Cancer chemoprevention with dietary isothiocyanates mature for clinical translational research

Characterization of flavor and taste profile of different radish (Raphanus Sativus L.) varieties by headspace-gas chromatography-ion mobility spectrometry (GC/IMS) and E-nose/tongue

A comprehensive study of the overall flavor and taste profile of different radishes is lacking. This study systematically compared the volatile profile of six radish varieties using HS-GC-IMS and their correlation with the E-nose analysis. Organic acids and amino acids were quantified, and their association with the E-tongues analysis was explored. A total of 73 volatile compounds were identified, with diallyl sulfide and dimethyl disulfide being the primary sulfides responsible for the unpleasant flavor in radish. Compared to other varieties, cherry radishes boast a significantly higher concentration of allyl isothiocyanate, which likely contributes to their characteristic radish flavor. Moreover, oxalic acid was identified as the most abundant organic acid in radish, accounting for over 97% of its content, followed by malic acid and succinic acid. In conclusion, the distinct flavor and taste characteristics of different radish varieties partially explain their suitability for diverse culinary preferences.

Synthesis of N-β-brominated alkenyl isothiocyanates via dehydrogenation of alkyl isothiocyanates

This study presents a new dehydrogenative synthesis of alkenyl isothiocyanates, providing compounds with bromo and isothiocyanate groups. These reactive functionalities offer versatility for further transformations. Application in an amine sensor utilizing a coumarin-attached product demonstrates practical utility. This streamlined approach facilitates access to alkenyl isothiocyanates, valuable tools for biological studies.

Isothiocyanates: happy-go-lucky reagents in organic synthesis

Owing to their unique structural features, isothiocyanates (ITCs) are a class of highly useful and inimitable reagents as the -NCS group serves both as electrophile and nucleophile in organic synthesis. ITCs share a rich legacy in organic, medicinal, and combinatorial chemistry. Compared to their oxygen equivalents, isocyanates, ITCs are easily available, less unpleasant, and somewhat less harmful to work with (mild conditions) which makes them happy-go-lucky reagents. Functionalized ITCs can finely tune the reactivity of the -NCS group and thus can be exploited in the late-stage functionalization processes. This review's primary aim is to outline ITC chemistry in the construction and derivatization of heterocycles through the lens of sustainability. For ease and brevity, the sections are divided based on reactive centers present in functionalized ITCs and modes of cyclisation. Scrutinizing their probable unexplored directions for future research studies is also addressed.

Modifying Effects of Genetic Variations on the Association Between Dietary Isothiocyanate Exposure and Non-muscle Invasive Bladder Cancer Prognosis in the Be-Well Study

SCOPE

Dietary isothiocyanate (ITC) exposure from cruciferous vegetable (CV) intake may improve non-muscle invasive bladder cancer (NMIBC) prognosis. This study aims to investigate whether genetic variations in key ITC-metabolizing/functioning genes modify the associations between dietary ITC exposure and NMIBC prognosis outcomes.

METHODS AND RESULTS

In the Bladder Cancer Epidemiology, Wellness, and Lifestyle Study (Be-Well Study), a prospective cohort of 1472 incident NMIBC patients, dietary ITC exposure is assessed by self-reported CV intake and measured in plasma ITC-albumin adducts. Using Cox proportional hazards regression models, stratified by single nucleotide polymorphisms (SNPs) in nine key ITC-metabolizing/functioning genes, it is calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence and progression. The rs15561 in N-acetyltransferase 1 (NAT1) is alter the association between CV intake and progression risk. Multiple SNPs in nuclear factor E2-related factor 2 (NRF2) and nuclear factor kappa B (NFκB) are modify the associations between plasma ITC-albumin adduct level and progression risk (pint < 0.05). No significant association is observed with recurrence risk. Overall, >80% study participants are present with at least one protective genotype per gene, showing an average 65% reduction in progression risk with high dietary ITC exposure.

CONCLUSION

Despite that genetic variations in ITC-metabolizing/functioning genes may modify the effect of dietary ITCs on NMIBC prognosis, dietary recommendation of CV consumption may help improve NMIBC survivorship.

Recent advancement in the synthesis of isothiocyanates

Isothiocyanates exhibit various biological characteristics, including antimicrobial, anti-inflammatory, and anticancer properties. Their significance extends to synthetic chemistry, where they serve as valuable platforms for versatile transformations. Consequently, they have attracted the attention of biologists and chemists. This review summarizes recent advancements in the synthesis of isothiocyanates. Access to a variety of starting materials is important to prepare isothiocyanates with diverse structures. This review categorizes synthetic methods into three types based on the starting materials and functional groups: (i) type A, derived from primary amines; (ii) type B, derived from other nitrogen functional groups; and (iii) type C, derived from non-nitrogen groups. Recent trends in synthetic methods have revealed the prevalence of type-A reactions derived from primary amines. However, type B reactions have rarely been reported. Notably, over the past four years, there has been a notable increase in type C reactions, indicating a growing interest in non-nitrogen-derived isothiocyanates. Overall, this review not only outlines the advancements in the synthesis of isothiocyanates but also highlights trends in the methodology.

Sulforaphene suppresses oesophageal cancer growth through mitogen- and stress-activated kinase 2 in a PDX mouse model

BACKGROUND

Although sulforaphene has potential anticancer effects, little is known about its effect on oesophageal squamous cell carcinoma (ESCC) invasiveness.

METHODS

To investigate whether sulforaphene inhibits the growth of oesophageal cancer cells, MTT and anchorage-independent cell growth assays were performed. Global changes in the proteome and phosphoproteome of oesophageal cancer cells after sulforaphene treatment were analysed by mass spectrometry (MS), and the underlying molecular mechanism was further verified by in vivo and in vitro experiments.

RESULTS

Sulforaphene treatment markedly affected proteins that regulate several cellular processes in oesophageal cancer cells, and mitogen- and stress-activated kinase 2 (MSK2) was the main genetic target of sulforaphene in reducing the growth of oesophageal cancer cells. Sulforaphene significantly suppressed ESCC cell proliferation in vitro and reduced the tumour size in an oesophageal patient-derived xenograft (PDX) SCID mouse model. Furthermore, the binding of sulforaphane to MSK2 in vitro was verified using a cellular thermal dhift assay, and the effect of MSK2 knockdown on the ESCC phenotype was observed using a shMSK2 model.

CONCLUSION

The results showed that sulforaphene suppresses ESCC growth in both human oesophageal squamous cells and PDX mouse model by inhibiting MSK2 expression, implicating sulforaphene as a promising candidate for ESCC treatment.

A Naturally Derived Watercress Flower-Based Phenethyl Isothiocyanate-Enriched Extract Induces the Activation of Intrinsic Apoptosis via Subcellular Ultrastructural and Ca2+ Efflux Alterations in an In Vitro Model of Human Malignant Melanoma

The aim of the current study was to (i) extract isolated fractions of watercress flowers enriched in polyphenols, phenethyl isothiocyanate and glucosinolates and (ii) characterize the anticancer mode of action of non-lethal, sub-lethal and lethal concentrations of the most potent extract fraction in primary (A375) and metastatic (COLO-679) melanoma cells as well as non-tumorigenic immortalized keratinocyte (HaCaT) cells. Cytotoxicity was assessed via the Alamar Blue assay, whereas ultrastructural alterations in mitochondria and the endoplasmic reticulum were determined via transmission electron microscopy. Mitochondrial membrane depolarization was determined using Mito-MP dye, whereas apoptosis was evaluated through the activation of caspases-3, -8 and -9. Among all extract fractions, the phenethyl isothiocyanate-enriched one (PhEF) possessed significant cytotoxicity against A375 and COLO-679 cells, while HaCaT cells remained relatively resistant at sub-lethal and lethal concentrations. Additionally, ultrastructural subcellular alterations associated with apoptosis were observed by means of increased mitochondrial area and perimeter, decreased cristae density and a shorter distance of the endoplasmic reticulum to the mitochondria, all taking place during "early" time points (2-4 h) of exposure. Moreover, PhEF induced mitochondrial membrane depolarization associated with "late" time points (24 h) of exposure, thereby leading to the activation of intrinsic apoptosis. Finally, the inhibition of cytosolic Ca2+ efflux reduced levels of caspases-9 and -3 activity, suggesting the involvement of Ca2+ efflux in modulating the activation of intrinsic apoptosis. To conclude, our data demonstrate an association of "early" ultrastructural alterations in mitochondria and the endoplasmic reticulum with the "late" induction of intrinsic apoptosis via the modulation of Ca2+ efflux.

Isothiocyanates as Tubulin Polymerization Inhibitors-Synthesis and Structure-Activity Relationship Studies

Among the various substances that interfere with the microtubule formation process, isothiocyanates (ITCs) are the group of compounds for which the binding mode and mechanism of action have not yet been explained. To better understand the structure-activity relationship of tubulin-isothiocyanate interactions, we designed and synthesized a series of sixteen known and novel, structurally diverse ITCs, including amino acid ester-derived isothiocyanates, bis-isothiocyanates, analogs of benzyl isothiocyanate, and phosphorus analogs of sulforaphane. All synthesized compounds and selected natural isothiocyanates (BITC, PEITC, AITC, and SFN) were tested in vitro to evaluate their antiproliferative activity, tubulin polymerization inhibition potential, and influence on cell cycle progression. The antiproliferative activity of most of the newly tested compounds exceeded the action of natural isothiocyanates, with four structures being more potent as tubulin polymerization inhibitors than BITC. As a confirmation of anti-tubulin activity, the correlation between polymerization inhibition and cell cycle arrest in the G2/M phase was observed for the most active compounds. In light of the biological results indicating significant differences in the impact of structurally diverse isothiocyanate on tubulin polymerization, in silico analysis was conducted to analyze the possible mode of isothiocyanate-tubulin binding and to show how it can influence the polymerization reaction.

Associations of dietary isothiocyanate exposure from cruciferous vegetable consumption with recurrence and progression of non-muscle-invasive bladder cancer: findings from the Be-Well Study

BACKGROUND

High recurrence and progression rates are major clinical challenges for non-muscle-invasive bladder cancer (NMIBC). Dietary isothiocyanates (ITCs), phytochemicals primarily from cruciferous vegetables (CV), show strong anticancer activities in preclinical BC models, yet their effect on NMIBC prognosis remains unknown.

OBJECTIVES

This study aimed to investigate the associations of dietary ITC exposure at diagnosis with NMIBC recurrence and progression.

METHODS

The study analyzed 1143 participants from the Be-Well study, a prospective cohort of newly diagnosed NMIBC cases in 2015-2019 with no prior history of BC. Dietary ITC exposure was indicated by self-reported CV intake, estimated ITC intake, urinary metabolites, and plasma ITC-albumin adducts. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence and progression, and unconditional logistic regression models were used to calculate odds ratios (ORs) and 95% CIs for delayed and multiple recurrence.

RESULTS

Over a mean follow-up of 25 mo, 347 (30%) developed recurrence and 77 (6.7%) had disease progression. Despite no significant associations with the overall risk of recurrence, urinary ITC metabolites (OR: 1.96; 95% CI: 1.01, 4.43) and dietary ITC intake (OR: 2.13; 95% CI: 1.03, 4.50) were associated with late recurrence after 12-mo postdiagnosis compared with before 12-mo postdiagnosis. Raw CV intake was associated with reduced odds of having ≥2 recurrences compared with having one (OR: 0.34; 95% CI: 0.16, 0.68). Higher plasma concentrations of ITC-albumin adducts were associated with a reduced risk of progression, including progression to muscle-invasive disease (for benzyl ITC, HR: 0.40; 95% CI: 0.17, 0.93; for phenethyl ITC, HR: 0.40; 95% CI: 0.19, 0.86).

CONCLUSIONS

Our findings indicate the possible beneficial role of dietary ITCs in NMIBC prognosis. Given the compelling preclinical evidence, increasing dietary ITC exposure with CV intake could be a promising strategy to attenuate recurrence and progression risks in patients with NMIBC.

How to Tackle Bacteriophages: The Review of Approaches with Mechanistic Insight

Bacteriophage-based applications have a renaissance today, increasingly marking their use in industry, medicine, food processing, biotechnology, and more. However, phages are considered resistant to various harsh environmental conditions; besides, they are characterized by high intra-group variability. Phage-related contaminations may therefore pose new challenges in the future due to the wider use of phages in industry and health care. Therefore, in this review, we summarize the current knowledge of bacteriophage disinfection methods, as well as highlight new technologies and approaches. We discuss the need for systematic solutions to improve bacteriophage control, taking into account their structural and environmental diversity.

The Dietary Isothiocyanate Erucin Reduces Kidney Cell Motility by Disturbing Tubulin Polymerization

SCOPE

Epidemiological evidence associates the consumption of cruciferous vegetables with reduced risk of several cancers, including renal cell carcinoma. Erucin can be generated by in vivo reduction of sulforaphane or by enzymatic hydrolysis of glucoerucin. Contrarily to sulforaphane, only limited studies have addressed the anticancer properties of erucin. This study aims at evaluating the impact of erucin on renal cell biology.

METHODS AND RESULTS

The effects of erucin were assessed in 786-O and Vero-E6 cells, representative of human renal cancer and non- cancer kidney cells, respectively. Erucin induced a concentration-dependent decrease in cell viability and cell cycle arrest at G2/Mitosis. In Vero-E6 cells erucin modestly reduced intracellular reactive oxygen species levels while in 786-O no effects were detected. After erucin treatment, both cell lines revealed altered morphology, with a concentration-dependent change from an elongated shape towards a smaller round conformation. Moreover, erucin affected cell adhesion and strongly altered the tubulin network structure and specifically microtubule polymerization. These results are in line with the observed decrease in collective and single cell migration and G2/Mitosis arrest.

CONCLUSIONS

Overall, erucin may have a beneficial impact in reducing the motility of renal cancer cells. Our results contribute to explore possible dietary approaches for secondary/tertiary renal cancer chemoprevention.

Chemical Composition and Biological Activity of Essential Oil and Extract from the Seeds of Tropaeolum majus L. var. altum

Research background

Plant Tropaeolum majus L. (garden nasturtium) belongs to the family Tropaeolaceae and contains benzyl glucosinolate. The breakdown product of benzyl glucosinolate, benzyl isothiocyanate (BITC), exhibits various biological activities such as antiproliferative, antibacterial and antiinflammatory. In order to optimize the content of biologically active volatile compounds in plant extract and essential oil, the use of appropriate extraction technique has a crucial role.

Experimental approach

The current study investigates the effect of two modern extraction methods, microwave-assisted distillation (MAD) and microwave hydrodiffusion and gravity (MHG), on the chemical composition of volatile components present in the essential oil and extract of garden nasturtium (T. majus L. var. altum) seeds. Investigation of the biological activity of samples (essential oil, extract and pure compounds) was focused on the antiproliferative effect against different cancer cell lines: cervical cancer cell line (HeLa), human colon cancer cell line (HCT116) and human osteosarcoma cell line (U2OS), and the antibacterial activity which was evaluated against the growth and adhesion of Staphylococcus aureus and Escherichia coli to polystyrene surface.

Results and conclusions

Essential oil and extract of garden nasturtium (T. majus) seeds were isolated by two extraction techniques: MAD and MHG. BITC and benzyl cyanide (BCN) present in the extract were identified by gas chromatography-mass spectrometry. Essential oil of T. majus showed higher antiproliferative activity (IC50<5 µg/mL) than T. majus extract (IC50<27 µg/mL) against three cancer cell lines: HeLa, HCT116 and U2OS. BITC showed much higher inhibitory effect on all tested cells than BCN. The essential oil and extract of T. majus showed strong antimicrobial activity against S. aureus and E. coli.

Novelty and scientific contribution

This work represents the first comparative report on the antiproliferative activity of the essential oil and extract of T. majus seeds, BITC and BCN against HeLa, HCT116 and U2OS cells as well as their antimicrobial activity against S. aureus and E. coli. This study demonstrates that the essential oil of T. majus seeds exhibits stronger antiproliferative and antimicrobial activity than the plant extract.

Benzyl Isothiocyanate-Induced Cytotoxicity via the Inhibition of Autophagy and Lysosomal Function in AGS Cells

Gastric adenocarcinoma is among the top causes of cancer-related death and is one of the most commonly diagnosed carcinomas worldwide. Benzyl isothiocyanate (BITC) has been reported to inhibit the gastric cancer metastasis. In our previous study, BITC induced apoptosis in AGS cells. The purpose of the present study was to investigate the effect of BITC on autophagy mechanism in AGS cells. First, the AGS cells were treated with 5, 10, or 15 μM BITC for 24 h, followed by an analysis of the autophagy mechanism. The expression level of autophagy proteins involved in different steps of autophagy, such as LC3B, p62/SQSTM1, Atg5-Atg12, Beclin1, p-mTOR/mTOR ratio, and class III PI3K was measured in the BITC-treated cells. Lysosomal function was investigated using cathepsin activity and Bafilomycin A1, an autophagy degradation stage inhibitor. Methods including qPCR, western blotting, and immunocytochemistry were employed to detect the protein expression levels. Acridine orange staining and omnicathepsin assay were conducted to analyze the lysosomal function. siRNA transfection was performed to knock down the LC3B gene. BITC reduced the level of autophagy protein such as Beclin 1, class III PI3K, and Atg5-Atg12. BITC also induced lysosomal dysfunction which was shown as reducing cathepsin activity, protein level of cathepsin, and enlargement of acidic vesicle. Overall, the results showed that the BITC-induced AGS cell death mechanism also comprises the inhibition of the cytoprotective autophagy at both initiation and degradation steps.

Multi-Target Antibacterial Mechanism of Moringin From Moringa oleifera Seeds Against Listeria monocytogenes

Moringin [4-(α-L-rhamnosyloxy) benzyl isothiocyanate] is an isothiocyanate from Moringa oleifera seeds. It is the bioactivated form of the glucosinolate precursor glucomoringin with various health benefits. However, few studies have examined the antibacterial activity of moringin. This study aimed to investigate the antimicrobial activity and mechanism of moringin against Listeria monocytogenes. The minimum inhibitory concentration (MIC), and growth curves were used to evaluate the bacteriostatic effect of moringin against L. monocytogenes. Transcriptome analysis by RNA sequencing was performed to elucidate the underlying mechanism of moringin against L. monocytogenes. The transcriptome results were validated. The results showed that moringin inhibited the growth of L. monocytogenes with a MIC of 400 μM. RNA sequencing results showed that the differences in the expression of genes related to the cell wall and membrane biosynthesis, phosphotransferase system (PTS), oxidative stress, energy metabolism, and DNA binding were significantly affected. As with the transcriptome results, the results of the mechanism verification found that moringin damaged the integrity of the cell wall and cell membrane, stimulated oxidative stress, interfered with energy metabolism and DNA replication, and finally led to the death of L. monocytogenes. The present study provides evidence that moringin exhibits strong antimicrobial activity against L. monocytogenes and insight into its potential mechanism.

Combined Straw and Plastic Film Mulching Can Increase the Yield and Quality of Open Field Loose-Curd Cauliflower

To evaluate the impact of straw mulching on the production of open field loose-curd cauliflower, this study analyzed the "Feicui No.9" cauliflower variety, grown in field trials in Northwest China, in 2019 and 2020. Plots in an open field were prepared without mulch (CK1) and with plastic film mulch (CK2), as experimental controls, along with three experimental mulching methods, including dual straw and plastic film mulch (T1), inter-row straw mulch (T2), and full straw mulch (T3). The effects of the different ground cover alternatives on loose-curd cauliflower's dry matter accumulation, yield, quality, and volatile compounds, were explored. The results showed that, compared with CK2 treatment, T1 treatment promoted the accumulation of dry matter, and increased the economic and biological yield, by 12.98 and 6.51%, respectively. The soluble sugar and vitamin C content in loose-curd cauliflower heads, subjected to T1 treatment, increased by 18.46 and 8.12%, respectively, and the nitrate content decreased by 25.57%. Moreover, the T1, T2, and T3 treatments significantly increased the levels of macro-, meso-, and microelements. Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to determine the volatile substances in loose-curd cauliflower heads from the 2020 harvesting period. Detected compounds included 17 aldehydes, 15 ketones, 10 alcohols, 15 esters, 29 hydrocarbons, 12 nitrogen-containing compounds, and 17 other substances. T1, T2, and T3 treatments increased the volatile substance content, whereas T1 treatment increased the quantity of volatile substances. In summary, dual mulching with straw and plastic film could promote dry matter accumulation, significantly increase the yield and quality, and effectively improve the flavor of loose-curd cauliflower. This mulching technique can be applied to open field vegetable and corn production areas, providing technical and theoretical support for the realization of high-yield, high-quality production models and a new straw recycling method.

Simultaneous analysis of derivatized allyl isothiocyanate together with its phase II metabolites by ultra-high-performance liquid chromatography/tandem mass spectrometry

RATIONALE

Allyl isothiocyanate (AITC) in food products such as wasabi is commonly analyzed by gas chromatography/mass spectrometry (GC/MS), while liquid chromatography/mass spectrometry (LC/MS) is more suitable for the polar metabolites. The development of an effective method for the simultaneous determination of AITC and its phase II metabolites is needed to support drug metabolism and pharmacokinetics (DMPK) studies.

METHODS

Derivatization of AITC by reaction with N-(tert-butoxycarbonyl)-L-cysteine methyl ester (^t BocCysME) was used for ultra-high-performance liquid chromatography/electrospray ionization mass spectrometry (UHPLC/ESI-MS) analysis, allowing the simultaneous determination with its phase II metabolites. At room temperature, reaction conditions have been optimized to maximize the reaction of AITC with ^t BocCysME quantitively. Reaction selectivity was examined by the presence of AITC metabolites. Quantification of AITC was performed by multiple reaction monitoring (MRM) with an external calibration method and applied on the serum of C57BL/6 J mouse for a DMPK study.

RESULTS

The limit of quantification (LOQ) was determined to be 0.842 nM from the derivatization method and by UHPLC/MS/MS analysis. The method accuracy in the mouse serum samples was 75 ± 2% with a relative standard deviation (RSD) of 3.0% of method variation. The UHPLC/MS/MS analysis gave RSDs of 0.2% and 1.8% for intra-day and inter-day variations. With the newly developed method, AITC could be detected in mouse serum upon oral administration for the first time.

CONCLUSIONS

An analytical method involving a rapid derivatization pre-treatment and quantitative UHPLC/ESI-QqQ-MS/MS analysis has been developed for a biological sample assay of AITC, enabling selective and sensitive detection of the AITC derivative and AITC metabolites simultaneously. The method developed could be applied to the DMPK study of AITC as well.

Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity

For decades, various plants have been studied as sources of biologically active compounds. Compounds with anticancer and antimicrobial properties are the most frequently desired. Cruciferous plants, including Brussels sprouts, broccoli, and wasabi, have a special role in the research studies. Studies have shown that consumption of these plants reduce the risk of lung, breast, and prostate cancers. The high chemopreventive and anticancer potential of cruciferous plants results from the presence of a large amount of glucosinolates, which, under the influence of myrosinase, undergo an enzymatic transformation to biologically active isothiocyanates (ITCs). Natural isothiocyanates, such as benzyl isothiocyanate, phenethyl isothiocyanate, or the best-tested sulforaphane, possess anticancer activity at all stages of the carcinogenesis process, show antibacterial activity, and are used in organic synthesis. Methods of synthesis of sulforaphane, as well as its natural or synthetic bifunctional analogues with sulfinyl, sulfanyl, sulfonyl, phosphonate, phosphinate, phosphine oxide, carbonyl, ester, carboxamide, ether, or additional isothiocyanate functional groups, and with the unbranched alkyl chain containing 2-6 carbon atoms, are discussed in this review. The biological activity of these compounds are also reported. In the first section, glucosinolates, isothiocyanates, and mercapturic acids (their metabolites) are briefly characterized. Additionally, the most studied anticancer and antibacterial mechanisms of ITC actions are discussed.

Diisothiocyanate-Derived Mercapturic Acids Are a Promising Partner for Combination Therapies in Glioblastoma

Glioblastoma represents the most aggressive tumor of the central nervous system. Due to invasion of glioblastoma stem cells into the healthy tissue, chemoresistance, and recurrence of the tumor, it is difficult to successfully treat glioblastoma patients, which is demonstrated by the low life expectancy of patients after standard therapy treatment. Recently, we found that diisothiocyanate-derived mercapturic acids, which are isothiocyanate derivatives from plants of the Cruciferae family, provoked a decrease in glioblastoma cell viability. These findings were extended by combining diisothiocyanate-derived mercapturic acids with dinaciclib (a small-molecule inhibitor of cyclin-dependent kinases with anti-proliferative capacity) or temozolomide (TMZ, standard chemotherapeutic agent) to test whether the components have a cytotoxic effect on glioblastoma cells when the dosage is low. Here, we demonstrate that the combination of diisothiocyanate-derived mercapturic acids with dinaciclib or TMZ had an additive or even synergistic effect in the restriction of cell growth dependent on the combination of the components and the glioblastoma cell source. This strategy could be applied to inhibit glioblastoma cell growth as a therapeutic interference of glioblastoma.

Untargeted Metabolomic Analysis of Nonvolatile and Volatile Glucosinolates in Brassicaceae

Glucosinolates (GLSs) are a group of plant secondary metabolites mainly found in Cruciferous plants. The main hydrolysis products of GLSs, isothiocyanates (ITCs), are the bioactive metabolites that have shown plant defense and human cancer prevention properties. Untargeted metabolomic analysis of plant metabolites can uncover the profiles of these bioactive phytochemicals in specific plants and discover potential human health promoting products. We have developed an integrated metabolomic analysis method for plant samples, with specific focus on nonvolatile GLSs and volatile ITCs. In this chapter, we describe in detail the protocols, including metabolite extraction, high resolution LC-MS and GC-MS analysis, and data processing. The method is readily applicable to untargeted analysis of other nonvolatile and volatile metabolites in plants.

The Inhibitory Effect of Sulforaphane on The Proliferation of Acute Myeloid Leukemia Cell Lines through Controlling miR-181a

OBJECTIVE

The present study investigated the role of miR-181a as a small non-coding RNA molecule in acute myeloid leukemia (AML) pathogenesis and reflected on the effects of Sulforaphane (SFN) on AML progression.

MATERIALS AND METHODS

This experimental study had two parts. In vivo study, the miR-181a levels was measured in patients with symptoms of AML and compared to healthy controls (HCs) to investigate its role in AML pathogenesis. Afterward, an in vitro study was performed to examine the effects of SFN on the growth, apoptosis and proliferation rate of AML cell lines. Finally, the effect of SFN on miR-181a was evaluated as a major miRNA involved in hematopoiesis.

RESULTS

The results of this study showed an increasing trend (2.9-fold, P=0.0019) in miR-181a expression levels in AML patients as compared with HCs. The data associated with MTT assay and flow cytometry (FCM) additionally demonstrated the anti-proliferative effects of SFN against AML cell lines, with a reduction in miR-181a levels. As well, no significant difference was noted between 24 hours and 48 hours treatments by SFN. It was deduced that modulation of miR-181a expression levels could be one of the mechanisms associated with the anti-proliferative effects of SFN against AML.

CONCLUSION

MiR-181a levels contribute to AML pathogenesis and thus they can be considered as a strategy in controlling AML progression in patients. Accordingly, SFN can arrest cell proliferation and induce apoptosis in AML cell lines through retardation expression of miR-181a and affecting miR-181a pathway, which already clarified its role in the differentiation of hematopoietic stem cells and indicates another mode of anti-cancer action of sulforaphane.

Physiological Effects of Green-Colored Food-Derived Bioactive Compounds on Cancer

Green-colored foods, such as broccoli, sprouts, soybean, and green leafy vegetables are considered one of the representative healthy foods for containing various functional ingredients that can combat chronic diseases, including diabetes, obesity, and cancer. Herein, we reviewed the anti-cancer activities and the underlying mechanisms of some important bioactive compounds, such as sulforaphane, catechins, chlorophyll, isoflavone, indole dervatives, and lutein, present in green-colored foods. In vivo and clinical studies suggest that sulforaphane, a sulfur-containing compound found in cruciferous vegetables, can ameliorate prostate and breast cancer symptoms by arresting cell-cycle progression and modulating Ki67 and HDAC expression. A green tea compound, known as epigallocatechin-3-gallate (EGCG), has shown remarkable anti-cancer effects against prostate cancer and lung adenocarcinoma in human trials through its antioxidative defense and immunomodulatory functions. Chlorophyll, a natural pigment found in all green plants, can regulate multiple cancer-related genes, including cyclin D1, CYP1A, CYP1B1, and p53. Epidemiological studies indicate that chlorophyll can substantially reduce aflatoxin level and can mitigate colon cancer in human subjects. Remarkably, the consumption of soy isoflavone has been found to be associated with the lower incidence and mortality of breast and prostate cancers in East Asia and in Canada. In vivo and in vitro data point out that isoflavone has modulatory effects on estrogen and androgen signaling pathways and the expression of MAPK, NfκB, Bcl-2, and PI3K/AKT in different cancer models. Other green food bioactive compounds, such as indole derivatives and lutein, also exhibited suppressing effects in rodent models of lung, liver, stomach, cervical, and prostate cancers. In addition, some micronutrients, such as folate, riboflavin, retinoic acid, and vitamin D3 present in green foods, also showed potential cancer suppressing effects. Taken together, these data suggest potential chemopreventive functions of the bioactive compounds from green-colored foods. This paper could be beneficial for further research on the anti-carcinogenic effects of green-colored food-derived compounds, in order to develop green chemotherapeutics for cancers.

Effects and mechanisms of dietary bioactive compounds on breast cancer prevention

Breast cancer (BC) is the most often diagnosed cancer among females globally and has become an increasing global health issue over the last decades. Despite the substantial improvement in screening methods for initial diagnosis, effective therapy remains lacking. Still, there has been high recurrence and disease progression after treatment of surgery, endocrine therapy, chemotherapy, and radiotherapy. Considering this view, there is a crucial requirement to develop safe, freely accessible, and effective anticancer therapy for BC. The dietary bioactive compounds as auspicious anticancer agents have been recognized to be active and their implications in the treatment of BC with negligible side effects. Hence, this review focused on various dietary bioactive compounds as potential therapeutic agents in the prevention and treatment of BC with the mechanisms of action. Bioactive compounds have chemo-preventive properties as they inhibit the proliferation of cancer cells, downregulate the expression of estrogen receptors, and cell cycle arrest by inducing apoptotic settings in tumor cells. Therapeutic drugs or natural compounds generally incorporate engineered nanoparticles with ideal sizes, shapes, and enhance their solubility, circulatory half-life, and biodistribution. All data of in vitro, in vivo, and clinical studies of dietary bioactive compounds and their impact on BC were collected from Science Direct, PubMed, and Google Scholar. The data of chemopreventive and anticancer activity of dietary bioactive compounds were collected and orchestrated in a suitable place in the review. These shreds of data will be extremely beneficial to recognize a series of additional diet-derived bioactive compounds to treat BC with the lowest side effects.

Evaluation of the Anti-Shigellosis Activity of Dietary Isothiocyanates in Galleria mellonella Larvae

Cruciferous vegetables, widely present in daily diets, are a rich source of organosulfur compounds with proven health benefits, especially chemopreventive or antioxidative effects. Isothiocyanate derivatives (ITCs) exhibit a broad spectrum of biological and pharmacological activity and recently, their antibacterial properties have been of particular importance. Here, we have focused on the anti-shigellosis activity of sulforaphane (SFN) and phenethyl ITC (PEITC). The genus Shigella causes gastroenteritis in humans, which constitutes a threat to public health. Production of a potent Stx toxin by S. dysenteriae type 1 results not only in more severe symptoms but also in serious sequela, including the hemolytic uremic syndrome. Here, we present evidence that two aliphatic and aromatic ITCs derivatives, SFN and PEITC, have an effective antibacterial potency against S. dysenteriae, also negatively regulating the stx gene expression. The molecular mechanism of this effect involves induction of the global stress-induced stringent response. ITCs also inhibit bacterial virulence against the Vero and HeLa cells. We present evidence for the therapeutic effect of sulforaphane and phenethyl ITC against a S. dysenteriae infection in the Galleria mellonella larvae model. Thus, our results indicate that isothiocyanates can be effectively used to combat dangerous bacterial infections.

The retention and bioavailability of phytochemicals in the manufacturing of baked snacks

There is a growing body of evidence supporting the role that phytochemicals play in reducing the risk of various chronic diseases. Although there has been a rise in health products marketed as being "supergrains," "superfood," or advertising their abundance in antioxidants, these food items are often limited to powdered blends, dried fruit, nuts, or seeds, rarely intercepting the market of baked snacks. This is in part due to the still limited understanding of the impact that different industrial processes have on phytochemicals in a complex food matrix and their corresponding bioavailability. This review brings together the current data on how various industrial dehydration processes influence the retention and bioaccessibility of phytochemicals in baked snacks. It considers the interplay of molecules in an intricate snack matrix, limitations of conventional technologies, and constraints with consumer acceptance preventing wider utilization of novel technologies. Furthermore, the review takes a holistic approach, encompassing each stage of production-discussing the potential for inclusion of by-products to promote a circular economy and the proposal for a shift in agriculture toward biofortification or tailored growing of crops for their nutritional and post-harvest attributes.

Sulforaphane as a potential remedy against cancer: Comprehensive mechanistic review

Sulforaphane belongs to the active class of isothiocyanates capable of delivering various biological benefits for health promotion and disease prevention. This compound is considered vital to curtail numerous metabolic disorders. Various studies have proven its beneficial effects against cancer prevention and its possible utilization as a therapeutic agent in cancer treatment. Understanding the mechanistic pathways and possible interactions at cellular and subcellular levels is key to design and develop cancer therapeutics for humans. In this respect, a number of mechanisms such as modulation of carcinogen metabolism & phase II enzymatic activities, cell cycle arrest, activation of Nrf2, cytotoxic, proapoptotic and apoptotic pathways have been reported to be involved in cancer prevention. This article provides sufficient information by critical analysis to understand the mechanisms involved in cancer prevention attributed to sulforaphane. Furthermore, various clinical studies have also been included for design and development of novel therapies for cancer prevention and cure. PRACTICAL APPLICATIONS: Diet and dietary components are potential tools to address various lifestyle-related disorders. Due to plenty of environmental and cellular toxicants, the chances of cancer prevalence are quite large which are worsen by adopting unhealthy lifestyles. Cancer can be treated with various therapies but those are acquiring side effects causing the patients to suffer the treatment regime. Nutraceuticals and functional foods provide safer options to prevent or delay the onset of cancer. In this regard, sulforaphane is a pivotal compound to be targeted as a potential agent for cancer treatment both in preventive and therapeutic regimes. This article provides sufficient evidence via discussing the underlying mechanisms of positive effects of sulforaphane to further the research for developing anticancer drugs that will help assuage this lethal morbidity.

Mechanistic Targets of Diallyl Trisulfide in Human Breast Cancer Cells Identified by RNA-seq Analysis

Diallyl trisulfide (DATS), a metabolic by-product of processed garlic, is highly effective in inhibiting growth of human breast cancer cells in vitro and in vivo, but the underlying mechanisms are still not fully understood. In this study, we performed RNA-seq analyses using luminal-type (MCF-7) and basal-like (MDA-MB-231) human breast cancer cells to identify mechanistic targets of DATS. The Reactome Pathway Analysis revealed upregulation of genes associated with SLIT/ROBO tumor suppressor signaling following DATS treatment in both MCF-7 and MDA-MB-231 cells. However, the expression of SLIT2 and ROBO1 proteins or their downstream target C-X-C motif chemokine receptor 4 was not affected by DATS treatment in both cell lines. The Reactome as well as the Gene Ontology Pathways Analyses of the RNA-seq data from DATS-treated cells indicated downregulation of genes associated with G2/M phase cell cycle arrest in comparison with vehicle-treated control cells. Consistent with the RNA-seq data, DATS treatment caused a significant increase in the fraction of the G2/M population in both cell lines when compared to corresponding control cells. In addition, Ser10 phosphorylation of histone H3, a mitotic marker, was also increased significantly following DATS treatment in MCF-7 and MDA-MB-231 cells. These results indicate that while SLIT/ROBO signaling is not affected by DATS treatment, cell cycle arrest likely contributes to the antitumor effect of this phytochemical.

Synthesis of Isothiocyanates Using DMT/NMM/TsO- as a New Desulfurization Reagent

Thirty-three alkyl and aryl isothiocyanates, as well as isothiocyanate derivatives from esters of coded amino acids and from esters of unnatural amino acids (6-aminocaproic, 4-(aminomethyl)benzoic, and tranexamic acids), were synthesized with satisfactory or very good yields (25-97%). Synthesis was performed in a "one-pot", two-step procedure, in the presence of organic base (Et3N, DBU or NMM), and carbon disulfide via dithiocarbamates, with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TsO-) as a desulfurization reagent. For the synthesis of aliphatic and aromatic isothiocyanates, reactions were carried out in a microwave reactor, and selected alkyl isothiocyanates were also synthesized in aqueous medium with high yields (72-96%). Isothiocyanate derivatives of L- and D-amino acid methyl esters were synthesized, under conditions without microwave radiation assistance, with low racemization (er 99 > 1), and their absolute configuration was confirmed by circular dichroism. Isothiocyanate derivatives of natural and unnatural amino acids were evaluated for antibacterial activity on E. coli and S. aureus bacterial strains, where the most active was ITC 9e.

Induction of the Stringent Response Underlies the Antimicrobial Action of Aliphatic Isothiocyanates

Bacterial resistance to known antibiotics comprises a serious threat to public health. Propagation of multidrug-resistant pathogenic strains is a reason for undertaking a search for new therapeutic strategies, based on newly developed chemical compounds and the agents present in nature. Moreover, antibiotic treatment of infections caused by enterotoxin toxin-bearing strain—enterohemorrhagic Escherichia coli (EHEC) is considered hazardous and controversial due to the possibility of induction of bacteriophage-encoded toxin production by the antibiotic-mediated stress. The important source of potentially beneficial compounds are secondary plant metabolites, isothiocyanates (ITC), and phytoncides from the Brassicaceae family. We reported previously that sulforaphane and phenethyl isothiocyanate, already known for their chemopreventive and anticancer features, exhibit significant antibacterial effects against various pathogenic bacteria. The mechanism of their action is based on the induction of the stringent response and accumulation of its alarmones, the guanosine penta- and tetraphosphate. In this process, the amino acid starvation path is employed via the RelA protein, however, the precise mechanism of amino acid limitation in the presence of ITCs is yet unknown. In this work, we asked whether ITCs could act synergistically with each other to increase the antibacterial effect. A set of aliphatic ITCs, such as iberin, iberverin, alyssin, erucin, sulforaphen, erysolin, and cheirolin was tested in combination with sulforaphane against E. coli. Our experiments show that all tested ITCs exhibit strong antimicrobial effect individually, and this effect involves the stringent response caused by induction of the amino acid starvation. Interestingly, excess of specific amino acids reversed the antimicrobial effects of ITCs, where the common amino acid for all tested compounds was glycine. The synergistic action observed for iberin, iberverin, and alyssin also led to accumulation of (p)ppGpp, and the minimal inhibitory concentration necessary for the antibacterial effect was four- to eightfold lower than for individual ITCs. Moreover, the unique mode of ITC action is responsible for inhibition of prophage induction and toxin production, in addition to growth inhibition of EHEC strains. Thus, the antimicrobial effect of plant secondary metabolites by the stringent response induction could be employed in potential therapeutic strategies.

Phytochemicals in Gynecological Cancer Prevention

Gynecological cancer confers an enormous burden among women worldwide. Accumulating evidence points to the role of phytochemicals in preventing cervical, endometrial, and ovarian cancer. Experimental studies emphasize the chemopreventive and therapeutic potential of plant-derived substances by inhibiting the early stages of carcinogenesis or improving the efficacy of traditional chemotherapeutic agents. Moreover, a number of epidemiological studies have investigated associations between a plant-based diet and cancer risk. This literature review summarizes the current knowledge on the phytochemicals with proven antitumor activity, emphasizing their effectiveness and mechanism of action in gynecological cancer.

Effects of cooking methods on total isothiocyanate yield from cruciferous vegetables

Cruciferous vegetables are primary sources of dietary isothiocyanates (ITCs), a group of phytochemicals showing promising cancer-chemopreventive activities in multiple cancer models. However, no study has thoroughly examined how cooking affects the yields of ITCs from cruciferous vegetables. In this study, a high-performance liquid chromatography (HPLC)-based cyclocondensation assay was performed to examine the ITC yields from four major cruciferous vegetables (broccoli, cabbage, cauliflower, and kale) under six cooking conditions (stir-frying, steaming, microwaving, boiling, stewing, and chip-baking for kale only) and measured the level of ITCs under the raw condition for a comprehensive list of cruciferous vegetables and ITC-containing condiments. A wide range of ITC yields was found across vegetables and condiments. Cooking significantly altered the ITC yields, showing an averagely four-fold increase by lightly cooking (stir-frying, steaming, and microwaving) and a 58% decrease by heavily cooking (boiling, stewing, and chip-baking). These findings will provide the evidence-based cooking guidance on cruciferous vegetable consumption and help better estimate dietary ITC exposure in epidemiologic studies.

Intake of total cruciferous vegetable and its contents of glucosinolates and isothiocyanates, glutathione S-transferases polymorphisms and breast cancer risk: a case-control study in China

Cruciferous vegetables contain high levels of glucosinolates (GSL) and isothiocyanates (ITC). ITC are known to induce glutathione S-transferases (GST) and thus exert their anticarcinogenic effects. This study explored the combined effects of cruciferous vegetable, GSL and ITC intake and GST polymorphisms on breast cancer risk. A total of 737 breast cancer cases and 756 controls were recruited into this case-control study. OR and 95 % CI were assessed by multivariable logistic regression. Higher cruciferous vegetable, GSL and ITC intakes were inversely associated with breast cancer risk, with adjusted OR of 0·48 (95 % CI 0·35, 0·65), 0·54 (95 % CI 0·40, 0·74) and 0·62 (95 % CI 0·45, 0·84), respectively. Compared with women carrying the GSTP1 rs1695 wild AA genotype and high cruciferous vegetable, GSL or ITC intake, carriers of the AA genotype with low cruciferous vegetable, GSL and ITC intake had greater risk of breast cancer, with adjusted OR of 1·43 (95 % CI 1·01, 1·87), 1·34 (95 % CI 1·02, 1·75) and 1·37 (95 % CI 1·05, 1·80), respectively. Persons with the GSTM1-null genotype and lower intake of cruciferous vegetables, GSL and ITC had higher risk of breast cancer than those with the GSTM1-present genotype and higher intake, with OR of 1·42 (95 % CI 1·04, 1·95), 1·43 (95 % CI 1·05, 1·96) and 1·45 (95 % CI 1·06, 1·98), respectively. Among women possessing the GSTT1-present genotype, low intake of cruciferous vegetables, GSL or ITC was associated with higher risk of breast cancer. But these interactions were non-significant. This study indicated that there were no significant interactions between cruciferous vegetable, GSL or ITC intake and GST polymorphisms on breast cancer risk.

Osteolytic metastasis in breast cancer: effective prevention strategies

INTRODUCTION

Breast cancer is the most common cancer in women throughout the world. Patients who are diagnosed early generally have better prognosis and survivability. Indeed, advanced stage breast cancer often develops osteolytic metastases, leading to bone destruction. Although there are select drugs available to treat bone metastatic disease, these drugs have shown limited success.

AREA COVERED

This paper emphasizes updated mechanisms of bone remodeling and osteolytic bone metastases of breast cancer. This article also aims to explore the potential of novel natural and synthetic therapeutics in the effective prevention of breast cancer-induced osteolysis and osteolytic metastases of breast cancer.

EXPERT OPINION

Targeting TGFβ and BMP signaling pathways, along with osteoclast activity, appears to be a promising therapeutic strategy in the prevention of breast cancer-induced osteolytic bone destruction and metastatic growth at bone metastatic niches. Pilot studies in animal models suggest various natural and synthetic compounds and monoclonal antibodies as putative therapeutics in the prevention of breast cancer stimulated osteolytic activity. However, comprehensive pre-clinical studies demonstrating the PK/PD and in-depth understanding of molecular mechanism(s) by which these potential molecules exhibit anti-tumor growth and anti-osteolytic activity are still required to develop effective therapies against breast cancer-induced osteolytic bone disease.

Natural and herbal compounds targeting breast cancer, a review based on cancer stem cells

Cancer stem cells (CSCs) are known as the major reason for therapy resistance. Recently, natural herbal compounds are suggested to have a significant role in inhibiting the breast cancer stem cells (BCSCs). The aim of this study was to explore the effective natural herbal compounds against BCSCs.This review article was designed based on the BCSCs, mechanisms of therapy resistance and natural herbal compounds effective to inhibit their activity. Therefore, Science direct, PubMed and Scopus databases were explored and related original articles were investigated from 2010 to 2019. BCSCs use different mechanisms including special membrane transporters, anti-apoptotic, pro-survival, and self-renewal- related signaling pathways. Natural herbal compounds could disturb these mechanisms, therefore may inhibit or eradicate the BCSCs. Studies show that a broad range of plants, either as a food or medicine, contain anti-cancer agents that phenolic components and their different derivatives share a large quantity. Natural herbal compounds play a pivotal role in the eradication of BCSCs, through the inhibition of biological activities and induction of apoptosis. Although it is necessary to conduct more clinical investigation.

Diet-Derived Phytochemicals Targeting Colon Cancer Stem Cells and Microbiota in Colorectal Cancer

Colorectal cancer (CRC) is a fatal disease caused by the uncontrolled propagation and endurance of atypical colon cells. A person's lifestyle and eating pattern have significant impacts on the CRC in a positive and/or negative way. Diet-derived phytochemicals modulate the microbiome as well as targeting colon cancer stem cells (CSCs) that are found to offer significant protective effects against CRC, which were organized in an appropriate spot on the paper. All information on dietary phytochemicals, gut microbiome, CSCs, and their influence on CRC were accessed from the various databases and electronic search engines. The effectiveness of CRC can be reduced using various dietary phytochemicals or modulating microbiome that reduces or inverses the progression of a tumor as well as CSCs, which could be a promising and efficient way to reduce the burden of CRC. Phytochemicals with modulation of gut microbiome continue to be auspicious investigations in CRC through noticeable anti-tumorigenic effects and goals to CSCs, which provides new openings for cancer inhibition and treatment.

Reversal of the Warburg phenomenon in chemoprevention of prostate cancer by sulforaphane

Inhibition of metabolic re-programming represents an attractive approach for prevention of prostate cancer. Studies have implicated increased synthesis of fatty acids or glycolysis in pathogenesis of human prostate cancers. We have shown previously that prostate cancer prevention by sulforaphane (SFN) in Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model is associated with inhibition of fatty acid metabolism. This study utilized human prostate cancer cell lines (LNCaP, 22Rv1 and PC-3), two different transgenic mouse models (TRAMP and Hi-Myc) and plasma specimens from a clinical study to explore the glycolysis inhibition potential of SFN. We found that SFN treatment: (i) decreased real-time extracellular acidification rate in LNCaP, but not in PC-3 cell line; (ii) significantly downregulated expression of hexokinase II (HKII), pyruvate kinase M2 and/or lactate dehydrogenase A (LDHA) in vitro in cells and in vivo in neoplastic lesions in the prostate of TRAMP and Hi-Myc mice; and (iii) significantly suppressed glycolysis in prostate of Hi-Myc mice as measured by ex vivo1H magnetic resonance spectroscopy. SFN treatment did not decrease glucose uptake or expression of glucose transporters in cells. Overexpression of c-Myc, but not constitutively active Akt, conferred protection against SFN-mediated downregulation of HKII and LDHA protein expression and suppression of lactate levels. Examination of plasma lactate levels in prostate cancer patients following administration of an SFN-rich broccoli sprout extract failed to show declines in its levels. Additional clinical trials are needed to determine whether SFN treatment can decrease lactate production in human prostate tumors.

The Role of Lysosome-associated Membrane Protein 2 in Prostate Cancer Chemopreventive Mechanisms of Sulforaphane

Prostate cancer chemoprevention by sulforaphane, which is a metabolic by-product of glucoraphanin found in broccoli, in preclinical models is associated with induction of both apoptosis and autophagy. However, the molecular mechanism underlying sulforaphane-mediated autophagy, which is protective against apoptotic cell death by this phytochemical, is still poorly understood. This study demonstrates a role for lysosome-associated membrane protein 2 (LAMP2) in sulforaphane-mediated autophagy and apoptosis. Western blotting revealed dose-dependent induction of LAMP2 protein after treatment with sulforaphane as well as its naturally occurring analogs in PC-3 and 22Rv1 human prostate cancer cell lines that was confirmed by microscopy (sulforaphane). The mRNA level of LAMP2 was also increased upon treatment with sulforaphane in both cell lines. Sulforaphane-mediated increase in the level of autophagy marker microtubule-associated protein light-chain 3B was augmented by RNAi of LAMP2 in PC-3 and 22Rv1 cells. Apoptosis induction by sulforaphane treatment was also increased significantly by knockdown of the LAMP2 protein in PC-3 and 22Rv1 cells. Augmentation of sulforaphane-mediated apoptosis by RNAi of LAMP2 was accompanied by induction and activation of proapoptotic protein Bak. Oral administration of sulforaphane to TRAMP mice also resulted in induction of LAMP2 protein expression. Targeted microarray in sulforaphane-treated PC-3 cells revealed induction of many autophagy-related genes (e.g., HSP90AA1, NRF2, etc) and their expression positively correlated with that of LAMP2 in prostate cancer The Cancer Genome Atlas. In conclusion, this study reveals that induction of LAMP2 by sulforaphane inhibits its ability to induce apoptotic cell death at least in human prostate cancer cells.

Akt/survivin pathway inhibition enhances the apoptotic cell death-induced by alpha-santalol in human prostate cancer cells

We have shown previously that alpha-santalol, a major component of sandalwood oil inhibits growth of cultured prostate cancer cells in vitro by causing apoptosis, but the mechanism of cell death is not fully elucidated. The present study was undertaken to investigate the role of PI3K/Akt/survivin pathway in alpha-santalol-induced apoptosis employing cultured LNCaP and PC-3 human prostate cancer cells. Treatment of prostate cancer cells with alpha-santalol (20, 40 μM) resulted in the down regulation of survivin and p-AKT (s-473) expression and statistically significant reduction in total survivin levels as evidenced by survivin ELISA assay. Furthermore, inhibition of PI3K-Akt pathway by pharmacological inhibitor, LY294002 enhanced the apoptotic cell death induced by alpha-santalol as determined by cell viability, cellular morphology, active caspase-3 activity and expression of cleaved PARP, cleaved caspase-3 levels. In conclusion, the present study provides novel insight into the molecular circuitry of alpha-santalol-induced cell death and reveals that alpha-santalol targets Akt/Survivin pathway to induce cell death and that the cell death is increased in the presence of a known inhibitor of the pathway.

A Novel Sulforaphane-Regulated Gene Network in Suppression of Breast Cancer-Induced Osteolytic Bone Resorption

Bone is the most preferred site for colonization of metastatic breast cancer cells for each subtype of the disease. The standard of therapeutic care for breast cancer patients with bone metastasis includes bisphosphonates (e.g., zoledronic acid), which have poor oral bioavailability, and a humanized antibody (denosumab). However, these therapies are palliative, and a subset of patients still develop new bone lesions and/or experience serious adverse effects. Therefore, a safe and orally bioavailable intervention for therapy of osteolytic bone resorption is still a clinically unmet need. This study demonstrates suppression of breast cancer-induced bone resorption by a small molecule (sulforaphane, SFN) that is safe clinically and orally bioavailable. In vitro osteoclast differentiation was inhibited in a dose-dependent manner upon addition of conditioned media from SFN-treated breast cancer cells representative of different subtypes. Targeted microarrays coupled with interrogation of The Cancer Genome Atlas data set revealed a novel SFN-regulated gene signature involving cross-regulation of runt-related transcription factor 2 (RUNX2) and nuclear factor-κB and their downstream effectors. Both RUNX2 and p65/p50 expression were higher in human breast cancer tissues compared with normal mammary tissues. RUNX2 was recruited at the promotor of NFKB1 Inhibition of osteoclast differentiation by SFN was augmented by doxycycline-inducible stable knockdown of RUNX2. Oral SFN administration significantly increased the percentage of bone volume/total volume of affected bones in the intracardiac MDA-MB-231-Luc model indicating in vivo suppression of osteolytic bone resorption by SFN. These results indicate that SFN is a novel inhibitor of breast cancer-induced osteolytic bone resorption in vitro and in vivo.

Targeting Glucose Transporters for Breast Cancer Therapy: The Effect of Natural and Synthetic Compounds

Reprogramming of cellular energy metabolism is widely accepted to be a cancer hallmark. The deviant energetic metabolism of cancer cells-known as the Warburg effect-consists in much higher rates of glucose uptake and glycolytic oxidation coupled with the production of lactic acid, even in the presence of oxygen. Consequently, cancer cells have higher glucose needs and thus display a higher sensitivity to glucose deprivation-induced death than normal cells. So, inhibitors of glucose uptake are potential therapeutic targets in cancer. Breast cancer is the most commonly diagnosed cancer and a leading cause of cancer death in women worldwide. Overexpression of facilitative glucose transporters (GLUT), mainly GLUT1, in breast cancer cells is firmly established, and the consequences of GLUT inhibition and/or knockout are under investigation. Herein we review the compounds, both of natural and synthetic origin, found to interfere with uptake of glucose by breast cancer cells, and the consequences of interference with that mechanism on breast cancer cell biology. We will also present data where the interaction with GLUT is exploited in order to increase the efficiency or selectivity of anticancer agents, in breast cancer cells.

Cysteine specific bioconjugation with benzyl isothiocyanates

Protein labelling has a wide variety of applications in medicinal chemistry and chemical biology. In addition to covalent inhibition, specific labelling of biomolecules with fluorescent dyes is important in both target discovery, validation and diagnostics. Our research was conducted through the fragment-based development of a new benzyl-isothiocyanate-activated fluorescent dye based on the fluorescein scaffold. This molecule was evaluated against fluorescein isothiocyanate, a prevalent labelling agent. The reactivity and selectivity of phenyl- and benzyl isothiocyanate were compared at different pHs, and their activity was tested on several protein targets. Finally, the clinically approved antibody trastuzumab (and it's Fab fragment) were specifically labelled through reaction with free cysteines reductively liberated from their interchain disulfide bonds. The newly developed benzyl-fluorescein isothiocyanate and its optimized labelling protocol stands to be a valuable addition to the tool kit of chemical biology.

We present herein the development of a new fluorescent dye equipped with a benzyl isothiocyanate warhead, which resulted improved photophysical properties and enhanced labelling efficiency on the Fab antibody subunit and the trastuzumab antibody.

Suppression of multiple processes relevant to cancer progression by benzyl isothiocyanate may result from the inhibition of Aurora A kinase activity

The anti-cancer properties of BITC may result from the inhibition of Aurora A kinase activity.

Repurposing old drugs as new inhibitors of the ubiquitin-proteasome pathway for cancer treatment

The ubiquitin-proteasome system (UPS) plays a central role in the degradation of cellular proteins. Targeting protein degradation has been validated as an effective strategy for cancer therapy since 2003. Several components of the UPS have been validated as potential anticancer targets, including 20S proteasomes, 19S proteasome-associated deubiquitinases (DUBs) and ubiquitin ligases (E3s). 20S proteasome inhibitors (such as bortezomib/BTZ and carfilzomib/CFZ) have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of multiple myeloma (MM) and some other liquid tumors. Although survival of MM patients has been improved by the introduction of BTZ-based therapies, these clinical 20S proteasome inhibitors have several limitations, including emergence of resistance in MM patients, neuro-toxicities, and little efficacy in solid tumors. One of strategies to improve the current status of cancer treatment is to repurpose old drugs with UPS-inhibitory properties as new anticancer agents. Old drug reposition represents an attractive drug discovery approach compared to the traditional de novo drug discovery process which is time-consuming and costly. In this review, we summarize status of repurposed inhibitors of various UPS components, including 20S proteasomes, 19S-associated DUBs, and ubiquitin ligase E3s. The original and new mechanisms of action, molecular targets, and potential anticancer activities of these repurposed UPS inhibitors are reviewed, and their new uses including combinational therapies for cancer treatment are discussed.

Benzyl Isothiocyanate Induces Apoptosis via Reactive Oxygen Species-Initiated Mitochondrial Dysfunction and DR4 and DR5 Death Receptor Activation in Gastric Adenocarcinoma Cells

Benzyl isothiocyanate (BITC) is known to inhibit the metastasis of gastric cancer cells but further studies are needed to confirm its chemotherapeutic potential against gastric cancer. In this study, we observed cell shrinkage and morphological changes in one of the gastric adenocarcinoma cell lines, the AGS cells, after BITC treatment. We performed 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2H-tetrazolium bromide (MTT) assay, a cell viability assay, and found that BITC decreased AGS cell viability. Reactive oxygen species (ROS) analyses using 2',7'-dichlorofluorescin diacetate (DCFDA) revealed that BITC-induced cell death involved intracellular ROS production, which resulted in mitochondrial dysfunction. Additionally, cell viability was partially restored when BITC-treated AGS cells were preincubated with glutathione (GSH). Western blotting indicated that BITC regulated the expressions of the mitochondria-mediated apoptosis signaling molecules, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cytochrome c (Cyt c). In addition, BITC increased death receptor DR5 expression, and activated the cysteine-aspartic proteases (caspases) cascade. Overall, our results showed that BITC triggers apoptosis in AGS cells via the apoptotic pathways involved in ROS-promoted mitochondrial dysfunction and death receptor activation.

Synergistic Actions of Benzyl Isothiocyanate with Ethylenediaminetetraacetic Acid and Efflux Pump Inhibitor Phenylalanine-Arginine β-Naphthylamide Against Multidrug-Resistant Escherichia coli

The aim of this study was to assess the efficacy of benzyl isothiocyanate (BITC) in combination with efflux inhibitors and metal chelators against multidrug-resistant Escherichia coli. In vitro synergism between testing molecules was observed based on the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), fractional inhibitory concentration index (FICI), bactericidal kinetics, and growth inhibition assay. BITC alone exhibited moderate antibacterial activity against E. coli strains with MIC and MBC values of 0.625-1.25 μM and 1.25-2.5 μM, respectively. In contrast, double and triple combinations of BITC, ethylenediaminetetraacetic acid (EDTA), and phenylalanine-arginine β-naphthylamide (PAβN) resulted in synergistic activities with FICI values between 0.18 and 0.5, whereas combination of BITC with carbonyl cyanide m-chlorophenyl hydrazone or 2, 2'-dipyridyl revealed additive or indifference effect with FICI values of 0.75-1.5 and 1-1.5, respectively. Results of bactericidal kinetics and growth inhibition assays also supported the synergistic effects of EDTA and PAβN with BITC against E. coli strains. Our data demonstrate the possible use of adjuvant agents, such as the chelating agent EDTA and the efflux inhibitor PAβN to improve the antibacterial potential of isothiocyanate and may help to develop an alternative strategy for reducing the occurrence of multidrug resistance.

Bioactive Compounds: Multi-Targeting Silver Bullets for Preventing and Treating Breast Cancer

Each cell in our body is designed with a self-destructive trigger, and if damaged, can happily sacrifice itself for the sake of the body. This process of self-destruction to safeguard the adjacent normal cells is known as programmed cell death or apoptosis. Cancer cells outsmart normal cells and evade apoptosis and it is one of the major hallmarks of cancer. The cardinal quest for anti-cancer drug discovery (bioactive or synthetic compounds) is to be able to re-induce the so called “programmed cell death” in cancer cells. The importance of bioactive compounds as the linchpin of cancer therapeutics is well known as many effective chemotherapeutic drugs such as vincristine, vinblastine, doxorubicin, etoposide and paclitaxel have natural product origins. The present review discusses various bioactive compounds with known anticancer potential, underlying mechanisms by which they induce cell death and their preclinical/clinical development. Most bioactive compounds can concurrently target multiple signaling pathways that are important for cancer cell survival while sparing normal cells hence they can potentially be the silver bullets for targeting cancer growth and metastatic progression.

Mechanism of selective anticancer activity of isothiocyanates relies on differences in DNA damage repair between cancer and healthy cells

Purpose

Isothiocyanates (ITCs) are compounds derived from Brassica plants with documented anticancer activity. Molecular mechanisms of their selective activity against cancer cells are still underexplored. In this work, the impact of ITC on DNA replication and damage was compared between PC-3 prostate cancer cells and HDFa normal fibroblasts as well as PNT2 prostate epithelial cells.

Methods

Cells were treated with sulforaphane or phenethyl isothiocyanate. [³H]thymidine incorporation and the level of histone γH2A.X were estimated as indicators of DNA replication and double-strand breaks (DSB), respectively. Levels of HDAC3, CtIP, and p-RPA were investigated by immunoblotting. Comet assay was performed to visualize DNA damage.

Results

ITCs inhibited DNA replication in all tested cell lines, and this activity was independent of reactive oxygen species of mitochondrial origin. It was followed by DSB which were more pronounced in cancer than noncancerous cells. This difference was independent of HDAC activity which was decreased in both cell lines when treated with ITCs. On the other hand, it correlated with faster removal of DSB, and thus, transient activation of repair proteins in normal cells, while in PC-3 prostate cancer, cell DNA repair was significantly less effective.

Conclusion

DNA damage induced by ITCs is a consequence of the block in DNA replication which is observed in both, cancer and normal cells. Selective antiproliferative activity of ITCs towards cancer cells results from less efficient DNA repair in cancer cells relative to normal cells.

Benzyl isothiocyanate inhibits invasion and induces apoptosis via reducing S100A4 expression and increases PUMA expression in oral squamous cell carcinoma cells

Benzyl isothiocyanate (BITC) has been shown to inhibit invasion and induce apoptosis of various types of cancer. However, its role on human oral squamous cell carcinoma (OSCC) cells is still not well elucidated. In the present study, we investigated the effect of BITC on apoptosis and invasion of SCC9 cells, and its underlying mechanisms in vitro and in vivo. SCC9 cells were exposed to BITC (5 and 25 μM) for 24 and 48 h. Cell growth, apoptosis, invasion, and migration were detected in vitro by MTT, FITC-conjugated annexin V/propidium iodide staining followed by flow cytometry, Matrigel-coated semi-permeable modified Boyden, and wound-healing assay. S100A4, PUMA, and MMP-9 expressions were detected to investigate its mechanisms. Xenotransplantation experiments were used to investigate the role of BITC on tumor growth and lung metastasis. BITC inhibited cell viability and induced cell apoptosis in a dose- and time-dependent manner through upregulation of PUMA signals. BITC inhibited cell invasion and migration by downregulation of S100A4 dependent MMP-9 signals. The ip administration of BITC reduced tumor growth but not lung metastasis of SCC9 cells subcutaneously implanted in nude mice. BITC treatment activated pro-apoptotic PUMA and inhibited S100A4-dependent MMP-9 signals, resulting in the inhibition of cell growth and invasion in cultured and xenografted SCC9 cells. Thereby, BITC is a potential therapeutic approach for OSCC.