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PubMed1990

[Quantitative methods in diagnostic pathology].

The classical pathological diagnosis is of decisive importance for adequate therapy choice. Unfortunately, inconsistency in judgement of the same case and disagreement in diagnosis between different pathologists can be pronounced. Nevertheless, techniques of quantitative pathology largely improve the reliability of diagnosis because of their, in principle, high objectivity and reproducibility. Besides stereology, morphometry and flow cytometry recently also digital image processing, three dimensional laser scan microscopy and multimedial integrated image-database expert systems are becoming increasingly applicated. However, to gain maximum profit of these quantitative methods, sufficient measurement error handling is indispensable. In addition, concepts of standardisation and ongoing quality control should be available to assure confident measurements as a valuable aid in the diagnostic process.

Cytodiagnosis↗
PubMed2005

[Suppressive effects of par-4 antisense oligodeoxynucleotide on up-regulation of intracellular calcium concentration in PC12 cell induced by glutamate and its anti-apoptosis effects].

OBJECTIVE: To investigate the uppressive effects of par-4 antisense oligodeoxynucleotide on the up-regulation of intracellular calcium concentration in PC12 cell induced by glutamate and its anti-apoptosis effects. METHODS: Cationic lipid-mediated par-4 antisense oligodeoxynucleotide (par-4-AS-ODN) was transfected into PC12 cells and followed by glutamate for treatment. Mismatch oligodeoxy-nucleotide (MS-ODN) was used as the control. Morphological assessment and evaluation of the anti-apoptosis effects of par-4-AS-ODN on PC12 cells were performed by laser scanning confocal microscopy by double staining of the cells with Hoechest 33258/propidium iodide (Hoe/PI) and flow cytometry respectively. The mRNA and protein levels of calpain 10 and par-4 were measured by RT-PCR and Western blot. Intracellular calcium concentration was determined by using laser scanning confocal microscope with Fura-2/AM as the fluorescent dye. RESULTS: Par-4-AS-ODN repress the increase of par-4 protein in PC12 cell (52.3 +/- 5.0 vs 90.0 +/- 3.2, < 0.01). Par-4-AS-ODN significantly inhibited the apoptosis of PC12 cells induced by glutamate (53% vs 31%, < 0.01). Par-4-AS-ODN significantly suppress the up-regulation of intracellular calcium concentration in PC12 cells induced by glutamate (Rate of fluorescent density: 167.9 +/- 32.4 vs 228.8 +/- 36.8, < 0.01). Par-4-AS-ODN inhibited the increase of calpain 10 mRNA in PC12 cells induced by glutamate (46.3 +/- 3.7 vs 34.8 +/- 2.1, < 0.01). CONCLUSIONS: par-4-AS-ODN enables to inhibit apoptosis of PC12 cells induced by glutamate. The mechanism of the inhibition may be closely related to suppression of the up-regulation of intracellular calcium concentration and calpain transcription expression.

Animals↗
PubMed1995

Single-step procedure for labeling DNA strand breaks with fluorescein- or BODIPY-conjugated deoxynucleotides: detection of apoptosis and bromodeoxyuridine incorporation.

The methods of in situ labeling of DNA strand breaks have been used to identify apoptotic cells and/or DNA replicating cells. While discrimination of apoptotic cells is based on the inherent presence of numerous DNA strand breaks in their chromatin, DNA proliferating cells can be discriminated by the selective DNA strand break induction by photolysis (SBIP) methodology at the sites that contain incorporated bromodeoxyuridine (BrdUrd) or iododeoxyuridine (IdUrd). In both instances, DNA strand breaks are labeled with biotin- or digoxygenin-conjugated deoxynucleotides, preferably in the reaction catalyzed by exogenous terminal deoxynucleotidyl transferase; fluorescein tagged avidin (streptavidin) or digoxygenin antibody is used in the second step of the reaction. In the present study, DNA strand break labeling was simplified by using directly labeled deoxynucleotides, in a single-step reaction. Cell fluorescence was measured by flow cytometry as well as by a microscope-based laser scanning multiparameter cytometer. Apoptotic cells in HL-60 cultures treated with camptothecin or in primary cultures of non-Hodgkin's lymphoma cells treated with prednisolone were easily identified utilizing BODIPY-conjugated dUTP (B-dUTP). Apoptotic cells were also recognized using fluorescein-conjugated dUTP or dATP, although the discrimination was more pronounced with B-dUTP. The single-step procedure, requiring fewer centrifugation steps, resulted in less cell loss compared to the two-step cell labeling technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Apoptosis↗
PubMed1995

Ploidy analysis on Wilms' tumour touch imprints using ethidium bromide and automated image analysis integrated confocal laser scanning microscopy.

Although image analysis (IA) is increasingly being used to quantitate nuclear DNA, comparative data between fluorescence methods of IA and flow cytometry (FCM) is limited. In this study fluorescence IA was compared with FCM data in a series of Wilms' tumour touch preparations. Airdried touch imprints that had previously been Giemsa stained were restained with ethidium bromide. Confocal fluorescence images were obtained with a confocal laser scanning microscope and assessed by a fully automated IA package. Data was collected from 400 nuclei per imprint. The resulting DNA histograms were analysed and ploidy status and DNA indices determined using standard criteria. Results were compared with those derived from FCM analysis of nuclear suspensions. Ten of twelve tumours were concordant by both techniques. However in two cases assessed as diploid by FCM, IA identified aneuploidy. Excellent correlation between DNA indices as assessed by both techniques was observed (r = 0.987). In the three cases for which both unstained and Giemsa stained touch imprints were available for IA, the histogram configurations did not differ significantly. Fluorescence IA is an accurate and sensitive technique for DNA quantitation, which appears at least comparable to FCM assessment and which has a number of important advantages.

Child, Preschool↗
PubMed2001

Early effects of AZT on mitochondrial functions in the absence of mitochondrial DNA depletion in rat myotubes.

Zidovudine (AZT) is a potent inhibitor of human immunodeficiency virus (HIV) replication. In humans, as well as in animal models, long-term treatment with AZT induces a severe myopathy characterised by structural and functional alterations of mitochondria associated with depletion of mitochondrial DNA (mtDNA). In the present work, we compared the effects induced by AZT on mitochondria upon short- or long-term treatments of cultured rat myotubes. Morphological alterations were investigated by electron microscopy, and mtDNA depletion and deletions were analysed by Southern blot. Mitochondrial membrane potential was determined after JC-1 staining by laser-scanning confocal microscopy in whole cells, and by flow cytometry in isolated muscle mitochondria. We found that the early effects of AZT on mitochondrial functions were a marked, yet reversible reduction in mitochondrial membrane potential, in the absence of any effect on mtDNA. The long-term treatment, in addition to mitochondrial membrane potential alterations, induced morphological changes in mitochondria, and a remarkable reduction in the amount of mtDNA, without any significant evidence of mtDNA deletions. In both treatments, a block of the spontaneous contraction of myotubes was observed. To study in more detail the early effects induced by AZT, the ability of the drug to interact with cardiolipin, an important component of internal mitochondrial membrane, was investigated by atomic force microscopy (AFM) in an artificial membrane model system. The results suggest that the primary effects of AZT may be related to a physical interference with the membrane structure leading to a consequent modification of its physical characteristics.

Animals↗
PubMed2005

Proapoptotic and pronecrosis effect of different truncated hepatitis C virus core proteins.

OBJECTIVE: To study the roles of different truncated hepatitis C virus (HCV) core proteins (CORE) in the pathogenesis of HCV persistent infection and hepatocellular carcinoma (HCC) and to assess intracellular localization in transiently transfected cells. METHODS: Seven truncated GFP (green fluorescent protein)-CORE fusion protein expression plasmids were constructed, which contained HCV CORE sequences derived from tumor tissues (BT) and non-tumor tissues (BNT) from one patient infected with HCV. Amino acid (aa) lengths were BT: 1-172 aa, 1-126 aa, 1-58 aa, 59-126 aa, 127-172 aa; BNT: 1-172 aa and C191: 1-172 aa respectively. Subcellular localization of CORE-GFP was analyzed by con-focal laser scanning microscope. Apoptosis and necrosis were quantified by flow cytometry. RESULTS: Different truncated CORE-GFP localized mainly in the cytoplasm, but nuclear staining was also observed. HCV CORE could induce apoptosis and necrosis, and different truncated COREs could induce cell apoptosis and necrosis at different levels. Among the same length 1-172 aa of BT, BNT and C191, the cell apoptosis and necrosis percentage of BT is highest, and C191 is the lowest (BT>BNT>C191). To the different fragment COREs of BT, N-terminal of CORE induced apoptosis and necrosis higher, compared with that of C-terminal (1-172 aa>1-126 aa>1-58 aa>127-172 aa>59-126 aa). CONCLUSION: These results suggest HCV CORE could induce apoptosis and necrosis of cells, which might play an important role in the pathogenesis of HCV persistent infection and HCC and the different CORE domains of different HCV quasi-species might have some difference in their pathogenesis.

Apoptosis↗
PubMed2002

Mechanism of 5-fluorouracil required resistance in human hepatocellular carcinoma cell line Bel(7402).

AIM: To investigate the resistance mechanism of 5-fluorouracil (5-FU) in Bel(7402)/5-FU cells which was established in our lab by in vitro continuous stepwise exposure of human hepatocellular carcinoma (HCC) cell line Bel(7402) to 5-FU. METHODS: The expression of multidrug resistance-associated protein (MRP) and thymidylate synthase (TS) in Bel(7402) cells was detected by immonocytochemistry. The fluorescein (FLU) accumulation, an index of MRP functional activity, was determined by flow cytometry. The distribution of FLU was observed by confocal laser scanning microscope. The spectrofluorometry was used to show the intracelluar content of glutathione (GSH). Cell growth inhibition was determined by MTT assay. The activity of glutathione S-transferases (GSTs) was determined by spectrophotometry. RESULTS: A higher expression of MRP in the Bel(7402)/5-FU cells was observed by using monoclonal mouse anti-MRP antibody, MRPr-1, in comparison with Bel(7402) cells. Bel(7402)/5-FU cells also showed a significant decrease of FLU accumulation. FLU mainly accumulated in the nucleus with a high nuclear/cytoplasmic ratio in Bel(7402) cells, whereas there was no difference of FLU accumulation between the nucleus and cytoplasm in Bel(7402)/5-FU cells. The intracellular GSH content in Bel(7402)/5-FU cells was almost 3 folds higher than that in Bel(7402) cells. Addition of D, L-buthione-S, R-sulfoximine (BSO) dose-dependently reduced the GSH content in Bel(7402)/5-FU cells, however, only a weak enhancement on the cytotoxicity of 5-FU and doxorubicin (Dox) to Bel(7402)/5-FU cells was observed. Bel(7402)/5-FU cells also exhibited 29.1 % higher total GSTs activity than Bel(7402) cells. Immunocytochemical staining by using anti-TS monoclonal antibody TS 106 showed that the level of TS in Bel(7402)/5-FU cells elevated markedly as compared with Bel(7402) cells. CONCLUSION: The continuous exposure of Bel(7402) cells to 5-FU led to overexpression of TS and MRP, as well as increased intracellular GSH content and total GST activity.

Buthionine Sulfoximine↗
PubMed2004

Confocal 3D DNA cytometry: assessment of required coefficient of variation by computer simulation.

BACKGROUND: Confocal Laser Scanning Microscopy (CLSM) provides the opportunity to perform 3D DNA content measurements on intact cells in thick histological sections. So far, sample size has been limited by the time consuming nature of the technology. Since the power of DNA histograms to resolve different stemlines depends on both the sample size and the coefficient of variation (CV) of histogram peaks, interpretation of 3D CLSM DNA histograms might be hampered by both a small sample size and a large CV. The aim of this study was to analyze the required CV for 3D CLSM DNA histograms given a realistic sample size. METHODS: By computer simulation, virtual histograms were composed for sample sizes of 20000, 10000, 5000, 1000, and 273 cells and CVs of 30, 25, 20, 15, 10 and 5%. By visual inspection, the histogram quality with respect to resolution of G0/1 and G2/M peaks of a diploid stemline was assessed. RESULTS: As expected, the interpretability of DNA histograms deteriorated with decreasing sample sizes and higher CVs. For CVs of 15% and lower, a clearly bimodal peak pattern with well distinguishable G0/1 and G2/M peaks were still seen at a sample size of 273 cells, which is our current average sample size with 3D CLSM DNA cytometry. CONCLUSIONS: For unambiguous interpretation of DNA histograms obtained using 3D CLSM, a CV of at most 15% is tolerable at currently achievable sample sizes. To resolve smaller near diploid stemlines, a CV of 10% or better should be aimed at. With currently available 3D imaging technology, this CV is achievable.

Computer Simulation↗
PubMed2005

Human macrophages simultaneously express membrane-C1q and Fc-receptors for IgG.

Membrane C1q (mC1q) of macrophages (MPhi) is a precursor of the IgG-binding serum protein C1q. Thus, mC1q potentially provides one of several Fcgamma binding sites of mature MPhi and we analyzed whether simultaneous expression occurs of established receptors for IgG, FcgammaRI, II, and III, and mC1q during in vitro differentiation of MPhi. Using flow cytometry, immunoprecipitation combined with Western blotting and Northern blot analysis mC1q was hardly detected in freshly isolated blood monocytes, but increasingly in developing monocyte-derived MPhi. Laser scanning fluorescence microscopy confirmed the membrane localization of mC1q. Two-color-staining flow cytometry experiments indicated that mC1q and all three types of FcgammaRs are simultaneously expressed on mature monocyte-derived MPhi. A high correlation was found for the expression of mC1q and FcgammaRs, in particular FcgammaRII, but not mC1q and CD14, another marker of monocytes/MPhi.

Cell Differentiation↗
PubMed2006

Inhibitory effects of saponins from Anemarrhena asphodeloides Bunge on the growth of vascular smooth muscle cells.

OBJECTIVE: To investigate the effects of saponins from Anemarrhena asphodeloides Bunge (SAaB) (Botanical Name: Anemarrhena Asphodeloidis Rhizoma) on the growth of vascular smooth muscle cells (VSMCs). METHODS: Cell proliferation was measured by a newly developed cell proliferation reagent, WST-1. Cell apoptosis was assayed by flow cytometry through detecting annexin V. Nitric oxide production was evaluated using confocal laser scanning microscopy with diaminofluorescein diacetate (DAF-2, DA). Cell aldose reductase (AR) activity, as well as the effect of Epalrestat and interleukin-1beta were also explored. RESULTS: WST assay showed that cell proliferation induced by serum was significantly inhibited by SAaB (P<0.01). Flow cytometry analysis revealed that SAaB could enhance apoptotic rate of VSMCs (P<0.01). Nitric oxide production was significantly enhanced after administration of SAaB and interleukin-1beta. Moreover, AR activity of VSMCs was also remarkably inhibited by both SAaB and Epalrestat (P<0.01). CONCLUSION: SAaB can inhibit proliferation and enhance apoptosis of VSMCs. It may protect vascular cells by inhibiting VSMC proliferation and augmenting apoptotic rate of VSMCs via NO-dependent pathway.

Anemarrhena↗
PubMed2004

Reactive oxygen species mediation of baizhu-induced apoptosis in human leukemia cells.

Baizhu (Atractylodes macrocephala Koidz) has traditionally been used as an important ingredient of several Chinese herbal medicines, which have been used for abdominal pain and gastroenterology diseases for thousands of years. Despite its popularity in herbal therapies, little is known about the anticancer effect of Baizhu. In this study, the anticancer potential of Baizhu on human hepatoma and leukemia cell lines was evaluated. Baizhu methanol extract induced apoptosis in human lymphoma Jurkat T cells, leukemia U937, and HL-60 cells. This was confirmed by several methods, including hypodiploid cells detection using flow cytometry, the examination of apoptotic bodies containing cells using confocal laser scanning microscopy, and hypodiploid cell population inhibition using the broad spectrum caspase inhibitor z-VAD. Finally, the intracellular reactive oxygen species (ROS), especially hydrogen peroxide (H(2)O(2)) and superoxide anion (O(2)(-)), were found to be elevated after treatment of these cells with Baizhu extracts. Antioxidant N-acetyl cysteine (NAC) pretreatment almost completely inhibited Baizhu-induced apoptosis, suggesting that ROS are the key mediators for Baizhu-induced apoptosis. All these data indicate that Baizhu is a possible anti-tumor agent that induces apoptosis of human leukemia cells through ROS generation.

Antineoplastic Agents↗
PubMed2002

Confocal DNA cytometry: a contour-based segmentation algorithm for automated three-dimensional image segmentation.

BACKGROUND: Confocal laser scanning microscopy (CLSM) presents the opportunity to perform three-dimensional (3D) DNA content measurements on intact cells in thick histological sections. So far, these measurements have been performed manually, which is quite time-consuming. METHODS: In this study, an intuitive contour-based segmentation algorithm for automatic 3D CLSM image cytometry of nuclei in thick histological sections is presented. To evaluate the segmentation algorithm, we measured the DNA content and volume of human liver and breast cancer nuclei in 3D CLSM images. RESULTS: A high percentage of nuclei could be segmented fully automatically (e.g., human liver, 92%). Comparison with (time-consuming) interactive measurements on the same CLSM images showed that the results were well correlated (liver, r = 1.00; breast, r = 0.92). CONCLUSIONS: Automatic 3D CLSM image cytometry enables measurement of volume and DNA content of large numbers of nuclei in thick histological sections within an acceptable time. This makes large-scale studies feasible, whereby the advantages of CLSM can be exploited fully. The intuitive modular segmentation algorithm presented in this study detects and separates overlapping objects, also in two-dimensional (2D) space. Therefore, this algorithm may also be suitable for other applications.

Algorithms↗
PubMed2000

Automated data acquisition by confocal laser scanning microscopy and image analysis of triple stained immunofluorescent leukocytes in tissue.

The aim of the study was to develop a novel system permitting automated analysis of multicolor immunofluorescence-staining of cells in solid tissues which would be comparable to the analytical capacity of flow cytometry. In the user friendly automated data acquisition and image processing system which was established, the software includes a set of pre-defined processing steps for improved object identification and can be either interactive or fully automatic. As with multi color flow cytometry, stained cells can be analyzed in a fully automated manner regardless of tissue type. The software organizes computerized sample movement, autofocus, laser readjustment, data capture and storage as well as calculation. Data are presented as histograms indicating the staining intensity and frequency of each antigen, and in dotplots with each channel plotted against the other. The calculated statistics give information about how many of the cells are single-, double- or triple-reactive and how intensely they react with the respective antibodies. Comparison of data generated by this automated fluorescence confocal laser scanning microscopy (AF-CLSM) with flow cytometry using triple stained peripheral blood lymphocytes revealed a highly significant correlation between the methods (P<0.001). A correlation was also observed when sections triple stained for anti-CD45, -CD3 and -CD8 were analyzed by AF-CLSM and the data were compared to visual/manual cell counting (P<0.01). The AF-CLSM system permits for the first time, fast (online) and reproducible analysis of immunofluorescence staining of an unlimited number of cells in tissue sections. The software, including a manual, is available for a small fee to cover the costs of printing and postage.

CD3 Complex↗
PubMed1996

Concanavalin A-induced apoptosis in murine macrophages through a Ca(2+)- independent pathway.

Concanavalin A (ConA), normally a mitogen of T lymphocytes, was found to induce apoptosis or programmed cell death in murine peritoneal macrophages. The following observations support this assertion: 1) incubation of peritoneal macrophages or cultured PU5-1.8 macrophage cells with ConA caused a dose- and time-dependent reduction of mitochondrial dehy-drogenase activity as measured by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, 2) treatment of cells with ConA induced formation of apoptotic bodies as seen under the confocal laser scanning microscope, 3) challenge of cells with ConA produced a considerable amount of cell debris with DNA content next to G0 phase as revealed by flow cytometry and 4) ConA was able to elicit DNA fragmentation in these cells. The involvement of Ca(2+) in mediating the apoptosis was studied in single cells by confocal laser scanning microscope using the Ca(2+) fluorescence dye, fluo-3. Our results show that ConA induced an immediate rise of intracellular free Ca(2+) concentration as well as opening of Ca(2+) channels on cell surface. But when the cells were treated with 1,2-bis(o-aminophenoxy) ethane-N, N, N', N'-tetraacetic acid/AM (BAPTA/AM), a Ca(2+) chelator, to buffer the rise of internal Ca(2+), ConA still caused DNA fragmentation. Furthermore, injection of Ca(2+) into the cell with ionomycin had no stimulatory effect on DNA fragmentation. These results suggest that Ca(2+) changes induced by ConA are not a prerequisite for apoptosis in macrophages.

Journal Article↗
PubMed2004

Analysis of gene expression profile in gastric cancer cells stimulated with Helicobacter pylori isogenic strains.

To understand the biological processes within host cells induced by VacA, isogenic strains of Helicobacter pylori (NCTC 11638 or 11638-DeltavacA) were used to stimulate gastric cancer cells SGC7901, and differentially expressed genes in host cells were identified using cDNA microarray technology. More than 300 genes were found to alter their mRNA expression at different time points, among which 68 were related to the cytoskeleton, 87 were associated with cell cycle, cell death and proliferation, IL8 expression was also found to be up-regulated. Cells co-cultured with broth-culture supernatant (BCS) of NCTC 11638 showed more alteration in microtubule cytoskeleton morphology, as observed by laser scanning confocal microscopy, and a lower apoptosis rate, detected by flow cytometry, compared with those co-cultured with BCS of 11638-DeltavacA. The supernatants of cells co-cultured with NCTC 11638 showed significantly higher IL8 expression than those co-cultured with 11638-DeltavacA. It is concluded that VacA disrupts cytoskeletal architecture by influencing the expression of cytoskeleton-associated genes. VacA breaks the balance between cell proliferation and cell death by inducing the maladjustment of genes related to cell cycle. VacA is also able to induce the inflammatory response.

Apoptosis↗
PubMed2002

The F-actin content of multiple myeloma cells as a measure of their migration.

One of the main characteristics of multiple myeloma (MM) cells is their specific homing and growth in the bone marrow (BM). For their homing, MM cells need chemotactic signals to be attracted towards the BM and to be activated. Profound knowledge of the different chemokines for MM cells and their signal transduction pathways is necessary to interfere in this process. We studied here an extra possible tool for the investigation of the different chemokines and their pathways. The 5T experimental mouse model was used to investigate the migration of MM cells towards BM stromal cells. We studied the changes of the F-actin content in the 5TMM cells in the presence of BM stromal cell conditioned medium and we correlated this with their migratory capacity. F-actin became polarized when the cells were migrating, in contrast to nonmigrating cells. This polarization could not only be seen by fluorescence and confocal laser scanning microscopy, but also could be quantified by fluorometry and flow cytometry. The correlation between the F-actin content of the MM cells and their migration capacity thus makes its quantification a useful tool in studying their migratory behavior.

Actins↗
PubMed2001

Chromium (VI)-induced oxidative stress, apoptotic cell death and modulation of p53 tumor suppressor gene.

Chromium (VI) is a widely used industrial chemical, extensively used in paints, metal finishes, steel including stainless steel manufacturing, alloy cast irons, chrome, and wood treatment. On the contrary, chromium (III) salts such as chromium polynicotinate, chromium chloride and chromium picolinate, are used as micronutrients and nutritional supplements, and have been demonstrated to exhibit a significant number of health benefits in rodents and humans. However, the cause for the hexavalent chromium to induce cytotoxicity is not entirely understood. A series of in vitro and in vivo studies have demonstrated that chromium (VI) induces an oxidative stress through enhanced production of reactive oxygen species (ROS) leading to genomic DNA damage and oxidative deterioration of lipids and proteins. A cascade of cellular events occur following chromium (VI)-induced oxidative stress including enhanced production of superoxide anion and hydroxyl radicals, increased lipid peroxidation and genomic DNA fragmentation, modulation of intracellular oxidized states, activation of protein kinase C, apoptotic cell death and altered gene expression. In this paper, we have demonstrated concentration- and time-dependent effects of sodium dichromate (chromium (VI) or Cr (VI)) on enhanced production of superoxide anion and hydroxyl radicals, changes in intracellular oxidized states as determined by laser scanning confocal microscopy, DNA fragmentation and apoptotic cell death (by flow cytometry) in human peripheral blood mononuclear cells. These results were compared with the concentration-dependent effects of chromium (VI) on chronic myelogenous leukemic K562 cells and J774A.1 murine macrophage cells. Chromium (VI)-induced enhanced production of ROS, as well as oxidative tissue and DNA damage were observed in these cells. More pronounced effect was observed on chronic myelogenous leukemic K562 cells and J774A.1 murine macrophage cells. Furthermore, we have assessed the effect of a single oral LD50 dose of chromium (VI) on female C57BL/6Ntac and p53-deficient C57BL/6TSG p53 mice on enhanced production of superoxide anion, lipid peroxidation and DNA fragmentation in the hepatic and brain tissues. Chromium (VI)-induced more pronounced oxidative damage in p53 deficient mice. This in vivo study highlighted that apoptotic regulatory protein p53 may play a major role in chromium (VI)-induced oxidative stress and toxicity. Taken together, oxidative stress and oxidative tissue damage, and a cascade of cellular events including modulation of apoptotic regulatory gene p53 are involved in chromium (VI)-induced toxicity and carcinogenesis.

Animals↗
PubMed2000

[Effect of rhTFAR19 protein on cell cycle and apoptosis of MCF-7 induced by gamma-ray].

OBJECTIVE: To investigate the effect of protein product of TFAR19, an apoptosis-related gene previously cloned from leukemia cell line TF-1 cultured in medium deprived of growth factor, on cell cycle and apoptosis of human breast cancer induced by gamma-ray. METHODS: Cell morphology, fluorescence microscopy, laser scanning confocal microscopy, single-cell gel electrophoresis (SCGE) and flow cytometry (FCM) were applied to study cell cycle and apoptosis of breast cancer cell line MCF-7. RESULTS: rhTFAR19 protein itself had no effect on cell cycle arrest and apoptosis of MCF-7 cell induced by gamma-ray. When MCF-7 cells were pretreated with 10 micrograms/ml rhTFAR19 and then irradiated with 12 Gy gamma-ray, cell apoptosis was observed. It was characterized morphologically by chromatin condensation, nucleoar disintegration, formation of apoptotic bodies, and typical "cornet" on SCGE. CONCLUSION: TFAR19 protein has no apparent effect on MCF-7 cell cycle induced by gamma-ray. However, it synergizes with gamma-radiation in the induction and enhancement of apoptosis.

Apoptosis↗