cell–matrix adhesions, actin cytoskeleton, epithelial–mesenchymal transitions, and acting on several signaling pathways facilitating cancer progression. Close connections have also been identified between the aquaporins and hematological malignancies. However, it is difficult to identify a unique action exerted by aquaporins in different hemopathies, and each aquaporin has specific effects that vary according to the class of aquaporin examined and to the different neoplastic cells. However, the expression of aquaporins is altered in cell cultures and in patients with acute and chronic myeloid leukemia, in lymphoproliferative diseases and in multiple myeloma, and the different expression of aquaporins seems to be able to influence the efficacy of treatment and could have a prognostic significance, as greater expression of aquaporins is correlated to improved overall survival in leukemia patients. Finally, we assessed the possibility that modifying the aquaporin expression using aquaporin-targeting regulators, specific monoclonal antibodies, and even aquaporin gene transfer could represent an effective therapy of hematological malignancies.

Shedding New Light on Methylmercury-induced Neurotoxicity Through the Crosstalk Between Autophagy and Apoptosis

Methylmercury (MeHg) is a bio-accumulative global environmental contaminant present in fish and seafood. MeHg accumulates in the aquatic environment and eventually reaches the human system via the food chain by bio-magnification. The central nervous system is the primary target of toxicity and is particularly vulnerable during development. It is well documented that developmental MeHg exposure can lead to neurological alterations, including cognitive and motor dysfunction. Apoptosis is a primary characteristic of MeHg-induced neurotoxicity, and may be regulated by autophagic activity. However, mechanisms mediating the interaction between apoptosis and autophagy remains to be explored. Autophagy is an adaptive response under stressful conditions, and the basal level of autophagy ensures the physiological turnover of old and damaged organelles. Autophagy can regulate cell fate through different crosstalk signaling pathways. A complex interplay between autophagy and apoptosis determines the degree of apoptosis and the progression of MeHg-induced neurotoxicity as demonstrated by pre-clinical models and clinical trials. This review summarizes recent advances in the roles of autophagy and apoptosis in MeHg neurotoxicity and thoroughly explores the relationship between them. The autophagic pathway may be a potential therapeutic target in MeHg neurotoxicity through modulation of apoptosis.

Sulforaphane: A Broccoli Bioactive Phytocompound with Cancer Preventive Potential

Simple Summary

As of the past decade, phytochemicals have become a major target of interest in cancer chemopreventive and chemotherapeutic research. Sulforaphane (SFN) is a metabolite of the phytochemical glucoraphanin, which is found in high abundance in cruciferous vegetables, such as broccoli, watercress, Brussels sprouts, and cabbage. In both distant and recent research, SFN has been shown to have a multitude of anticancer effects, increasing the need for a comprehensive review of the literature. In this review, we critically evaluate SFN as an anticancer agent and its mechanisms of action based on an impressive number of in vitro, in vivo, and clinical studies.

Abstract

There is substantial and promising evidence on the health benefits of consuming broccoli and other cruciferous vegetables. The most important compound in broccoli, glucoraphanin, is metabolized to SFN by the thioglucosidase enzyme myrosinase. SFN is the major mediator of the health benefits that have been recognized for broccoli consumption. SFN represents a phytochemical of high interest as it may be useful in preventing the occurrence and/or mitigating the progression of cancer. Although several prior publications provide an excellent overview of the effect of SFN in cancer, these reports represent narrative reviews that focused mainly on SFN’s source, biosynthesis, and mechanisms of action in modulating specific pathways involved in cancer without a comprehensive review of SFN’s role or value for prevention of various human malignancies. This review evaluates the most recent state of knowledge concerning SFN’s efficacy in preventing or reversing a variety of neoplasms. In this work, we have analyzed published reports based on in vitro, in vivo, and clinical studies to determine SFN’s potential as a chemopreventive agent. Furthermore, we have discussed the current limitations and challenges associated with SFN research and suggested future research directions before broccoli-derived products, especially SFN, can be used for human cancer prevention and intervention.

Genistein enhances the effects of L-asparaginase on inducing cell apoptosis in human leukemia cancer HL-60 cells

Genistein (GEN) has been shown to induce apoptotic cell death in various human cancer cells. L-asparaginase (Asp), a clinical drug for leukemia, has been shown to induce cell apoptosis in leukemia cells. No available information concerning GEN combined with Asp increased the cell apoptosis compared to GEN or Asp treatment alone. The objective of this study is to evaluate the anti-leukemia activity of GEN combined with Asp on human leukemia HL-60 cells in vitro. The cell viability, the distribution of cell cycle, apoptotic cell death, and the level of ΔΨ_m were examined by flow cytometric assay. The expressions of apoptosis-associated proteins were measured by western blotting. GEN combined with Asp revealed a more significant decrease in total viable cells and induced a higher percentage of G2/M phase arrest, DNA damage, and cell apoptosis than that of GEN or Asp treatment only in HL-60 cells. Furthermore, the combined treatments (GEN and Asp) showed a higher decrease in the level of ΔΨ_m than that of GEN or Asp treatment only. These results indicated that GEN combined with Asp induced mitochondria dysfunction by disrupting the mitochondrial membrane potential. The results from western blotting demonstrated that the treatment of GEN combined with Asp showed a higher increase in the levels of Bax and Bak (pro-apoptotic proteins) and an active form of caspase-3 and a higher decrease in Bcl-2 (anti-apoptotic protein) than that of GEN or Asp treatment alone. GEN significantly enhances the efficiency of Asp on cytotoxic effects (the induction of apoptosis) in HL-60 cells.

Dimethyl sulfoxide stimulates the AhR-Jdp2 axis to control ROS accumulation in mouse embryonic fibroblasts

The aryl hydrocarbon receptor (AhR) is a ligand-binding protein that responds to environmental aromatic hydrocarbons and stimulates the transcription of downstream phase I enzyme–related genes by binding the cis element of dioxin-responsive elements (DREs)/xenobiotic-responsive elements. Dimethyl sulfoxide (DMSO) is a well-known organic solvent that is often used to dissolve phase I reagents in toxicology and oxidative stress research experiments. In the current study, we discovered that 0.1% DMSO significantly induced the activation of the AhR promoter via DREs and produced reactive oxygen species, which induced apoptosis in mouse embryonic fibroblasts (MEFs). Moreover, Jun dimerization protein 2 (Jdp2) was found to be required for activation of the AhR promoter in response to DMSO. Coimmunoprecipitation and chromatin immunoprecipitation studies demonstrated that the phase I–dependent transcription factors, AhR and the AhR nuclear translocator, and phase II–dependent transcription factors such as nuclear factor (erythroid-derived 2)–like 2 (Nrf2) integrated into DRE sites together with Jdp2 to form an activation complex to increase AhR promoter activity in response to DMSO in MEFs. Our findings provide evidence for the functional role of Jdp2 in controlling the AhR gene via Nrf2 and provide insights into how Jdp2 contributes to the regulation of ROS production and the cell spreading and apoptosis produced by the ligand DMSO in MEFs.

Sulforaphane induces S-phase arrest and apoptosis via p53-dependent manner in gastric cancer cells

Sulforaphane (SFN) extracted from broccoli sprout has previously been investigated for its potential properties in cancers, however, the underlying mechanisms of the anticancer activity of SFN remain not fully understood. In the present study, we investigate the effects of SFN on cell proliferation, cell cycle, cell apoptosis, and also the expression of several cell cycle and apoptosis-related genes by MTT assay, flow cytometry and western blot analysis in gastric cancer (GC) cells. The results showed that SFN could impair the colony-forming ability in BGC-823 and MGC-803 cell lines compared with the control. In addition, SFN significantly suppressed cell proliferation by arresting the cell cycle at the S phase and enhancing cell apoptosis in GC cells in a dose-dependent manner. Western blot results showed that SFN treatment significantly increased the expression levels of p53, p21 and decreased CDK2 expression, which directly regulated the S phase transition. The Bax and cleaved-caspase-3 genes involved in apoptosis executive functions were significantly increased in a dose-dependent manner in BGC-823 and MGC-803 cells. These results suggested that SFN-induced S phase cell cycle arrest and apoptosis through p53-dependent manner in GC cells, which suggested that SFN has a potential therapeutic application in the treatment and prevention of GC.

P311 regulates distal lung development via its interaction with several binding proteins

Little is known about the molecular mechanisms underlying alveolar development. P311, a putative neuronal protein originally identified for its high expression during neuronal development, has once been reported to play a potential role in distal lung generation. However, the function of this protein has been poorly understood so far. Hence, we carried out a yeast two-hybrid screen, combining with other protein-protein interaction experiments, to isolate several binding partners of P311 during lung development, which may help us explore its function. We report 7 proteins here, including Gal-1, Loxl-1 and SPARC, etc, that can interact with it. Most of them have similar spatio-temporal expression patterns to P311. In addition, it was also found that P311 could stimulate their expression indirectly in L929 mouse fibroblast. Besides, computational methods were applied to construct a P311 centered protein-protein interaction network during alveolarization, using the 7 binding partners and their protein interaction information provided by public data resources. By analyzing the structure and function of this network, the effects of P311 on lung development were further clarified and all of the bioinformatic predictions from the network could be validated by real experiments. We have found here that P311 can control lung redox events, extracellular matrix and cell cycle progression, which are all crucial to pulmonary morphogenesis. This gives us a novel thought to explore the mechanisms controlling alveolarization.

Sulforaphane alters the acidification of the yeast vacuole

Sulforaphane (SFN) is a compound [1-isothiocyanato-4-(methylsulfinyl)-butane] found in broccoli and other cruciferous vegetables that is currently of interest because of its potential as a chemopreventive and a chemotherapeutic drug. Recent studies in a diverse range of cellular and animal models have shown that SFN is involved in multiple intracellular pathways that regulate xenobiotic metabolism, inflammation, cell death, cell cycle progression, and epigenetic regulation. In order to better understand the mechanisms of action behind SFN-induced cell death, we undertook an unbiased genome wide screen with the yeast knockout (YKO) library to identify SFN sensitive (SFN^S) mutants. The mutants were enriched with knockouts in genes linked to vacuolar function suggesting a link between this organelle and SFN's mechanism of action in yeast. Our subsequent work revealed that SFN increases the vacuolar pH of yeast cells and that varying the vacuolar pH can alter the sensitivity of yeast cells to the drug. In fact, several mutations that lower the vacuolar pH in yeast actually made the cells resistant to SFN (SFN^R). Finally, we show that human lung cancer cells with more acidic compartments are also SFN^R suggesting that SFN's mechanism of action identified in yeast may carry over to higher eukaryotic cells.

Alyssin and Iberin in Cruciferous Vegetables Exert Anticancer Activity in HepG2 by Increasing Intracellular Reactive Oxygen Species and Tubulin Depolymerization

To determine the chemopreventive potential of alyssin and iberin, the in vitro anticancer activities and molecular targets of isothiocyanates (ITCs) were measured and compared to sulforaphane in hepatocellular carcinoma cell HepG2. The SR-FTIR spectra observed a similar pattern vis-à-vis the biomolecular alteration amongst the ITCs-treated cells suggesting a similar mode of action. All of the ITCs in this study cause cancer cell death through both apoptosis and necrosis in concentration dependent manner (20–80 μM). We found no interactions of any of the ITCs studied with DNA. Notwithstanding, all of the ITCs studied increased intracellular reactive oxygen species (ROS) and suppressed tubulin polymerization, which led to cell-cycle arrest in the S and G₂/M phase. Alyssin possessed the most potent anticancer ability; possibly due to its ability to increase intracellular ROS rather than tubulin depolymerization. Nevertheless, the structural influence of alkyl chain length on anticancer capabilities of ITCs remains inconclusive. The results of this study indicate an optional, potent ITC (viz., alyssin) because of its underlying mechanisms against hepatic cancer. As a consequence, further selection and development of effective chemotherapeutic ITCs is recommended.

The Glucosinolates: A Sulphur Glucoside Family of Mustard Anti-Tumour and Antimicrobial Phytochemicals of Potential Therapeutic Application

This study reviewed aspects of the biology of two members of the glucosinolate family, namely sinigrin and glucoraphanin and their anti-tumour and antimicrobial properties. Sinigrin and glucoraphanin are converted by the β-sulphoglucosidase myrosinase or the gut microbiota into their bioactive forms, allyl isothiocyanate (AITC) and sulphoraphanin (SFN) which constitute part of a sophisticated defence system plants developed over several hundred million years of evolution to protect them from parasitic attack from aphids, ticks, bacteria or nematodes. Delivery of these components from consumption of cruciferous vegetables rich in the glucosinolates also delivers many other members of the glucosinolate family so the dietary AITCs and SFN do not act in isolation. In vitro experiments with purified AITC and SFN have demonstrated their therapeutic utility as antimicrobials against a range of clinically important bacteria and fungi. AITC and SFN are as potent as Vancomycin in the treatment of bacteria listed by the World Health Organisation as antibiotic-resistant “priority pathogens” and also act as anti-cancer agents through the induction of phase II antioxidant enzymes which inactivate potential carcinogens. Glucosinolates may be useful in the treatment of biofilms formed on medical implants and catheters by problematic pathogenic bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus and are potent antimicrobials against a range of clinically important bacteria and fungi. The glucosinolates have also been applied in the prevention of bacterial and fungal spoilage of food products in advanced atmospheric packaging technology which improves the shelf-life of these products.

Sulforaphane Modulates AQP8-Linked Redox Signalling in Leukemia Cells

Sulforaphane, a biologically active isothiocyanate compound extracted from cruciferous vegetables, has been shown to exert cytotoxic effects on many human cancer cells, including leukemia. However, the exact molecular mechanisms behind the action of sulforaphane in hematological malignancies are still unclear. Like other cancer cells, leukemia cells produce high level of reactive oxygen species; in particular, hydrogen peroxide derived from Nox family is involved in various redox signal transduction pathways, promoting cell proliferation and survival. Recent evidence show that many tumour cell types express elevated level of aquaporin isoforms, and we previously demonstrated that aquaporin-8 acts as H₂O₂ transport facilitator across the plasma membrane of B1647 cells, a model of acute myeloid human leukemia. Thus, the control of AQP8-mediated H₂O₂ transport could be a novel strategy to regulate cell signalling and survival. To this purpose, we evaluated whether sulforaphane could somehow affect aquaporin-8-mediated H₂O₂ transport and/or Nox-mediated H₂O₂ production in B1647 cell line. Results indicated that sulforaphane inhibited both aquaporin-8 and Nox2 expression, thus decreasing B1647 cells viability. Moreover, the data obtained by coimmunoprecipitation technique demonstrated that these two proteins are linked to each other; thus, sulforaphane has an important role in modulating the downstream events triggered by the axis Nox2-aquaporin-8. Cell treatment with sulforaphane also reduced the expression of peroxiredoxin-1, which is increased in almost all acute myeloid leukemia subtypes. Interestingly, sulforaphane concentrations able to trigger these effects are achievable by dietary intake of cruciferous vegetables, confirming the importance of the beneficial effect of a diet rich in bioactive compounds.

New highlights on the health-improving effects of sulforaphane

In this paper, we review recent evidence about the beneficial effects of sulforaphane (SFN), which is the most studied member of isothiocyanates, on both in vivo and in vitro models of different diseases, mainly diabetes and cancer. The role of SFN on oxidative stress, inflammation, and metabolism is discussed, with emphasis on those nuclear factor E2-related factor 2 (Nrf2) pathway-mediated mechanisms. In the case of the anti-inflammatory effects of SFN, the point of convergence seems to be the downregulation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), with the consequent amelioration of other pathogenic processes such as hypertrophy and fibrosis. We emphasized that SFN shows opposite effects in normal and cancer cells at many levels; for instance, while in normal cells it has protective actions, in cancer cells it blocks the induction of factors related to the malignity of tumors, diminishes their development, and induces cell death. SFN is able to promote apoptosis in cancer cells by many mechanisms, the production of reactive oxygen species being one of the most relevant ones. Given its properties, SFN could be considered as a phytochemical at the forefront of natural medicine.

Fisetin Induces Apoptosis of HSC3 Human Oral Cancer Cells Through Endoplasmic Reticulum Stress and Dysfunction of Mitochondria-mediated Signaling Pathways

BACKGROUND/AIM

Oral cancer has been reported to be one of the major cancer-related diseases in human populations and the treatment of oral cancer is still unsatisfied. Fisetin, is a flavonoid from plants and has several biological activities such as antioxidant, anti-inflammatory and anticancer function, but its cytotoxicity in human oral cancer cells is unknown. In the present study, we investigated fisetin-induced cytotoxic effects on HSC3 human oral cancer cells in vitro. Materials and Methods/Results: We used flow cytometric assay to show fisetin induced apoptotic cell death through increased reactive oxygen species and Ca²⁺, but reduced the mitochondrial membrane potential and increased caspase-8, -9 and -3 activities in HSC3 cells. Furthermore, we also used 4' 6-diamidino-2-phenylindole staining to show that fisetin induced chromatin condensation (apoptotic cell death), and Comet assay to show that fisetin induced DNA damage in HSC3 cells. Western blotting was used to examine the levels of apoptotic-associated protein and results indicated that fisetin increased expression of pro-apoptotic proteins such as B-cell lymphoma 2 (BCL2) antagonist/killer (BAK) and BCL2-associated X (BAX) but reduced that of anti-apoptotic protein such as BCL2 and BCL-x, and increased the cleaved forms of caspase-3, -8 and -9, and cytochrome c, apoptosis-inducing factor (AIF) and endonuclease G (ENDO G) in HSC3 cells. Confocal microscopy showed that fisetin increased the release of cytochrome c, AIF and ENDO G from mitochondria into the cytoplasm.

CONCLUSION

Based on these observations, we suggest that fisetin induces apoptotic cell death through endoplasmic reticulum stress- and mitochondria-dependent pathways.

Phytochemicals as potent modulators of autophagy for cancer therapy

The dysregulation of autophagy is involved in the pathogenesis of a broad range of diseases, and accordingly universal research efforts have focused on exploring novel compounds with autophagy-modulating properties. While a number of synthetic autophagy modulators have been identified as promising cancer therapy candidates, autophagy-modulating phytochemicals have also attracted attention as potential treatments with minimal side effects. In this review, we firstly highlight the importance of autophagy and its relevance in the pathogenesis and treatment of cancer. Subsequently, we present the data on common phytochemicals and their mechanism of action as autophagy modulators. Finally, we discuss the challenges associated with harnessing the autophagic potential of phytochemicals for cancer therapy.

Antitumor activity and expression profiles of genes induced by sulforaphane in human melanoma cells

Purpose

Human melanoma is a highly aggressive incurable cancer due to intrinsic cellular resistance to apoptosis, reprogramming, proliferation and survival during tumour progression. Sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables, plays a role in carcinogenesis in many cancer types. However, the cytotoxic molecular mechanisms and gene expression profiles promoted by SFN in human melanoma remain unknown.

Methods

Three different cell lines were used: two human melanoma A375 and 501MEL and human epidermal melanocytes (HEMa). Cell viability and proliferation, cell cycle analysis, cell migration and invasion and protein expression and phosphorylation status of Akt and p53 upon SFN treatment were determined. RNA-seq of A375 was performed at different time points after SFN treatment.

Results

We demonstrated that SFN strongly decreased cell viability and proliferation, induced G₂/M cell cycle arrest, promoted apoptosis through the activation of caspases 3, 8, 9 and hampered migration and invasion abilities in the melanoma cell lines. Remarkably, HEMa cells were not affected by SFN treatment. Transcriptomic analysis revealed regulation of genes involved in response to stress, apoptosis/cell death and metabolic processes. SFN upregulated the expression of pro-apoptotic genes, such as p53, BAX, PUMA, FAS and MDM2; promoted cell cycle inhibition and growth arrest by upregulating EGR1, GADD45B, ATF3 and CDKN1A; and simultaneously acted as a potent inhibitor of genotoxicity by launching the stress-inducible protein network (HMOX1, HSPA1A, HSPA6, SOD1).

Conclusion

Overall, the data show that SFN cytotoxicity in melanoma derives from complex and concurrent mechanisms during carcinogenesis, which makes it a promising cancer prevention agent.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-017-1527-7) contains supplementary material, which is available to authorized users.

The NmrA-like family domain containing 1 pseudogene Loc344887 is amplified in gallbladder cancer and promotes epithelial-mesenchymal transition

The expression pattern and biological role of long non-coding RNA (lncRNA) in cancer has been reported to be involved in many cancers. Here, we report the expression and biological role of a newly discovered lncRNA NmrA-like family domain containing 1 pseudogene (Loc344887) in gallbladder cancer (GBC). In this study, we found that the expression of Loc344887 was significantly elevated in GBC tissues and cell lines when compared with matched normal tissues and normal epithelial bile duct cell line, respectively. High Loc344887 was associated with larger tumor size. Loc344887 was upregulated significantly after ectopic expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in GBC cells. Downregulation of Loc344887 in GBC cells suppressed cell proliferation, blocked cells in G0/S phase, and decreased the migration and invasion cell numbers. In addition, downregulation of Loc344887 decreased the expression of transcription factor Twist, mesenchymal marker Vimentin, and N-cadherin and increased the expression of epithelial maker E-cadherin, which could prompt a mesenchymal-to-epithelial transition phenotype. These results demonstrated that Loc344887 might contribute to cell proliferation and epithelial-to-mesenchymal transition process in GBC, which might be a potential therapeutic target.

18α-Glycyrrhetinic Acid Induces Apoptosis of HL-60 Human Leukemia Cells through Caspases- and Mitochondria-Dependent Signaling Pathways

In this study we investigate the molecular mechanisms of caspases and mitochondria in the extrinsic and intrinsic signal apoptosis pathways in human leukemia HL-60 cells after in vitro exposure to 18α-glycyrrhetinic acid (18α-GA). Cells were exposed to 18α-GA at various concentrations for various time periods and were harvested for flow cytometry total viable cell and apoptotic cell death measurements. Cells treated with 18α-GA significantly inhibited cell proliferation and induced cell apoptosis in a dose-dependent manner, with an IC₅₀ value of 100 μM at 48 h. The cell growth inhibition resulted in induction of apoptosis and decreased the mitochondria membrane potential (ΔΨ_m) and increased caspase-8, -9 and -3 activities. Furthermore, cytochrome c and AIF were released from mitochondria, as shown by western blotting and confirmed by confocal laser microscopy. Western blotting showed that 18α-GA increased the levels of pro-apoptotic proteins such as Bax and Bid and decreased the anti-apoptotic proteins such as Bcl-2 and Bcl-xl, furthermore, results also showed that 18α-GA increased Fas and Fas-L which are associated with surface death receptor in HL-60 cells. Based on those observations, the present study supports the hypothesis that 18α-GA-induced apoptosis in HL-60 cells involves the activation of the both extrinsic and intrinsic apoptotic pathways.