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1.
Late-stage malignant melanoma is a cancer that is refractory to current chemotherapeutic treatments. The average survival time for patients with such a diagnosis is 6 months. In general, the vast majority of anticancer drugs operate through induction of cell cycle arrest and cell death in either the DNA synthesis (S) or mitosis (M) phase of the cell cycle. Unfortunately, the same mechanisms that melanocytes possess to protect cells from DNA damage often confer resistance to drugs that derive their toxicity from S or M phase arrest. Described herein is the synthesis of a combinatorial library of potential proapoptotic agents and the subsequent identification of a class of small molecules (triphenylmethylamides, TPMAs) that arrest the growth of melanoma cells in the G1 phase of the cell cycle. Several of these TPMAs are quite potent inducers of apoptotic death in melanoma cell lines (IC(50) approximately 0.5 muM), and importantly, some TPMAs are comparatively nontoxic to normal cells isolated from the bone marrow of healthy donors. Furthermore, the TPMAs were found to dramatically reduce the level of active nuclear factor kappa-B (NFkappaB) in the cell; NFkappaB is known to be constitutively active in melanoma, and this activity is critical for the proliferation of melanoma cells and their evasion of apoptosis. Compounds that reduce the level of NFkappaB and arrest cells in the G1 phase of the cell cycle can provide insights into the biology of melanoma and may be effective antimelanoma agents.  相似文献   

2.
In this study antiproliferation, cell cycle arrest and apoptosis induced by daphnoretin in human osteosarcoma (HOS) cells were investigated. Antiproliferative activity was measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The IC(50) value of daphnoretin was 3.89 μM after 72 h treatment. Induction of apoptosis was evidenced by apoptotic body appearance and Annexin V-FITC/PI apoptosis detection kit. Flow cytometric analysis indicated daphnoretin arrested the cell cycle in the G2/M phase. Western-blot assay showed that the G2/M phase arrest was accompanied by down-regulation of cdc2, cyclin A and cyclin B1. Moreover, daphnoretin inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade. Our results demonstrated that daphnoretin caused death of HOS cells by blocking cells successively in G2/M phases and activating the caspase-3 pathway.  相似文献   

3.
Parthenolide, the principal component of sesquiterpene lactones present in medical plants such as feverfew (Tanacetum parthenium), has been reported to have anti-tumor activity. In this study, we evaluated the therapeutic potential of parthenolide against bladder cancer and its mechanism of action. Treatment of bladder cancer cells with parthenolide resulted in a significant decrease in cell viability. Parthenolide induced apoptosis through the modulation of Bcl-2 family proteins and poly (ADP-ribose) polymerase degradation. Treatment with parthenolide led to G1 phase cell cycle arrest in 5637 cells by modulation of cyclin D1 and phosphorylated cyclin-dependent kinase 2. Parthenolide also inhibited the invasive ability of bladder cancer cells. These findings suggest that parthenolide could be a novel therapeutic agent for treatment of bladder cancer.  相似文献   

4.
Murraya koenigii is an edible herb widely used in folk medicine. Here we report that girinimbine, a carbazole alkaloid isolated from this plant, inhibited the growth and induced apoptosis in human hepatocellular carcinoma, HepG2 cells. The MTT and LDH assay results showed that girinimbine decreased cell viability and increased cytotoxicity in a dose-and time-dependent manner selectively. Girinimbine-treated HepG2 cells showed typical morphological features of apoptosis, as observed from normal inverted microscopy and Hoechst 33342 assay. Furthermore, girinimbine treatment resulted in DNA fragmentation and elevated levels of caspase-3 in HepG2 cells. Girinimbine treatment also displayed a time-dependent accumulation of the Sub-G(0)/G(1) peak (hypodiploid) and caused G(0)/G(1)-phase arrest. Together, these results demonstrated for the first time that girinimbine could effectively induce programmed cell death in HepG2 cells and suggests the importance of conducting further investigations in preclinical human hepatocellular carcinoma models, especially on in vivo efficacy, to promote girinimbine for use as an anticancer agent against hepatocellular carcinoma.  相似文献   

5.
Ferula gummosa Boiss. has medicinal applications in treating a wide range of diseases including cancer. The objective of this study was to evaluate the antiproliferative activities of the seed and gum extracts of F. gummosa as well as to study the effect of the potent extract on the induction of apoptosis and cell cycle arrest. Our results demonstrated that the ethanolic extract had the lowest IC50 value at 72 h (0.001 ± 1.2 mg/mL) in BHY cells. Moreover, flowcytometry and annexin-V analysis revealed that the ethanolic extract induced apoptosis and cell-cycle arrest in BHY cells at G1/S phase. In addition, colorimetric methods exhibited the highest amount of total phenolics and flavonoids in the aqueous and gum extracts (0.12 ± 0.037, 0.01 ± 2.51 mg/g of dry powder). Generally, the results obtained indicate that F. gummosa ethanol extract may contain effective compounds which can be used as a chemotherapeutic agent.  相似文献   

6.
BackgroundNasopharyngeal cancer is a tumor that occurs in the mucous epithelium of the nasopharynx. Due to its rapid growth and early metastatic nature, the successful treatment of nasopharyngeal cancer is highly challenging.ObjectiveHere, we intended to assess the in vitro anticancer property of brassinin against the nasopharyngeal cancer C666-1 cells.MethodologyThe in vitro free radical scavenging property of the brassinin was assessed by various free radical scavenging activities such as FRAP, DPPH, chemiluminescence (CL), and ORAC assays. The cytotoxic level of the brassinin (1–50 µM) against the nasopharyngeal cancer C666-1 cells and normal Vero cells were assessed by the MTT cytotoxicity assay. The levels of TBARS, GSH, and the SOD activity was assessed using kits. The level of ROS generation, MMP, and apoptosis were investigated by the respective fluorescent staining techniques. The flow cytometry analysis was done to scrutinize the cell cycle arrest. The Bax/Bcl-2 level and caspase activities were examined using respective kits.ResultsThe brassinin treatment effectively scavenged the free radicals, which are assessed by the FRAP, DPPH, chemiluminescence (CL), and ORAC assays. The proliferation of brassinin treated C666-1 cells were decreased remarkably, while the same concentration of brassinin did not disturbed the Vero cell viability. The 30 µM of brassinin effectively increased the ROS production, depleted the MMP, and stimulated the apoptosis in the C666-1 cells. The brassinin increased the TBARS and depleted the GSH and SOD in the C666-1 cells. The flow cytometry analysis revealed that the brassinin administration improved the G0/G1 ratio and decreased the proportion of cells with ‘S’ and ‘G2/M’ phase. The Bax, caspase-3 and ?9 were elevated and Bcl-2 level was decreased in the brassinin administered C666-1 cells.ConclusionOur findings discovered that the brassinin has the capacity to prevent the proliferation and stimulate the apoptotic cell death C666‐1 cells via blocking cell cycle and increasing oxidative stress and apoptotic markers. Hence, it can be a talented therapeutic agent to treat the nasopharyngeal cancer in the future.  相似文献   

7.
By 5-h reaction of cis-[RuIICl2(DMSO)4] (M2) with K102-P2W17O61] (M3) in ice-cooled, HCl-acidic aqueous solution, a water-soluble 1:2-type diamagnetic ruthenium(II) complex of formula K18[RuII(DMSO)2(P2W17O61)2]·35H2O (M1) was unexpectedly obtained as an analytically pure, homogeneous tan-colored solid, in which two DMSO ligands are coordinated to the ruthenium(II) atom. The cytotoxic potential of the complex was tested on C33A, DLD-1, and HepG-2 cancer cells and human normal embryonic lung fibroblasts cell MRC-5; the viability of the treated cells was evaluated by MTT assay. The mode of cell death was assessed by morphological study of DNA damage and apoptosis assays. Compound M1 induced cell death in a dose-dependent manner, and the mode of cell death was essentially apoptosis though necrosis was also noticed. Cell cycle analysis by flow cytometry indicated that M1 caused cell cycle arrest and accumulated cells in S phase.  相似文献   

8.
Three ruthenium(II) polypyridyl complexes [Ru(dmb)2(dadppz)]2+ 1, [Ru(bpy)2(dadppz)]2+ 2 and [Ru(phen)2(dadppz)]2+ 3 were synthesized and characterized by elemental analysis, ES-MS, 1H NMR and 13C NMR. Their DNA-binding behaviors were investigated by absorption titration, fluorescence spectroscopy and viscosity measurements. Cytotoxicity in vitro, apoptosis, cell cycle arrest, cellular uptake and reactive oxygen species assays were performed. The complexes were found to show moderate DNA-binding affinities and high cytotoxicities toward A549, BEL-7402, MG-63 and SKBR-3 cell lines. These complexes can effectively induce apoptosis of BEL-7402. In cell cycle assays, the complexes induced S-phase arrest on BEL-7402 cells and G0/G1-phase arrest on SKBR-3 cells. The DNA-binding experiments showed that the three complexes interact with CT-DNA through an intercalative mode.  相似文献   

9.
Abstract

Xanthatin is a natural plant bicyclic sesquiterpene lactone extracted from Xanthium plants (Asteraceae). In the present study, we demonstrated for the first time that Xanthatin inhibited cell proliferation and mediated G2/M phase arrest in human colon cancer cells. Xanthatin also activated caspase and mediated apoptosis in these cells. Concomitantly, Xanthatin triggered cell autophagic response. We found down-regulation of X-linked inhibitor of apoptosis protein (XIAP) contribute to the induction of apoptosis and autophagy. Moreover, reactive oxygen species (ROS) production was triggered upon exposure to Xanthatin in colon cancer cells. ROS inhibitor N-acetylcysteine (NAC) significantly reversed Xanthatin-mediated XIAP down-regulation, G2/M phase arrest, apoptosis and autophagosome accumulation. In summary, our findings demonstrated that Xanthatin caused G2/M phase arrest and mediated apoptosis and autophagy through ROS/XIAP in human colon cancer cells. We provided molecular bases for developing Xanthatin as a promising antitumor candidate for colon cancer therapy. Abbreviations ROS reactive oxygen species

DMSO dimethyl sulfoxide

5-FU 5-Fluorouracil

3-MA 3-Methyladenine

DCFH-DA 2’7’-dichlorfluorescein-diacetate

NAC N-acetylcysteine

XIAP X-linked inhibitor of apoptosis protein

  相似文献   

10.
Calotropis procera (family: Asclepiadaceae) contains cardiac glycosides which are cytotoxic to cancer cells. The extracts of C. procera have been reported to be cytotoxic to many cancer cell lines and this is the first report against the human skin melanoma cells (SK-MEL-2). The SK-MEL-2 cells treated with C. procera methanolic extract (CPME) were analysed for growth inhibition and apoptosis. The exposure of phosphatidylserine in apoptotic SK-MEL-2 was analysed by using the Annexin-V FITC flow cytometry method. In CPME-treated SK-MEL-2 cells, 19.6% of apoptotic and 58.3% dead cells were observed. The 15.97% and 15.85% of early apoptotic cells were found at 20 μg/mL of the ouabain and paclitaxel, respectively. Active caspases, nuclear degradation confirmed apoptotic SK-MEL-2 cells in time- and dose-dependent manner. The cell cycle analysis shows that CPME treated cells halt at G2/M phase. Significant cytotoxic activity of CPME against SK-MEL-2 may be attributed to its high cardenolide content.  相似文献   

11.
The CDC25 phosphatases regulate the cell division cycle by controlling the activity of cyclin-dependent kinases. While screening for inhibitors of phosphatases among natural products we repeatedly found that some polyprenyl-hydroquinones and polyprenyl-furans (furanoterpenoids) (furospongins, furospinosulins) were potent CDC25 phosphatase inhibitors. These compounds were extracted, isolated and identified independently from three sponge species (Spongia officinalis, Ircinia spinulosa, Ircinia muscarum), collected at different locations in the Mediterranean Sea. The compounds were inactive on the Ser/Thr phosphatase PP2C-alpha and on three kinases (CDK1, CDK5, GSK-3), suggesting that some potent and selective CDC25 phosphatase might be designed from these initial structures.  相似文献   

12.
Four new polycyclic diterpenoids euphoranes A ? D (14), together with 12 known terpenoids (516) were isolated from the whole plants of Euphorbia dracunculoides. Compound 2 represents the first example of aromatic 15,16,17-trinorabietane diterpenoid in Euphorbia species, and euphorane C (3) is an unusual 17-norabietane diterpenoid. The absolute configurations of 1, 2, and 4 were determined by single crystal X-ray diffraction, while that of 3 was established with the aid of ECD and 1D NMR quantum chemical calculation. Moreover, the absolute stereochemistry of 11 was demonstrated for the first time by crystallographic data. Compounds 116 were screened for antiproliferative activities against five human cancer cell lines, and 3 showed significant cytotoxicity against the human leukemia K562 cells with IC50 value of 3.59 μM. Preliminary mechanistic investigation revealed that 3 could induce cell cycle arrest at G0/G1 phase and apoptosis in K562 cells.  相似文献   

13.
Research on Chemical Intermediates - Searching for new active molecules against human breast cancer cell line MCF-7, novel quinoline based thiazolidinones has been efficiently synthesized under...  相似文献   

14.
The eukaryotic cell cycle is regulated by a complicated chemical reaction network. Although many deterministic models have been proposed, stochastic models are desired to capture noise in the cell resulting from low numbers of critical species. However, converting a deterministic model into one that accurately captures stochastic effects can result in a complex model that is hard to build and expensive to simulate. In this paper, we first apply a hybrid (mixed deterministic and stochastic) simulation method to such a stochastic model. With proper partitioning of reactions between deterministic and stochastic simulation methods, the hybrid method generates the same primary characteristics and the same level of noise as Gillespie's stochastic simulation algorithm, but with better efficiency. By studying the results generated by various partitionings of reactions, we developed a new strategy for hybrid stochastic modeling of the cell cycle. The new approach is not limited to using mass-action rate laws. Numerical experiments demonstrate that our approach is consistent with characteristics of noisy cell cycle progression, and yields cell cycle statistics in accord with experimental observations.  相似文献   

15.
In our previous study we have proved that colon cancer cells HT-29 pre-treated with specific 5-lipoxygenase inhibitor MK-886 became more susceptible to photodynamic therapy (PDT) with hypericin and we also found that this mutual combination induced cell cycle arrest and stimulated onset of apoptosis (Kleban et al., 2007. J. Photochem. Photobiol. B 84, 2). To further explain events associated with MK-886 mediated sensitization of tumor cells toward PDT with hypericin, more detailed study of signaling pathways leading to increase in apoptosis as well as cell cycle perturbations was performed and is presented herein. Intensive accumulation of HT-29 cells in G0/G1 phase of cell cycle led to expression analyses of several G0/G1 checkpoint molecules (cyclin A, cyclin E, cdk-2, pRb). Similarly, accumulation of apoptotic cells invoked analyses of key molecules involved in apoptotic signaling (caspase-3, -8, -9; PARP; Lamin B; Mcl-1; Bax) by Western blotting and caspase activity assay. Long term survival of cells was examined by clonogenicity test. As the effect of PDT is mediated by ROS production, levels of hydrogen peroxides and superoxide anion were monitored by flow cytometric analyses. In addition, an impact of MK-886 on LTB4 production and expression of 5-LOX was monitored. Massive G0/G1 arrest in the cell cycle accompanied by increase in cyclin E level and decrease/absention of cyclin A, cdk-2 and pRb expression indicated incapability for G1/S transition. Minimal changes in cleavage of procaspases observed in cells treated with non-toxic concentrations of either agent alone or their mutual combination were not quite in line with their activity (caspase-3, -8, -9) which was significantly increased mainly in combinations. Treatment with non-toxic concentration of MK-886 had minimal influence over ROS production compared to control cells. In contrast, hypericin alone markedly increased the level of ROS, but no additional effect of MK-886 pre-treatment was detected. Further analyses of particular ROS groups unveiled an impact of increasing MK-886 concentration on superoxide accumulation accompanied with depletion of hydrogen peroxide level within the cells. The clonogenicity test revealed disruption of colony formation after mutual combination of both agents as compared to MK-886 or PDT alone. In conclusion, we presume that stimulation of apoptosis in our experimental model was accomplished preferentially through the mitochondrial pathway, although caspase-8 activation was also noticed. Interestingly, pre-treatment with MK-886 modulated distribution of ROS production in mutual combination with PDT.  相似文献   

16.
It is reported that exposure to 50 Hz extremely low-frequency electromagnetic field (ELF-EMF) can produce apoptosis and small variations in cell cycle distribution on different cell lines. In order to study the effect of ELF-EMF on tumoral cells in vitro, two cell lines (U-937, from a histiocytic lymphoma, and HCA-2/1cch, from a human colon adenocarcinoma) were exposed to 25 Hz, 1.5 mT, for 2 h and 45 min. Cell cycle distribution, apoptosis (spontaneous and dexamethasone-induced) and cell growth were evaluated. Neither significant alteration in cell cycle phases nor induction of apoptosis was observed. Nevertheless, the relative cell number was found to decrease to 55.84+/-7.35% (p <0.05, Student's t-test) for HCA-2/1cch cells after exposure to EMF in the presence of dexamethasone. The presence of dexamethasone during the EMF exposure could probably produce a decrease in the cell growth of this cell line.  相似文献   

17.
A new diterpenoid glycoside, 6E,10E,14Z-(3S)-17-hydroxygeranyllinalool-17-O-β-d-glucopyranosyl-(1?→?2)-[α-l-rhamnopyranosyl-(1?→?6)]-β-d-glucopyranoside (1) together with the known diterpenoid glycoside (2) and two known flavonoid glycosides (3, 4) were isolated from the methanol extract of Blumea lacera leaves. The structures were determined by the interpretation of their spectroscopic data and comparison with the literature. All compounds were isolated for the first time from B. lacera and evaluated for their cytotoxic activity. Only the new compound (1) showed strong cytotoxic activity with the lowest IC50 value (8.3 μM) being displayed against MCF-7 breast cancer cells. In apoptosis and cell cycle analysis, 1 revealed strong apoptotic activity against MCF-7 cells (45.5% AV+/PI?) after 24 h, but showed no arresting of any of the cell cycle phases in MCF-7.  相似文献   

18.
We report an improved synthesis of bis(5,7,3',4'-tetra-O-benzyl)epicatechin 4beta,8-dimer (3) from 5,7,3',4'-tetra-O-benzylepicatechin (1) and 5,7,3',4'-tetra-O-benzyl-4-(2-hydroxyethoxy)epicatechin (2) by replacing the previously employed Lewis acid, titanium tetrachloride, with the clay mineral Bentonite K-10. Under the same conditions, the benzyl-protected all-4beta,8-trimer, -tetramer, and -pentamer were obtained regioselectively from their lower homologues, albeit in rapidly decreasing yields. Reaction of 2 with an organoaluminum thiolate generated from 2-mercaptobenzothiazole and trimethylaluminum followed by acetylation produced 3-O-acetyl-4-[(2-benzothiazolyl)thio]-5,7,3',4'-tetra-O-benzylepicatechin (12). Medium-sized protected oligomers with 4beta,8-interflavan linkages are obtained in improved yields by using this compound as the electrophile and silver tetrafluoroborate as activator and are isolated by reversed-phase HPLC. Their deprotection by ester saponification followed by hydrogenolysis yielded the free procyanidins, which were characterized as their peracetates. The synthetic procyanidins are identical by normal-phase HPLC with fractions isolated from cocoa. The principle of chain extension by two members was demonstrated using a dimeric electrophile obtained by self-condensation of compound 12. Both the synthetic and natural pentamer 32 inhibit the growth of several breast cancer cell lines. Using the MDA MB 231 line, it was established that this outcome is based on the induction of cell cycle arrest in the G0/G1 phase. Subsequent cell death is more likely necrotic rather than apoptotic. Control experiments demonstrate that the polyphenol itself, rather than hydrogen peroxide potentially formed by its autoxidation, is the causative agent.  相似文献   

19.
The JNK inhibitor SP600125 strongly inhibits cell proliferation in many human cancer cells by blocking cell-cycle progression and inducing apoptosis. Despite extensive study, the mechanism by which SP600125 inhibits mitosis-related effects in human leukemia cells remains unclear. We investigated the effects of SP600125 on the inhibition of cell proliferation and the cell cycle, and on microtubule dynamics in vivo and in vitro. Treatment of synchronized leukemia cells with varying concentrations of SP600125 results in significant G2/M cell cycle arrest with elevated p21 levels, phosphorylation of histone H3 within 24 h, and endoreduplication with elevated Cdk2 protein levels after 48 h. SP600125 also induces significant abnormal microtubule dynamics in vivo. High concentrations of SP600125 (200 µM) were required to disorganize microtubule polymerization in vitro. Additionally, SP600125-induced delayed apoptosis and cell death was accompanied by significant poly ADP-ribose polymerase (PARP) cleavage and caspase-3 activity in the late phase (at 72 h). Endoreduplication showed a greater increase in ectopic Bcl-2-expressing U937 cells at 72 h than in wild-type U937 cells without delayed apoptosis. These results indicate that Bcl-2 suppresses apoptosis and SP600125-induced G2/M arrest and endoreduplication. Therefore, we suggest that SP600125 induces mitotic arrest by inducing abnormal spindle microtubule dynamics.  相似文献   

20.
Lung cancer has been shown to be resistant to treatment with some chemotherapy drugs due to epithelial-mesenchymal transmission (EMT). Because the rate of cytotoxicity and induction of apoptosis by methotrexate (MTX) is negligible in A549 lung cancer cells, a CD44 positive cell line, we decided to synthesize magnetic nanoparticles (MNPs) containing hyaluronic acid (HA) and MTX to evaluate the effect of CD44 receptor targeting on the expression of genes involved in apoptosis. The TNF genes can modulate the expression of CD44 and implicate carcinogenesis and metastases. Therefore, inhibition of the TNF gene and study of its interaction with the CD44 receptor can determine the success of a treatment method. The results of the MTT assay confirmed that the MNPs-HA-MTX offered better cellular cytotoxic effects on cell viability than free MTX. The real-time PCR test also showed that the Bak1/Bclx ratio was 52.5 times higher than the control. On the other hand, the expression of the TNF gene was severely reduced, which could be due to the binding of HA-moiety of the MNPs-HA-MTX to the receptor and endocytosis. All the results gave us hope that we could increase the effectiveness of methotrexate in lung cancer by targeting the CD44 receptor.  相似文献   

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