Realgar Research Articles

Liquid-Phase Exfoliation of Arsenic Trisulfide (As2S3) Nanosheets and Their Use as Anodes in Potassium-Ion Batteries.

Here, we demonstrate the production of 2D nanosheets of arsenic disulfide (As2S3) via liquid-phase exfoliation of the naturally occurring mineral, orpiment. The resultant nanosheets had mean lateral dimensions and thicknesses of 400 and 10 nm, and had structures indistinguishable from the bulk. The nanosheets were solution mixed with carbon nanotubes and cast into nanocomposite films for use as anodes in potassium-ion batteries. These anodes exhibited outstanding electrochemical performance, demonstrating an impressive discharge capacity of 619 mAh/g at a current density of 50 mA/g. Even after 1000 cycles at 500 mA/g, the anodes retained an impressive 94% of their capacity. Quantitative analysis of the rate performance yielded a capacity at a very low rate of 838 mAh/g, about two-thirds of the theoretical capacity of As2S3 (1305 mAh/g). However, this analysis also implied As2S3 to have a very small solid-state diffusion coefficient (∼10-17 m2/s), somewhat limiting its potential for high-rate applications.

Arsenic disulfide promoted the demethylation of PTPL1 in diffuse large B cell lymphoma cells.

Promoter hypermethylation of the tumor suppressor gene is one of the well-studied causes of cancer development. The drugs that reverse the process by driving demethylation could be a candidate for anticancer therapy. This study was designed to investigate the effects of arsenic disulfide on PTPL1 methylation in diffuse large B cell lymphoma (DLBCL). We knocked down the expression of PTPL1 in two DLBCL cell lines (i.e., DB and SU-DHL-4 cells) using siRNA. Then the DLBCL proliferation was determined in the presence of PTPL1 knockdown. The methylation of PTPL1 in DLBCL cells was analyzed by methylation specific PCR (MSPCR). The effect of arsenic disulfide on the PTPL1 methylation was determined in DLBCL cell lines in the presence of different concentrations of arsenic disulfide (5 µM, 10 µM and 20 µM), respectively. To investigate the potential mechanism on the arsenic disulfide-mediated methylation, the mRNA expression of DNMT1, DNMT3B and MBD2 was determined. PTPL1 functioned as a tumor suppressor gene in DLBCL cells, which was featured by the fact that PTPL1 knockdown promoted the proliferation of DLBCL cells. PTPL1 was found hypermethylated in DLBCL cells. Arsenic disulfide promoted the PTPL1 demethylation in a dose-dependent manner, which was related to the inhibition of DNMTs and the increase of MBD2. Experimental evidence shows that PTPL1 functions as a tumor suppressor gene in DLBCL progression. PTPL1 hyper-methylation could be reversed by arsenic disulfide in a dose-dependent manner.

Comparative analysis of immunological changes following realgar and arsenic trioxide treatments in a murine model of myelodysplastic syndrome

Background Myelodysplastic syndrome (MDS) is a prevalent hematological neoplastic disorder in clinics and its immunopathogenesis has garnered growing interest. Oral and intravenous arsenic agents have long been used to treat hematological malignancies. The main component of oral arsenic is realgar (arsenic disulfide), while arsenic trioxide is the main component of intravenous arsenic. Methods This study aimed to assess the effects of ATO and Realgar on the enhancement of peripheral blood, drug safety, and T cell immune status in the NUP98-HOXD13 (NHD13) mice model of MDS, specifically in the peripheral blood, spleen, and liver. Results The study findings indicate that realgar and arsenic trioxide (ATO) can improve peripheral hemogram in mice, whereas realgar promotes higher peripheral blood cell production than ATO. Furthermore, the clinical administration method and dose did not cause significant toxicity or side effects and thus can be considered safe. Coexistence and interconversion of hyperimmune function and immunosuppression in mice were also observed in this study. In addition, there were interactions between immune cells in the peripheral blood, spleen, and liver to regulate the immune balance of the body and activate immunity via T-cell activation. Conclusion In summary, oral and intravenous arsenic agents are beneficial in improving peripheral hemogram and immunity in mice.

Inoculum density-dependent, additive effectiveness of fungicides or biofungicides with cultivar resistance for integrated management of Cercospora leaf spot on beet greens

Cercospora leaf spot, caused primarily by Cercospora beticola, is common on red beet wherever this vegetable crop is grown. The effectiveness of a conventional (propiconazole rotated with azoxystrobin) and an organic biofungicide (Bacillus amyloliquefaciens mixed with copper octanoate) program were tested on four cultivars of beet that differed in susceptibility. Three inoculum densities were established by inoculating a 1-m portion of one row, allowing conidia to splash to the adjacent row, and not inoculating the remainer of the plot. Foliar severity was reduced by both fungicide programs compared to the water-treated control, but the conventional fungicides were more effective in the high inoculum area than the organic fungicides. The conventional fungicides also increased the fresh weight of healthy leaves compared to the water control, but the organic fungicides did not differ from the other two treatments. All cultivars except the most resistant one, Bull's Blood, had greater healthy weights in 2022 when the inoculum density was lower than in 2021. Cultivars sorted in the same order of susceptibility regardless of fungicide program. In all treatments, mean weight of diseased individual leaves was greater than healthy leaves. Partial cultivar resistance and fungicides or biofungicides had additive effects for integrated management of Cercospora leaf spot on red beet.

Tetraarsenic tetrasulfide triggers ROS-induced apoptosis and ferroptosis in B-cell acute lymphoblastic leukaemia by targeting HK2

PurposeAcute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children. Despite cure rates of higher than 85 %, refractory or relapsed ALL still exhibits a bleak prognosis indicative of the dearth of treatment modalities specific for relapsed or refractory ALL. Prior research has implicated metabolic alterations in leukemia pathogenesis, and literature on the therapeutic efficacy of arsenic compounds targeting metabolic pathways in B-cell acute lymphoblastic leukemia (B-ALL) cells is scarce. MethodsA compound extracted from realgar, tetraarsenic tetrasulfide (As4S4), and its antitumor effects on B-ALL were experimentally examined in vitro and in vivo. ResultsAs4S4 apparently targets B-ALL cells by inducing specific cellular responses, including apoptosis, G2/M arrest, and ferroptosis. Interestingly, these effects are attributed to reactive oxygen species (ROS) accumulation, and increased ROS levels have been linked to both the mitochondria-dependent caspase cascade and the activation of p53 signaling. The ROS scavenger N-acetylcysteine (NAC) can counteract the effects of As4S4 treatment on Nalm-6 and RS4;11 cells. Specifically, by targeting Hexokinase-2 (HK2), As4S4 induces alterations in mitochondrial membrane potential and disrupts glucose metabolism, leading to ROS accumulation, and was shown to inhibit B-ALL cell proliferation in vitro and in vivo. Intriguingly, overexpression of HK2 can partially desensitize B-ALL cells to As4S4 treatment. ConclusionTetraarsenic tetrasulfide can regulate the Warburg effect by controlling HK2 expression, a finding that provides both new mechanistic insight into metabolic alterations and pharmacological evidence for the clinical treatment of B-ALL.

Exploring the Mechanism of Realgar against Esophageal Cancer Based on Ferroptosis Induced by ROS-ASK1-p38 MAPK Signaling Pathway.

Background Realgar (REA), a Chinese herbal decoction, has been used to treat various tumors and has produced positive outcomes; however, there is a lack of convincing evidence for the treatment of esophageal cancer. The present study aimed to investigate the effects of REA on esophageal cancer (EC) and explore its mechanism. Methods EC cells Eca109 and KYSE150 were selected for this study, and different groups of treated cells were set up. We studied the inhibition rate and half inhibition concentration (IC50) by CCK-8 method, the clone formation assay was used to detect the clone formation ability, the scratch assay is used to determine the cell migration ability, the Transwell assay was used to detect the cell invasion ability, the protein expressions of E-cadherin, Slug, N-cadherin, ASK1, p38 MAPK, p-p38 MAPK, and GPX4 were determined using Western blot, the mRNA expressions of ASK1 and p38 MAPK were assessed using qRT-PCR, transmission electron microscopy was used to observe the cellular ultrastructure, Prussian blue staining was used to observe the intracellular iron particle distribution, and biochemical analysis of cellular MDA, SOD, GSH, and GPXS activities, flow cytometric analysis of cellular ROS levels, immunofluorescence staining to detect cellular GPX4 expression, and JC-1 method to detect mitochondrial membrane potential were used. Results REA inhibited the proliferation of Eca109 and KYSE150 cells in a time- and concentration-dependent manner, and REA significantly inhibited the migration and invasion of Eca109 and KYSE150 cells and activated the cellular ferroptosis and ROS-ASK1-p38 MAPK signaling pathways (P < 0.05). Inhibition of activation of the ROS-ASK1-p38 MAPK signaling pathway promoted the inhibition of proliferation, migration, and invasion of Eca109 and KYSE150 cells and the induction of ferroptosis by REA. Conclusion REA induced ferroptosis and inhibited the migration of EC cells by activating the ROS-ASK1-p38 MAPK signaling pathway.

Particle design for improving taste and homogeneity of traditional Chinese medicinal powder: taking Zhuhuang Chuihou Powder as an example

Due to the complex source and different physical and chemical properties of traditional Chinese medicines(TCM) powder, there are many common pharmaceutical problems in its preparation, such as large particle size difference, poor mixing uniformity, and poor compliance with oral intake, which has directly affected the quality of solid preparations as well as their clinical efficacy and safety. This study observed the property of Zhuhuang Chuihou Powder and extract its pharmaceutical defects. It was found that realgar and calcined Borax in Zhuhuang Chuihou Powder were heavy in texture and toxic, and they were easy to be isolated, indicating the potential safety hazard. At the same time, Coptidis Rhizoma and Phellodendri Chinensis Cortex were the main sources of its bitterness. Therefore, based on the idea of &quot;drug-excipients unity&quot;, the particle design technology was used to prepare core/shell-type composite particles with bitter medicines as the core and mineral medicines as shell. Both infrared spectroscopy and scanning electron microscopy results indicated the formation of composite particles, and the taste of these composite particles were improved. Compared with the physical mixtures, the composite particles exhibited significantly decreased RSD values in the content uniformity of berberine hydrochloride, arsenic disulfide, and sodium tetraborate and appearance uniformity. The introduction of particle design technology solved the problem of uneven dispersion of Zhuhuang Chuihou Powder, thus ensuring its uniform dispersion, stability, and control and improving the quality of the original preparation. This has provided a scientific basis for the quality control of TCM powder.

Effects of Arsenic Disulfide Combined with Itraconazole on Proli- feration and Apoptosis and Hedgehog Pathway of Diffuse Large B-Cell Lymphoma Cells

To investigate the effect of arsenic disulfide (AS2S2) combined with itraconazole on the proliferation, apoptosis and hedgehog pathway of diffuse large B-cell lymphoma (DLBCL) cells. The human DLBCL cell OCI-LY3 was treated with different concentrations of AS2S2 and itraconazole. Cell proliferation inhibition was detected by CCK-8, cell apoptosis rate was determined by flow cytometry. The expression levels of BCL-2, BAX, SMO and GLi1 were detected by Western blot. The DLBCL cell viability was decreased significantly at 24, 48 or 72 h as cultured with itraconazole. Along with the increasing of itraconazole concentration, the DLBCL cell viability was significantly reduced as compared with that in control group, and the results showed statistically significant(r=-0.690，r=-0.639, r=-0.833, r=-0.808, r=-0.578). The inhibitory and apoptosis rates of the cells were significantly increased as compared with those of the single drug-treated group after treated by the combination of itraconazole and AS2S2(P<0.05). The protein levels of SMO and Glil were significantly down-regulated after treated by arsenic disulfide and itraconazole alone(P<0.01). The protein expression levels of SMO and Glil was down-regulated in the combined-treatment group(P<0.01). Itraconazole can inhibit proliferation of DLBCL cells in a concentration-and time-dependent manner. In addition, the combination of AS2S2 and itraconazole show a synergistic effects, which may be related with the down-regulated protein expression of SMO and Glil of Hedgehog signaling pathway.

Population Pharmacokinetics and Safety of Oral Tetra-Arsenic Tetra-Sulfide Formula in Pediatric Acute Promyelocytic Leukemia.

BackgroundAn oral tetra-arsenic tetra-sulfide (AS4S4) formula has been recommended as an outpatient post-remission treatment for Chinese adults with acute promyelocytic leukemia (APL) but limited data are available for children. In this exploratory study, we aimed to evaluate the pharmacokinetics and safety of the AS4S4 formula in children.MethodsEleven newly diagnosed and one relapsed pediatric patient (4–14 years of age) treated with the AS4S4 formula were included. Blood samples were collected from 12 children, and drug concentrations were quantified by ICP-MS. Population pharmacokinetic analysis and Monte-Carlo simulation were performed using NONMEM software. Toxic effects were graded according to the NCI-CTCAE, Version 3.ResultsA total of 107 arsenic concentrations (0.1–75.0 µg L−1) were used for population pharmacokinetic analysis. The median (range) of estimated weight-normalized CL and volume distribution at steady-state were 45.26 (35.63–82.18) L h−1 kg−1 and 230.37 (85.96–495.68) L kg−1, respectively. No patients discontinued AS4S4 treatment owing to adverse events, and there were no drug-related adverse events over grades 3–4. All newly diagnosed APL patients were in MCR with a median follow-up of 28 months (range, 23 to 37 months). Both the estimated 3-year EFS and OS rates were 100%.ConclusionThe pharmacokinetics and safety oral AS4S4 formula was evaluated for the first time in pediatric APL. The pharmacokinetic assessment demonstrated that the dosing regimen of 60 mg/kg/d TID resulted in a higher steady-state through concentration in children than that which was achieved in adults. The results of this study indicate that the AS4S4 formula is safe in newly diagnosed pediatric APL patients.

Corrigendum] Antitumor effects of arsenic disulfide on the viability, migratory ability, apoptosis and autophagy of breast cancer cells.

Following the publication of the above paper, an interested reader drew to our attention the fact that the same β‑actin bands had been included in the western blots featured in Figs.7 and 10. Upon consulting the authors in relation to this matter, they were able to offer a legitimate explanation for this apparent duplication of the bands; essentially, in the western blotting experiments, different antibodies were used in one membrane to present different target proteins by stripping and reprobing the membrane. That the authors had performed this additional step in their protocol was inadvertently omitted from the 'Western blot analyses' subsection of the Materials and methods section. The authors are grateful to the interested reader for drawing this matter to their attention, and apologize for any inconvenience caused to the readership of the Journal. [the original article was published in Oncology Reports 41: 27-42, 2019; DOI: 10.3892/or.2018.6780].

Influence of cadmium on the cellular part of the immune system of young cattle

The article presents the results of research on the effect of cadmium load on the body of young cattle. The negative effect of Cadmium on the liver causes a wide range of pathological changes at different levels of its organization. The impact of heavy metals on the immune system is particularly significant, because it performs a leading role in maintaining health and is recognized as one of the most sensitive to adverse factors, even in relatively low concentrations. The aim of the study was to investigate the influence of cadmium on the cellular part of the immune system of young cattle. The research was carried out on 10 bulls of six months of age, Ukrainian black-and-white dairy breed, which were formed into 2 groups of 5 animals each: control and experimental. The bulls of the control group were on a normal diet. Animals of the experimental group were administered cadmium chloride at a dose of 0.04 mg/kg body weight of the animal. It was found that feeding bulls with a diet of cadmium chloride, the number of B-lymphocytes on the 5th day of the experiment was 17.54 ± 0.95 %. The lowest number of B-lymphocytes was on the 20th day of testing – 15.12 ± 0.37 %. The study of the number of T-lymphocytes shows that at the beginning of analysis the number of T-lymphocytes in the blood of animals of the control and experimental groups ranged from 40.70 ± 3.62 and 40.85 ± 2.54 %. Subsequently, the number of T-lymphocytes in the blood of the experimental group began to decline. The lowest number of T-lymphocytes was in the experimental group of animals on the 20th day of the research, compared with the control group, this figure decreased by 3.63 %. The state of immunity of animals under cadmium load significantly depends on the ratio of T-helpers to T-suppressors. It was found that the immunoregulatory index of blood of bulls of the experimental group probably decreased from 10 days of the research. The number of T-helper lymphocytes in the blood of the experimental group of bulls under cadmium loading is probably reduced by 15, 20 and 30 days of testing. A probable increase in the number of T-suppressors was noted in the bull's blood of the experimental group on the 20th day of the research. Immunoglobulins of different classes are crucial among bull’s serum proteins under cadmium loading. The concentration of immunoglobulins in the blood under cadmium load decreased by 15.9 % relative to the control group on the 20th day of analysis.

Arsenic Disulfide Promoted Hypomethylation by Increasing DNA Methyltransferases Expression in Myelodysplastic Syndrome.

BackgroundPrevious studies have shown that DNA methylation plays a significant role in myelodysplastic syndrome (MDS). In addition to hypermethylation, aberrant hypomethylation can result in the transcriptional activation of oncogenes in cancer, including MDS. Therefore, drugs targeting DNA hypomethylation are needed for the treatment of MDS. This study aimed to investigate whether As2S2 promoted hypomethylation by increasing DNA methyltransferases (DNMTs) expression in MDS.Patients and MethodsTen bone marrow samples from MDS patients and 3 healthy donors were obtained for the examination of the DNA methylation with a Human Methylation 850K BeadChip. The mRNA expressions for the DNMTs in the ten MDS patients and 3 controls were compared by Q-PCR. Then, the MDS cell line SKM-1 was treated with As2S2. After 2 days of treatment, Human Methylation 850K BeadChip was applied to analyze the changes of gene methylation status in the cells. Q-PCR and Western blot were taken to test the changes of mRNA and protein expressions for DNMTs in SKM-1 cells after treatment.ResultsFive hundred ninety-two abnormally hypomethylated genes were found in MDS patients compared to those in controls by Human Methylation 850K. The mRNA expressions of DNMTs (DNMT1, DNMT3a and DNMT3b) in MDS patients were significantly lower than those in healthy individuals. The IC50 value of As2S2 for SKM-1 cells was 4.97 μmol/L.Treatment with As2S2 at 2 μmoL/L resulted in significant alterations in the methylation levels at 1718 sites in SKM-1 cells compared to those in the controls. Hypermethylation was observed in 1625 sites (94.58%), corresponding to 975 genes, compared to those in the controls. Finally, the expression levels of DNMTs (DNMT1, DNMT3a, and DNMT3b) significantly increased in SKM-1 cells treated with As2S2 at 2 μmoL/L and 4 μmoL/L.ConclusionThese data show a potential clinical application of As2S2 as an innovative hypermethylation agent in MDS.

Microgreens: Consumer sensory perception and acceptance of an emerging functional food crop.

Microgreens are an emerging functional food crop with promise for sustainably diversifying global food systems, facilitating adaptations to urbanization and global climate change, and promoting human health. Previous work suggests microgreens have high nutritional quality, low environmental impacts, and broad consumer acceptance. For better reception into the global food system and increased per capita consumption, research is needed to elucidate consumer acceptance of various microgreens species, including factors contributing to their acceptance or lack thereof. Using a consumer panel (n = 99), this study evaluated consumer sensory perception and acceptability of six microgreens species (arugula, broccoli, bull's blood beet, red cabbage, red garnet amaranth, and tendril pea), and potential drivers and barriers to consumer acceptance. All microgreens species received high mean liking scores for acceptability by consumers (means ranged from highly acceptable to slightly acceptable), with more distinct differences across microgreens species for flavor and overall acceptability, which appeared to be driven by specific sensory properties. Data from principal component analysis demonstrated that high acceptability scores were associated with higher intent to purchase microgreens and negatively associated with food neophobia. Participants indicated that factors such as knowledge and familiarity of microgreens, cost, access/availability, freshness/shelf life, among other factors, influence their intention to purchase microgreens. These findings suggest that further integration of microgreens into the global food system will be met with high consumer acceptability, but needs to be aligned with enhanced consumer education regarding microgreens, as well as considerations of cost, availability/access, and freshness/shelf life. PRACTICAL APPLICATION: Researchers investigated consumer sensory perception and acceptability of six microgreens species (arugula, broccoli, bull's blood beet, red cabbage, red garnet amaranth, and tendril pea), and potential drivers and barriers to consumer acceptance. All microgreens tested had high consumer acceptability, but certain factors such as sensory perception and food neophobia impacted their acceptability. Additionally, participants indicated that factors such as knowledge, access and availability, cost, freshness, and shelf life may impact the purchasing of microgreens and thus are important factors to consider for further integration of this emerging functional food crop into the global food system.

Chronic toxicity study of Sameera Pannaga Rasa in Charle's foster albino rats.

Introduction:SameeraPannagaRasa (SPR) is a Kupi Pakwa Rasayana (a mercurial–arsenical formulation of Ayurveda prepared by specific pharmaceutical-controlled, indirect heat treatment [sand bath] in glass bottle) that contains Shodhita Parada (processed mercury), Shodhita Gandhaka (processed sulfur), Shodhita Haratala (processed arsenic trisulfide), Shodhita Somala (processed arsenic oxide) and Shodhita Manahshila (process arsenic disulfide) in equal quantity as ingredients. Parada, Haratala, Manahshila and Somala are highly potent minerals which are included in the Drug and Cosmetic Act 1940 under Schedule E1 because of their toxic nature in crude form.Materials and methods:In the present study, SPR was evaluated for safety profile through its chronic toxicity study in Charle’s foster albino rats. The test drug was made into suspension in vehicle (4 ml honey and 7 ml distilled water). The test drug was administered orally once a day for 90 consecutive days in the dose of 11.25 (therapeutic dose [TED]), 56.25 (5 times TED) and 112.25 mg/kg (10 times TED). Animals were sacrificed on 91st day and animals of recovery group were sacrificed on 121st day. Parameters such as hematological, serum biochemical, and histopathology of various organs were studied.Results:Test drug at a higher dose level and recovery study showed no toxic effect in albino rats during chronic toxicity study.Conclusion:SPR is found to have no toxic effect in albino rats during the repeated dose, oral, chronic toxicity study of 90 days, even at 10 times therapeutic equivalent dose (112.25 mg/kg) and even during recovery period of 1 month. It may be safety used at TED level.

Novel acaricides by nanotechnology against cattle ticks and their effect on physiological and productive performance

A field trail was conducted to evaluate the efficacy of capsules suspension formulation (CS) by nanotechnology and conventional acaricides against the cattle ticks (Hyalomma marginatum) and its effects on the body weight and blood parameters of Aberdeen angus cattle. Acaricides residues were determined in an animal's blood and milk. Thirty infested cattle were randomly divided into five groups, each one contains (3 bulls and 3 cows) based on the mean tick count. Results showed that, permethrin 25 % CS and lambada-cyhalothrin 10 % CS were significantly the most effective against ticks (2.7 and 3.8 ticks/animal, respectively) compared to fipronil 20 % SC and Acetamiprid 20 % SL (8.3 and 6.3 ticks/animal, respectively) after 70 days of treatment. Permethrin 25 % CS achieved 100 % control against highly ticks' infestation after 3 days of treatment and maintained for 56 days without its residues in blood and milk samples. Conversely, fipronil residue was detected in the cow's blood and milk (1.3 and 2.7 µg/l, respectively) however, it's non detected in bull's blood after 1 week of treatment. They gradually decreased to below detection limits after 3 and 6 weeks respectively. The animal body weight was significantly increased, additionally: the liver and kidney function were decreased to normal level in all treated animals. Finally, permethrin and lambda-cyhalothrin that formulated CS can be used as efficient acaricides and a safe alternative in tick control strategy in tropical areas.

Nano-realgar Inhibits the Proliferation of Bladder Cancer Cell and Induces the Expression of Apoptosis-related Proteins

Background The main component of realgar is arsenic disulfide (As2S2). Modern medical research shows that realgar can inhibit tumorigenesis and development of tumor by regulating cell proliferation and apoptosis. However, the lack of the traditional realgar preparations present with lower bioavailability, which further affects the therapeutic effect. With the improvement of new drug preparation processes, nano-androgen is increasingly used for anti-tumor drugs. Objective In order to investigate the effect of nano-realgar on proliferation of bladder cancer cell line RT4, we performed the research. Methods Nano-realgar was prepared by mechanical milling method. RT4 cell was used as target cell. MTT assay was used to detect the proliferation of RT4 cell treated with nano-realgar. And western blot was used to detect the expression of apoptosis-related proteins (Bax, Caspase-3) in the RT4 cell treated with nano-realgar. Results Nano-realgar could significantly inhibit the proliferation of RT4 cell. After treated with 10 ug/ml, 20 ug/ml and 40 ug/ml nano-realgar for 24 h and 48 h, the proliferation inhibition rate of RT4 cell increased significantly compared with the negative control group (P<0.05), and the expression of apoptosis-related proteins, Bad and Caspase-3, increased significantly after treated with 20 ug/ml and 40 ug/ml nano-realgar for 48 h (P<0.05). Conclusion Nano-realgar can inhibit the proliferation of RT4 cell, and induces the expression of Bax and Caspase-3.

Arsenic Disulfide Combined with L-Buthionine-(S, R)-Sulfoximine Induces Synergistic Antitumor Effects in Two-Dimensional and Three-Dimensional Models of MCF-7 Breast Carcinoma Cells.

Three-dimensionally (3D) cultured tumor cells (spheroids) exhibit more resistance to therapeutic agents than the cells cultured in traditional two-dimensional (2D) system (monolayers). We previously demonstrated that arsenic disulfide (As2 exerted significant anticancer efficacies in both 2D- and 3D-cultured MCF-7 cells, whereas 3D spheroids were shown to be resistant to the As2S2 treatment. L-buthionine-(S, R)-sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, has been regarded to be a potent candidate for combinatorial treatment due to its GSH modulation function. In the present study, we introduced BSO in combination with As2S2 at a low concentration to investigate the possible enhancing anticancer efficacy by the combinatorial treatment on 2D- and 3D-cultured MCF-7 cells. Our results presented for the first time that the combination of As2S2 and BSO exerted potent anticancer synergism in both MCF-7 monolayers and spheroids. The values of As2S2 in combinatorial treatment were significantly lower than those in treatment of As2S2 alone in both 2D- and 3D-cultured MCF-7 cells (, respectively). In addition, augmented induction of apoptosis and enhanced cell cycle arrest along with the regulation of apoptosis- and cell cycle-related proteins, as well as synergistic inhibitions of PI3K/Akt signals, were also observed following co-treatment of As2S2 and BSO. Notably, the combinatorial treatment significantly decreased the cellular GSH levels in both 2D- and 3D-cultured MCF-7 cells in comparison with each agent alone ( in each). Our results suggest that the combinatorial treatment with As2S2 and BSO could be a promising novel strategy to reverse arsenic resistance in human breast cancer.

Antitumor effects of arsenic disulfide on the viability, migratory ability, apoptosis and autophagy of breast cancer cells.

In the present study, the antitumor effects of arsenic disulfide (As2S2) on the proliferative, survival and migratory ability of human breast cancer MCF-7 and MDA-MB-231 cells were investigated, and its potential underlying molecular mechanisms with an emphasis on cell cycle arrest, apoptosis induction, autophagy induction and reactive oxygen species (ROS) generation were determined. The results indicated that As2S2 significantly inhibited the viability, survival and migration of breast cancer cells in a dose-dependent manner. In addition, it was identified that As2S2 induced cell cycle arrest primarily at G2/M phase in the two breast cancer cell lines by regulating the expression of associated proteins, including cyclin B1 and cell division cycle protein 2. In addition to cell cycle arrest, As2S2 also triggered the induction of apoptosis in cells by activating the expression of pro-apoptotic proteins, including caspase-7 and −8, as well as increasing the B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 ratio, while decreasing the protein expression of anti-apoptotic B-cell lymphoma extra-large. In addition, As2S2 stimulated the accumulation of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II and increased the LC3-II/LC3-I ratio, indicating the occurrence of autophagy. As2S2 treatment also inhibited the protein expression of matrix metalloproteinase-9 (MMP-9), but increased the intracellular accumulation of ROS in the two breast cancer cell lines, which may assist in alleviating metastasis and attenuating the progression of breast cancer. Taken together, the results of the present study suggest that As2S2 inhibits the progression of human breast cancer cells through the regulation of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, MMP-9 signaling and ROS generation.

Arsenic disulfide‑induced apoptosis and its potential mechanism in two‑ and three‑dimensionally cultured human breast cancer MCF‑7 cells.

In China, arsenic disulfide (As2S2) has been used for the treatment of hematological malignancies. The present study aimed to evaluate the effects of As2S2 on the human breast cancer MCF‑7 cell line cultured in both two‑dimensional(2D) monolayers and three‑dimensional(3D) spheroids to explore its therapeutic potential in breast cancer treatment. Cellular viability and the induction of apoptosis were examined with a cell counting kit‑8(CCK‑8) assay and flow cytometric analysis, respectively. Alterations in the expression levels of apoptosis‑associated proteins, including Bcl‑2‑associatedX protein (Bax), B‑cell lymphoma2 (Bcl‑2), p53, and caspase‑7, as well as the cell survival‑associated proteins, phosphatidylinositol 3‑kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR), were assessed by western blotting. Although a dose‑dependent reduction in cell viability, which occurred in association with the induction of apoptosis triggered by the addition of 2‑24µM As2S2, was observed in both 2D‑ and 3D‑culture systems, 3D spheroids were less sensitive to the cytotoxic effect of As2S2 compared with the 2D cultured cells. A significant increase in the expression levels of Bax, p53, and caspase‑7 was observed in treated 2D‑cultured cells, whereas a similar increase in the expression levels of Bax was only confirmed in treated 3D spheroids, although there was a trend towards the increased expression of p53 and caspase‑7 in the 3D spheroids. These results suggested that these molecules are closely associated with As2S2‑mediated cytotoxicity in the two culture systems, and further suggested that the difference in the sensitivity to As2S2 between 2D monolayers and 3Dspheroids may be attributed to the differential alterations in the expression levels of proteins associated with cell mortality. Significant downregulation of the expression levels of Bcl‑2, PI3K, Akt and mTOR was observed in the two culture systems. Taken together, the results of the present study demonstrated that As2S2 inhibits cell viability and induces apoptosis in both 2D‑ and 3D‑ cultured MCF‑7 cells, which may be associated with activation of the pro‑apoptotic pathway and the inhibition of pro‑survival signaling. These results have provided novel insights into clinical applications of As2S2 in the treatment of patients with breast cancer.

Chemo-sensitivity of Two-dimensional Monolayer and Three-dimensional Spheroid of Breast Cancer MCF-7 Cells to Daunorubicin, Docetaxel, and Arsenic Disulfide.

Chemo-sensitivity of two-dimensional (2D) monolayers and three-dimensional (3D) spheroids of human breast cancer MCF-7 cells were investigated. MCF-7 cells were cultured in monolayers or spheroids established using a thermo-reversible gelatin polymer, in the presence of daunorubicin, docetaxel, or As2S2 Cell proliferation was examined by a Cell Counting Kit-8 assay. Daunorubicin, docetaxel, and As2S2 dose-dependently decreased the MCF-7 cell proliferation in both 2D- and 3D-culture systems. The 3D spheroids were less sensitive to these agents than the 2D cultured cells. Verapamil, an inhibitor of P-glycoprotein, partially enhanced the antiproliferative effects of the agents. DL-buthionine-(S, R)-sulfoximine significantly increased (p<0.05), while N-acetyl-L-cysteine significantly inhibited the antiproliferative effects of As2S2 (p<0.003). The 3D spheroids showed less sensitivity to the antiprolliferative efficacies of anticancer agents than the 2D cultured cells. P-Glycoprotein is suggested to be partially implicated in drug resistance. Reduction of cellular glutathione level enhanced the As2S2 cytotoxicity.