Chinese Hamster Fibroblast Cell Line Research Articles

Glucose Metabolism in Cardiac Hypertrophy and Heart Failure.

Glucose Metabolism in Cardiac Hypertrophy and Heart Failure.

A Nucleoside Anticancer Drug, 1-(3-C-Ethynyl-β-D-Ribo-Pentofuranosyl)Cytosine, Induces Depth-Dependent Enhancement of Tumor Cell Death in Spread-Out Bragg Peak (SOBP) of Proton Beam.

The effect of 1-(3-C-ethynyl-β-D-ribo-pentofuranosyl)cytosine (ECyd) on proton-induced cell death was evaluated in human lung carcinoma cell line A549 and Chinese hamster fibroblast cell line V79 to enhance relative biological effectiveness (RBE) within the spread-out Bragg peak (SOBP) of proton beams. Treatment with ECyd significantly enhanced the proton-induced loss of clonogenicity and increased senescence at the center, but not at the distal edge of SOBP. The p53-binding protein 1 foci formation assay showed that ECyd decelerated the rate of DNA double-strand break (DSB) repair at the center, but not the distal region of SOBP, suggesting that the ECyd-induced enhancement of proton-induced cell death is partially associated with the inhibition of DSB repair. This study demonstrated that ECyd enhances proton-induced cell killing at all positions of SOBP, except for the distal region and minimizes the site-dependent differences in RBE within SOBP. Thus, ECyd is a unique radiosensitizer for proton therapy that may be useful because it levels the biological dose within SOBP, which improves tumor control and reduces the risk of adverse effects at the distal edge of SOBP.

Cytotoxicity Effect of Agaricus blazei, Grifola frondosa and Hericium erinaceus Used in Traditional Medicine

Agaricus blazei Murrill (ABM), Grifola frondosa (GF) and Hericium erinaceus (HE) are mushrooms that are native to China and are widely cultivated in Malaysia for its medicinal uses. They are considered as the most important edible and culinary-medicinal biotechnology species. This study was carried out to determine the in vitro toxicity of these medicinal mushrooms and their possible risk to human health. Extracts were prepared from these mushrooms using various solvents. The cytotoxicity of these extracts was determined using the MTT assay (3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) in Chinese hamster fibroblast cell line (V79-4). Five different concentrations of the mushroom extracts (2mg/ml, 1mg/ml, 0.5mg/ml, 0.25mg/ml and 0.125mg/ml) were used and cytotoxicity was determined following 24 hours treatment. The results showed that only aqueous extracts of Agaricus blazeii Murrill display cytotoxicity effects (IC50—1.7mg/ml) compared to the methanol extracts. In conclusion, the aqueous extracts of Agaricus blazeii Murrill showed weak cytotoxicity in vitro compared to methanol extracts, suggesting that these mushrooms are safe to consume.

The antibacterial effect of the co-administration of poly(propylene imine) dendrimers and ciprofloxacin

Fluoroquinolones, including ciprofloxacin, are often used to treat bacterial diseases. Due to the spread of drug resistance among microorganisms, alternative treatments are being sought. We report here on the antimicrobial activity of generation 4 (G4) PPI dendrimers in the presence of ciprofloxacin against the reference strains of Gram-positive bacterium Staphylococcus aureus ATCC 6538 and Gram-negative bacterium Escherichia coli ATCC 25922. Cytotoxicity of these compounds was investigated in the eukaryotic B14 Chinese hamster fibroblast cell line, HepG2 human liver hepatocellular carcinoma cell line, mouse neuroblastoma N2a cell line and BRL-3A rat liver cell line. For both strains, the administration of PPI dendrimers along with ciprofloxacin significantly improved its antibacterial effect compared to the cultures given the drug alone. The simultaneous application of dendrimers and ciprofloxacin shows the opportunity of using it at lower doses. Ciprofloxacin and PPI dendrimers are harmful to bacterial strains at the concentrations non-toxic to the eukaryotic cells.

Cytotoxicity Effect of Agaricuss Blazei Murill, Grifola Frondosa and Hericium Erinaceus Used In Traditional Medicine

Agaricus blazei Murrill (ABM), Grifola frondosa (GF) and Hericium erinaceus (HE) are mushrooms that are native to China and are widely cultivated in Malaysia for its medicinal uses. They are considered as the most important edible and culinary-medicinal biotechnology species. This study was carried out to determine the in vitro toxicity of these medicinal mushrooms and their possible risk to human health. Extracts were prepared from these mushrooms using various solvents. The cytotoxicity of these extracts was determined using the MTT assay (3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) in Chinese hamster fibroblast cell line (V79-4). Five different concentrations of the mushroom extracts (2mg/ml, 1mg/ml, 0.5mg/ml, 0.25mg/ml and 0.125mg/ml) were used and cytotoxicity was determined following 24 hours treatment. The results showed that only aqueous extracts of Agaricus blazeii Murrill display cytotoxicity effects (IC50—1.7mg/ml) compared to the methanol extracts. In conclusion, the aqueous extracts of Agaricus blazeii Murrill showed weak cytotoxicity in vitro compared to methanol extracts, suggesting that these mushrooms are safe to consume.

Enhancement of antimicrobial activity by co-administration of poly(propylene imine) dendrimers and nadifloxacin

Despite the studies of dendrimers for biomedical application, the antibacterial activity of dendrimers has not been extensively explored. In the presented study we evaluate the antimicrobial activity of poly(propylene imine) dendrimers (PPI-G4) and their derivatives modified with maltose (PPI-25%mG4) in combination with nadifloxacin against Gram-negative bacteria Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 15442 and Proteus hauseri ATCC 13315. Cytotoxicity of all studied dendrimers and nadifloxacin was investigated in a Chinese hamster fibroblast cell line (B14), a human liver hepatocellular carcinoma cell line (HepG2), a mouse neuroblastoma cell line (N2a) and a rat liver cell line (BRL-3A). The obtained results indicate that co-administration of nadifloxacin and studied dendrimers enhances the antimicrobial activity of the antibiotic against Gram-negative bacteria, at concentrations that are at the same time harmless to the eukaryotic cell lines. Moreover, the contribution of dendrimers allows using lower doses of the antibiotic.

Antimicrobial activity of poly(propylene imine) dendrimers

Poly(propylene imine) dendrimers have been investigated for their biological applications but their antibacterial activity has not been extensively explored. Thus, the fourth generation of poly(propylene imine) dendrimers (PPI-G4) and PPI dendrimers with a surface modified by attaching maltose in 25% and 100% (PPI-25%mG4 and PPI-100%mG4, respectively) was evaluated for the antibacterial activity against Gram-positive bacteria: Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Gram-negative bacteria: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 15442 and yeast Candida albicans ATCC 10231. Cytotoxicity of all tested dendrimers was checked on a Chinese hamster fibroblast cell line (B14), human liver hepatocellular carcinoma cell line (HepG2), mouse neuroblastoma cell line (N2a) and rat liver cell line (BRL-3A). The obtained results indicate that studied nano-sized macromolecules possess the greatest antimicrobial activity against S. aureus. PPI G4 dendrimers modified with 25% of maltose display antibacterial activity and a striking selectivity toward S. aureus, at the concentrations, which are at the same time harmless for the eukaryotic cell lines. Moreover, at the higher concentrations of unmodified dendrimers efficient growth inhibition of S. epidermidis and C. albicans has been observed.

Comparative analysis of the nucleosome structure of cell nuclei by small-angle neutron scattering

The nucleosome structure in native nuclei of normal (chicken erythrocyte and rat leukocyte nuclei) and anomalously proliferating (the human cervical adenocarcinoma cell line HeLa and the Chinese hamster fibroblast cell line A238) cells has been investigated using small-angle neutron scattering. The experimental results obtained allow one to make the inference that the parameters of the nucleosome structure for the chicken erythrocyte and rat leukocyte nuclei (on average over the nucleus) are close to the universally accepted values and that the distance distribution function is bimodal. The bimodality of the distance distribution function reflects a narrow distribution of distances between nucleosomes (on average over the nucleus) at the fibril level of the chromatin organization. The histone core of the nucleosome structure in the nuclei of the HeLa and A238 cells (on average over the nucleus) is considerably less compact than that in the chicken erythrocyte and rat leukocyte nuclei, and the distance distribution function does not exhibit indications of the bimodality.

Experimental research on impairment of CdS quantum dots on Chinese hamster fibroblast cell line

目的 探讨硫化镉量子点(CdS quantum dots,CdS QDs)对中国仓鼠肺成纤维细胞(CHL)的毒性作用及其可能的作用机制.方法 实验设2.5、5.0、10.0、20.0、50.0、100.0μg/ml CdS QDs(乳化膜法合成)6个剂量组作用于CHL细胞,对照组予等量的生理盐水.用荧光倒置显微镜观察细胞的形态学变化,噻唑蓝(MTT)法检测CdS QDs对CHL细胞增殖的抑制作用.CHL细胞分别暴露于不同浓度的CdS QDs 24 h后.测定细胞内乳酸脱氢酶(LDH)释放率及丙二醛(MDA)、谷胱甘肽(GSH)含量.结果 CdS QDs染毒24 h后,细胞变形、收缩,胞体折光性脆弱.随着CdS QDs染毒剂量的增加,CHL细胞存活率逐渐下降,且各剂量组间与对照组相比,差异均有统计学意义(P<0.05或P<0.01).CdS QDs染毒24 h后,随染毒剂鼍的增加,各剂量组细胞LDH释放率均明显上升,差异有统计学意义(P<0.01).20.0、50.0μg/ml CdS QDs剂量组的MDA含量分别为(1.284±0.025)和(2.182±0.699)mmol/mg,与对照组相比[(0.493±0.018)nmol/mg],差异有统计学意义(P<0.05或P<0.01);20.0、50.0、100.0μg/ml CdS QDs剂量组的GSH含量分别为(125.101±20.441)、(105.574±17.575)和(99.697±4.591)mg/g pro,与对照组[(242.852±20.821)mg/g pro]比较,差异有统计学意义(P<0.05或P<0.01).结论 CdS QDs对CHL细胞具有一定的损伤作用,其作用机制可能为氧化损伤。

α/β ratio: A dose range dependence study

To investigate the dependence of the alpha/beta ratio determined from in vitro survival curves on the dose ranges. Detailed clonogenic cell survival experiments were used to determine the least squares estimators for the linear quadratic model for different dose ranges. The cell lines used were CHO AA8, a Chinese hamster fibroblast cell line; U-373 MG, a human glioblastoma cell line; and CP3 and DU-145, two human prostate carcinoma cell lines. The alpha, beta, and alpha/beta ratio behaviors, combined with a goodness-of-fit analysis and Monte Carlo simulation of the experiments, were assessed within different dose regions. Including data from the low-dose region has a significant influence on the determination of the alpha, beta, and alpha/beta ratio from in vitro survival curve data. In this region, the values are poorly determined and have significant variability. The mid-dose region is characterized by more precise and stable values and is in agreement with the linear quadratic model. The high-dose region shows relatively small statistical error in the fitted parameters but the goodness-of-fit and Monte Carlo analyses showed poor quality fits. The dependence of the fitted alpha and beta on the dose range has an impact on the alpha/beta ratio determined from the survival data. The low-dose region had a significant influence that could be a result of a strong linear, rather than quadratic, component, hypersensitivity, and adaptive responses. This dose dependence should be interpreted as a caution against using inadequate in vitro cell survival data for alpha/beta ratio determination.

In vitro genotoxicity of the West African anti-malarial herbal Cryptolepis sanguinolenta and its major alkaloid cryptolepine

Cryptolepine (CLP), the major alkaloid of the West African anti-malarial herbal Cryptolepis sanguinolenta (Periplocaceae) is a DNA intercalator that exhibits potent toxicity to a variety of mammalian cells in vitro. We have hypothesized that the DNA intercalating properties of cryptolepine could trigger genetic damage in mammalian cells. The objective of the present study was therefore to assess the ability of both cryptolepine (CLP) and the traditional anti-malarial formulation, the aqueous extract from the roots (CSE) to induce mutation at the hprt locus and micronuclei (MN) formation in V79, a Chinese hamster fibroblast cell line commonly used in genetic toxicity studies. CSE at a high concentration (50 microg/ml) induced an apparent significant ten fold increase in mutant frequency compared to vehicle control (mean of 38 versus 4 mutant clones/10(6) surviving cells) but, this concentration of CSE was very toxic (<15% cell survival). CLP did not appear to be mutagenic in the dosage range used (up to 2.5 microM, equivalent to 1.1 microg/ml). However, after 24h treatment of V79 cells both CSE and CLP induced a dose-dependent increase in micronuclei of 4.15% and 6.43% (25 microg/ml CSE and 2.5 microM, equivalent to 1.1 microg/ml CLP, respectively) compared to 0.36% in vehicle control. These results show that treatment of mammalian cells with CSE and CLP can lead to DNA damage and we suggest that the routine use of CSE and the potential use of CLP derivatives in malaria chemotherapy could carry a genotoxic risk.

Cell-cycle arrest by PD184352 requires inhibition of extracellular signal-regulated kinases (ERK) 1/2 but not ERK5/BMK1.

Serum and growth factors activate both the canonical extracellular signal-regulated kinase (ERK) 1/2 pathway and the ERK5/big mitogen-activated protein kinase 1 (BMK) 1 pathway. Pharmacological inhibition of the ERK1/2 pathway using PD98059 and U0126 prevents cyclin D1 expression and inhibits cell proliferation, arguing that the ERK1/2 pathway is rate limiting for cell-cycle re-entry. However, both PD98059 and U0126 also inhibit the ERK5/BMK1 pathway, raising the possibility that the anti-proliferative effect of such drugs may be due to inhibition of ERK5 or both pathways. Here we characterize the effect of the novel mitogen-activated protein kinase/ERK kinase (MEK) inhibitor, PD184352, on the ERK1/2 and ERK5 pathways in the Chinese hamster fibroblast cell line CCl39. In quiescent cells, serum-stimulated ERK1 activity was completely inhibited by PD184352 with an IC50 below 1 microM, whereas ERK5 activation was unaffected even at 20 microM. Serum-stimulated DNA synthesis and cyclin D1 expression was inhibited by low doses of PD184352, which abolished ERK1 activity but had no effect on ERK5. Similarly, in cycling cells PD184352 caused a dose-dependent G1 arrest and inhibition of cyclin D1 expression at low doses, which inhibited ERK1 but were without effect on ERK5. These results indicate that the anti-proliferative effect of PD184352 is due to inhibition of the classical ERK1/2 pathway and does not require inhibition of the ERK5 pathway.

Mechanisms Involved in Responses to the Peroxisome Proliferator WY-14,643 on Gap Junctional Intercellular Communication in V79 Hamster Fibroblasts

WY-14,643, a potent hepatic peroxisome proliferator, decreased gap junctional intercellular communication when used at low and intermediate concentrations (1 nM to 10 μM) in the V79 Chinese hamster fibroblast cell line. It did not decrease intercellular communication in early passage Syrian hamster embryo fibroblasts. The mechanism of WY-14,643-induced suppression of intercellular communication was studied by preexposure of V79 cells to inhibitors of protein kinase C, mitogen-activated protein kinases, phosphatidylinositol 3-kinase, or mammalian target-of-rapamycin before addition of WY-14,643. Only protein kinase C, particularly the δ isoform, appeared involved in the inhibition of communication by WY-14,643. Also clofibrate-induced suppression of GJIC in V79 cells appeared to involve protein kinase Cδ. Furthermore, WY-14,643 did not cause any activation of the mitogen-activated protein kinases p44/42, p38, or Jun N-terminal kinase. When WY-14,643 was used at a higher concentration (100 μM), intercellular communication was increased both in V79 and Syrian hamster embryo cells. This effect was inhibited by preexposure of V79 cells to brefeldin A. Thus, there may be a pool of connexins in the Golgi complex that could be recruited to the plasma membrane upon exposure to high concentrations of WY-14,643.

Methylmercury, but not inorganic mercury, causes abnormality of centrosome integrity (multiple foci of γ-tubulin), multipolar spindles and multinucleated cells without microtubule disruption in cultured Chinese hamster V79 cells

Abnormalities of centrosome integrity and spindle organization in the cultured Chinese hamster fibroblast cell line V79 exposed to methylmercury (MeHgCl) and inorganic mercury (Hg 2+) were investigated in conjunction with inductions of mitotic arrest and multinucleated cells. The centrosome integrity and spindle organization were investigated by immunofluorescence of centrosome proteins, γ-tubulin, and β-tubulin, respectively. MeHgCl at subtoxic concentrations caused an increase in mitotic index 6 h after exposure. Ameboid cells with multiple pseudopodia were also induced and chromosomes were distributed even in the pseudopodia. After the increase in mitotic index caused by MeHgCl, multinucleated cells with multiple micronuclei appeared. MeHgCl caused abnormality of centrosome integrity (multiple foci of γ-tubulin) colocalized with aberrant spindles in a concentration-dependent manner, while it did not cause disruption of centrosome integrity and microtubule organization in interphase cells. In addition, MeHgCl led to the appearance of monoastral cells with a one-dot signal of γ-tubulin. By contrast, Hg 2+ did not cause any of the changes induced by MeHgCl. Thus, MeHgCl caused centrosome abnormality and the related changes without microtubule disruption, suggesting that the mitotic centrosome is a critical target for the cytotoxic effects of MeHgCl.

Application of laser scanning cytometry to the analysis of chromosomal aberrations induced by benzo[a]pyrene in CHO-WBLT cells.

A recently developed laser scanning cytometry technique was applied to cytometric studies to detect rapidly stable chromosomal aberrations induced by a carcinogen in a Chinese hamster fibroblast cell line, CHO-WBLT. Individual chromosomes were collected from metaphase cells by a syringe technique and spread on slides. The DNA content of each chromosome stained with propidium iodide was measured with a laser scanning cytometer (LSC). A characteristic DNA histogram, designated as the "laser scanning karyotype (LSK)," was obtained from about 20,000 chromosomes of CHO-WBLT cells. Each chromosome was confirmed morphologically under the microscope by using a "re-location" system built into the LSC. A total of 21 chromosomes, including marker chromosomes specific to the cell line, were assigned to 10 major peaks in the LSK, which was analogous to the karyotype demonstrated with the classical Q-banding technique. In contrast, clonal sublines isolated after exposure to the carcinogen benzo[a]pyrene showed LSKs different from those found in untreated control cells, and seven of 20 clones were found to be abnormal, with a small number of chromosomal translocations and/or deletions, which were confirmed by Q-banding. The laser scanning cytometry technique was employed to detect stable chromosomal aberrations in CHO-WBLT cells after treatment with benzo[a]pyrene. The results obtained with this technique were comparable to those obtained by Q-banding; therefore, this method may be useful for rapid primary screening to detect stable, abnormal karyotypes induced by environmental chemicals and/or radiation.

An antigenicity study of calcipotriol (MC903)

Antigenicity of calcipotriol (MC903), an anti-psoriasic agent, was investigated in mice and guinea-pigs. 1. In mice, MC903 administered alone or with an adjuvant (Alum) did not result in the production of MC903-specific IgE antibody. 2. In guinea-pigs sensitized with MC903 alone or plus an adjuvant (FCA), systemic anaphylaxis was not induced by challenging with MC903. IgG1 antibody in MC903-sensitized guinea-pigs was not detected by the 4-hr PCA test. 3. Ovalbumin induced the production of ovalbumin-specific IgE antibody in mice, and ovalbumin-specific IgG1 antibody in guinea-pigs. Intense systemic anaphylaxis in the ovalbumin-sensitized guinea-pigs was induced by challenging with ovalbumin. 4. Results obtained in the present study suggest that MC903 does not induce the production of IgE antibody in mouse, and IgG1 antibody in guinea-pig, and in MC903-sensitized guinea-pig systemic anaphylaxis is not induced by challenging with MC903.

A mutagenicity study of calcipotriol (MC903)

Calcipotriol (MC903), an anti-psoriasic agent, was examined for mutagenicity in the reverse mutation test and the chromosomal aberration test in vitro, and the micronucleus test in Slc:ddY mice. 1. In the reverse mutation test using Salmonella typhimurium (TA100, TA1535, TA98, TA1537) and Escherichia coli (WP2uvrA), MC903 did not significantly increase revertant colonies in any of the test strains with or without metabolic system. 2. In the chromosomal aberration test with a Chinese hamster fibroblast cell line (CHL), MC903 did not significantly increase aberrant cells in the direct method or in the activation method. 3. In the micronucleus test with male mice, MC903 did not significantly increase in the number of polychromatic erythrocytes with micronuclei in the bone marrow. These results suggest that MC903 has no mutagenic as well as clastogenic effects under the present experimental condition.

Contribution of increased glutathione content to mechanisms of oxidative stress resistance in hydrogen peroxide resistant hamster fibroblasts.

An H2O2-resistant variant (OC14) of the HA1 Chinese hamster fibroblast cell line, which demonstrates cross resistance to 95% O2 and a 2-fold increase in total glutathione content, was utilized to investigate mechanisms responsible for cellular resistance to H2O2- and O2-toxicity. OC14 and HA1 cells were pretreated with buthionine sulfoximine (BSO) to deplete total cellular glutathione. Following BSO pretreatment, cells were either placed in 250 microM BSO to maintain the glutathione depleted condition and challenged with 95% O2, or challenged with hydrogen peroxide in the absence of BSO. Total glutathione and the activities of CuZn superoxide dismutase, Mn superoxide dismutase, catalase, glutathione peroxidase, and glutathione transferase were evaluated immediately following the BSO pretreatment as well as following 39 to 42 hr of exposure to 250 microM BSO. BSO treatment did not cause significant decreases in any cellular antioxidant tested, except total glutathione. Glutathione depletion resulted in significant (P < 0.05) sensitization to O2-toxicity and H2O2-toxicity in both cell lines at every time point tested. However, glutathione depletion did not completely abolish the resistance to either O2- or H2O2-toxicity demonstrated by OC14 cells, relative to HA1 cells. Also, glutathione depletion did not effect the ability of OC14 cells to metabolize extracellular H2O2. These data indicate that glutathione dependent processes significantly contribute to cellular resistance to acute H2O2- and O2-toxicity, but are not the only determinants of resistance in cell lines. The contribution of aldehydes formed by lipid peroxidation in mechanisms involved with the sensitization to O2-toxicity in glutathione depleted cells was tested by measuring the lipid peroxidation byproduct, 4-hydroxy-2-nonenal (4HNE), bound in Schiff-base linkages or in its free form in cell homogenates at 49 hr of 95% O2-exposure. No significant increase in 4HNE was detected in glutathione depleted cells relative to glutathione competent cells, indicating that glutathione depletion does not sensitize these cells to O2-toxicity by altering the intracellular accumulation of free or Schiff-base bound 4HNE.

Human Platelet Phenolsulfotransferases: cDNA Cloning, Stable Expression in V79 Cells, and Identification of a Novel Allelic Variant of the Phenol-Sulfating Form

We have isolated cDNA clones encoding phenol- and monoamine-sulfating phenolsulfotransferases, using the reverse transcription-polymerase chain reaction method with human platelet mRNA as template. These cDNAs were stably expressed in the Chinese hamster fibroblast cell line V79 and their substrate specificities towards known sulfotransferase isoenzyme-selective compounds determined. The nucleotide and derived amino acid sequences of the monoamine-sulfating form were identical to those previously identified in human liver and brain, but the cDNA for the human platelet phenol-sulfating form we isolated contained 5 and 2 amino acid changes from the two previously published sequences from human liver and brain, suggesting that we have identified a new allelic variant of human phenol-sulfating phenol sulfotransferase.

Mutagenicity studies with palm fruit carotene.

The mutagenicity of palm fruit carotene was examined using the reverse mutation test with bacteria, the chromosomal aberration test with mammalian cells and the micronucleus test in mice. The carotene induced neither reverse mutation in Salmonella typhimurium TA98, TA1537, TA100, TA1535 and in Escherichia coli WP2uvrA, nor structural and numerical (polyploidy) chromosomal aberrations in the Chinese hamster fibroblast cell line (CHL). In addition, no increase in micronucleated polychromatic erythrocytes was elicited in the micronucleus test in CD-1(ICR) male mice. It is concluded that palm fruit carotene had no mutagenic activity in these in vitro and in vivo tests.