Allyl isothiocyanate, a potent chemopreventive agent targets AhR/Nrf2 signaling pathway in chemically induced mammary carcinogenesis

Chemopreventive effects of atractylenolide-III on mammary tumorigenesis via activation of the Nrf2/ARE pathway through autophagic degradation of Keap1

The incidence of breast cancer is increasing annually, making it a major health threat for women. Chemoprevention using natural, dietary, or synthetic products has emerged as a promising approach to address this growing burden. Atractylenolide-III (AT-III), a sesquiterpenoid present in various medicinal herbs, has demonstrated potential therapeutic effects against several diseases, including tumors, nonalcoholic fatty liver disease, and cerebral ischemic injury. However, its impact on breast cancer chemoprevention remains unexplored. In this study, we used an N-methyl-N-nitrosourea (NMU)-induced rat breast cancer model and 17β-estradiol (E2)-treated MCF-10A cells to evaluate the chemopreventive potential of AT-III on mammary tumorigenesis. AT-III inhibited mammary tumor progression, evidenced by reduced tumor volume and multiplicity, prolonged tumor latency, and the reversal of NMU-induced weight loss. Furthermore, AT-III suppressed NMU-induced inflammation and oxidative stress through the Nrf2/ARE pathway in breast cancer tissues. In vitro, AT-III effectively suppressed E2-induced anchorage-independent growth and cell migration in MCF-10A cells. Nrf2 knockdown attenuated the protective effects of AT-III, highlighting the pivotal role of Nrf2 in AT-III-mediated suppression of tumorigenesis. The mechanism involves the induction of Nrf2 expression by AT-III through the autophagic degradation of Kelch-like ECH-associated protein 1 (Keap1). Overall, the results of this study indicate that AT-III is a promising candidate for breast cancer chemoprevention and provide valuable insights into its molecular interactions and signaling pathways.

Isothiocyanates in medicine: A comprehensive review on phenylethyl-, allyl-, and benzyl-isothiocyanates

In recent years, isothiocyanates (ITCs), bioactive compounds primarily derived from Brassicaceae vegetables and herbs, have gained significant attention within the biomedical field due to their versatile biological effects. This comprehensive review provides an in-depth exploration of the therapeutic potential and individual biological mechanisms of the three specific ITCs phenylethyl isothiocyanate (PEITC), allyl isothiocyanate (AITC), and benzyl isothiocyanate (BITC), as well as their collective impact within the formulation of ANGOCIN® Anti-Infekt N (Angocin). Angocin comprises horseradish root (Armoracia rusticanae radix, 80 mg) and nasturtium (Tropaeoli majoris herba, 200 mg) and is authorized for treating inflammatory diseases affecting the respiratory and urinary tract. The antimicrobial efficacy of this substance has been confirmed both in vitro and in various clinical trials, with its primary effectiveness attributed to ITCs. PEITC, AITC, and BITC exhibit a wide array of health benefits, including potent anti-inflammatory, antioxidant, and antimicrobial properties, along with noteworthy anticancer potentials. Moreover, we highlight their ability to modulate critical biochemical pathways, such as the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and signal transducer and activator of transcription (STAT) pathways, shedding light on their involvement in cellular apoptosis and their intricate role to guide immune responses.

Allyl isothiocyanate induces DNA damage and inhibits DNA repair-associated proteins in a human gastric cancer cells in vitro

Allyl isothiocyanate (AITC) is abundant in cruciferous vegetables and it present pharmacological activity including anticancer activity in many types of human cancer cells in vitro and in vivo. Currently, no available information to show AITC affecting DNA damage and repair-associated protein expression in human gastric cancer cells. Therefore, in the present studies, we investigated AITC-induced cytotoxic effects on human gastric cancer in AGS and SNU-1 cells whether or not via the induction of DNA damage and affected DNA damage and repair associated poteins expressions in vitro. Cell viability and morphological changes were assayed by flow cytometer and phase contrast microscopy, respectively, the results indicated AITC induced cell morphological changes and decreased total viable cells in AGS and SNU-1 cells in a dose-dependently. AITC induced DNA condensation and damage in a dose-dependently which based on the cell nuclei was stained by 4', 6-diamidino-2-phenylindole present in AGS and SNU-1 cells. DNA damage and repair associated proteins expression in AGS and SNU-1 cells were measured by Western blotting. The results indicated AITC decreased nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), glutathione, and catalase, but increased superoxide dismutase (SOD (Cu/Zn)), and nitric oxide synthase (iNOS) in AGS cells, however, in SNU-1 cells are increased HO-1. AITC increased DNA-dependent protein kinase (DNA-PK), phosphorylation of gamma H2A histone family member X on Ser139 (γH2AXpSer139 ), and heat shock protein 90 (HSP90) in AGS cells. AITC increased DNA-PK, mediator of DNA damage checkpoint protein 1 (MDC1), γH2AXpSer139 , topoisomerase II alpha (TOPIIα), topoisomerase II beta (TOPIIβ), HSP90, and heat shock protein 70 (HSP70) in SNU-1 cells. AITC increased p53, p53pSer15 , and p21 but decreased murine double minute 2 (MDM2)pSer166 and O6 -methylguanine-DNA methyltransferase (MGMT) in AGS cells; however, it has a similar effect of AITC except increased ataxia telangiectasia and Rad3 -related protein (ATR)pSer428 , checkpoint kinase 1 (CHK1), and checkpoint kinase 2 (CHK2) in SNU-1 cells. Apparently, both cell responses to AITC are different, nonetheless, all of these observations suggest that AITC inhibits the growth of gastric cancer cells may through induction off DNA damage in vitro.

Allyl isothiocyanate regulates oxidative stress, inflammation, cell proliferation, cell cycle arrest, apoptosis, angiogenesis, invasion and metastasis via interaction with multiple cell signaling pathways

Cancer growth is a molecular mechanism initiated by genetic and epigenetic modifications that are involved in cell proliferation, differentiation, apoptosis, and senescence pathways. Chemoprevention is an important strategy for cancer treatment that leads to blocking, reversing, or impeding the multistep process of tumorigenesis, including the blockage of its vital morphogenetic milestones viz. normal, preneoplasia, neoplasia, and metastasis. Naturally occurring phytochemicals are becoming ever more popular compared to synthetic drugs for many reasons, including safety, bioavailability, efficacy, and easy availability. Allyl isothiocyanate (AITC) is a natural compound present in all plants of the Cruciferae family, such as Brussels sprouts, cauliflower, mustard, cabbage, kale, horseradish, and wasabi. In vitro and in vivo studies carried out over the decades have revealed that AITC inhibits tumorigenesis without any toxicity and undesirable side effects. The bioavailability of AITC is exceedingly high, as it was reported that nearly 90% of orally administered AITC is absorbed. AITC exhibits multiple pharmacological properties among which its anticancer activity is the most significant for cancer treatment. Its anticancer activity is exerted via selective modulation of multiple cell signaling pathways related to oxidative stress, inflammation, cell proliferation, cell cycle arrest, apoptosis, angiogenesis, invasion, and metastasis. This review highlights the current knowledge on molecular targets that are involved in the anticancer effect of AITC associated with (i) inhibition of carcinogenic activation and induction of antioxidants, (ii) suppression of pro-inflammatory and cell proliferative signals, (iii) induction of cell cycle arrest and apoptosis, and (iv) inhibition of angiogenic and invasive signals related to metastasis.

Chemopreventive aspects, investigational anticancer applications and current perspectives on allyl isothiocyanate (AITC): a review

Allyl isothiocyanates (AITC) have gained recognition in recent years as effective chemotherapeutic and epigenetic modulators. The chemopreventive properties and toxicological perspectives of AITCs from the last few decades were taken into account by a number of investigations. Their active therapeutic relevance was hindered by a number of factors, including instability under typical physiological conditions and low bioavailability due to low aqueous solubility. In this review, we highlighted the chemopreventive attributes of AITC in relation to its molecular mechanisms and metabolic fate for cancer. Moreover, we emphasized on investigational anticancer activities and various strategies for delivery of AITC in different types of cancer. Considering cellular interactions, we shed light on the toxicological properties of AITCs to address further issues regarding their assessment in therapeutic development. This review identifies knowledge gaps with various contemporary approaches involving most recent studies and may pave the way for a better understanding for the development of novel AITC therapeutics.

Allyl-isothiocyanate against colorectal cancer via the mutual dependent regulation of p21 and Nrf2

Allyl-isothiocyanate (AITC) is a common Isothiocyanates (ITC) and its chemo-preventive and anti-tumor effects are believed to be related to the activation of NF-E2 p45-related Factor 2 (Nrf2). However, its anti-tumor effects on colorectal cancer (CRC) are not well elucidated. Here, we investigated the therapeutic in vitro and/or in vivo effects and mechanisms of action (MOA) for AITC on CRC cell line HCT116 (human) and MC38 (mouse). AITC treatment in a low concentration range (1 mg/kg in vivo) significantly inhibited the tumor cell growth and increased the expression of p21 and Nrf2. The AITC-mediated induction of p21 was dependent on Nrf2 but independent on p53 in vitro and in vivo at low dose. In contrast, the high dose of AITC (5 mg/kg in vivo) failed to increase substantial levels of p21/MdmX, and impaired the total antioxidant capacity of tumors and subsequent anti-tumor effect in vivo. These results suggest that an optimal dose of AITC is important and required for the proper Nrf2 activation and its anti-CRC effects and thus, providing insights into the potential applications of AITC for the prevention and treatment of CRC.

C-type natriuretic peptide (CNP) inhibits 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor growth by modulating inflammation in Swiss albino mice

C-type natriuretic peptide (CNP) exhibits anti-inflammatory activity besides its natriuretic and diuretic functions. The present study aimed to determine the anticancer and synergistic therapeutic activity of CNP against a 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor mouse model. CNP (2.5 µg/kg body weight) was injected either alone and/or in combination with Cisplatin (CDDP) (2 mg/kg body weight) for 4 weeks. The dorsal skin tumor incidences/growth and mortality rate were recorded during the experimental period of 16 weeks. The serum C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels, infiltrating mast cells, and AgNORs proliferating cells count were analyzed in control and experimental mice. Further, the expression profile of marker genes of proliferation, inflammation, and progression molecules were analyzed using Reverse transcriptase-polymerase chain reaction (RT-PCR)/quantitative PCR (qPCR), western blot, and immunohistochemistry. The DMBA/Croton oil-induced mice exhibited 100% tumor incidence. Whereas, CNP alone, CDDP alone, and CNP+CDDP combination-treated mice exhibited 58%, 46%, and 24% tumor incidence, respectively. Also, a marked reduction in the levels of serum CRP and LDH, the number of infiltrating mast cells count and AgNORs proliferating cells count were noticed in the mice skin sections. Further, a significant reduction in both mRNA and protein expression levels of proliferation, inflammation, and progression markers were noticed in CNP (p < 0.01), CDDP (p < 0.01), and CNP+CDDP combination (p < 0.001) treated mice, respectively. The results of the present study suggest that CNP has anticancer activity. Further, the CNP+CDDP treatment has more promising anticancer activity as compared with CNP or CDDP alone treatment, probably due to the synergistic antiproliferative and anti-inflammatory activities of CNP and CDDP.

Allyl Isothiocyanate Suppresses the Proliferation in Oral Squamous Cell Carcinoma via Mediating the KDM8/CCNA1 Axis

The dysregulated expression of cyclin genes can lead to the uncontrolled proliferation of cancer cells. Histone demethylase Jumonji-C domain-containing protein 5 (KDM8, JMJD5) and cyclin A1 (CCNA1) are pivotal in cell cycle progression. A promising candidate for augmenting cancer treatment is Allyl isothiocyanate (AITC), a natural dietary chemotherapeutic and epigenetic modulator. This study aimed to investigate AITC's impact on the KDM8/CCNA1 axis to elucidate its role in oral squamous cell carcinoma (OSCC) tumorigenesis. The expression of KDM8 and CCNA1 was assessed using a tissue microarray (TMA) immunohistochemistry (IHC) assay. In vitro experiments with OSCC cell lines and in vivo experiments with patient-derived tumor xenograft (PDTX) and SAS subcutaneous xenograft tumor models were conducted to explore AITC's effects on their expression and cell proliferation. The results showed elevated KDM8 and CCNA1 levels in the OSCC patient samples. AITC exhibited inhibitory effects on OSCC tumor growth in vitro and in vivo. Additionally, AITC downregulated KDM8 and CCNA1 expression while inducing histone H3K36me2 expression in oral cancer cells. These findings underscore AITC's remarkable anticancer properties against oral cancer, highlighting its potential as a therapeutic option for oral cancer treatment by disrupting the cell cycle by targeting the KDM8/CCNA1 axis.

Allyl isothiocyanate inhibits invasion and angiogenesis in breast cancer via EGFR-mediated JAK-1/STAT-3 signaling pathway

Angiogenesis, invasion, and metastasis are the main events of cancer cells. JAK-1/STAT-3 is a key intracellular signaling transduction pathway, which controls the growth, differentiation, apoptosis, invasion, and angiogenesis of various cancer cells. The present study explored the impact of allyl isothiocyanate (AITC) on the JAK-1/STAT-3 pathway in DMBA-induced rat mammary tumorigenesis. The mammary tumor was initiated through a single dose of 25 mg DMBA/rat by a subcutaneous injection administered near the mammary gland. We observed decreased body weight and increased the total number of tumors, tumor incidence, tumor volume, well-developed tumor, and histopathological abnormalities in DMBA-induced rats that were modulated after being treated with AITC. Staining of mammary tissues showed a high accumulation of collagen in DMBA-induced rats and it was normalized by the AITC treatment. Moreover, DMBA-induced mammary tissues showed up-regulated expressions of EGFR, pJAK-1, pSTAT-3, nuclear fraction of STAT-3, VEGF, VEGFR2, HIF-1α, MMP-2, and MMP-9 and the down-regulated expressions of cytosolic fraction of STAT-3 and TIMP-2. Oral administration of AITC on DMBA-induced rats inhibits angiogenesis and invasion by modifying these angiogenic and invasive markers. The finding of the present study was further confirmed by molecular docking analysis that shows a strong binding interaction between AITC with STAT-3 and cocrystal structure of STAT-3 glide energy of -18.123 and -72.246 (kcal/mole), respectively. Overall, the results suggested that AITC inhibits activation of the JAK-1/STAT-3 pathway, which subsequently prevents angiogenesis and invasion. It was recommended that AITC might develop a beneficial effect against breast cancer.

Effect of allyl isothiocyanate on oxidative stress in COPD via the AhR / CYP1A1 and Nrf2 / NQO1 pathways and the underlying mechanism

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death globally. Oxidative stress affects various molecular mechanisms and is the main driving factor of COPD. Ally isothiocyanate (AITC) is an effective component of Semen Sinapis Albae, which has favorable effects for the treatment of COPD, but its mechanism has not been fully elucidated.

PURPOSE

This study aimed to elucidate the antioxidant effect of AITC on COPD and its molecular mechanism, and preliminarily determine the role of AhR in the progression of COPD.

STUDY DESIGN

The COPD rat model was established by smoking combined with intratracheal instillation of lipopolysaccharide. Different doses of AITC, positive control drug acetylcysteine, AhR inhibitor alpha-naphthoflavone, and agonist beta-naphthoflavone were administered by gavage. Human bronchial epithelial cells induced by cigarette smoke extract (CSE) were used in an in vitro model to explore the molecular mechanisms of AITC.

METHODS

The effects of AITC on lung function and oxidative stress in rats were evaluated in vivo using the respiratory function test, white blood cell count, enzyme-linked immunosorbent assay, and histological staining. The changes in protein expression in the lung tissue were detected by immunohistochemistry and Western blotting. RT-PCR, western blotting, and immunofluorescence were used to explore the molecular mechanisms of AITC. Enzyme-linked immunosorbent assay, reactive oxygen species probing, and flow cytometry were used to determine the antioxidant effect of AITC.

RESULTS

AITC can improve the lung function of rats with COPD, restore lung tissue structure, improve oxidative stress, reduce inflammation, and inhibit lung cell apoptosis. AITC reversed the upregulation of AhR and CYP1A1 and the down-regulation of Nrf2 and NQO1 in the lung tissues of rats with COPD. CSE stimulation can increase the expressions of AhR and CYP1A1 and decrease the expressions of Nrf2 and NQO1 in 16HBE cells, leading to severe oxidative stress and inflammatory response and, ultimately, apoptosis. AITC inhibited AhR and CYP1A1 expressions, induced Nrf2 and NQO1 expressions, promoted Nrf2 nuclear translocation, and improved CSE-induced toxicological effects.

CONCLUSION

AITC may improve lung oxidative stress by inhibiting the AhR / CYP1A1 and activating the Nrf2 / NQO1 pathways, thereby delaying the pathological progression of COPD.

Isothiocyanate-Rich Extracts from Cauliflower (Brassica oleracea Var. Botrytis) and Radish (Raphanus sativus) Inhibited Metabolic Activity and Induced ROS in Selected Human HCT116 and HT-29 Colorectal Cancer Cells

Cruciferous vegetables such as cauliflower and radish contain isothiocyanates exhibiting chemoprotective effects in vitro and in vivo. This research aimed to assess the impact of cauliflower (CIE) and radish (RIE) isothiocyanate extracts on the metabolic activity, intracellular reactive oxygen species (ROS), and LDH production of selected human colorectal adenocarcinoma cells (HCT116 and HT-29 for early and late colon cancer development, respectively). Non-cancerous colon cells (CCD-33Co) were used as a cytotoxicity control. The CIE samples displayed the highest allyl isothiocyanate (AITC: 12.55 µg/g) contents, whereas RIE was the most abundant in benzyl isothiocyanate (BITC: 15.35 µg/g). Both extracts effectively inhibited HCT116 and HT-29 metabolic activity, but the CIE impact was higher than that of RIE on HCT116 (IC₅₀: 0.56 mg/mL). Assays using the half-inhibitory concentrations (IC₅₀) of all treatments, including AITC and BITC, displayed increased (p < 0.05) LDH (absorbance: 0.25-0.40 nm) and ROS release (1190-1697 relative fluorescence units) in both cell lines. BITC showed the highest in silico binding affinity with all the tested colorectal cancer molecular markers (NF-kB, β-catenin, and NRF2-NFE2). The theoretical evaluation of AITC and BITC bioavailability showed high values for both compounds. The results indicate that CIE and RIE extracts display chemopreventive effects in vitro, but additional experiments are needed to validate their effects.

Anticancer Activity, Mechanism, and Delivery of Allyl Isothiocyanate

Allyl isothiocyanate (AITC) is a phytochemical that is abundantly present in cruciferous vegetables of the Brassicaceae family, such as cabbage, broccoli, mustard, wasabi, and cauliflower. The pungent taste of these vegetables is mainly due to the content of AITC present in these vegetables. AITC is stored stably in the plant as its precursor sinigrin (a type of glucosinolate), which is physically separated from myrosin cells containing myrosinase. Upon tissue disruption, myrosinase gets released and hydrolyzes the sinigrin to produce AITC and by-products. AITC is an organosulfur compound, both an irritant and toxic, but it carries pharmacological properties, including anticancer, antibacterial, antifungal, and anti-inflammatory activities. Despite the promising anticancer effectiveness of AITC, its clinical application still possesses challenges due to several factors, i.e., low aqueous solubility, instability, and low bioavailability. In this review, the anticancer activity of AITC against several cancer models is summarized from the literature. Although the mechanism of action is still not fully understood, several pathways have been identified; these are discussed in this review. Not much attention has been given to the delivery of AITC, which hinders its clinical application. However, the few studies that have demonstrated the use of nanotechnology to facilitate the delivery of AITC are addressed.

Dietary phytochemicals targeting Nrf2 for chemoprevention in breast cancer

Breast cancer accounts for 11.7% of all newly diagnosed cancer cases and has become the leading cause of cancer worldwide. Currently, more effective and less toxic chemopreventive strategies for breast cancer are urgently needed. Notably, naturally occurring dietary phytochemical compounds, such as curcumin and resveratrol, are generally considered to be the most promising breast cancer preventive agents. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a key regulatory role in the expression of multiple antioxidant and anti-inflammatory enzymes, which can effectively suppress the excessive accumulation of carcinogens and their metabolites. Therefore, modulation of Nrf2 by dietary phytochemicals appears to be a promising approach for breast cancer prevention, which further removes excessive carcinogenic metabolites by inducing Phase II cytoprotective enzymes such as heme oxygenase-1 (HO-1) and NAD(P)H quinine oxidoreductase 1 (NQO1). In this review, we summarize recently published findings on the prevention of breast cancer with potential natural phytochemical compounds targeting Nrf2, as well as a mechanistic discussion of Nrf2 activation and its contribution in inhibiting breast cancer carcinogenesis. The epigenetic regulation of Nrf2 by phytochemicals is also explored.

Beneficial Health Effects of Glucosinolates-Derived Isothiocyanates on Cardiovascular and Neurodegenerative Diseases

Neurodegenerative diseases (NDDs) and cardiovascular diseases (CVDs) are illnesses that affect the nervous system and heart, all of which are vital to the human body. To maintain health of the human body, vegetable diets serve as a preventive approach and particularly Brassica vegetables have been associated with lower risks of chronic diseases, especially NDDs and CVDs. Interestingly, glucosinolates (GLs) and isothiocyanates (ITCs) are phytochemicals that are mostly found in the Cruciferae family and they have been largely documented as antioxidants contributing to both cardio- and neuroprotective effects. The hydrolytic breakdown of GLs into ITCs such as sulforaphane (SFN), phenylethyl ITC (PEITC), moringin (MG), erucin (ER), and allyl ITC (AITC) has been recognized to exert significant effects with regards to cardio- and neuroprotection. From past in vivo and/or in vitro studies, those phytochemicals have displayed the ability to mitigate the adverse effects of reactive oxidation species (ROS), inflammation, and apoptosis, which are the primary causes of CVDs and NDDs. This review focuses on the protective effects of those GL-derived ITCs, featuring their beneficial effects and the mechanisms behind those effects in CVDs and NDDs.

Brassica Bioactives Could Ameliorate the Chronic Inflammatory Condition of Endometriosis

Endometriosis is a chronic, inflammatory, hormone-dependent disease characterized by histological lesions produced by the presence of endometrial tissue outside the uterine cavity. Despite the fact that an estimated 176 million women are affected worldwide by this gynecological disorder, risk factors that cause endometriosis have not been properly defined and current treatments are not efficient. Although the interaction between diet and human health has been the focus of many studies, little information about the correlation of foods and their bioactive derivates with endometriosis is available. In this framework, Brassica crops have emerged as potential candidates for ameliorating the chronic inflammatory condition of endometriosis, due to their abundant content of health-promoting compounds such as glucosinolates and their hydrolysis products, isothiocyanates. Several inflammation-related signaling pathways have been included among the known targets of isothiocyanates, but those involving aquaporin water channels have an important role in endometriosis. Therefore, the aim of this review is to highlight the promising effects of the phytochemicals present in Brassica spp. as major candidates for inclusion in a dietary approach aiming to improve the inflammatory condition of women affected with endometriosis. This review points out the potential roles of glucosinolates and isothiocyanates from Brassicas as anti-inflammatory compounds, which might contribute to a reduction in endometriosis symptoms. In view of these promising results, further investigation of the effect of glucosinolates on chronic inflammatory diseases, either as diet coadjuvants or as therapeutic molecules, should be performed. In addition, we highlight the involvement of aquaporins in the maintenance of immune homeostasis. In brief, glucosinolates and the modulation of cellular water by aquaporins could shed light on new approaches to improve the quality of life for women with endometriosis.

Potential effects of allyl isothiocyanate on inhibiting cellular proliferation and inducing apoptotic pathway in human cisplatin-resistant oral cancer cells

BACKGROUND/PURPOSE

Cisplatin-resistant oral cancer is clinically difficult to manage and the dose-dependent toxicities of cisplatin has been widely concerned. Allyl isothiocyanate (AITC), known as mustard oil, is a plant-derived compound abundant in cruciferous vegetables. It is reported to have anti-cancer potential as a natural dietary chemopreventive compound against a variety of cancers, but the effect of AITC on cisplatin-resistant cancer cells is still little-known.

METHODS

Human CAL27-cisplatin-resistant oral cancer cells (CAR cells) were examined to investigate the antitumor properties of AITC. 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, IncuCyte™ S3 cell proliferation assay, 4',6-diamidino-2-phenylindole (DAPI) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining as well as Western blot analysis were deployed.

RESULTS

AITC decreased CAR cell viability, induced cell death of CAR cells and inhibited the confluences of cultured CAR cells. When CAR cells were treated with AITC, activation of caspase-3 and caspase-9 by AITC was observed and could be reversed by Z-VAD-fmk (pan-caspase inhibitor). Furthermore, the protein expressions of phosphorylated protein kinase B (p-AKT) and phosphorylated mammalian target of rapamycin (p-mTOR) were suppressed in AITC-treated CAR cells, whereas protein expressions of Bax, cytochrome c, Apaf-1, cleaved caspase-3, and cleaved caspase-9 were upregulated in AITC-treated CAR cells.

CONCLUSION

AITC can inhibit Akt/mTOR proliferation signaling and promote mitochondria-dependent apoptotic pathway through AITC-enhanced activities of caspase-3 and caspase-9 in CAR cells.

Potential Applications of NRF2 Modulators in Cancer Therapy

The nuclear factor erythroid 2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) regulatory pathway plays an essential role in protecting cells and tissues from oxidative, electrophilic, and xenobiotic stress. By controlling the transactivation of over 500 cytoprotective genes, the NRF2 transcription factor has been implicated in the physiopathology of several human diseases, including cancer. In this respect, accumulating evidence indicates that NRF2 can act as a double-edged sword, being able to mediate tumor suppressive or pro-oncogenic functions, depending on the specific biological context of its activation. Thus, a better understanding of the mechanisms that control NRF2 functions and the most appropriate context of its activation is a prerequisite for the development of effective therapeutic strategies based on NRF2 modulation. In line of principle, the controlled activation of NRF2 might reduce the risk of cancer initiation and development in normal cells by scavenging reactive-oxygen species (ROS) and by preventing genomic instability through decreased DNA damage. In contrast however, already transformed cells with constitutive or prolonged activation of NRF2 signaling might represent a major clinical hurdle and exhibit an aggressive phenotype characterized by therapy resistance and unfavorable prognosis, requiring the use of NRF2 inhibitors. In this review, we will focus on the dual roles of the NRF2-KEAP1 pathway in cancer promotion and inhibition, describing the mechanisms of its activation and potential therapeutic strategies based on the use of context-specific modulation of NRF2.

Molecular Mechanisms of the Anti-Cancer Effects of Isothiocyanates from Cruciferous Vegetables in Bladder Cancer

Bladder cancer (BC) is a representative of urological cancer with a high recurrence and metastasis potential. Currently, cisplatin-based chemotherapy and immune checkpoint inhibitors are used as standard therapy in patients with advanced/metastatic BC. However, these therapies often show severe adverse events, and prolongation of survival is unsatisfactory. Therefore, a treatment strategy using natural compounds is of great interest. In this review, we focused on the anti-cancer effects of isothiocyanates (ITCs) derived from cruciferous vegetables, which are widely cultivated and consumed in many regions worldwide. Specifically, we discuss the anti-cancer effects of four ITC compounds—allyl isothiocyanate, benzyl isothiocyanate, sulforaphane, and phenethyl isothiocyanate—in BC; the molecular mechanisms underlying their anti-cancer effects; current trends and future direction of ITC-based treatment strategies; and the carcinogenic potential of ITCs. We also discuss the advantages and limitations of each ITC in BC treatment, furthering the consideration of ITCs in treatment strategies and for improving the prognosis of patients with BC.