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The spatial distribution and pollution level of heavy metal(loid)s in soil (0-6 m) from a typical industrial region in Jiangmen City, Southeast China was investigated. Their bioaccessibility, health risk, and human gastric cytotoxicity in topsoil were also evaluated using an in vitro digestion/human cell model. The average concentrations of Cd (87.52 mg/kg), Co (106.9 mg/kg), and Ni (1007 mg/kg) exceeded the risk screening values. The distribution profiles of metal(loid)s showed a downward migration trend to reach a depth of 2 m. The highest contamination was found in topsoil (0-0.5 m), with the concentrations of As, Cd, Co, and Ni being 46.98, 348.28, 317.44, and 2395.60 mg/kg, respectively, while Cd showed the highest bioaccessibility in the gastric phase (72.80 %), followed by Co (21.08 %), Ni (18.27 %), and As (5.26 %) and unacceptable carcinogenic risk. Moreover, the gastric digesta of topsoil suppressed the cell viability and triggered cell apoptosis, evidenced by disruption of mitochondrial transmembrane potential and increase of Cytochrome c (Cyt c) and Caspases 3/9 mRNA expression. Bioaccessible Cd in topsoil was responsible for those adverse effects. Our data suggest the importance to reduce Cd in the soil to decrease its adverse impacts on the human stomach.

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Aim To investigate the effect of methionine restriction on the proliferation, migration and invasion of human oral squamous carcinoma CAL-27 cells. Methods Cell proliferation and colony formation ability were detected by cell counting and colony forming assay. The changes in cell cycle and apoptosis were detected by propidium iodide (PI) staining flow cytometry and Annexin V/7-amino-actinomycin staining flow cytometry. The migration and invasion ability of CAL-27 was detected by scratch and Transwell assay. The expression levels of apoptosis proteins Bax and Bcl-2, cyclins CDK2 and CDK4 and migration and invasion proteins N-cadherin and E-cadherin were examined by Western blot. Results Methionine restriction significantly inhibited the proliferation and clone formation of oral squamous cancer cell CAL-27 (P < 0. 01), induced cell cycle arrest at G

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Aim To study the inhibitory effect of attenuated salmonella SGN1, overexpressing methioninase, on nasopharyngeal carcinoma (NPC) and the underlying mechanism. Methods The cell proliferation, cell cycle, cell apoptosis, clony formation and migration a-bility of 5-8F, HNE-2, CNE-2 cells were measured u-sing flow cytometry assay, clone formation assay, and wound assay after the methionine restriction treatment. 5-8F, HNE-2, CNE-2 cells were infected with SGN1 at the multiplicity of infection (MOI) of 1: 100 for 5 hours, followed with the measurement of cell growth. A xenograft model was constructed by subcutaneous injection of 5-8F cells in mice to observe the inhibitory effect of SGN1 on nasopharyngeal carcinoma. Results Compared with the control group, methionine restriction significantly inhibited the proliferation, migration ability, and clone formation of nasopharyngeal carcinoma cells and blocked the G

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OBJECTIVE@#To investigate the effects of methionine restriction on proliferation, cell cycle and apoptosis of human acute leukemia cells.@*METHODS@#Cell Counting Kit-8 (CCK-8) assay was used to detect the effect of methionine restriction on HL-60 and Jurkat cells proliferation. The effect of methionine restriction on cell cycle of HL-60 and Jurkat cells was examined by PI staining. Annexin V-FITC / PI double staining was applied to detect apoptosis of HL-60 and Jurkat cells following methionine restriction. The expression of cell cycle-related proteins cyclin B1, CDC2 and apoptosis-related protein Bcl-2 was evaluated by Western blot assay.@*RESULTS@#Methionine restriction significantly inhibited the proliferation of HL-60 and Jurkat cells in a time-dependent manner (HL-60: r =0.7773, Jurkat: r =0.8725), arrested the cells at G2/M phase (P < 0.001), and significantly induced apoptosis of HL-60 and Jurkat cells (HL-60: P < 0.001; Jurkat: P < 0.05). Furthermore, Western blot analysis demonstrated that methionine restriction significantly reduced the proteins expression of Cyclin B1 (P < 0.05), CDC2 (P < 0.01) and Bcl-2 (P < 0.001) in HL-60 and Jurkat cells.@*CONCLUSION@#Acute leukemia cells HL-60 and Jurkat exhibit methionine dependence. Methionine restriction can significantly inhibit the proliferation, promote cell cycle arrest and induce apoptosis of HL-60 and Jurkat cells, which suggests that methionine restriction may be a potential therapeutic strategy for acute leukemia.

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Tris (1-chloro-2-propyl) phosphate (TCPP) is one of the most frequently detected organophosphorus flames in the environment. Continuous daily exposure to TCPP may harm human skin. However, little is known about the adverse effects of TCPP on human skin. In this study, we first evaluated the detrimental effects and tried to uncover the underlying mechanisms of TCPP on human skin keratinocytes (HaCaT) after 24 h exposure. We found that TCPP caused a concentration-dependent decrease in HaCaT cell viability after exposure to 1.56-400 µg/mL for 24 h, with an IC50 of 275 µg/mL. TCPP also promoted the generation of intracellular reactive oxygen species (ROS) and triggered DNA damage, evidenced by an increase of phosphorylated histone H2A.X (γH2A.X) in the nucleus. Furthermore, the cell cycle was arrested at the G1 phase at 100 µg/mL by upregulation of the mRNA expression of p53 and p21 and downregulation of cyclin D1 and CDK4 expression. Additionally, both the senescence-associated-ß-galactosidase activity and related proinflammatory cytokine IL-1ß and IL-6 were elevated, indicating that TCPP exposure caused cellular senescence may be through the p53-dependent DNA damage signal pathway in HaCaT cells. Taken together, our data suggest that flame-retardant exposure may be a key precipitating factor for human skin aging.

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Cadmium (Cd) is one of the toxic heavy metals found widely in the environment. Skin is an important target organ of Cd exposure. However, the adverse effects of Cd on human skin are still not well known. In this study, normal human skin keratinocytes (HaCaT cells) were studied for changes in cell viability, morphology, DNA damage, cycle, apoptosis, and the expression of endoplasmic reticulum (ER) stress-related genes (XBP-1, BiP, ATF-4, and CHOP) after exposure to Cd for 24 h. We found that Cd decreased cell viability in a concentration-dependent manner, with a median lethal concentration (LC50) of 11 µM. DNA damage induction was evidenced by upregulation of the level of γ-H2AX. Furthermore, Cd induced G0/G1 phase cell cycle arrest and apoptosis in a dose-dependent manner and upregulated the mRNA levels of ER stress biomarker genes (XBP-1, BiP, ATF4, and CHOP). Taken together, our results showed that Cd induced cytotoxicity and DNA damage in HaCaT cells, eventually resulting in cell cycle arrest in the G0/G1 phase and apoptosis. In addition, ER stress may be involved in Cd-induced HaCaT apoptosis. Our data imply the importance of reducing Cd pollution in the environment to reduce its adverse impacts on human skin.

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Aim To explore the anti-cancer effects of ZL-n-91, a novel and highly selective phosphodiesterase 4 inhibitor, on the osteosarcoma U2OS cells.Methods CCK-8 assay was used to detect the inhibitory effect of ZL-n-91 with different concentrations(0, 20, 40, 80, 160, 240, 320, 400, 480 μmol·L-1)and different intervention time(0, 24, 48, 72, 96 h)on the proliferation of U2OS cells.Tablet clone forming experiment was used to detect the effect of ZL-n-91 on the clonality of U2OS cells.Flow cytometry was used to detect the cell apoptosis and cell cycle distribution.Western blot was employed to detect the expression of Bcl-2, CDK2, CDK4, CyclinD1, CyclinE1 protein.Results The inhibitory rate of ZL-n-91 on U2OS cells was concentration- and time-dependent(P<0.05), and its half inhibition rate IC50 was 174.1 μmol·L-1.ZL-n-91 significantly inhibited the clonality of U2OS cells(P<0.01).ZL-n-91 significantly induced cell apoptosis, and caused cell cycle arrest at G0/G1 phase in U2OS cells(P<0.01).The results of Western blot showed that ZL-n-91 significantly down-regulated the expression of Bcl-2, CDK2, CDK4, CyclinD1, CyclinE1 proteins in U2OS cells(P<0.05).Conclusions The novel selective phosphodiesterase 4 inhibitor, ZL-n-91, can significantly inhibit the proliferation of osteosarcoma U2OS cells with induction of cell cycle arrest and cell apoptosis, and may become a potential anti-cancer agent.

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OBJECTIVE@#To investigate the inhibitory effects of novel phosphodiesterase 4 inhibitor ZL-n-91 to the proliferation of leukemia cells L1210 and K562.@*METHODS@#CCK-8 method was used to detect the effect of ZL-n-91 to the proliferation of L1210 and K562 cells, and the proliferation rate, IC@*RESULTS@#ZL-n-91 showed a significant inhibitory effect to the proliferation of leukemia cells L1210 and K562 in a dose-dependent manner (P<0.001). After treated by ZL-n-91, the leukemia cells L1210 and K562 in the S-phase in cell cycle decreased significantly compared with those in control group (P<0.01). The apoptosis of leukemia cells L1210 and K562 could be induced by ZL-n-91 (P<0.001), and the expression level of apoptosis related protein BAX significantly increased. In the animal experiment, the result showed that ZL-n-91 could significantly inhibit the growth of subcutaneously transplantation tumor (P<0.05).@*CONCLUSION@#The novel phosphodiesterase 4 inhibitor ZL-n-91 can effectively inhibit the proliferation of leukemia cells L1210 and K562, which has the potential of anti-leukemia drug development.

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Aim: To investigate the effect of ZL-n-91, a novel phosphodiesterase 4 (PDE4) inhibitor, on proliferation, cell cycle and apoptosis of human glioma U87 cells. Methods In vitro the different concentrations of ZL-n-91 were set up to evaluate the proliferation of U87 cells by CCK-8 assay. The cell apoptosis and cell cycle distribution were examined by flow cytometry. The expression of CDK2, CDK4, cyclin Dl and apoptosis-related protein Bax and Bcl-2 proteins were detected by Western blot. A subcutaneous transplanted tumor model of U87 in nude mice was established for the in vivo experiment using a dosage of 5 mg · kg