Erk is involved in the differentiation induced by diallyl disulfide in the human gastric cancer cell line MGC803

Flexible dynamic quantitative phase imaging based on division of focal plane polarization imaging technique

This paper proposes a flexible and accurate dynamic quantitative phase imaging (QPI) method using single-shot transport of intensity equation (TIE) phase retrieval achieved by division of focal plane (DoFP) polarization imaging technique. By exploiting the polarization property of the liquid crystal spatial light modulator (LC-SLM), two intensity images of different defocus distances contained in orthogonal polarization directions can be generated simultaneously. Then, with the help of the DoFP polarization imaging, these images can be captured with single exposure, enabling accurate dynamic QPI by solving the TIE. In addition, our approach gains great flexibility in defocus distance adjustment by adjusting the pattern loaded on the LC-SLM. Experiments on microlens array, phase plate, and living human gastric cancer cells demonstrate the accuracy, flexibility, and dynamic measurement performance for various objects. The proposed method provides a simple, flexible, and accurate approach for real-time QPI without sacrificing the field of view.

Garlic constituents for cancer prevention and therapy: From phytochemistry to novel formulations

Garlic (Allium sativum L.) is one of the oldest plants cultivated for its dietary and medicinal values. This incredible plant is endowed with various pharmacological attributes, such as antimicrobial, antiarthritic, antithrombotic, antitumor, hypoglycemic, and hypolipidemic activities. Among the various beneficial pharmacological effects of garlic, the anticancer activity is presumably the most studied. The consumption of garlic provides strong protection against cancer risk. Taking into account the multi-targeted actions and absence of considerable toxicity, a few active metabolites of garlic are probably to play crucial roles in the killing of cancerous cells. Garlic contains several bioactive molecules with anticancer actions and these include diallyl trisulfide, allicin, diallyl disulfide, diallyl sulfide, and allyl mercaptan. The effects of various garlic-derived products, their phytoconstituents and nanoformulations have been evaluated against skin, prostate, ovarian, breast, gastric, colorectal, oral, liver, and pancreatic cancers. Garlic extract, its phytocompounds and their nanoformulations have been shown to inhibit the different stages of cancer, including initiation, promotion, and progression. Besides, these bioactive metabolites alter the peroxidation of lipid, activity of nitric oxide synthetase, nuclear factor-κB, epidermal growth factor receptor, and protein kinase C, cell cycle, and survival signaling. The current comprehensive review portrays the functions of garlic, its bioactive constituents and nanoformulations against several types of cancers and explores the possibility of developing these agents as anticancer pharmaceuticals.

Improving the bioavailability and bioactivity of garlic bioactive compounds via nanotechnology

This review highlights main bioactive compounds and important biological functions especially anticancer effects of the garlic. In addition, we review current literature on the stability and bioavailability of garlic components. Finally, this review aims to provide a potential strategy for using nanotechnology to increase the stability and solubility of garlic components, providing guidelines for the qualities of garlic products to improve their absorption and prevent their early degradation, and extend their circulation time in the body. The application of nanotechnology to improve the bioavailability and targeting of garlic compounds are expected to provide a theoretical basis for the functional components of garlic to treat human health. We review the improvement of bioavailability and bioactivity of garlic bioactive compounds via nanotechnology, which could promisingly overcome the limitations of conventional garlic products, and would be used to prevent and treat cancer and other diseases in the near future.

Garlic and its Active Compounds: A Potential Candidate in The Prevention of Cancer by Modulating Various Cell Signalling Pathways

BACKGROUND

Cancer is a multi-factorial disease including alterations in the cell signalling pathways. Currently, several drugs are in use to treat cancer but such drugs show negative side effects on normal cells and cause severe toxicity.

METHODS

The current research is mainly focused on medicinal plants with potential therapeutic efficacy in the treatment of cancer without any adverse effects on normal cells. In this regard, garlic and its active compounds including diallyl sulfide, diallyl trisulfide, ajoene, and allicin have been established to suppress the growth of cancer and killing of cancer cells.

RESULT

The review focuses on garlic and its active compounds chemopreventive effect through modulating various cell signalling pathways. Additionally, garlic and its active compound were established to induce cell cycle arrest at the G0/G1 phase and G2/M phases in cancer cells, increase the expression of tumor suppressor genes, inhibit the angiogenesis process, induction of apoptosis and modulation of various other genetic pathways.

CONCLUSION

This review sketches the diverse chemopreventive activities of garlic and their active ingredients in the management of cancer mainly focusing on cell signalling pathways.

Diallyl disulfide induces downregulation and inactivation of cofilin 1 differentiation via the Rac1/ROCK1/LIMK1 pathway in leukemia cells

Cofilin is associated with cell differentiation; however, to the best of our knowledge, no data have indicated an association between the cofilin 1 pathway and leukemia cell differentiation. The present study investigated the involvement of the cofilin 1 signaling pathway in diallyl disulfide (DADS)-induced differentiation and the inhibitory effects on the proliferation, migration, and invasion of human leukemia HL-60 cells. First, it was identified that 8 µM DADS suppressed cell proliferation, migration and invasion, and induced differentiation based on the reduced nitroblue tetrazolium ability and increased CD11b and CD33 expression. DADS significantly downregulated the expression of cofilin 1 and phosphorylated cofilin 1 in HL-60 leukemia cells. Second, it was verified that silencing cofilin 1 markedly promoted 8 µM DADS-induced differentiation and the inhibitory effect on cell proliferation and invasion. Overexpression of cofilin 1 obviously suppressed 8 µM DADS-induced differentiation and the inhibitory effect on cell proliferation and invasion. Third, the present study examined the mechanisms by which 8 µM DADS decreases cofilin 1 expression and activation. The results revealed that 8 µM DADS inhibited the mRNA and protein expression of Rac1, Rho-associated protein kinase 1 (ROCK1) and LIM domain kinase 1 (LIMK1) as well as the phosphorylation of LIMK1 in HL-60 cells, while 8 µM DADS enhanced the effects of the Rac1-ROCK1-LIMK1 pathway in cells overexpressing cofilin 1 compared with that in control HL-60 cells. These results suggest that the anticancer function of DADS on HL-60 leukemia cells is regulated by the Rac1-ROCK1-LIMK1-cofilin 1 pathway, indicating that DADS could be a promising anti-leukemia therapeutic compound.

Phytochemicals for the Prevention and Treatment of Gastric Cancer: Effects and Mechanisms

Gastric cancer is the fifth most common cancer, and the third most prevalent cause of cancer-related deaths in the world. Voluminous evidence has demonstrated that phytochemicals play a critical role in the prevention and management of gastric cancer. Most epidemiological investigations indicate that the increased intake of phytochemicals could reduce the risk of gastric cancer. Experimental studies have elucidated the mechanisms of action, including inhibiting cancer cell proliferation, inducing apoptosis and autophagy, and suppressing angiogenesis as well as cancer cell metastasis. These mechanisms have also been related to the inhibition of Helicobacter pylori and the modulation of gut microbiota. In addition, the intake of phytochemicals could enhance the efficacy of anticancer chemotherapeutics. Moreover, clinical studies have illustrated that phytochemicals have the potential for the prevention and the management of gastric cancer in humans. To provide an updated understanding of relationships between phytochemicals and gastric cancer, this review summarizes the effects of phytochemicals on gastric cancer, highlighting the underlying mechanisms. This review could be helpful for guiding the public in preventing gastric cancer through phytochemicals, as well as in developing functional food and drugs for the prevention and treatment of gastric cancer.

Vicenin-2 acts as a radiosensitizer of the non-small cell lung cancer by lowering Akt expression

Non-small cell lung cancer (NSCLC) has a very high rate of incidence and is resistant to chemo- and radiotherapy. Vicenin-2 (VCN-2) is a flavonoid obtained from Ocimum sanctum L. and it has been reported to have radioprotective, anticancer, and radiosensitizing properties. We have conducted this study to check the effect of VCN-2 on the cell viability and the effect on PTEN (Phosphatase and tensin homolog), PI3KCA (Phosphatidylinositol 4, 5-biphosphate 3-kinase catalytic subunit alpha isoform/PI3K 110α subunit), and Akt1 when VCN-2 was used alone and in combination with radiation in the NSCLC cell line NCI-H23 (H23). We have also checked the effect of VCN-2 on various pro- and anti-apoptotic genes and the ultra-morphological changes that occurred in the cells when VCN-2 is used alone and in combination with radiation. VCN-2 was able to lower cancer cell survival and phosphorylated Akt while promoting the expression of pro-apoptotic genes and down-regulating anti-apoptotic genes. We also observed the apoptosis-associated ultra-morphological changes in the VCN-2-treated cells. Our study have demonstrated that VCN-2 can be a potential chemotherapeutic and radiosensitizing agent in NSCLC. © 2018 BioFactors, 45(2):200-210, 2019.

The garlic allelochemical DADS influences cucumber root growth involved in regulating hormone levels and modulating cell cycling

Most allelochemicals are phytotoxic to the receiver plants and may influence the cell micro- and ultrastructure, cell division, phytohormone levels, and ultimately growth. In order to understand the allelopathic potential of garlic, the effects of its main bioactive allelochemical diallyl disulfide (DADS), experiments were carried out to observe the seed germination, root growth, and developmental responses in cucumber seedlings treated with various concentrations of DADS. The obtained data suggested active influence of DADS on cucumber root growth and development. Significant responses were observed in early root growth and elongation, mitotic cell division and elongation, and root architecture modulation. The effect, however, was dose dependent, and lower concentrations of DADS proved to be promotional whereas higher concentrations of DADS inhibited cucumber root growth and development. Relative root elongation (RRE) revealed that DADS could increase growth of cucumber roots in the early developmental days. Moreover, DADS application significantly influenced mitosis-related gene expression. Observed genes CYCA and CDKB were initially downregulated in the first 24 h but significantly upregulated after 48 h, while gene CDKA was upregulated in the first 24 h. Similarly, DADS application significantly altered primary plant hormones, such as IAA, ABA, GA₃, and ZR, in the cucumber roots. Taken together, low concentrations of DADS treatment could promote cucumber root growth and induce main root elongation by upregulating CDKA and CDKB gene expression and regulating hormone balance in root. The current findings offer insight into the allelopathic potential of garlic allelochemical DADS and can be considered vital for establishing plant allelopathic studies.

Identification of potential targets for differentiation in human leukemia cells induced by diallyl disulfide

Diallyl disulfide (DADS) is a primary component of garlic, which has chemopreventive potential. We previously found that moderate doses (15-120 µM) of DADS induced apoptosis and G2/M phase cell cycle arrest. In this study, we observed the effect of low doses (8 µM) of DADS on human leukemia HL-60 cells. We found that DADS could inhibit proliferation, migration and invasion in HL-60 cells, and arrested cells at G0/G1 stage. Then, cell differentiation was displayed by morphologic observation, NBT reduction activity and CD11b evaluation of cytometric flow. It showed that DADS induced differentiation, reduced the ability of NBT and increased CD11b expression. Likewise, DADS inhibited xenograft tumor growth and induced differentiation in vivo. In order to make sure how DADS induced differentiation, we compared the protein expression profile of DADS-treated cells with that of untreated control. Using high resolution mass spectrometry, we identified 18 differentially expressed proteins after treatment with DADS, including four upregulated and 14 downregulated proteins. RT-PCR and western blot assay showed that DJ-1, cofilin 1, RhoGDP dissociation inhibitor 2 (RhoGDI2), Calreticulin (CTR) and PCNA were decreased by DADS. These data suggest that the effects of DADS on leukemia may be due to multiple targets for intervention.

Diallyl disulfide suppresses epithelial-mesenchymal transition, invasion and proliferation by downregulation of LIMK1 in gastric cancer

Diallyl disulfide (DADS) has been shown to have multi-targeted antitumor activities. We have previously discovered that it has a repressive effect on LIM kinase-1 (LIMK1) expression in gastric cancer MGC803 cells. This suggests that DADS may inhibit epithelial-mesenchymal transition (EMT) by downregulating LIMK1, resulting in the inhibition of invasion and growth in gastric cancer. In this study, we reveal that LIMK1 expression is correlated with tumor differentiation, invasion depth, clinical stage, lymph node metastasis, and poor prognosis. DADS downregulated the Rac1-Pak1/Rock1-LIMK1 pathway in MGC803 cells, as shown by decreased p-LIMK1 and p-cofilin1 levels, and suppressed cell migration and invasion. Knockdown and overexpression experiments performed in vitro demonstrated that downregulating LIMK1 with DADS resulted in restrained EMT that was coupled with decreased matrix metalloproteinase-9 (MMP-9) and increased tissue inhibitor of metalloproteinase-3 (TIMP-3) expression. In in vitro and in vivo experiments, the DADS-induced suppression of cell proliferation was enhanced and antagonized by the knockdown and overexpression of LIMK1, respectively. Similar results were observed for DADS-induced changes in the expression of vimentin, CD34, Ki-67, and E-cadherin in xenografted tumors. These results indicate that downregulation of LIMK1 by DADS could explain the inhibition of EMT, invasion and proliferation in gastric cancer cells.

Involvement of calreticulin in cell proliferation, invasion and differentiation in diallyl disulfide-treated HL-60 cells

Diallyl disulfide (DADS) has shown potential as a therapeutic agent in various cancers. Previously, calreticulin (CRT) was found to be downregulated in differentiated HL-60 cells treated with DADS. The present study investigated the role of CRT proteins in DADS-induced proliferation, invasion and differentiation in HL-60 cells. The present study demonstrated that DADS treatment significantly changed the morphology of HL-60 cells and caused the significant time-dependent downregulation of CRT. Small interfering RNA (siRNA)-mediated knockdown of CRT expression significantly inhibited proliferation, decreased invasion ability, increased the expression of cluster of differentiation (CD)11b and reduced the expression of CD33 in DADS-treated HL-60 cells. DADS also significantly affected cell proliferation, invasion and differentiation in CRT-overexpressed HL-60 cells. Nitroblue tetrazolium (NBT) reduction assays showed decreased NBT reduction activity in the CRT overexpression group and increased NBT reduction in the CRT siRNA group. Following treatment with DADS, the NBT reduction abilities in all groups were increased. In conclusion, the present study clearly demonstrates the downregulation of CRT during DADS-induced differentiation in HL-60 cells and indicates that CRT is involved in cell proliferation, invasion and differentiation in DADS-treated HL-60 cells.

Identification of potential targets for diallyl disulfide in human gastric cancer MGC-803 cells using proteomics approaches

Diallyl disulfide (DADS) is characterized as an effective agent for the prevention and therapy of cancer, however, mechanisms regarding its anticancer effects are not fully clarified. In the present study, we compared the protein expression profile of gastric cancer MGC-803 cells subjected to DADS treatment with that of untreated control cells to explore potential molecules regulated by DADS. Using proteomic approaches, we identified 23 proteins showing statistically significant differences in expression, including 9 upregulated and 14 downregulated proteins. RT-PCR and western blot analysis confirmed that retinoid-related orphan nuclear receptor α (RORα) and nM23 were increased by DADS, whereas LIM kinase-1 (LIMK1), urokinase-type plasminogen activator receptor (uPAR) and cyclin-dependent kinase-1 (CDK1) were decreased. DADS treatment and knockdown of uPAR caused suppression of ERK/Fra-1 pathway, downregulation of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9) and vimentin, and upregulation of tissue inhibitor of metalloproteinase-3 (TIMP-3) and E-cadherin, concomitant with inhibition of cell migration and invasion. Moreover, knockdown of uPAR potentiated the effects of DADS on MGC-803 cells. These data demonstrate that downregulation of uPAR may partially be responsible for DADS-induced inhibition of ERK/Fra-1 pathway, as well as cell migration and invasion. Thus, the discovery of DADS-induced differential expression proteins is conducive to reveal unknown mechanisms of DADS anti-gastric cancer.

Role of H2S Donors in Cancer Biology

Hydrogen sulfide (H2S) donors including organosulfur compounds (OSC), inorganic sulfide salts, and synthetic compounds are useful tools in studies to elucidate the effects of H2S in cancer biology. Studies using such donors have shown the ability of H2S to suppress tumor growth both in vitro and in vivo, with some of them suggesting the selectivity of its cytotoxic effects to cancer cells. In addition to promoting cancer cell death, H2S donors were also found to inhibit cancer angiogenesis and metastasis. The underlying mechanisms for the anticancer activities of H2S involve (1) cell signaling pathways, such as MAPK and STAT; (2) cell cycle regulation; (3) microRNAs regulation; and (4) cancer metabolism and pH regulation. Altogether, compiling evidences have demonstrated the great potential of using H2S donors as anticancer agents. Nevertheless, the application and development of H2S for therapy are still facing challenges as identification of molecular targets of H2S awaits further investigation.

Diallyl disulfide selectively causes checkpoint kinase-1 mediated G2/M arrest in human MGC803 gastric cancer cell line

Previous studies have shown that diallyl disulfide (DADS), a naturally occurring anticancer agent in garlic, arrested human gastric cancer cells (MGC803) in the G2/M phase of the cell cycle. Due to the importance of cell cycle redistribution in DADS-mediated anticarcinogenic effects, we investigated the role of checkpoint kinases (Chk1 and Chk2) during DADS-induced cell cycle arrest. In the present study, the northern blot analysis showed that mRNA expression of for Chkl and Chk2 was unchanged. Notably, DADS induced the accumulation of phosphorylated Chk1, but not of Chk2, activated phospho-ATR (ATM-RAD3-related gene), and dowregulated CDC25C and cyclin B1 expression. Furthermore, CDC25C was immunoprecipitated by anti-Chk1 but not anti-Chk2. Results of the overexpression and knockdown studies, showed that Chk1 but not Chk2 regulated the DADS-induced G2/M arrest of MGC803 cells. The overexpression of Chk1 resulted in significantly increased DADS-induced G2/M arrest, increased DADS-induced Chk1 phosphorylation and inhibited CDC25C expression. Knockdown of Chk1 reduced DADS‑induced G2/M arrest and blocked the DADS-induced inhibition of CDC25C and cyclin B1 expression. These results suggested that Chk1 is important in DADS‑induced cell cycle G2/M arrest in the human MGC803 gastric cancer cell line. Furthermore, the DADS-induced G2/M checkpoint response is mediated by Chk1 signaling through ATR/Chk1/CDC25C/cyclin B1.

Chk1, but not Chk2, is responsible for G2/M phase arrest induced by diallyl disulfide in human gastric cancer BGC823 cells

Diallyl disulfide (DADS) has been shown to cause G2/M phase cell cycle arrest in several human cancers. Here we demonstrate a mechanism by which DADS induces G2/M phase arrest in BGC823 human gastric cancer cells via Chk1. From cell cycle gene array results, we next confirmed that cyclin B1 expression was decreased by DADS, while the expression of p21, GADD45α and p53 were increased. Despite the lack of change in Chk1 gene expression in response to DADS according to the array analysis, intriguingly overexpression of Chk1, but not Chk2, exhibited increased accumulation in G2/M phase. Moreover, overexpression of Chk1 promoted the effect of DADS-induced G2/M arrest. Augmented phosphorylation of Chk1 by DADS was observed in Chk1-transfected cells, followed by downregulation of Cdc25C and cyclin B1 proteins. In contrast, phosphorylated Chk2 showed no obvious change in Chk2-transfected cells after DADS treatment. Furthermore, knockdown of Chk1 by siRNA partially abrogated DADS-induced downregulation of Cdc25C and cyclin B1 proteins and G2/M arrest. In contrast, knockdown of Chk2 did not show these effects. Therefore, these data indicate that DADS may specifically modulate Chk1 phosphorylation, and DADS-induced G2/M phase arrest in BGC823 cells could result in part from Chk1-mediated inhibition of the Cdc25C/cyclin B1 pathway.

Fresh Garlic Extract Induces Growth Arrest and Morphological Differentiation of MCF7 Breast Cancer Cells

Consumption of diets rich in fruits and vegetables is often associated with a reduced risk of developing cancer, particularly breast cancer. Considering that 1 in 8 women in the United States will develop breast cancer in the course of her lifetime, dietary manipulation could have a major impact on the incidence of breast cancer. We report here that fresh extracts of garlic (not boiled) arrested the growth and altered the morphology of MCF7 breast cancer cells. Deregulated levels of E-cadherin, cytokeratin8/18, and β-catenin correlated with the altered phenotype. We propose that early down-regulation of cyclin D1, reduced phosphorylation of ERK1, and increased phosphorylation of eIF2-α triggered the phenotypical changes. Reduced expression of hsp27 and sam68 and elevated levels of Rb and p21 further contributed to the sustained growth reduction. These findings provide a better understanding of the cellular responses to dietary supplements and provide potential options to treat breast cancer.

Role of Ras-related C3 botulinum toxin substrate 2 (Rac2), NADPH oxidase and reactive oxygen species in diallyl disulphide-induced apoptosis of human leukaemia HL-60 cells

1. Diallyl disulphide (DADS) has potential as a chemopreventive and therapeutic agent. Previous studies have reported that Ras-related C3 botulinum toxin substrate 2 (Rac2), a regulatory subunit of the NADPH oxidase complex, is upregulated in DADS-induced apoptosis in human leukaemia HL-60 cells. The aim of the present study was to investigate the role of Rac2, NADPH oxidase and reactive oxygen species (ROS) in DADS-induced apoptosis. 2. Expression of the Rac2 gene along with that of five other genes of NADPH oxidase subunits were in HL-60 cells measured by Sybergreen quantitative real-time polymerase chain reaction. RNA interference was used to test the effect of Rac2. Protein expression was evaluated using western blot analysis and ROS levels were measured by 2',7'-dichlorofluorescein diacetate (DCFH-DA) fluorescence. DNA fragmentation and flow cytometry analysis were used to detect apoptotic cells. 3. Levels of Rac2 gene and protein were significantly upregulated and NADPH oxidase was activated in DADS-induced apoptosis. Pretreatment of HL-60 cells with small interfering (si) RNAs to inhibit Rac2 blocked DADS-induced apoptosis. Diallyl disulphide-induced intracellular ROS production was increased in phorbol myristate acetate-stimulated cells, but decreased in Rac2 siRNA-treated cells. In Rac2 siRNA-treated cells, activator protein-1 and caspase 3 levels decreased, c-myc protein levels were increased and p38 protein levels were unchanged compared with Rac2-competent, DADS-treated cells. 4. These results demonstrate that NADPH oxidase is the main source of DADS-induced ROS. In addition, Rac2 selectively activates the c-Jun N-terminal kinase pathway, but not the p38 pathway, in DADS-induced apoptosis. So, Rac2, NADPH oxidase and ROS have a critical role in DADS-induced apoptosis in human leukaemia HL-60 cells.

Garlic: nature's protection against physiological threats

Currently reliance on natural products is gaining popularity to combat various physiological threats including oxidative stress, cardiovascular complexities, cancer insurgence, and immune dysfunction. The use of traditional remedies may encounter more frequently due to an array of scientific evidence in their favor. Garlic (Allium sativum) holds a unique position in history and was recognized for its therapeutic potential. Recent advancements in the field of immunonutrition, physiology, and pharmacology further explored its importance as a functional food against various pathologies. Extensive research work has been carried out on the health promoting properties of garlic, often referred to its sulfur containing metabolites i.e. allicin and its derivatives. Garlic in its preparations are effective against health risks and even used as dietary supplements such as age garlic extract (AGE) and garlic oil etc. Its components/formulations can scavenge free radicals and protect membranes from damage and maintains cell integrity. It also provides cardiovascular protection mediated by lowering of cholesterol, blood pressure, anti-platelet activities, and thromboxane formation thus providing protection against atherosclerosis and associated disorders. Besides this, it possesses antimutagenic and antiproliferative properties that are interesting in chemopreventive interventions. Several mechanisms have been reviewed in this context like activation of detoxification phase-I and II enzymes, reactive oxygen species (ROS) generation, and reducing DNA damage etc. Garlic could be useful in preventing the suppression of immune response associated with increased risk of malignancy as it stimulates the proliferation of lymphocytes, macrophage phagocytosis, stimulates the release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma, and enhances natural killer cells. In this paper much emphasis has been placed on garlic's ability to ameliorate oxidative stress, core role in cardiovascular cure, chemopreventive strategies, and indeed its prospective as immune booster.

Apoptosis induced by diallyl disulfide in human breast cancer cell line MCF-7

AIM

To investigate the effect of diallyl disulfide (DADS), a component of garlic, on apoptosis in human mammary cancer cell line (MCF-7) and its mechanisms.

METHODS

Cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assays. Morphology of apoptotic cells was detected by acridine orange and ethidium bromide staining. Apoptotic cells stained with propidium iodide were examined using flow cytometry. Protein levels were detected by Western blot analysis.

RESULTS

DADS inhibited the proliferation of MCF-7 cells and induced the apoptotic ratio to increase rapidly. Cleavage of the caspase-3 and caspase-3 substrate poly(ADP-ribose) polymerase was observed in MCF-7 cells after 24 h of treatment with DADS. When the MCF-7 cells were treated with 200 micromol x L DADS, the stress-activated protein kinase extracellular signal-regulated kinase (ERK), a mitogen-activated protein kinase, was inhibited after 6 h; c-Jun N-terminal kinase (JNK), that is stress-activated protein kinase (SAPK), and p38 mitogen-activated protein kinase were activated after 6 h.

CONCLUSION

These results suggest that DADS both inhibits the proliferation of MCF-7 cells and induces apoptosis of MCF-7 cells. The mechanisms may include the inhibition of ERK and the activation of the SAPK/JNK and p38 pathways.