Norsolorinic acid from Aspergillus nidulans inhibits the proliferation of human breast adenocarcinoma MCF-7 cells via Fas-mediated pathway

Norsolorinic acid, isolated from the Aspergillus nidulans, was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. To identity the anticancer mechanism of norsolorinic acid, we assayed its effect on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that norsolorinic acid induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that Fas/Fas ligand apoptotic system is the main pathway of norsolorinic acid-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of norsolorinic acid in MCF-7 cells.     

Antiproliferative activity of paeoniflorin is through cell cycle arrest and the Fas/Fas ligand-mediated apoptotic pathway in human non-small cell lung cancer A549 cells

1. Paeoniflorin (PF), isolated from the paeony root, is reported to have immunoregulatory, neuromuscular blocking, anticonvulsant, antihyperglycaemic and antihypotensive effects. 2. The present study investigated the antiproliferative activity of PF. The results showed that PF inhibited the proliferation of A549 by blocking cell cycle progression in the G(0)/G(1) phase and inducing apoptosis. 3. An ELISA showed that G(0)/G(1) phase arrest may be due to p53-independent induction of p21/wild-type p53-activated fragment 1 (WAF1). Increased protein expression of Fas/apoptosis-1 (APO-1) and its two ligands, membrane-bound Fas ligand and soluble Fas ligand, may be responsible for the PF-induced apoptosis. 4. This is the first study to show that the induction of p21/WAF1 and the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of PF in A549 cells.     

Antiproliferative activity of aucubin is through cell cycle arrest and apoptosis in human non-small cell lung cancer A549 cells

Aucubin, an iridoid glycoside isolated from the leaves of Aucuba japonica, inhibits human non-small cell lung cancer A549 cells by blocking cell cycle progression in the G(0)/G(1) phase and inducing apoptosis. An ELISA showed that the G(0)/G(1) phase arrest is due to p53-mediated induction of p21. Enhancement of Fas and its two ligands, membrane-bound and soluble Fas ligand, may be responsible for the apoptotic effect induced by aucubin. The present study shows, for the first time, that the induction of p53 and activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of aucubin in A549 cells.     

Casuarinin from the bark of Terminalia arjuna induces apoptosis and cell cycle arrest in human breast adenocarcinoma MCF-7 cells

Casuarinin, a hydrolyzable tannin isolated from the bark of Terminalia arjuna L. (Combretaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. The results showed that casuarinin inhibited the proliferation of MCF-7 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. An enzyme-linked immunosorbent assay showed that casuarinin increased the expression of p21/WAF1 concomitantly as the MCF-7 cells underwent G0/G1 arrest. An enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by casuarinin. Our study reports here for the first time that the induction of p21/WAF1 and the activity of Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of casuarinin in MCF-7 cells.     

Upregulation of Fas/Fas ligand-mediated apoptosis by gossypol in an immortalized human alveolar lung cancer cell line

Gossypol has wide antineoplastic effects in vitro, but its effects on human lung cancer have not been explored. To evaluate the activity of gossypol against alveolar cell lung cancer and to provide information on the mechanism of action, we examined the effects of gossypol on the proliferation of A549 cells indirectly using an XTT assay and on the distribution of cells within the phases of the cell cycle using flow cytometry. We also examined several factors that may affect apoptosis, including p53, p21/WAF1, Fas receptor, Fas ligand (FasL) and caspase 8 activity. The results showed that gossypol inhibited proliferation of A549 cells at a concentration of 0.5 micromol/L after 12 h treatment. The effect was both dose- and time-dependent by the induction of apoptosis without the effect of p53 and p21/WAF1. Upregulation of Fas/FasL, in association with the activation of downstream caspase 8 activity, was observed following treatment with gossypol. The Fas/FasL pathway accounted for 75% of gossypol-mediated apoptosis. We suggest that the Fas/FasL apoptotic system is the major pathway for gossypol-mediated apoptosis of A549 cells. Gossypol had no effect on the distribution of A549 cells within the phases of the cell cycle. In conclusion, gossypol inhibited A549 cells mainly by induction of the Fas/FasL apoptotic pathway, but not the p53 and p21/WAF1 pathway.     

Putranjivain A from Euphorbia jolkini inhibits proliferation of human breast adenocarcinoma MCF-7 cells via blocking cell cycle progression and inducing apoptosis

Putranjivain A, isolated from the whole plant of Euphorbia jolkini Bioss (Euphorbiaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. The results showed that putranjivain A inhibited the proliferation of MCF-7 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Enzyme-linked immunosorbent assay showed that putranjivain A increased the expression of p21/WAF1 concomitantly as MCF-7 cell underwent G0/G1 arrest. An enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by putranjivain A. Our study reports here for the first time that the induction of p21/WAF1 and the activity of Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of putranjivain A in MCF-7 cells.     

Induction of apoptosis in human breast adenocarcinoma MCF-7 cells by pterocarnin A from the bark of Pterocarya stenoptera via the Fas-mediated pathway

Pterocarnin A, isolated from the bark of Pterocarya stenoptera (Juylandaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. To identify the anticancer mechanism of pterocarnin A, we assayed its effects on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that pterocarnin A induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that the Fas/Fas ligand apoptotic system is the main pathway of pterocarnin A-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of pterocarnin A in MCF-7 cells.     

Induction of cell cycle arrest and apoptosis in human non-small cell lung cancer A549 cells by casuarinin from the bark of Terminalia arjuna Linn

Casuarinin, a hydrolyzable tannin isolated from the bark of Terminalia arjuna Linn. (Combretaceae), inhibits human non-small cell lung cancer A549 cells by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Enzyme-linked immunosorbent assay showed that the G0/G1 phase arrest is due to p53-dependent induction of p21/WAF1. An enhancement in Fas/APO-1 and the two forms of Fas ligand (FasL), membrane-bound FasL and soluble FasL, might be responsible for the apoptotic effect induced by casuarinin. Our study reports here for the first time that the induction of p53 and the activity of the Fas/FasL apoptotic system may participate in the antiproliferative activity of casuarinin in A549 cells.     

Isoliquiritigenin inhibits the proliferation and induces the apoptosis of human non-small cell lung cancer a549 cells

1. Isoliquiritigenin (ISL) is a natural pigment with the simple chalcone structure 4,2',4'-trihydroxychalcone. In the present study, we report, for the first time, ISL-induced inhibition of the proliferation of the human non-small cell lung cancer A549 cell line. 2. The results showed that ISL not only inhibited A549 cell proliferation, but also induced apoptosis and blocked cell cycle progression in the G1 phase. An ELISA assay demonstrated that ISL significantly increased the expression of p53 and p21/WAF1 protein, which caused cell cycle arrest. 3. An enhancement in Fas and its two ligands, namely membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), may be responsible for the apoptotic effect induced by ISL. 4. Taken together, the results indicate that the p53 and Fas/FasL apoptotic system may participate in the antiproliferative activity of ISL in A549 cells.     

Acacetin inhibits the proliferation of Hep G2 by blocking cell cycle progression and inducing apoptosis

Flavonoids are a broadly distributed class of plant pigments, universally present in vascular plants and responsible for much of the coloring in nature. They are strong antioxidants that occur naturally in foods and can inhibit carcinogenesis in rodents. In this study, we examined acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, for its effect on proliferation in a human liver cancer cell line, Hep G2. The results showed that acacetin inhibited the proliferation of Hep G2 by inducing apoptosis and blocking cell cycle progression in the G1 phase. Enzyme-linked immunosorbent assay showed that acacetin significantly increased the expression of p53 and p21/WAF1 protein, contributing to cell cycle arrest. An enhancement in Fas/APO-1 and its two form ligands, membrane-bound Fas ligand and soluble Fas ligand, as well as Bax protein, was responsible for the apoptotic effect induced by acacetin. Taken together, our study suggests that the induction of p53 and activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of acacetin in Hep G2 cells.     

Rhein inhibits the growth and induces the apoptosis of Hep G2 cells

The effects of rhein on the human hepatoblastoma G2 (Hep G2) cell line were investigated in this study. The results showed that rhein not only inhibited Hep G2 cell growth but also induced apoptosis and blocked cell cycle progression in the G1 phase. An ELISA assay demonstrated that rhein significantly increased the expression of p53 and p21/WAF1 protein, which caused cell cycle arrest. An enhancement in CD95 and its two forms of ligands, membrane-bound CD95 ligand (mCD95L) and soluble CD95 ligand (sCD95L), might be responsible for the apoptotic effect induced by rhein. Taken together, p53 and the CD95/CD95L apoptotic system possibly participated in the antiproliferative activity of rhein in Hep G2 cells.     

Chalcone inhibits the proliferation of human breast cancer cell by blocking cell cycle progression and inducing apoptosis.

Chalcones are discussed to represent cancer preventive food components in a human diet that is rich in fruits and vegetables. In this study, we examined chalcone (1,3-diphenyl-2-propenone) for its effect on proliferation in human breast cancer cell lines, MCF-7 and MDA-MB-231. The results showed that chalcone inhibited the proliferation of MCF-7 and MDA-MB-231 by inducing apoptosis and blocking cell cycle progression in the G2/M phase. Immunoblot assay showed that chalcone significantly decreased the expression of cyclin B1, cyclin A and Cdc2 protein, as well as increased the expression of p21 and p27 in a p53-independent manner, contributing to cell cycle arrest. An enhancement in Fas/APO-1 and its two form ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), was responsible for the apoptotic effect induced by chalcone. In addition, chalcone also triggered the mitochondrial apoptotic signaling by increasing the amount of Bax and Bak and reducing the level of Bcl-2 and Bcl-X(L), and subsequently activated caspase-9 in MCF-7 and MDA-MB-231 cells. Taken together, our study suggests that the blockade of cell cycle progression and initiation of cell apoptotic system may participate in the antiproliferative activity of chalcone in human breast cancer cells.     

Asperfuranone from Aspergillus nidulans Inhibits Proliferation of Human Non‐Small Cell Lung Cancer A549 Cells via Blocking Cell Cycle Progression and Inducing Apoptosis

Abstract: Asperfuranone, a novel compound of genomic mining in Aspergillus nidulans, was investigated for its anti‐proliferative activity in human non‐small cell lung cancer A549 cells. To identity the anti‐cancer mechanism of asperfuranone, we assayed its effect on apoptosis, cell cycle distribution, and levels of p53, p21 Waf1/Cip1, Fas/APO‐1 receptor and Fas ligand. Enzyme‐linked immunosorbent assay showed that the G0/G1 phase arrest might be due to p53‐dependent induction of p21 Waf1/Cip1. An enhancement in Fas/APO‐1 and its two form ligands, membrane‐bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by asperfuranone. Our study reports here for the first time that the induction of p53 and the activity of Fas/Fas ligand apoptotic system may participate in the anti‐proliferative activity of asperfuranone in A549 cells.     

Role of Fas/Fas ligand-mediated apoptosis in murine contact hypersensitivity

Apoptosis plays an important role in immune responses, but little is known about its involvement in contact hypersensitivity (CH). In this study, we have investigated the role of Fas/Fas ligand (FasL)-mediated apoptosis in the pathogenesis of CH. Mice were sensitized by one topical application of 100 microl of 3% oxazolone to shaved skin of the abdomen. Six days later, CH was provoked by challenging both sides of sensitized mouse right ear with 15 microl of 1% oxazolone. Using a DNA ladder assay, we found that apoptosis was induced in the skin of oxazolone-sensitized mice 24-96 h after allergen challenge. Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) apoptosis flow cytometric assay showed that early apoptotic CD4(+) T cells (annexin V-FITC(+)PI(-)), but not late apoptotic CD4(+) T cells (annexin V-FITC(+)PI(+)), increased in the inflamed skin of mice with CH. Moreover, the expressions of mRNAs for T helper (Th2) cytokine (interleukin (IL)-4), Th1 cytokine (interferon (IFN)-gamma) and proapoptotic molecules (Bax, Fas, FasL and IL-1beta-converting enzyme (ICE)/caspase-1) were significantly elevated in the oxazolone-sensitized mouse skin 6-72 h after allergen challenge. Dramatic increase in IL-10 mRNA was only observed in the sensitized mouse skin 6 and 12 h after allergen challenge. Furthermore, CH was significantly inhibited with decreased apoptosis and early apoptotic CD4(+) T cells in inflamed skin in Fas mutant lpr/lpr mice compared to wild-type mice, whereas there were no significant differences in IL-4, IFN-gamma, IL-10, Bax and ICE mRNAs in the inflamed skin of CH between lpr/lpr and wild-type mice. Our results thus suggest that Fas/FasL pathway partially contributes to apoptosis in murine CH and that Fas/FasL-mediated apoptosis plays a partial role in the development of CH. The contribution of Fas/FasL-mediated apoptosis to CH appears independent of Th1 and Th2 cytokines.     

Cantharidin-induced cytotoxicity and cyclooxygenase 2 expression in human bladder carcinoma cell line

Mylabris is used in clinical therapy, but is always accompanied by cystitis. The toxic effects of mylabris on bladder are attributed to its active principle: cantharidin. In the present study, we explored how cantharidin induces cytotoxicity in the bladder. Human bladder carcinoma cell line T 24 cells were used as target cells, and human colon carcinoma HT 29 cells as native cells. Cantharidin exhibited acute cytotoxicity in the T 24 cells, and IC(50) was 21.8, 11.2 and 4.6 microM after treatment for 6, 24 and 48 h, respectively. The cytotoxicity of cantharidin was not significantly enhanced when T 24 cells were treated for a longer time. Moreover, PARP proteins and pro-caspase 3, Bcl-2 were significantly inhibited after cantharidin treatment in T 24 cells. Pretreatment with the caspase 3 inhibitor markedly inhibited cantharidin-induced cell death. Therefore, we suggested that cantharidin could induce apoptosis via active caspase 3 in T 24 cells. When T 24 cells were treated with cantharidin at a low dose, the cell cycle was arrested in the G(2)/M phase. Furthermore, p21(Cip1/Waf1) was enhanced, and cyclin A, B1 and cdk1 decreased. At a high dose (more 12.5 microM), cantharidin could stimulate T 24 cells to deplete a large number of ATP and induce secondary necrosis. In addition, cantharidin also stimulated COX 2 over-expression and PGE(2) production in T 24 cells, in a dose-dependent manner. However, cantharidin also induced apoptosis and G(2)/M phase arrest in HT 29 cells, but did not induce COX 2 over-expression. Therefore, we suggest that cantharidin may induce cystitis through secondary necrosis and COX 2 over-expression.     

Effects of specific antisense oligonucleotide inhibition of Fas expression on T cell apoptosis induced by Fas ligand

To investigate the effect of specific antisense oligodeoxynucleotide (ASODN) inhibition of Fas expression on T cell apoptosis induced by hepatocarcinoma cells. Fas receptor (Fas) and Fas ligand (FasL) expressed by the hepatocarcinoma cell line HepG2.2.15 and Jurkat T cells were detected by flow cytometry (FCM) and the ability of FasL-inducing T cell apoptosis was tested by co-culture assay in vitro with HepG2.2.15 cells and Jurkat T cells. The Jurkat cells were transfected with Fas-ASODN using lipofectin, and the effects of Fas-ASODN on Fas mRNA level, Fas expression on T cells surface, and apoptosis were investigated by RT-PCR, FCM and co-culture assay, respectively. It was found that HepG2.2.15 cells expressing functional FasL could induce the apoptosis of Jurkat cells as demonstrated by co-culture assays. After the Jurkat cells were transfected with Fas ASODN, the level of Fas mRNA, the expression rate of Fas and the apoptotic rate induced by hepatocarcinoma cells were all decreased. As a conclusion, it is evident that hepatocarcinoma cells expressing FasL can induce apoptosis in Fas-expressing T cells, indicating that transfection of Fas ASODN can partially convert the immune inhibitory condition induced by hepatocarcinoma cells.     

Fluoxetine mediates G0/G1 arrest by inducing functional inhibition of cyclin dependent kinase subunit (CKS)1

Fluoxetine, a well-known antidepressant used clinically for mental depression has gained attention in cancer research owing to its chemosensitizing potential in drug resistant cell lines. Some preliminary reports, however, suggested its independent cytotoxic potential which is not yet well characterized. Our aim in this study was to characterize its antiproliferative activity in tumor cells and to further elucidate the mechanism. We found that fluoxetine sensitized the effect of cyclophosphamide even in drug sensitive MDA MB 231 and SiHa cells. IC(50) values of 28 and 32 microM were obtained for fluoxetine mediated antiproliferative response in these cells. Further, PARP and caspase 3 cleavage analyses confirmed fluoxetine mediated apoptosis at molecular level. Cell cycle analysis showed that fluoxetine arrested cells at G0/G1 phase in a time dependent manner. The application of bioinformatics tools at this juncture predicted CKS1 as one of the possible targets of fluoxetine, which is of relevance to cell cycle biology. Fluoxetine showed the potential to disrupt skp2-CKS1 assembly required for ubiquitination and proteasomal degradation of p27 and p21. Our in vitro results were in agreement with the predictions made in silico. We found that fluoxetine treatment could accumulate p27 and p21, an immediate outcome characteristic of functional inhibition of CKS1. This was accompanied by the accumulation of cyclin E, another possible target of CKS1. We observed CKS1 downregulation also upon prolonged fluoxetine treatment. Fluoxetine had downregulated cyclin A which confirmed G0/G1 arrest at the molecular level. We conclude that fluoxetine induced cell cycle arrest is CKS1 dependent.     

Induction of apoptosis in human breast adenocarcinoma MCF-7 cells by prodelphinidin B-2 3,3'-di-O-gallate from Myrica rubra via Fas-mediated pathway

Myrica rubra Sieb et Zucc. (Myricaceae) is well known as a rich source of tannins. Prodelphinidin B-2 3,3'-di-O-gallate (PB233'OG) is a proanthocyanidin gallate that has been reported to exhibit antioxidant and antiviral activity. In this study, we evaluated the anti-proliferative activity of PB233'OG isolated from the bark of M. rubra in human breast adenocarcinoma MCF-7 cells. To identity the anti-cancer mechanism of PB233'OG, we assayed its effect on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that PB233'OG induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that Fas/Fas ligand apoptotic system is the main pathway of PB233'OG-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the anti-proliferative activity of PB233'OG in MCF-7 cells.