Ochratoxin A causes cell cycle arrest in G1 and G1/S phases through p53 in HK-2 cells

Aloperine Suppresses Cancer Progression by Interacting with VPS4A to Inhibit Autophagosome-lysosome Fusion in NSCLC

Aloperine (ALO), a quinolizidine-type alkaloid isolated from a natural Chinese herb, has shown promising antitumor effects. Nevertheless, its common mechanism of action and specific target remain elusive. Here, it is demonstrated that ALO inhibits the proliferation and migration of non-small cell lung cancer cell lines in vitro and the tumor development in several mouse tumor models in vivo. Mechanistically, ALO inhibits the fusion of autophagosomes with lysosomes and the autophagic flux, leading to the accumulation of sequestosome-1 (SQSTM1) and production of reactive oxygen species (ROS), thereby inducing tumor cell apoptosis and preventing tumor growth. Knockdown of SQSTM1 in cells inhibits ROS production and reverses ALO-induced cell apoptosis. Furthermore, VPS4A is identified as a direct target of ALO, and the amino acids F153 and D263 of VPS4A are confirmed as the binding sites for ALO. Knockout of VPS4A in H1299 cells demonstrates a similar biological effect as ALO treatment. Additionally, ALO enhances the efficacy of the anti-PD-L1/TGF-β bispecific antibody in inhibiting LLC-derived subcutaneous tumor models. Thus, ALO is first identified as a novel late-stage autophagy inhibitor that triggers tumor cell death by targeting VPS4A.

Involvement of multiple epigenetic mechanisms by altered DNA methylation from the early stage of renal carcinogenesis before proliferative lesion formation upon repeated administration of ochratoxin A

Ochratoxin A (OTA) is a rat renal carcinogen that induces karyomegaly and micronuclei in proximal tubular epithelial cells (PTECs). We previously performed comprehensive gene profiling of alterations in promoter-region methylation and gene expression in PTECs of rats treated with OTA for 13 weeks. The OTA-specific gene profile was obtained by excluding genes showing expression changes similar to those upon treatment with 3-chloro-1,2-propanediol, a renal carcinogen not inducing karyomegaly. In this study, we validated the candidate genes using methylated DNA enrichment PCR and real-time RT-PCR, and identified Gen1, Anxa3, Cdkn1a, and Osm as genes showing OTA-specific epigenetic changes. These genes and related molecules were subjected to gene expression and immunohistochemical analyses in the PTECs of rats treated with OTA, other renal carcinogens, or non-carcinogenic renal toxicants for 4 or 13 weeks. Cdkn1a upregulation and increase of p21WAF1/CIP1+ karyomegalic PTECs were observed with OTA, matching the findings associated with micronucleus-inducing carcinogens. This suggested that the increase of p21WAF1/CIP1+ karyomegalic PTECs is linked to micronucleus formation, which in turn accelerates chromosomal instability. The upregulation of Cdkn1a-related genes with OTA suggests the acquisition of a senescence-associated secretory phenotype, which promotes the establishment of a carcinogenic environment. Meanwhile, OTA specifically caused a decrease of GEN1+ PTECs reflecting Gen1 downregulation and an increase of ANXA3+ PTECs reflecting Anxa3 upregulation, as well as Osm upregulation. OTA may efficiently disrupt pathways for repairing the DNA double-strand breaks that it itself causes, via Gen1 downregulation, and enhance cell proliferation through the upregulation of Anxa3 and Osm. This may exacerbate the chromosomal instability from the early stage of OTA-induced renal carcinogenesis before proliferative lesions form. OTA may cause renal carcinogenesis involving multiple epigenetic mechanisms.

Grape pomace as a novel functional ingredient: Mitigating ochratoxin A bioaccessibility and unraveling cytoprotective mechanisms in vitro

Mycotoxins, secondary metabolites produced by molds, pose significant health risk through contamination of globally consumed cereals. Ochratoxin A (OTA), a prevalent mycotoxin in cereals, is associated with various health hazards, including immunotoxicity. This study explores the bioaccessibility of OTA in bread and its impact on the gastrointestinal barrier. A focus is placed on grape pomace (GP), a by-product of the wine industry, as a potential mitigator of OTA toxicity. Results demonstrate that GP reduces OTA bioaccessibility in the human gastrointestinal system from 94% to 81% at intestinal level, showing promise in limiting the absorption of the harmful toxin. Additionally, GP exhibits cytoprotective effects, enhancing cell viability and mitigating OTA-induced toxicity in both Caco-2 and Jurkat T cells. In view of the above, to understand the mechanisms by which OTA exhibits its toxic effects, flow cytometry was chosen as the main technique for the analysis of cell cycle, reactive oxygen species levels and mitochondrial parameters. Cytofluorimetric evaluation indicates GP's potential in limiting OTA-induced damage at cellular level. The study suggests that GP could serve as functional ingredient to reduce mycotoxin bioaccessibility and toxicity in cereal-based foods, offering a novel and promising approach to enhance food safety and protect public health. The finding highlights the potential of utilizing grape pomace in food formulations to mitigate mycotoxin contamination, providing a valuable contribution to the ongoing efforts to ensure the safety of globally consumed cereal products.

Unveiling the emerging role of curcumin to alleviate ochratoxin A-induced muscle toxicity in grass carp (Ctenopharyngodon idella): in vitro and in vivo studies

BACKGROUND

Ochratoxin A (OTA), a globally abundant and extremely hazardous pollutant, is a significant source of contamination in aquafeeds and is responsible for severe food pollution. The developmental toxicity of OTA and the potential relieving strategy of natural products remain unclear. This study screened the substance curcumin (Cur), which had the best effect in alleviating OTA inhibition of myoblast proliferation, from 96 natural products and investigated its effect and mechanism in reducing OTA myotoxicity in vivo and in vitro.

METHODS

A total of 720 healthy juvenile grass carp, with an initial average body weight of 11.06 ± 0.05 g, were randomly assigned into 4 groups: the control group (without OTA and Cur), 1.2 mg/kg OTA group, 400 mg/kg Cur group, and 1.2 mg/kg OTA + 400 mg/kg Cur group. Each treatment consisted of 3 replicates (180 fish) for 60 d.

RESULTS

Firstly, we cultured, purified, and identified myoblasts using the tissue block culture method. Through preliminary screening and re-screening of 96 substances, we examined cell proliferation-related indicators such as cell viability and ultimately found that Cur had the best effect. Secondly, Cur could alleviate OTA-inhibited myoblast differentiation and myofibrillar development-related proteins (MyoG and MYHC) in vivo and in vitro and improve the growth performance of grass carp. Then, Cur could also promote the expression of OTA-inhibited protein synthesis-related proteins (S6K1 and TOR), which was related to the activation of the AKT/TOR signaling pathway. Finally, Cur could downregulate the expression of OTA-enhanced protein degradation-related genes (murf1, foxo3a, and ub), which was related to the inhibition of the FoxO3a signaling pathway.

CONCLUSIONS

In summary, our data demonstrated the effectiveness of Cur in alleviating OTA myotoxicity in vivo and in vitro. This study confirms the rapidity, feasibility, and effectiveness of establishing a natural product screening method targeting myoblasts to alleviate fungal toxin toxicity.

Does Boric Acid Inhibit Cell Proliferation on MCF-7 and MDA-MB-231 Cells in Monolayer and Spheroid Cultures by Using Apoptosis Pathways?

Most breast cancers originate in the lobules or ducts of the breast. Breast cancer as the second main cause of death among women in the world is the most common kind of cancer in women. Studies have been conducted to find the optimal treatment for breast cancer. Moreover, the therapeutic effects of different drugs and substances on this disease have been intensively researched. Boric acid accounts for 96% of the boron content in body fluids, and its derivatives are absorbed by the human body. It is assumed to be represented as (B(OH)2). Experimental studies have shown a reduction of cell proliferation and stimulation of apoptosis in some melanoma, prostate, and colon cancer cell lines through boric acid. The aim of this study was to investigate if boric acid could be used for treating breast cancer. The impacts of boric acid on the human breast carcinoma cell lines MCF-7 and MDA-MB-231 were studied with TUNEL, BrdU, caspase-3, and endo-G immunohistochemical studies in 3D and 2D culture systems. Furthermore, we conducted a qRT-PCR study to show changes in the expression of some genes involved in apoptosis. Suppression of cell proliferation through boric acid-inducing apoptosis was observed both in 3D and 2D culture conditions. These results are compatible with the gene expression results. The ENDOG, CASP3, CASP8, and CASP9 gene expression significantly changed at all time intervals in MCF-7 and MD-MB-231 cell lines boric acid can potentially treat breast cancer as an anti-cancer agent candidate.

Novel Perspective on Mechanism in Muscle Growth Inhibited by Ochratoxin A Associated with Ferroptosis: Model of Juvenile Grass Carp (Ctenopharyngodon idella) In Vivo and In Vitro Trials

Ochratoxin A (OTA) is a common mycotoxin in food and feed that seriously harms human and animal health. This study investigated the effect of OTA on the muscle growth of juvenile grass carp (Ctenopharyngodon idella) and its possible mechanism in vitro. Our results have the following innovative findings: (1) Dietary OTA increased the expression of increasing phase I metabolic enzymes and absorbing transporters while reducing the expression of efflux transporters, thereby increasing their residue in muscles; (2) OTA inhibited the expressions of cell cycle and myogenic regulatory factors (MyoD, MyoG, and MyHC) and induced ferroptosis by decreasing the mRNA and protein expressions of FTH, TFR1, GPX4, and Nrf2 both in vivo and in vitro; and (3) the addition of DFO improved OTA-induced ferroptosis of grass carp primary myoblasts and promoted cell proliferation, while the addition of AKT improved OTA-inhibited myoblast differentiation and fusion, thus inhibiting muscle growth. Overall, this study provides a potential research target to further mitigate the myotoxicity of OTA.

Cell cycle and enzymatic activity alterations induced by ROS production in human neuroblastoma cells SH-SY5Y exposed to Fumonisin B1, Ochratoxin A and their combination

The presence of mycotoxins such as Fumonisin B1(FB1) and Ochratoxin A (OTA) in food and feed has become a threat to human and animal health since they can produce several afflictions. Different mechanisms of action by which they exercise their cytotoxic activity have been attributed to them, including the production of reactive oxygen species (ROS). For this reason, a measurement of the production of ROS species, and an evaluation of the intrinsic cell enzymatic antioxidant activity, including glutathione peroxidase (GPx), glutathione transferase (GTS), and catalase (CAT) together with a cytotoxicity and cell cycle assay have been performed in undifferentiated SH-SY5Y cells exposed to FB1, OTA and [FB1 + OTA] after 24 h and 48 h. FB1 and OTA. Monitoring of intracellular ROS production was carried out by the H2-DCFDA probe; while spectrometry analysis of absorbances was used for measuring GPx, GST and CAT activity. Finally, cell proliferation and cell cycle distribution were studied by flow cytometry. When cells were treated with OTA, an increase in GPx and GST activity was observed compared to FB1 and [FB1 + OTA]; conversely, a decrease in CAT activity was observed when cells were exposed to OTA coinciding with the results observed for ROS measurement. Regarding the cell cycle, when cells were exposed to OTA, a decrease in G0/G1 was detected, revealing an arrest of cell division for SH-SY5Y cells at the concentrations studied.

Apoptotic effects of Phlomis armeniaca mediated biosynthesized silver nanoparticles in monolayer (2D) and spheroid (3D) cultures of human breast cancer cell lines

The purpose of current research was to assess the apoptotic effects of biofabrication silver nanoparticles (AgNPs) mediated by the aqueous extract of Phlomis armeniaca on human breast cancer cells (MCF-7 and MDA-MB-231) in monolayer (2D) and spheroid (3D) cultures. The biosynthesized AgNPs were characterized by UV-Vis spectrophotometer (the peaks of resonances at 432 nm), scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS). 1-20 µM/mL AgNPs were applied to MCF-7 and MDA-MB-231 cell lines to determine IC50 values at 24, 48 and 72nd h and were found to be 10 µM/mL for both cell lines. Immunohistochemical staining results of BrdU, TUNEL, caspase-3 and Endo G in both 2D and 3D cultures and gene expression levels of caspases (caspase-3, -8 and -9) and Endo G were evaluated. Moreover, the total oxidant/antioxidant status (TOS-TAS) due to AgNPs application in both cell culture mediums was evaluated. AgNPs treatment results in both cell lines in both 2D and 3D cultures showed a significant decrease in the BrdU labeling index, while large amounts of cells were labelled with TUNEL and Endo G. In 2D culture, Endo G expression increased in MCF-7 cells at 48 and 72nd hours, while it increased significantly in MDA-MB-231 cells at all hours. OSI results show that ROS production is increased in cell medium treated with AgNPs. In conclusion, AgNPs mediated by Phlomis armeniaca, synthesized by a green method, successfully induced damage to mitochondria, resulting in cell cycle arrest and consequent cell proliferation blockade and death in both MCF-7 and MDA-MB-231 cells.

The importance of transcriptomics and proteomics for studying molecular mechanisms of mycotoxin exposure: A review

This review aims to highlight recent advances where transcriptomics and proteomics have been used as a key tool to understand molecular toxicity of mycotoxins. The most studied mycotoxin by using transcriptomic approach is deoxynivalenol (DON), followed by aflatoxins (AFs) and zearalenone (ZEA). Instead, proteomics mostly focuses on AFs but also in this case, mildly to ZEA and DON. However, in both omics approaches, fewer studies investigated the toxicological effect of emerging mycotoxins, patulin, ochratoxin A, T-2 toxin, alternariol and amino-14,16-dimethyloctadecan-3-ol. The study of changes in the expression of genes involved in immune system are the most common purposes for transcriptomics whereas cellular processes in proteomics field. Concerning the techniques used to perform the experiments, RT-qPCR is the most employed in gene expression analysis whereas liquid chromatography coupled with mass spectrometry is the master technique for proteomics assays. The gathered data have reported that the interest in using these omic approaches has increased in the last five years. However, in vitro models take precedence over the in vivo and ex vivo ones. Therefore, there is a need to enhance the use of in vivo models and alternative methods to better understand mycotoxins mode of action on animal and human health.

Protective and detoxifying effects conferred by selenium against mycotoxins and livestock viruses: A review

Animal feed can easily be infected with molds during production and storage processes, and this can lead to the production of secondary metabolites, such as mycotoxins, which eventually threaten human and animal health. Furthermore, livestock production is also not free from viral infections. Under these conditions, the essential trace element, selenium (Se), can confer various biological benefits to humans and animals, especially due to its anticancer, antiviral, and antioxidant properties, as well as its ability to regulate immune responses. This article reviews the latest literature on the antagonistic effects of Se on mycotoxin toxicity and viral infections in animals. We outlined the systemic toxicity of mycotoxins and the primary mechanisms of mycotoxin-induced toxicity in this analysis. In addition, we pay close attention to how mycotoxins and viral infections in livestock interact. The use of Se supplementation against mycotoxin-induced toxicity and cattle viral infection was the topic of our final discussion. The coronavirus disease 2019 (COVID-19) pandemic, which is currently causing a health catastrophe, has altered our perspective on health concerns to one that is more holistic and increasingly embraces the One Health Concept, which acknowledges the interdependence of humans, animals, and the environment. In light of this, we have made an effort to present a thorough and wide-ranging background on the protective functions of selenium in successfully reducing mycotoxin toxicity and livestock viral infection. It concluded that mycotoxins could be systemically harmful and pose a severe risk to human and animal health. On the contrary, animal mycotoxins and viral illnesses have a close connection. Last but not least, these findings show that the interaction between Se status and host response to mycotoxins and cattle virus infection is crucial.

Genotoxic effects of the ochratoxin A (OTA), its main metabolite (OTα) per se and in combination with fumonisin B1 in HepG2 cells and human lymphocytes

Ochratoxin A (OTA) and fumonisin B₁ (FB₁) are mycotoxins distributed in a wide variety of foods for human or animal consumption and are classified as possible carcinogens for humans. This study aimed to evaluate the cytotoxic, cytostatic and genotoxic effects of OTA and its main metabolite, ochratoxin α (OTα), FB₁ and three combinations of OTA and FB₁ at moderate and environmental doses. Cell viability was evaluated through MTT assay and the trypan blue exclusion method. The cytostatic and genotoxic effects were evaluated through the cytokinesis-block micronucleus assay. The results showed synergistic time- and concentration-dependent cytotoxic effects of one of the combinations of OTA and FB₁. In contrast, significant differences were observed in the micronuclei (MN) frequency from OTA, OTα and coexposure of OTA + FB₁. Some of these combinations increased the frequency of nuclear buds, nucleoplasmic bridges, donut-shaped nuclei, necrotic and apoptotic cells and MN in mononucleated cells. In conclusion, OTA and its main metabolite OTα, as well as the co-exposure of OTA and FB₁, cause stable DNA damage at environmentally relevant concentrations, which was greater in metabolically competent cells. More studies are needed to understand the chemical interactions that occur due to the joint presence of mycotoxins, which occurs commonly.

Pumpkin extract and fermented whey individually and in combination alleviated AFB1- and OTA-induced alterations on neuronal differentiation invitro

Food and feed are daily exposed to mycotoxin contamination which effects may be counteracted by functional compounds like carotenoids and fermented whey. Among mycotoxins, the most toxic and studied are aflatoxin B1 (AFB1) and ochratoxin A (OTA), which neurotoxicity is not well reported. Therefore, SH-SY5Y human neuroblastoma cells ongoing differentiation were exposed during 7 days to digested bread extracts contained pumpkin and fermented whey, individually and in combination, along with AFB1 and OTA and their combination, in order to evaluate their presumed effects on neuronal differentiation. The immunofluorescence analysis of βIII-tubulin and dopamine markers pointed to OTA as the most damaging treatment for cell differentiation. Cell cycle analysis reported the highest significant differences for OTA-contained bread compared to the control in phase G₀/G₁. Lastly, RNA extraction was performed and gene expression was analyzed by qPCR. The selected genes were related to neuronal differentiation and cell cycle. The addition of functional ingredients in breads not only enhancing the expression of neuronal markers, but also induced an overall improvement of gene expression compromised by mycotoxins activity. These data confirm that in vitro neuronal differentiation may be impaired by AFB1 and OTA-exposure, which could be modulated by bioactive compounds naturally found in diet.

Albicanol modulates oxidative stress and the p53 axis to suppress profenofos induced genotoxicity in grass carp hepatocytes

The organophosphorus pesticide profenofos (PFF) is widely used as an environmental contaminant, and it can remain in water bodies causing serious harm to aquatic organisms. Albicanol is a sesquiterpenoid with potent antioxidant and antagonistic activities against heavy metal toxicity. However, the mechanism of PFF induced genotoxicity in fish hepatocytes and the role Albicanol can play in this process are unknown. In this study, the model was established by treating grass carp hepatocytes with PFF (150 μM) and/or Albicanol (5 × 10^-5 μg mL^-1) for 24 h. The results showed that PFF exposure arrested L8824 cells in the G1-S phase. PFF caused the increase of MDA level in L8824 cells, while the decrease of SOD, CAT and T-AOC levels caused oxidative stress. Elevated levels of γH2AX, tail moment, tail length, % DNA and 8-OHdG indicated that PFF caused DNA damage in L8824 cells. PFF inhibited the expression levels of cell cycle related regulatory genes (cyclin A, cyclin D, cyclin E, CDK2 and CDK4) by upregulating p53/p21 genes and activating the p53 signaling pathway. Albicanol was used to significantly reduce the above effects caused by PFF exposure on hepatocytes in grass carp. Albicanol could reduce the increase in the proportion of cells in the G1-S phase caused by PFF. In summary, Albicanol could inhibit the genotoxicity of L8824 cells resulted from PFF exposure by decreasing oxidative stress and the p53 pathway.

Curcumin induces apoptosis through caspase dependent pathway in human colon carcinoma cells

BACKGROUND

We investigated the apoptotic effects of curcumin in the colon carcinoma cell line SW480.

METHODS AND RESULTS

Cells were treated with 40-200 μM curcumin for 24, 48, and 72 h, and the IC₅₀ values were determined for each time interval. BrdU, caspase-3, and TUNEL staining results and the gene expression of FADD, CASP8, and CASP3 were evaluated. Curcumin treatments significantly inhibited cell proliferation and significantly induced apoptosis for 24, 48, and 72 h. The proportion of BrdU-stained cells in the control groups were 58%, 57% and 61% and 28%, 27%, and 30% in the curcumin treatment groups at 24, 48, and 72 h, respectively. The proportion of apoptotic cells was 28%, 29%, and 28% in the control groups and 59%, 61%, and 60% in the curcumin treatment groups at 24, 48, and 72 h, respectively. As expected, caspase-3 staining also revealed a higher number of apoptotic cells in curcumin treatment groups at 24, 48, and 72 h compared to controls. The proportion of Caspase-3-stained cells in the control groups were 23%, 25%, and 24% and 59%, 60%, and 62% in the curcumin treatment groups at 24, 48, and 72 h, respectively. To prove caspase-3 staining results, FADD, CASP8, and CASP3 gene expressions were evaluated by real-time qPCR. Unlike the immunohistochemical results, no statistically significant upregulation was found at 24 and 48 h, while relative gene expressions of FADD, CASP8, and CASP3 was significantly upregulated at 72 h. The expression level increase was 0.88-, 1.19-, and 2.11-fold for FADD, 1.25-, 1.29-, and 1.59-fold for CASP8, and 1.33-, 1.46-, and 3.00-fold for CASP3 at 24, 48, and 72 h, respectively.

CONCLUSIONS

These results suggest that curcumin may be a potential protective or treatment agent against colon cancer; however, further studies on curcumin-rich diets and curcumin bioavailability are required.

Ochratoxin A-Induced Nephrotoxicity: Up-to-Date Evidence

Ochratoxin A (OTA) is a mycotoxin widely found in various foods and feeds that have a deleterious effect on humans and animals. It has been shown that OTA causes multiorgan toxicity, and the kidney is the main target of OTA among them. This present article aims to review recent and latest intracellular molecular interactions and signaling pathways of OTA-induced nephrotoxicity. Pyroptosis, lipotoxicity, organic anionic membrane transporter, autophagy, the ubiquitin-proteasome system, and histone acetyltransferase have been involved in the renal toxicity caused by OTA. Meanwhile, the literature reviewed the alternative or method against OTA toxicity by reducing ROS production, oxidative stress, activating the Nrf2 pathway, through using nanoparticles, a natural flavonoid, and metal supplement. The present review discloses the molecular mechanism of OTA-induced nephrotoxicity, providing opinions and strategies against OTA toxicity.

Exosomes mediated the delivery of ochratoxin A-induced cytotoxicity in HEK293 cells

Ochratoxin A (OTA) is one of the mycotoxins, which widely pollutes food systems and seriously threatens human health. OTA's target organ is the kidney. Exosome, as one of the extracellular vesicles, could be secreted by all kinds of cells. It contains different proteins, nucleic acid, and lipid, which are decided by their donor cells and could be uptake by the recipient cells, release their contents, and affect the recipient cell's life activity. In this study, a 24 h-treatment with 5 μM OTA was found to significantly reduce the cell viability of HEK293 cells and meanwhile to provide a sufficient quantity of exosomes, thus this concentration and time were selected for subsequent experiments. In addition, exosomes extracted by ultracentrifugation had higher purity, fewer impurities, and uniform morphology than that by the ExoQuick-TC kit. Furthermore, these exosomes increased ROS levels and decreased mitochondrial membrane potential in HEK293 cells. By RNA-seq, the cytotoxicity mechanisms induced by OTA-treated HEK293 cell-derived exosomes (EXO-OTA) and OTA were mainly the metabolism of proteins and the cell cycle respectively. Also, it proved that exosomes deliver partial OTA-induced cytotoxicity.

Secoisolariciresinol diglucoside induces caspase-3-mediated apoptosis in monolayer and spheroid cultures of human colon carcinoma cells

Apoptotic effects of secoisolariciresinol diglucoside (SDG) in 2D and 3D cultures of SW480 cells were investigated. 40-200 μM SDG was used and IC50 values were determined for three different time intervals as 24, 48, or 72 hr for further experiments. BrdU, TUNEL, AIF, and caspase-3 stainings were used. SDG inhibited cell proliferation almost half and half for all time intervals in 2D and 3D cultures and also, induced apoptosis. Apoptotic cell percentages in the control group for 24, 48, and 72 hr were 27.00%, 29.00%, and 28.00%, respectively, while in the SDG treatment group were 59.00%, 61.00%, and 62.00%, respectively. In the spheroid cell culture, apoptotic cell percentages in the control group for 24, 48, and 72 hr were 6.90%, 7.20%, and 7.10%, respectively, while in the SDG treatment group were 19.50%, 19.50%, and 20.70%, respectively. Caspase-3 and AIF antibodies were used to indicate caspase-dependent and -independent apoptotic pathways. Significant increases were seen in both AIF and caspase-3 stainings when compared to the control group but caspase-3 staining results were significantly greater when compared to the AIF staining at all time intervals (p < .05). To prove this, CASP3 gene expression was evaluated by RT-qPCR. Unlike staining results, there was no statistically significant change at 24 hr in 2D and 3D cultures. But, significant upregulation at 48 (2.32-fold in 2D and 2.46-fold in 3D) and 72 hr (5.04-fold in 2D and 6.45-fold in 3D) were seen. PRACTICAL APPLICATIONS: Colon cancer is one of the most prevalent cancer in the developed countries and its etiology is complex. Although the underlying mechanisms are mostly unknown, the link between diet and colon cancer is known and dietary habits can promote cancer or protect against it. In recent years, flaxseed is accepted as a significant functional food ingredient and feeding with it could help in to prevent cancer. Secoisolariciresinol diglucoside is a flaxseed lignan and is metabolized to mammalian lignans by the gut. In the present study, SDG was evaluated for its apoptotic effects in colon carcinoma cell line via monolayer and spheroid cultures using immunohistochemical and gene expression techniques. Findings of this study suggest that SDG may protect against cancers and in particularly against colon cancer and further investigations has to be carried out for detailed underlying mechanisms.

The Impact of the Nephrotoxin Ochratoxin A on Human Renal Cells Studied by a Novel Co-Culture Model Is Influenced by the Presence of Fibroblasts

The kidney is threatened by a lot of potentially toxic substances. To study the influence of the nephrotoxin ochratoxin A (OTA) we established a cell co-culture model consisting of human renal proximal tubule cells and fibroblasts. We studied the effect of OTA on cell survival, the expression of genes and/or proteins related to cell death, extracellular matrix and energy homeostasis. OTA-induced necrosis was enhanced in both cell types in the presence of the respective other cell type, whereas OTA-induced apoptosis was independent therefrom. In fibroblasts, but not in tubule cells, a co-culture effect was visible concerning the expression of the cell-cycle-related protein p21. The expression of the epithelial-to-mesenchymal transition-indicating protein vimentin was independent from the culture-condition. The expression of the OTA-induced lncRNA WISP1-AS1 was enhanced in co-culture. OTA exposure led to alterations in the expression of genes related to energy metabolism with a glucose-mobilizing effect and a reduced expression of mitochondrial proteins. Together we demonstrate that the reaction of cells can be different in the presence of cells which naturally are close-by, thus enabling a cellular cross-talk. Therefore, to evaluate the toxicity of a substance, it would be an advantage to consider the use of co-cultures instead of mono-cultures.

Inhibitory effect and mechanism of action (MOA) of hirsutine on the proliferation of T-cell leukemia Jurkat clone E6-1 cells

Background

The bark of Uncaria rhynchophylla has been traditionally used to treat convulsion, bleeding, hypertension, auto-immune conditions, cancer, and other diseases. The main focus of this research is done for the purpose of exploring the antitumor activity and mechanism of action (MOA) for hirsutine isolated from U. rhynchophylla.

Methods

Jurkat clone E6-1 cells were treated using 10, 25 and 50 μM for 48 h. Inhibition of cell proliferation due to hirsutine treatment was evaluated by CCK8 assay. Flow cytometry was applied to ascertain Jurkat cell cycle progression and apoptosis after treatment with 10, 25 and 50 μM hirsutine for 48 h. The expression and level of the apoptosis-related genes and proteins was analyzed by Real-time Quantitative polymerase chain reaction (qPCR) and Western blotting method, respectively.

Results

CCK8 analyses revealed that hirsutine could significantly inhibit the proliferation of Jurkat clone E6-1 cells, in a concentration and time-dependent fashion. Flow cytometry assays revealed that hirsutine could drive apoptotic death and G0/G1 phase arrest in Jurkat cells. Apoptotic cells frequencies were 4.99 ± 0.51%, 13.69 ± 2.00% and 40.21 ± 15.19%, and respective cell cycle arrest in G0/G1 accounted for 34.85 ± 1.81%, 42.83 ± 0.70% and 49.12 ± 4.07%. Simultaneously, compared with the control group, Western blot assays indicated that the up-regulation of pro-apoptotic Bax, cleaved-caspase3, cleaved-caspase9 and Cyto c proteins, as well as the down-regulation of Bcl-2 protein which guards against cell death, might be correlated with cell death induction and inhibition of cell proliferation. QPCR analyses indicated that hirsutine could diminish BCL2 expression and, at the same time, improve Bax, caspase-3 and caspase-9 mRNA levels, thus reiterating a putative correlation of hirsutine treatment in vitro with apoptosis induction and inhibition of cell proliferation (p-value < 0.05). Excessive hirsutine damages the ultrastructure in mitochondria, leading to the release of Cyt c from the mitochondria to cytoplasm in Jurkat clone E6-1 cells, thereby inducing the activated caspase cascade apoptosis process through a mitochondria-mediated pathway.

Conclusion

An important bioactive constituent-hirsutine-appears to have antitumor effects in human T-cell leukemia, thus enlightening the use of phytomedicines as a novel source for tumor therapy. It is speculated that hirsutine may induce apoptosis of Jurkat Clone E6-1 cells through the mitochondrial apoptotic pathway.

Central role of TRAP1 in the ameliorative effect of oleanolic acid on the mitochondrial-mediated and endoplasmic reticulum stress-excitated apoptosis induced by ochratoxin A

Ochratoxin A (OTA) is a nephrotoxic mycotoxin that is widely distributed in foodstuffs and feeds, meanwhile oleanolic acid (OA) is ubiquitous in various fruit skins, food materials, and medicinal herbs. Due to that OA has a nephroprotective effect, it has the poteintial to counteract OTA-induced nephrotoxicity by nutritional intervention of OA. Furthermore, tumor necrosis factor receptor-associated protein 1 (TRAP1) acts as the core of endoplasmic reticulum (ER)-mitochondria crosstalk, becoming our focus in the mechanism investigation. In this study, the cell viability, apoptosis rate, and protein expressions of human proximal tubule epithelial-originated kidney-2 (HK-2) cells in response to OTA and/or OA were determined. Results indicated that a 24 h-treatment of 1-5 μM OTA could notably induce mitochondrial-mediated and ER stress (ERS)-excitated apoptosis via inhibiting TRAP1, thereby activating CypD, Bax, Cyt-C, Cleaved Caspase-9, Cleaved Caspase-3, GRP78, p-PERK, p-eIF2α, ATF4, and CHOP and inhibiting Bcl-2 (P < 0.05). Results of the RNA interference of TRAP1 further ascertained its anti-apoptotic function via inhibiting CypD, Bax, GRP78, and CHOP and enhancing Bcl-2 (P < 0.05). The pre-treatment of 2 μM OA for 2 h could remarkably relieve OTA-induced suppression of TRAP1 (P < 0.05). In conclusion, TRAP1 played a central role in the ameliorative effect of OA on the mitochondrial-mediated and ERS-excitated apoptosis induced by OTA.