Benzyl isothiocyanate (BITC) triggers mitochondria-mediated apoptotic machinery in human cisplatin-resistant oral cancer CAR cells

Synergistic Action of Benzyl Isothiocyanate and Sorafenib in a Nanoparticle Delivery System for Enhanced Triple-Negative Breast Cancer Treatment

Triple-negative breast cancer (TNBC) presents a therapeutic challenge due to its complex pathology and limited treatment options. Addressing this challenge, our study focuses on the effectiveness of combination therapy, which has recently become a critical strategy in cancer treatment, improving therapeutic outcomes and combating drug resistance and metastasis. We explored a novel combination therapy employing Benzyl isothiocyanate (BITC) and Sorafenib (SOR) and their nanoformulation, aiming to enhance therapeutic outcomes against TNBC. Through a series of in vitro assays, we assessed the cytotoxic effects of BITC and SOR, both free and encapsulated. The BITC-SOR-loaded nanoparticles (NPs) were synthesized using an amphiphilic copolymer, which demonstrated a uniform spherical morphology and favorable size distribution. The encapsulation efficiencies, as well as the sustained release profiles at varied pH levels, were quantified, revealing distinct kinetics that were well-modeled by the Korsmeyer-Peppas equation. The NP delivery system showed a marked dose-dependent cytotoxicity towards TNBC cells, with an IC50 of 7.8 μM for MDA-MB-231 cells, indicating improved efficacy over free drugs, while exhibiting minimal toxicity toward normal breast cells. Furthermore, the NPs significantly inhibited cell migration and invasion in TNBC models, surpassing the effects of free drugs. These findings underscore the potential of BITC-SOR-NPs as a promising therapeutic approach for TNBC, offering targeted delivery while minimizing systemic toxicity.

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.

Bioactive phytocompounds for oral cancer prevention and treatment: A comprehensive and critical evaluation

The high incidence of oral cancer combined with excessive treatment cost underscores the need for novel oral cancer preventive and therapeutic options. The value of natural agents, including plant secondary metabolites (phytochemicals), in preventing carcinogenesis and representing expansive source of anticancer drugs have been established. While fragmentary research data are available on antioral cancer effects of phytochemicals, a comprehensive and critical evaluation of the potential of these agents for the prevention and intervention of human oral malignancies has not been conducted according to our knowledge. This study presents a complete and critical analysis of current preclinical and clinical results on the prevention and treatment of oral cancer using phytochemicals. Our in-depth analysis highlights anticancer effects of various phytochemicals, such as phenolics, terpenoids, alkaloids, and sulfur-containing compounds, against numerous oral cancer cells and/or in vivo oral cancer models by antiproliferative, proapoptotic, cell cycle-regulatory, antiinvasive, antiangiogenic, and antimetastatic effects. Bioactive phytochemicals exert their antineoplastic effects by modulating various signaling pathways, specifically involving the epidermal growth factor receptor, cytokine receptors, toll-like receptors, and tumor necrosis factor receptor and consequently alter the expression of downstream genes and proteins. Interestingly, phytochemicals demonstrate encouraging effects in clinical trials, such as reduction of oral lesion size, cell growth, pain score, and development of new lesions. While most phytochemicals displayed minimal toxicity, concerns with bioavailability may limit their clinical application. Future directions for research include more in-depth mechanistic in vivo studies, administration of phytochemicals using novel formulations, investigation of phytocompounds as adjuvants to conventional treatment, and randomized clinical trials.

Benzyl isothiocyanate attenuates activation of the NLRP3 inflammasome in Kupffer cells and improves diet-induced steatohepatitis

The NLRP3 inflammasome plays an important role in the pathogenesis of numerous inflammation-related diseases. Benzyl isothiocyanate (BITC) is rich in cruciferous vegetables and possesses potent antioxidant, anti-inflammatory, anti-cancer, and anti-obesogenic properties. In this study, we investigated the role of the NLRP3 inflammasome in the protection by BITC against steatohepatitis and insulin resistance. A mouse model of high-fat/cholesterol/cholic acid diet (HFCCD)-induced steatohepatitis, LPS/nigericin-stimulated primary Kupffer cells, and IL-1β treated primary hepatocytes were used. BITC attenuated LPS/nigericin-induced activation of the NLRP3 inflammasome by enhancing protein kinase A-dependent NLRP3 ubiquitination, which increased the degradation of NLRP3 and reduced IL-1β secretion in Kupffer cells. In hepatocytes, BITC pretreatment reversed the IL-1β-induced decrease in the phosphorylation of IR, AKT, and GSK3β in response to insulin. After 12 weeks of HFCCD feeding, increases in blood alanine aminotransferase (ALT) and glucose levels were ameliorated by BITC. Hepatic IL-1β production, macrophage infiltration, and collagen expression induced by HFCCD were also mitigated by BITC. BITC suppresses activation of the NLRP3 inflammasome in Kupffer cells by enhancing the PKA-dependent ubiquitination of NLRP3, which leads to suppression of IL-1β production and subsequently ameliorates hepatic inflammation and insulin resistance.

Carnosic acid attenuated cytochrome c release through the mitochondrial structural protein Mic60 by PINK1 in SH-SY5Y cells

Mitochondrial dysfunction has been implicated in Parkinson's disease. Mic60 is a critical component of mitochondrial crista remodeling and participates in maintaining mitochondrial structure and function. This study investigated whether the carnosic acid (CA) of rosemary protects the mitochondria of SH-SY5Y cells against the neurotoxicity of 6-hydroxydopamine (6-OHDA) by regulating Mic60. Our results showed that CA pretreatment reversed the reduction in the Mic60 and citrate synthase proteins, as well as the protein induction of PKA caused by 6-OHDA. Moreover, Mic60 and PINK1 siRNAs blocked the ability of CA to lessen the release of mitochondrial cytochrome c by 6-OHDA. As shown by immunoprecipitation assay, in 6-OHDA-treated cells, the interaction of Mic60 with its phosphorylated threonine residue was decreased, but the interaction with its phosphorylated serine residue was increased. PINK1 siRNA and forskolin, a PKA activator, reversed these interactions. Moreover, forskolin pretreatment prevented CA from rescuing the interaction of PINK1 and Mic60 and the reduction in cytochrome c release and mitophagy impairment in 6-OHDA-treated cells. In conclusion, CA prevents 6-OHDA-induced cytochrome c release by regulating Mic60 phosphorylation by PINK1 through a downregulation of PKA. The regulation of Mic60 by CA can be considered as a protective mechanism for the prevention of Parkinson's disease.

Encapsulation of Benzyl Isothiocyanate with β-Cyclodextrin Using Ultrasonication: Preparation, Characterization, and Antibacterial Assay

Benzyl isothiocyanate (BITC) is widely utilized in multiple biomedical fields, due to its significant antibacterial properties and low toxicity. However, poor water solubility and pungent odor has limited its application in the food industry. In this study, we first prepared inclusion complexes of BITC in GLU-β-CD and HP-β-CD using ultrasound, which is able to overcome the hindrance of poor water solubility and high volatility. Then, the BITC-β-CD inclusion complexes were characterized by using high-performance liquid chromatography (HPLC), nuclear magnetic resonance hydrogen spectra (¹H-NMR), infrared absorption spectra (IR), and differential scanning calorimetry (DSC) to confirm their stability. Further, the evaluation of antibacterial and antitumor effects of the BITC-β-CD inclusion complexes showed that they had great bactericidal activity against both Escherichia coli and Staphylococcus aureus cells, and also inhibited the growth of HepG2 cells in vitro. In addition, our results indicated that BITC-β-CD complexes were able to inhibit the growth of S. aureus in broccoli juice and extend the shelf life of broccoli juice, demonstrating the potential of β-cyclodextrin to improve the stability and controlled release of BITC. Taken together, our results show that BITC-β-CD complexes have good potential for application in the food industry.

Allyl-, Butyl- and Phenylethyl-Isothiocyanate Modulate Akt–mTOR and Cyclin–CDK Signaling in Gemcitabine- and Cisplatin-Resistant Bladder Cancer Cell Lines

Combined cisplatin–gemcitabine treatment causes rapid resistance development in patients with advanced urothelial carcinoma. The present study investigated the potential of the natural isothiocyanates (ITCs) allyl-isothiocyanate (AITC), butyl-isothiocyanate (BITC), and phenylethyl-isothiocyanate (PEITC) to suppress growth and proliferation of gemcitabine- and cisplatin-resistant bladder cancer cells lines. Sensitive and gemcitabine- and cisplatin-resistant RT112, T24, and TCCSUP cells were treated with the ITCs, and tumor cell growth, proliferation, and clone formation were evaluated. Apoptosis induction and cell cycle progression were investigated as well. The molecular mode of action was investigated by evaluating cell cycle-regulating proteins (cyclin-dependent kinases (CDKs) and cyclins A and B) and the mechanistic target of the rapamycin (mTOR)-AKT signaling pathway. The ITCs significantly inhibited growth, proliferation and clone formation of all tumor cell lines (sensitive and resistant). Cells were arrested in the G2/M phase, independent of the type of resistance. Alterations of both the CDK–cyclin axis and the Akt–mTOR signaling pathway were observed in AITC-treated T24 cells with minor effects on apoptosis induction. In contrast, AITC de-activated Akt–mTOR signaling and induced apoptosis in RT112 cells, with only minor effects on CDK expression. It is concluded that AITC, BITC, and PEITC exert tumor-suppressive properties on cisplatin- and gemcitabine-resistant bladder cancer cells, whereby the molecular action may differ among the cell lines. The integration of these ITCs into the gemcitabine-/cisplatin-based treatment regimen might optimize bladder cancer therapy.

Dietary Organosulfur-Containing Compounds and Their Health-Promotion Mechanisms

Dietary organosulfur-containing compounds (DOSCs) in fruits, vegetables, and edible mushrooms may hold the key to the health-promotion benefits of these foods. Yet their action mechanisms are not clear, partially due to their high reactivity, which leads to the formation of complex compounds during postharvest processing. Among postharvest processing methods, thermal treatment is the most common way to process these edible plants rich in DOSCs, which undergo complex degradation pathways with the generation of numerous derivatives over a short time. At low temperatures, DOSCs are biotransformed slowly during fermentation to different metabolites (e.g., thiols, sulfides, peptides), whose distinctive biological activity remains largely unexplored. In this review, we discuss the bioavailability of DOSCs in human digestion before illustrating their potential mechanisms for health promotion related to cardiovascular health, cancer chemoprevention, and anti-inflammatory and antimicrobial activities. In particular, it is interesting that different DOSCs react with glutathione or cysteine, leading to the slow release of hydrogen sulfide (H2S), which has broad bioactivity in chronic disease prevention. In addition, DOSCs may interact with protein thiol groups of different protein targets of importance related to inflammation and phase II enzyme upregulation, among other action pathways critical for health promotion.

Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Effect of Quercetin on Injury to Indomethacin-Treated Human Embryonic Kidney 293 Cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammation and pain and even to prevent the progression of cardiovascular disease. They have become widely used because of their effectiveness, especially among athletes performing high-intensity training. Indomethacin is used for pain management in sports medicine and is highly effective and versatile. However, several clinical studies have reported that indomethacin induces acute renal damage. In the present study, we determined that indomethacin reduced human embryonic kidney 293 (HEK293) cell viability in a concentration-dependent manner by triggering apoptosis. In addition, we demonstrated the effect of quercetin on indomethacin-treated HEK293 cells by inactivating the caspase-3 and caspase-9 signals. Furthermore, quercetin reduced ROS production and increased mitochondrial membrane potential (ΔΨm) in indomethacin-treated HEK293 cells. Our results indicate that quercetin can interrupt the activated caspase and mitochondrial pathway induced by indomethacin in HEK293 cells and affect apoptotic mRNA expression. Quercetin can protect against indomethacin-induced HEK293 cell apoptosis by regulating abnormal ΔΨm and apoptotic mRNA expression.

Perturbed ER homeostasis by IGF-IIRα promotes cardiac damage under stresses

The heart is a very dynamic pumping organ working perpetually to maintain a constant blood supply to the whole body to transport oxygen and nutrients. Unfortunately, it is also subjected to various stresses based on physiological or pathological conditions, particularly more vulnerable to damages caused by oxidative stress. In this study, we investigate the molecular mechanism and contribution of IGF-IIRα in endoplasmic reticulum stress induction in the heart under doxorubicin-induced cardiotoxicity. Using in vitro H9c2 cells, in vivo transgenic rat cardiac tissues, siRNAs against CHOP, chemical ER chaperone PBA, and western blot experiments, we found that IGF-IIRα overexpression enhanced ER stress markers ATF4, ATF6, IRE1α, and PERK which were further aggravated by DOX treatment. This was accompanied by a significant perturbation in stress-associated MAPKs such as p38 and JNK. Interestingly, PARKIN, a stress responsive cellular protective mediator was significantly downregulated by IGF-IIRα concomitant with decreased expression of ER chaperone GRP78. Furthermore, ER stress-associated pro-apoptotic factor CHOP was increased considerably in a dose-dependent manner followed by elevated c-caspase-12 and c-caspase-3 activities. Conversely, treatment of H9c2 cells with chemical ER chaperone PBA or siRNA against CHOP abolished the IGF-IIRα-induced ER stress responses. Altogether, these findings suggested that IGF-IIRα contributes to ER stress induction and inhibits cellular stress coping proteins while increasing pro-apoptotic factors feeding into a cardio myocyte damage program that eventually paves the way to heart failure.

Ouabain Induces DNA Damage in Human Osteosarcoma U-2 OS Cells and Alters the Expression of DNA Damage and DNA Repair-associated Proteins

BACKGROUND/AIM

Ouabain, isolated from natural plants, exhibits anticancer activities; however, no report has presented its mechanism of DNA damage induction in human osteosarcoma cancer cells in vitro. The aim of this study was to investigate whether ouabain induces DNA damage and repair, accompanied with molecular pathways in human osteosarcoma cancer U-2 OS cells in vitro.

MATERIALS AND METHODS

The percentage of viable cell number was measured by flow cytometric assay; DNA damage was assayed by DAPI staining, comet assay, and agarose gel electrophoresis. DNA damage and repair associated protein expressions were assayed by western blotting assays.

RESULTS

Ouabain reduced total cell viability, induced chromatin condensation, DNA fragmentation, and DNA damage in U-2 OS cells. Ouabain increased p-ATM^Ser1981, p-ATR^Ser428, and p53 at 2.5-10 μM, increased p-p53^Ser15 at 10 μM; however, it decreased p-MDM2^Ser166 at 2.5-10 μM. Ouabain increased p-H2A.X^Ser139, MDC-1, and PARP at 2.5-10 μM and BRCA1 at 5-10 μM; however, it decreased DNA-PK and MGMT at 2.5-10 μM in U-2 OS cells at 48 h treatment. Ouabain promoted expression and nuclear translocation of p-H2A.X^Ser139 in U-2 OS cells and this was confirmed by confocal laser microscopy.

CONCLUSION

Ouabain reduced total viable cell number through triggering DNA damage and altering the protein expression of DNA damage and repair system in U-2 OS cells in vitro.

LINC00662 Promotes Oral Squamous Cell Carcinoma Cell Growth and Metastasis through miR-144-3p/EZH2 Axis

PURPOSE

Long non-coding RNA (lncRNA) is identified as an important regulator involved in oral squamous cell carcinoma (OSCC) tumorigenesis. This study aimed to investigate the functional role and underlying mechanism of LINC00662 in OSCC.

MATERIALS AND METHODS

The expression levels of LINC00662, miR-144-3p, and enhancer of zeste homolog 2 (EZH2) mRNA were quantified with quantitative real-time polymerase chain reaction in OSCC tissues and cell lines. Western blot analysis was used to assay the expression levels of E-cadherin, Vimentin, and EZH2. Cell proliferation, migration, and invasion were monitored by cell counting kit-8 and Transwell assays. Dual-luciferase reporter and RNA immunoprecipitation assays were employed to verify the regulatory relationship between LINC00662 and miR-144-3p.

RESULTS

The expression of LINC00662, positively associated with the increased TNM stage and lymph node metastasis of the patients, was up-regulated in OSCC tissues and cells. The overexpression of LINC00662 facilitated the proliferation, migration, and invasion of OSCC cells. MiR-144-3p could bind to LINC00662, and the promoting effect of LINC00662 overexpression was counteracted by miR-144-3p mimic. Moreover, EZH2 expression was negatively regulated by miR-144-3p and positively regulated by LINC00662. The silencing of EZH2 attenuated the promoting effects of overexpression of LINC00662 on cell proliferation, migration, invasion, and epithelial-mesenchymal transition.

CONCLUSION

LINC00662, as an oncogenic lncRNA of OSCC, accelerates OSCC progression by repressing miR-144-3p expression and increasing EZH2 expression.

Anticancer activities of dietary benzyl isothiocyanate: A comprehensive review

Benzyl isothiocyanate (BITC) is one of the common isothiocyanates found in cruciferous vegetables such as broccoli, cabbage or watercress. Preclinical studies report of its effectiveness in the prevention and treatment against several cancers. This review aims to report and discuss findings on anticancer activities of BITC and its modes of action against 14 types of cancer. A literature search was conducted using the keywords "BITC" and "anticancer" from PubMed, Google Scholar and CINAHL Plus to obtain relevant research articles. This review highlights the anticancer efficacy of BITC through modulation of various signaling pathways involved in apoptosis, cell proliferation, cell cycle arrest, metastasis, angiogenesis, autophagy and the effects of BITC in combination with other drugs. With the available pharmacology evidence, we conclude that further studies are needed to validate its effectiveness in humans for further development and translation into prophylaxis or therapy by promoting optimal therapeutic effects and minimizing toxicity in cancer treatment.

Benzyl Isothiocyanate Induces Apoptosis and Inhibits Tumor Growth in Canine Mammary Carcinoma via Downregulation of the Cyclin B1/Cdk1 Pathway

Background: Canine mammary carcinoma is common in female dogs, and its poor prognosis remains a serious clinical challenge, especially in developing countries. Benzyl isothiocyanate (BITC) has attracted great interest because of its inhibitory effect against tumor activity. However, its effect and the underlying mechanisms of action in canine mammary cancer are not well-understood. Here, we show that BITC suppresses mammary tumor growth, both in vivo and in vitro, and reveal some of the potential mechanisms involved.

Methods: The effect of BITC on canine mammary cancer was evaluated on CIPp and CMT-7364, canine mammary carcinoma lines. The cell lines were treated with BITC and then subjected to wound healing and invasion assays. Cell cycles and apoptosis were measured using flow cytometry; TUNEL assay; immunohistochemistry (IHC) for caspase 3, caspase 9, and cyclin D1; hematoxylin and eosin (H&E) staining; and/or quantitative polymerase chain reaction (qPCR).

Results: BITC showed a strong suppressive effect in both CIPp and CMT-7364 cells by inhibiting cell growth in vitro; these effects were both dose- and time-dependent. BITC also inhibited migration and invasion of CIPp and CMT-7364 cells. BITC induced G2 arrest and apoptosis, decreasing tumor growth in nude mice by downregulation of cyclin B1 and Cdk1 expression.

Conclusion: BITC suppressed both invasion and migration of CIPp and CMT-7364 cells and induced apoptosis. BITC inhibited canine mammary tumor growth by suppressing cyclinB1 and Cdk1 expression in nude mice.

Natural Agents Targeting Mitochondria in Cancer

Mitochondria are the key energy provider to highly proliferating cancer cells, and are subsequently considered one of the critical targets in cancer therapeutics. Several compounds have been studied for their mitochondria-targeting ability in cancer cells. These studies’ outcomes have led to the invention of “mitocans”, a category of drug known to precisely target the cancer cells’ mitochondria. Based upon their mode of action, mitocans have been divided into eight classes. To date, different synthetic compounds have been suggested to be potential mitocans, but unfortunately, they are observed to exert adverse effects. Many studies have been published justifying the medicinal significance of large numbers of natural agents for their mitochondria-targeting ability and anticancer activities with minimal or no side effects. However, these natural agents have never been critically analyzed for their mitochondria-targeting activity. This review aims to evaluate the various natural agents affecting mitochondria and categorize them in different classes. Henceforth, our study may further support the potential mitocan behavior of various natural agents and highlight their significance in formulating novel potential anticancer therapeutics.

Characterisation of naturally occurring isothiocyanates as glutathione reductase inhibitors

Glutathione reductase (GR), an essential antioxidant enzyme against oxidative stress, has become an attractive drug target for the development of anticancer and antimalarial drugs. In this regard, we evaluated the naturally occurring isothiocyanates as promising GR inhibitors and elucidated the mechanism of action. It was found that benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC) inhibited yeast GR (yGR) and human GR (hGR) in a time- and concentration-dependent manner. The K_i and k_inact of BITC against yGR were determined to be 259.87 µM and 0.0266 min⁻¹, respectively. The GR inhibition occurred only in the presence of NADPH and persisted after extensive dialysis. The tandem mass spectrometric analysis revealed that Cys⁶¹ rather than Cys⁶⁶ at the active site of yGR was mono-benzyl thiocarbamoylated by BITC. Inhibition of intracellular GR by BITC and PEITC in cultured cancer cells was also observed. BITC and PEITC were evaluated as competitive and irreversible inhibitors of GR.

Combinational treatment of 5-fluorouracil and casticin induces apoptosis in mouse leukemia WEHI-3 cells in vitro

Leukemia is one of the major diseases causing cancer-related deaths in the young population, and its cure rate is unsatisfying with side effects on patients. Fluorouracil (5-FU) is currently used as an anticancer drug for leukemia patients. Casticin, a natural polymethoxyflavone, exerts anticancer activity against many human cancer cell lines in vitro, but no other reports show 5-FU combined with casticin increased the mouse leukemia cell apoptosis in vitro. Herein, the antileukemia activity of 5-FU combined with casticin in WEHI-3 mouse leukemia cells was investigated in vitro. Treatment of two-drug combination had a higher decrease in cell viability and a higher increase in apoptotic cell death, the level of DNA condensation, and the length of comet tail than that of 5-FU or casticin treatment alone in WEHI-3 cells. In addition, the two-drug combination has a greater production rate of reactive oxygen species but a lower level of Ca²⁺ release and mitochondrial membrane potential (ΔΨ_m ) than that of 5-FU alone. Combined drugs also induced higher caspase-3 and caspase-8 activities than that of casticin alone and higher caspase-9 activity than that of 5-FU or casticin alone at 48 hours treatment. Furthermore, 5-FU combined with casticin has a higher expression of Cu/Zn superoxide dismutase (SOD [Cu/Zn]) and lower catalase than that of 5-FU or casticin treatment alone. The combined treatment has higher levels of Bax, Endo G, and cytochrome C of proapoptotic proteins than that of casticin alone and induced lower levels of B-cell lymphoma 2 (BCL-2) and BCL-X of antiapoptotic proteins than that of 5-FU or casticin only. Furthermore, the combined treatment had a higher expression of cleaved poly (ADP-ribose) polymerase (PARP) than that of casticin only. Based on these findings, we may suggest that 5-FU combined with casticin treatment increased apoptotic cell death in WEHI-3 mouse leukemia cells that may undergo mitochondria and caspases signaling pathways in vitro.

Sensitivity of allyl isothiocyanate to induce apoptosis via ER stress and the mitochondrial pathway upon ROS production in colorectal adenocarcinoma cells

Allyl isothiocyanate (AITC), a bioactive phytochemical compound that is a constituent of dietary cruciferous vegetables, possesses promising chemopreventive and anticancer effects. However, reports of AITC exerting antitumor effects on apoptosis induction of colorectal cancer (CRC) cells in vitro are not well elucidated. The present study focused on the functional mechanism of the endoplasmic reticulum (ER) stress-based apoptotic machinery induced by AITC in human colorectal cancer HT-29 cells. Our results indicated that AITC decreased cell growth and number, reduced viability, and facilitated morphological changes of apoptotic cell death. DNA analysis by flow cytometry showed G2/M phase arrest, and alterations in the modulated protein levels caused by AITC were detected via western blot analysis. AITC also triggered vital intrinsic apoptotic factors (caspase-9/caspase-3 activity), disrupted mitochondrial membrane potential, and stimulated mitochondrial-related apoptotic molecules (e.g., cytochrome c, apoptotic protease activating factor 1, apoptosis-inducing factor, and endonuclease G). Additionally, AITC prompted induced cytosolic Ca²⁺ release and Ca²⁺-dependent ER stress-related signals, such as calpain 1, activating transcription factor 6α, glucose-regulated proteins 78 and 94, growth arrest- and DNA damage-inducible protein 153 (GADD153), and caspase-4. The level of reactive oxygen species (ROS) production was found to induce the hallmark of ER stress GADD153, proapoptotic marker caspase-3, and calpain activity after AITC treatment. Our findings showed for the first time that AITC induced G2/M phase arrest and apoptotic death via ROS-based ER stress and the intrinsic pathway (mitochondrial-dependent) in HT-29 cells. Overall, AITC may exert an epigenetic effect and is a potential bioactive compound for CRC treatment.

Casticin Induces DNA Damage and Affects DNA Repair Associated Protein Expression in Human Lung Cancer A549 Cells (Running Title: Casticin Induces DNA Damage in Lung Cancer Cells)

Casticin was obtained from natural plants, and it has been shown to exert biological functions; however, no report concerns the induction of DNA damage and repair in human lung cancer cells. The objective of this study was to investigate the effects and molecular mechanism of casticin on DNA damage and repair in human lung cancer A549 cells. Cell viability was determined by flow cytometric assay. The DNA damage was evaluated by 4',6-diamidino-2-phenylindole (DAPI) staining and electrophoresis which included comet assay and DNA gel electrophoresis. The protein levels associated with DNA damage and repair were analyzed by western blotting. The expression and translocation of p-H2A.X were observed by confocal laser microscopy. Casticin reduced total viable cell number and induced DNA condensation, fragmentation, and damage in A549 cells. Furthermore, casticin increased p-ATM at 6 h and increased p-ATR and BRCA1 at 6-24 h treatment but decreased p-ATM at 24-48 h, as well as decreased p-ATR and BRCA1 at 48 h. Furthermore, casticin decreased p-p53 at 6-24 h but increased at 48 h. Casticin increased p-H2A.X and MDC1 at 6-48 h treatment. In addition, casticin increased PARP (cleavage) at 6, 24, and 48 h treatment, DNA-PKcs and MGMT at 48 h in A549 cells. Casticin induced the expressions and nuclear translocation of p-H2AX in A549 cells by confocal laser microscopy. Casticin reduced cell number through DNA damage and condensation in human lung cancer A549 cells.

Protein Kinase B Inactivation Is Associated with Magnolol-Enhanced Therapeutic Efficacy of Sorafenib in Hepatocellular Carcinoma In Vitro and In Vivo

Although sorafenib, an oral multikinase inhibitor, was approved as a treatment drug of advance hepatocellular carcinoma (HCC), treatment efficacy still requires improvement. Searching for the adjuvant reagent for enhancing sorafenib efficacy remains as a critical issue. Sorafenib has been proved to suppress extracellular signal-regulated kinases (ERK) in HCC; however, protein kinase B (AKT) was not affected by it. Targeting AKT in combination with sorafenib could be an important breakthrough point of HCC treatment. Many herbal compounds and composite formulas have been shown to enhance anti-HCC activity of sorafenib. Magnolol is a bioactive compound extracted from the bark of the Magnolia officinalis and has been shown to induce apoptosis and inhibit cell invasion in HCC in vitro. However, whether magnolol sensitizes HCC to sorafenib is ambiguous. In this study, we indicated that magnolol significantly enhanced sorafenib-diminished tumor cell growth, expression of anti-apoptotic proteins, and migration/invasion ability compared to sorafenib alone. Magnolol significantly boosted sorafenib-induced extrinsic/intrinsic dependent apoptosis pathways in HCC. Notably sorafenib could not reduce protein level of AKT (Ser473), but expression of AKT (Ser473) was significantly decreased by magnolol or magnolol combined with sorafenib. LY294002 as specific AKT inhibitor was used to confirm that AKT inactivation may promote anticancer effect of sorafenib. Taken together, AKT inhibition is associated with magnolol-enhanced the therapeutic effect of sorafenib in HCC. We suggested magnolol as the potential adjuvant which may enhance therapeutic benefits of sorafenib in patients with HCC.

Combinational treatment of all-trans retinoic acid (ATRA) and bisdemethoxycurcumin (BDMC)-induced apoptosis in liver cancer Hep3B cells

The effects of two-drug combination, all-trans retinoic acid (ATRA) and bisdemethoxycurcumin (BDMC), on apoptosis induction of liver cancer cells were investigated in human liver Hep 3B cells. Two-drug combination caused a more effective decrease in cell viability and in induction of S phase arrest, DNA damage, and cell apoptosis than that of ATRA or BDMC only. Also, the two-drug combination caused more cells to undergo significantly increased ROS productions when compared to that of ATRA or BDMC only. Results of Western blotting demonstrated that two-drug combination increased expressions of Fas, pro-apoptotic proteins, and active form of caspase-3 and -9, but decreased that of anti-apoptotic proteins and XIAP than that of ATRA or BDMC only in Hep 3B cells. In conclusion, ATRA combined with BDMC enhance cell apoptosis and associated protein expression in Hep 3B cells. PRACTICAL APPLICATIONS: Bisdemethoxycurcumin (BDMC) derived from natural plants, turmeric (Curcuma longa), which had been used for Asia food for thousands of years. All-trans retinoid acid (ATRA) is currently used as a primary treatment for patients with acute promyelocytic leukemia. In previous study, ATRA and BDMC were reported to have anti-inflammatory and anticancer effects. Our results showed that treatment of ATRA combined with BDMC showed more effectively apoptosis than that of ATRA or BDMC only in Hep 3B cells. The findings also provided possible pathways concerning the induction of liver cancer cell apoptosis. We conclude that ATRA combined with BDMC may be potent anticancer agents or adjuvants for liver cancer therapy in the future.

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.

Insulin-like growth factor II receptor-α is a novel stress-inducible contributor to cardiac damage underpinning doxorubicin-induced oxidative stress and perturbed mitochondrial autophagy

Doxorubicin (DOX) is an anthracycline antibiotic commonly employed for the treatment of various cancers. However, its therapeutic uses are hampered by side effects associated with cumulative doses during the course of treatment. Whereas deregulation of autophagy in the myocardium has been involved in a variety of cardiovascular diseases, the role of autophagy in DOX-induced cardiomyopathy remains debated. Our earlier studies have shown that DOX treatment in a rat animal model leads to increased expression of the novel stress-inducible protein insulin-like growth factor II receptor-α (IGF-IIRα) in cardiac tissues, which exacerbated the cardiac injury by enhancing oxidative stress and p53-mediated mitochondria-dependent cardiac apoptosis. Through this study, we investigated the contribution of IGF-IIRα to dysregulation of autophagy in heart using both in vitro H9c2 cells (DOX treated, 1 µM) and in vivo transgenic rat models (DOX treated, 5 mg/kg ip for 6 wk) overexpressing IGF-IIRα specifically in the heart. We found that IGF-IIRα primarily localized to mitochondria, causing increased mitochondrial oxidative stress that was severely aggravated by DOX treatment. This was accompanied by a significant perturbation in mitochondrial membrane potential and increased leakage of cytochrome c, causing increased cleaved caspase-3 activity. There were significant alterations in phosphorylated AMP-activated protein kinase (p-AMPK), phosphorylated Unc-51 like kinase-1 (p-ULK1), PARKIN, PTEN-induced kinase 1 (PINK1), microtubule-associated protein 1 light chain 3 (LC3), and p62 proteins, which were more severely disrupted under the combined effect of IGF-IIRα overexpression plus DOX. Finally, LysoTracker Red staining showed that IGF-IIRα overexpression causes lysosomal impairment, which was rescued by rapamycin treatment. Taken together, we found that IGF-IIRα leads to mitochondrial oxidative stress, decreased antioxidant levels, disrupted mitochondrial membrane potential, and perturbed mitochondrial autophagy contributing to DOX-induced cardiomyopathy.

Protein Kinase B and Extracellular Signal-Regulated Kinase Inactivation is Associated with Regorafenib-Induced Inhibition of Osteosarcoma Progression In Vitro and In Vivo

Osteosarcoma is the most common type of bone cancer. Multimodality treatment involving chemotherapy, radiotherapy and surgery is not effective enough to control osteosarcoma. Regorafenib, the oral multi-kinase inhibitor, has been shown to have positive efficacy on disease progression delay in chemotherapy resistant osteosarcoma patients. However anti-cancer effect and mechanism of regorafenib in osteosarcoma is ambiguous. Thus, the aim of this study is to investigate the efficacy and molecular mechanism of regorafenib on osteosarcoma in vitro and in vivo. Human osteosarcomas U-2 OS or MG-63 were treated with regorafenib, miltefosine (protein kinase B (AKT) inhibitor), or PD98059 (mitogen-activated protein/extracellular signal-regulated kinase (MEK) pathway inhibitor) for 24 or 48 h. Cell viability, apoptotic signaling transduction, tumor invasion, expression of tumor progression-associated proteins and tumor growth after regorafenib treatment were assayed by MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, transwell assay, Western blotting assay and in vivo animal experiment, respectively. In these studies, we also indicated that regorafenib suppressed cell growth by prompting apoptosis of osteosarcoma cells, which is mediated through inactivation of ERK and AKT signaling pathways. After regorafenib treatment, downregulation of related genes in invasion (vascular endothelial growth factor (VEGF) and matrix metallopeptidase 9 (MMP-9)), proliferation (CyclinD1) and anti-apoptosis (X-linked inhibitor of apoptosis protein (XIAP), myeloid cell leukemia-1 (MCL-1), and cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein (C-FLIP)) were found. Moreover, upregulation of caspase-3 and caspase-8 cleavage were also observed. In sum, we suggest that regorafenib has potential to suppress osteosarcoma progression via inactivation of AKT and ERK mediated signaling pathway.

High-density lipoprotein ameliorates palmitic acid-induced lipotoxicity and oxidative dysfunction in H9c2 cardiomyoblast cells via ROS suppression

Background

High levels circulating saturated fatty acids are associated with diabetes, obesity and hyperlipidemia. In heart, the accumulation of saturated fatty acids has been determined to play a role in the development of heart failure and diabetic cardiomyopathy. High-density lipoprotein (HDL) has been reported to possess key atheroprotective biological properties, including cellular cholesterol efflux capacity, anti-oxidative and anti-inflammatory activities. However, the underlying mechanisms are still largely unknown. Therefore, the aim of the present study is to test whether HDL could protect palmitic acid (PA)-induced cardiomyocyte injury and explore the possible mechanisms.

Results

H9c2 cells were pretreated with HDL (50–100 μg/ml) for 2 h followed by PA (0.5 mM) for indicated time period. Our results showed that HDL inhibited PA-induced cell death in a dose-dependent manner. Moreover, HDL rescued PA-induced ROS generation and the phosphorylation of JNK which in turn activated NF-κB-mediated inflammatory proteins expressions. We also found that PA impaired the balance of BCL₂ family proteins, destabilized mitochondrial membrane potential, and triggered subsequent cytochrome c release into the cytosol and activation of caspase 3. These detrimental effects were ameliorated by HDL treatment.

Conclusion

PA-induced ROS accumulation and results in cardiomyocyte apoptosis and inflammation. However, HDL attenuated PA-induced lipotoxicity and oxidative dysfunction via ROS suppression. These results may provide insight into a possible molecular mechanism underlying HDL suppression of the free fatty acid-induced cardiomyocyte apoptosis.

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.

Cardamonin Induces Cell Cycle Arrest, Apoptosis and Alters Apoptosis Associated Gene Expression in WEHI-3 Mouse Leukemia Cells

Cardamonin, the chalcone class, is one of the natural components from the spicy herbaceous plant (Alpinia conchigera Griff) and has anticancer activities in many human cancer cell lines. There is, however, no information to show that cardamonin induces cell apoptosis and alters apoptosis associated gene expressions in mouse leukemia cells. Thus, we investigated the effects of cardamonin on the apoptotic cell death and associated gene expression in mouse leukemia WEHI-3 cells in vitro. Results indicated that cardamonin decreased total viable cell number via induced cell morphological changes and apoptotic cell death in WEHI-3 cells that were assay by contrast-phase microscopy and flow cytometry examinations, respectively. The flow cytometry assay indicated that cardamonin increased reactive oxygen species (ROS) and Ca[Formula: see text] production, decreased the levels of mitochondrial membrane potential ([Formula: see text] and increased caspase-3, -8 and -9 activities in WEHI-3 cells. Western blotting was performed to analyze expression of relevant pro- and anti-apoptotic proteins and results showed that cardamonin decreased anti-apoptotic protein of Bcl-2 but increased pro-apoptotic protein of Bax in WEHI-3 cells. Furthermore, cardamonin increased cytochrome c, AIF and Endo G release, increased GRP78, caspase-12 that were associated with ER stress and increased Fas, Fas-Ligand and FADD expression. Furthermore, cardamonin increased the gene expressions of DAP (death-associated protein), TMBIM4 transmembrane (BAX inhibitor motif containing 4), ATG5 (autophagy related 5) but decreased the gene expression of DDIT3 (DNA-damage inducible transcript 3), DDIT4 (DNA-damage-inducible transcript 4), BAG6 (BCL2-associated athanogene 6), BCL2L13 [BCL2-like 13 (apoptosis facilitator)] and BRAT1 (BRCA1-associated ATM activator 1) that are associated with apoptosis pathways. Based on those findings, we may suggest cardamonin induced apoptotic cell death through Fas and Fas-Ligand-, caspase- and mitochondria-dependently pathways and also affects the apoptotic gene expression in WEHI-3 cells in vitro.

Association of Resistin Gene Polymorphisms with Oral Squamous Cell Carcinoma Progression and Development

Oral squamous cell carcinoma (OSCC) accounts for over 90% of malignant neoplasms of the mouth. In Taiwan, OSCC is the fourth most common male cancer and the fourth leading cause of male cancer death. Resistin (RETN) is an adipokine that is associated with obesity, inflammation, and various cancers. Here, we examine the association between four single nucleotide polymorphisms (SNPs) of the RETN gene (rs3745367, rs7408174, rs1862513, and rs3219175) and OSCC susceptibility as well as clinical outcomes in 935 patients with OSCC and in 1200 cancer-free healthy controls. We found that, in 1465 smokers, RETN polymorphisms carriers with the betel-nut chewing habit had a 6.708–10.882-fold greater risk of having OSCC compared to RETN wild-type carriers without the betel-nut chewing habit. Patients with OSCC who had A/A homozygous of RETN rs3219175 polymorphism showed a high risk for an advanced tumor size (> T2), compared to those patients with G/G homozygotes. In addition, A/T/G/G haplotype significantly increased the risks for OSCC by 1.376-fold. This study is the first to examine the risk factors associated with RETN SNPs in OSCC progression and development in Taiwan.