OBJECTIVETo investigate the expression and gene mutation of cluster of differentiation 9 (CD9) in the pathway of the mineral powder induced malignant transformation in immortalized human bronchial epithelial cells (BEAS-2B) in Gejiu.

METHODSBEAS-2B cells served as the control group and its malignant transformation cells induced by mineral powder in Gejiu were considered as experiment group. The expression of CD9 protein in 20 bottles of BEAS-2B cells and 20 bottles of malignant transformation cells was evaluated by immunocytochemistry. The mRNA expression of CD9 in 10 bottles of BEAS-2B cells and 10 bottles of malignant transformation cells was examined by reverse transcriptase polymerase chain reaction (RT-PCR). Gene mutation was detected in the products of RT-PCR by DNA sequencing.

RESULTSThere was significant difference between the expression of CD9 protein in BEAS-2B cells (100%, 20/20) and that in its malignant transformation cells (35%, 7/20 P < 0.01). The expression of CD9 mRNA in BEAS-2B cells 0.91 +/- 0.09 was significantly higher than that in its malignant transformation cells (0.34 +/- 0.14) (P < 0.01). Two point mutation of CD9 gene was detected in the malignant transformation cells of BEAS-2B by DNA sequencing. The change of G-->T in the base of 231 led to the change of Gln-->His in the amino acids of 40. The change of T-->A in the base of 119 led to the change of Val-->Asp in the amino acids of 3.

CONCLUSIONThe absence or down-regulation of CD9 expression and point mutation in the malignant transformation cells of BEAS-2B may play a considerable role in the pathway of the malignant transformation in the BEAS-2B cells induced by mineral powder in Gejiu.

Bronchi ; pathology ; Cell Line ; Cell Transformation, Neoplastic ; drug effects ; genetics ; Dust ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Gene Expression Regulation ; drug effects ; Humans ; Lung Neoplasms ; chemically induced ; genetics ; metabolism ; pathology ; Mining ; Mutation ; drug effects ; Tetraspanin-29 ; genetics ; metabolism

OBJECTIVETo study the effect of hypoxia on cofilin activation in intestinal epithelial cells and its relation with distribution of tight junction protein zonula occludens 1 (ZO-1).

METHODSThe human intestinal epithelial cell line Caco-2 was used to reproduce monolayer cells. The monolayer-cell specimens were divided into control group (no treatment), hypoxic group ( exposed to hypoxia), and normoxic group (exposed to normoxia) according to the random number table. Western blotting was used to detect the protein expressions of cofilin and phosphorylatedl cofilin (p-cofilin) of cells in normoxic group and hypoxic group exposed to normoxia or hypoxia for 1, 2, 6, 12, and 24 h and control group, with 9 samples in control group and 9 samples at each time point in the other two groups. The other monolayer-cell specimens were divided into hypoxic group (exposed to hypoxia) and control group (no treatment) according to the random number table. Cells in hypoxic group exposed to hypoxia for 1, 2, 6, 12, and 24 h and control group were obtained. Morphology and distribution of F-actin was observd with laser scanning confocal microscopy, the ratio of F-actin to G-actin was determined by fluorescence method, and distribution of ZO-l and cellular morphology were observed with laser scanning confocal microscopy. The sample number of last 3 experiments was respectively 3, 6, and 3 in both hypoxic group (at each time point) and control group. Data were processed with paired ttest, analysis of variance of repeated measurement, and LSD-t test.

RESULTSThe protein expressions of cofilin and p-cofilin of cells between normoxic group exposed to normoxia for 1 to 24 h and control group showed no significant changes (with values from -0.385 to 1.701, t(p-cofilin)values from 0. 040 to 1.538, P values above 0.05). There were no obvious differences in protein expressions of en filmn of cells between hypoxic group exposed to hypoxia for 1 to 24 h and control group ( with values from 1.032 to 2.390, P values above 0.05). Compared with that in control group, the protein expressions of p-cofilin of cells were greatly reduced in hypoxic group exposed to hypoxia for 1 to 24 h (with values from 4.563 to 22.678, P values below 0.01), especially exposed to hypoxia for 24 h. The protein expressions of cofilin of cells between normoxic group and hypoxic group at each time point were close ( with t values from -0.904 to 1.433, P values above 0.05). In hypoxic group, the protein expressions of p-cofilin of cells exposed to hypoxia for 1, 2, 6, 12, and 24 h were 0.87 +/- 08, 0.780 .05, 0.89 +/- 0.07, 0.68+0. 07, and 0.57 +/- 0.06, respectively, significantly lower than those in normoxic group (0.90 +/- 0.07, 0.97 +/- 0.06, 1.00 +/- 0.06, 1.00 +/- 0.05, and 0.99 +/- 0.05, with t values from 3.193 to 16.434, P values below 0.01). In control group, F-actin in the cytoplasm was abundant, most of it was in bunches. The trend of F-actin was disorderly in hypoxic group from being exposed to hypoxia for 1 h, shortened in length or even dissipated. The ratios of F-actin to G-actin of cells in hypoxic group exposed to hypoxia for 12 and 24 h (0.89 +/- 0.12 and 0.84 +/- 0.19) were obviously decreased as compared with that in control group (1. 00, with t values respectively 3. 622 and 3. 577, P values below 0.01). There were no obvious differences in the ratios of F-actin to G-actin of cells between hypoxic group exposed to hypoxia for 1, 2, and 6 h and control group ( with values from 0.447 to 1.526, P values above 0.05). In control group, cells were compact in arrangement, and ZO-1 was distributed continuously along the cytomnembrane. From being exposed to hypoxia for 2 h, cells became irregular in shape in hypoxic group. ZO-1 was distributed in discontinuous fashion along the cytomembrane with breakage in hypoxic group exposed to hypoxia for 24 h.

CONCLUSIONSHypoxia may cause the disorder of dynamic balance between F-actin and G-actin by inducing cofilin activation, which in turn leads to the changes in distribution of tight junction protein ZO-1 in intestinal epithelial cells.

Actin Depolymerizing Factors ; Actins ; Blotting, Western ; Caco-2 Cells ; drug effects ; physiology ; Epithelial Cells ; cytology ; drug effects ; Humans ; Hypoxia ; metabolism ; Intestinal Mucosa ; drug effects ; metabolism ; pathology ; Intestines ; Oxygen ; pharmacology ; Tight Junctions ; drug effects ; metabolism ; Zonula Occludens-1 Protein ; metabolism

OBJECTIVETo study whether aristololactam I (AL-I) can enter renal proximal tubular epithelial cells and the situation of intracellular distribution and accumulation.

METHODCultured human renal proximal tubular epithelial cell line (HK-2) was used as the subject. Intracellular fluorescence from AL-I and its distribution are examined by fluorescence microscopy after a treatment with different concentration of AL-I, the intracellular accumulation of AL-I was also investigated by incubated cells in AL-I -free medium for 48 h after washing-out the media containing AL-I.

RESULTAfter treatment of AL-I (concentration from 5 microg x mL(-1) to 20 microg x mL(-1)), glaucous fluorescence could be observed inside renal proximal tubular epithelial cells at 0.5 h, and the fluorescence distributed only in cytoplasm while not be observed in nuclei. Moreover, the fluorescence of AL-I could be kept in cytoplasm for more than 48 h after washing out the media containing AL-I .

CONCLUSIONAL-I is able to enter renal proximal tubular epithelial cells in short time and accumulate in cytoplasm, but not enter nuclei. This property may contribute to the cytotoxic mechanism of renal injury induced by AL-I, which may partially explain the persistent renal toxicity of AAs and its metabolites in the development of aristolochic acid nephropathy.

Animals ; Aristolochic Acids ; metabolism ; toxicity ; Cell Line ; Cell Nucleus ; drug effects ; metabolism ; Cytoplasm ; drug effects ; metabolism ; Epithelial Cells ; cytology ; drug effects ; metabolism ; pathology ; Humans ; Kidney Diseases ; metabolism ; pathology ; Kidney Tubules, Proximal ; cytology ; pathology ; Microscopy, Fluorescence

OBJECTIVETo investigate the apoptosis rate and the reactive oxygen species (ROS) level induced by chrysotile fibers in BEAS-2B cells and the blockage effect of free radical scavengers on the induction of chrysotile fibers.

METHODSThe cell survival rate, the morphological variation of BEAS-2B cells, the apoptosis rate, the expression levels of gene caspase-3 and the ROS generation level were measured by using trypan blue phagocytosis, hematoxylin and eosin staining, oligonucleosomal DNA fragmentation assay, FCM, RT-PCR and fluorescent probe DCFH-DA in the suspension (0, 5, 10, 20, 100 and 200 microg/cm(2)) and the filtrate (0, 100, 200, 400, 800 and 1600 microg/ml) of chrysotile fibers. Addition of free radical scavengers such as catalase, dimethyl sulfoxide and mannitol prevented the radical generation and gene expression.

RESULTSSurvival rates of BEAS2B cells treated by the suspension (0, 5 and 10 microg/cm(2)) and the filtrate (0, 100 and 200 microg/ml) of chrysotile fibers for 24 hours were above 90%. The apoptotic rates of BEAS-2B were increased with the concentration of suspension and filtrate from chrysotile fibers (P < 0.05). Otherwise, caspase-3 mRNA and ROS were stimulated by chrysotile fibers. Free radical scavengers such as CAT, DMSO and mannitol could reduce these stimulations. The ROS blocking rate of suspension of chrysotile fibers was 23.7%, 21.6% and 11.2% respectively, and that of filtrate was 37.9%, 40.3% and 10.6% respectively.

CONCLUSIONApoptosis is induced in BEAS-2B cells exposed to chrysotile fibers suspension and filtrate. Generation of ROS plays an important role in chrysotile fibers-induced BEAS-2B cell apoptosis.

Apoptosis ; drug effects ; Asbestos, Serpentine ; toxicity ; Cell Line ; Drug Antagonism ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Free Radical Scavengers ; pharmacology ; Humans ; Oxidative Stress ; Reactive Oxygen Species ; metabolism

OBJECTIVETo study the interaction between transformation of human pulmonary epithelial cells and activation of fibroblasts induced by Yunnan tin mine dust.

METHODS(1) The immortalized human bronchial epithelial cell line BEAS-2B and human embryo lung fibroblast cell line WI-38 were grown in MEM medium containing 5% and 10% FBS, respectively, at 37 degrees C and 5% CO2 with saturated humidity. The cells were subcultured every 6 days. BEAS-2B cells and WI-38 cells were induced with Yunnan tin mine dust on every other generation at the concentration of 100 microg/ml. From the 11th generation, the cells were co-cultured. Epithelial cell transformation was tested using concanavalin A (ConA) agglutination and anchorage-independent growth assays. The cell cycles were analyzed through flow cytometry. The expressions of alpha-SMA in fibroblasts were determined with immunocytochemistry.

RESULTS(1) Cell morphology of mine dust-exposed epithelial cells began to transform at the 28th generation. Similar transformations were observed with mine dust-induced epithelial cells co-cultured with fibroblasts from the 20th generation and mine dust-induce epithelial cells co-cultured with mine dust-induced fibroblasts from the 16th generation. ConA agglutination assay and anchorage-independent growth assays were negative in normal BEAS-2B cells. At the 26 th generation, the agglutination test result of the mine dust-exposed epithelial cells was positive. Co-cultured with fibroblasts and mine dust-exposed fibroblasts, the agglutination time of the mine dust-exposed epithelial cells became short. Epithelial cell anchorage-independent growth assay was positive for mine dust-exposed epithelial cells co-cultured with fibroblasts at the 36th generations and for mine dust-exposed epithelial cells co-cultured with mine dust-exposed fibroblasts at the 26th generations. The clone formation rate of the 26th generation was 6.00 per thousand +/- 1.00 per thousand and 15.33 per thousand +/- 2.52 per thousand respectively, with the significant differences (P < 0.05). With generation adding, the portion of S phase increased for mine dust-exposed epithelial cells. (2) At the 26th generations, fibroblasts expressed alpha-SMA. Co-cultured with epithelial cell, the alpha-SMA expression of fibroblasts increased. Especially, positive cell numbers and intensity of staining dramatically increased with generation adding.

CONCLUSIONS(1) The tin mine dust can induce malignant transformation of human pulmonary epithelial cells BEAS-2B and activation of fibroblasts WI-38. (2) The epithelial cells are major target in carcinogenesis induced by Yunnan tin mine dust. (3) Transformation of epithelia and activation of fibroblasts co-evolve in the developing process of induced lung cancer by Yunnan tin mine dust.

Cell Cycle ; drug effects ; Cell Line ; Cell Transformation, Neoplastic ; drug effects ; Coculture Techniques ; Dust ; Epithelial Cells ; pathology ; Fibroblasts ; metabolism ; pathology ; Humans ; Tin ; toxicity

OBJECTIVE: To investigate the effect of SOX2 on chemotherapy sensitivity of human laryngeal epithelial cells Hep-2. METHOD: We designed and synthesized RNAis for silencing the expression of SOX2 in Hep-2 cells and selected the most effective RNAi by Western blot analysis. Then the recombinant plasmids of pGCsi-H1-SOX2 and pGCsi-H1-NC were constructed and transfected into Hep-2 cells to build cell lines of psiSOX2-Hep-2 and psiNC-Hep-2. CCK-8 assay had been used to test the sensitivity of Hep-2 cells to 5-FU and PTX after silencing SOX2 expression. Hoechst staining had been used to exam the changes of Hep-2 cells apoptosis treatment by 5-FU and PTX after silencing SOX2 expression. Furthermore, the changes of apoptosis-related genes expressions were detected by Western blotting. RESULT: The cell lines of psiSOX2-Hep-2 and psiNC-Hep-2 were successfully established, and the expression of SOX2 protein was decreased 78% in psiSOX2-Hep-2 cells compared with psiNC-Hep-2 cells. After reducing SOX2 expression, the sensitivity of Hep-2 cells to 5-FU and PTX were increased and the IC50 values for 48 h were decreased to 8.12 μg/ml and 5.16 μg/ml. Meanwhile, the apoptosis rate and the expression of apoptotic gene Bax and cleaved caspase-3 expression were dramatically increased and anti-apoptotic genes survivin and Bcl-2 were significantly decreased in psiSOX2-Hep-2 cells compared with psiNC-Hep-2 cells. CONCLUSION Down-regulating the protein expression of SOX2 by RNAi will significantly enhance the sensitivity of human laryngeal epithelial cells Hep-2 to 5-FU and PTX.
Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Fluorouracil ; pharmacology ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; RNA Interference ; SOXB1 Transcription Factors ; genetics

OBJECTIVETo analyze the effect of hyperoxia on the proliferation and surfactant associated protein messenger RNA levels of type II alveolar epithelial cells (AECIIs) of premature rat, and to investigate the effect of amygdalin on the change resulted from hyperoxia in AECIIs isolated from premature rat lung in vitro.

METHODSThe lung tissue of 20-day fetal rat was digested by trypsin and collagenase. AECIIs and lung fibroblasts (LFs) were isolated and purified at different centrifugal force and different adherence, then cultured. The nature of the cultures was identified by cytokeratin staining, vimentin staining and transmission electron micrography. For establishing hyperoxia-exposed cell model, purified AECIIs were cultured for 24 hours after culture flasks were filled with 95% oxygen-5% CO2 at 3 L/min for 10 min, and then sealed. Oxygen concentrations were tested in CYS-1 digital oxygen monitor after 24 hours of exposure. A sample was discarded if its oxygen concentration was < 90%. Cell proliferating vitality was examined by MTT assay after treatment with amygdalin at various concentrations. DNA content, protein expression of proliferating cell nuclear antigen (PCNA) and mRNA levels of SPs of AECIIs were analyzed with flow cytometric assay, Western blot and reverse transcription polymerase chain reaction (RT-PCR) respectively after 24 hours of air or hyperoxia exposure in the presence or absence of 200 micromol/L amygdalin.

RESULTSExcellent yields of highly purified, culturable AECIIs could be obtained from 20-day fetal lungs. The expression of cytokeratin in AECIIs was positive and that of vimentin negative by immunocytochemistry. Those, however, in LFs were just opposite. Lamellar bodies in purified AECIIs were revealed by transmission electron micrography. The established hyperoxia-exposed cell model assured the oxygen concentrations of culture flasks more than 90%. Amygdalin at the concentration range from 50 micromol/L to 200 micromol/L stimulated the proliferation of AECIIs in a dose-dependent manner; however, at the concentration of 400 micromol/L inhibited the proliferation of AECII. Flow cytometric analysis showed that the apoptosis rate and G0/G1 phase percentage increased significantly (P < 0.01), S phase and G2/M phase percentage decreased significantly (P < 0.01), in hyperoxia group compared with that of air group. The apoptosis rate of air plus 200 micromol/L amygdalin group, compared with air group, was not significantly different (P > 0.05); however, G0/G1 phase percentage decreased markedly, S phase percentage increased significantly, G2/M phase percentage did not significantly change (P > 0.05). The apoptosis rate of hyperoxia plus 200 micromol/L amygdalin group was not significantly different (P > 0.05) from that of hyperoxia group, S phase and G2/M phase percentage increased significantly (P < 0.01), G0/G1 phase percentage decreased significantly (P < 0.01). Western blot analysis showed that the protein expression levels of PCNA in all group was significantly different, in turn, hyperoxia group < hyperoxia plus 200 micromol/L amygdalin < air group < air puls 200 micromol/L amygdalin (P < 0.01). SPs mRNA levels were significantly decreased in hyperoxia group, as compared with air group (P < 0.01). After amygdalin was added, SPs mRNA levels were elevated in air plus amygdalin group and hyperoxia plus amygdalin group, as compared with hyperoxia group (P < 0.01, P < 0.05, respectively), but compared with air group, SP mRNA levels were not significantly elevated (P > 0.05).

CONCLUSIONAECIIs of premature rats were isolated, purified and cultured successfully. Hyperoxia-exposed cell model was established in AECIIs of premature rat in this experiment. Amygdalin promotes the proliferation of premature rat AECII exposed to air or hyperoxia, the concentration of amygdalin with the best effect was 200 micromol/L. Hyperoxia inhibited the proliferation and decreased SPs mRNAs levels in AECIIs in vitro, which may contribute to hyperoxia-induced lung injury in premature rats. Amygdalin could inhibit the changes of SPs mRNAs levels and cell proliferation of AECIIs resulted from hyperoxia and may play partial protective role in hyperoxia-induced premature lung injury.

Amygdalin ; pharmacology ; Animals ; Animals, Newborn ; Cell Proliferation ; drug effects ; Cytoprotection ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Hyperoxia ; metabolism ; pathology ; Proliferating Cell Nuclear Antigen ; analysis ; Pulmonary Alveoli ; drug effects ; metabolism ; pathology ; Pulmonary Surfactants ; analysis ; RNA, Messenger ; analysis ; Rats

PURPOSE: If cholesterol in the cell membrane is depleted by treating cells with methyl-beta-cyclodextrin (MbetaCD), the activities of transmembrane receptors are altered in a cell-specific and/or receptor-specific manner. The proinflammatory cytokines, IL-1beta is potent inducers of MUC5AC mRNA and protein synthesis in human airway epithelial cells. Cells activated by IL-1beta showed increased phosphorylation of extracellular signal regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). Thus, we investigated the effects of cholesterol depletion on the expression of MUC5AC in human airway epithelial cells and whether these alterations to MUC5AC expression were related to MAPK activity. MATERIALS AND METHODS: After NCI-H292 cells were pretreated with 1% MbetaCD before adding IL-1beta for 24 hours, MUC5AC mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and real time-PCR. Cholesterol depletion by MbetaCD was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK and p38 MAPK, was analyzed by western blot. RESULTS: Cholesterol in the cell membrane was significantly depleted by treatment with MbetaCD on cells. IL-1beta-induced MUC5AC mRNA expression was decreased by MbetaCD and this decrease occurred IL-1-receptor-specifically. Moreover, we have shown that MbetaCD suppressed the activation of ERK1/2 and p38 MAPK in cells activated with IL-1beta. This result suggests that MbetaCD-mediated suppression of IL-1beta-induced MUC5AC mRNA operated via the ERK- and p38 MAPK-dependent pathway. CONCLUSION: Cholesterol depletion in NCI-H292 cell membrane may be considered an anti-hypersecretory method since it effectively inhibits mucus secretion of respiratory epithelial cells.
Cell Membrane/drug effects/*metabolism ; Cholesterol/*metabolism ; Epithelial Cells/metabolism ; Gene Expression ; Humans ; Mucin 5AC/genetics/*metabolism ; Respiratory System/*metabolism/pathology ; beta-Cyclodextrins/pharmacology

OBJECTIVETo investigate the mechanism of methyl tertiary-butyl ether (MTBE)-induced animal carcinoma.

METHODSSingle cell gel electrophoresis assay (SCGE), DNA cross-links test and unscheduled DNA synthesis (UDS) assay were conducted with cultured rat type II pneumocytes and rat hepatocytes in vitro. Except UDS assay, the same experiment was performed in hepatocytes, renal cells and pneumocytes of mice administrated MTBE by inhalation at 0, 108, 1,440 and 4,968 mg/m(3) for 20 consecutive days. Simultaneously, the contents of malondialdehyde (MDA) in homogenates of lung and kidney were determined.

RESULTSThe lengths of DNA migration in mice hepatocytes at 1,440, 4,968 mg/m(3) of MTBE, renal cells at all doses of MTBE, and pneumocytes at 4,968 mg/m(3) were greater than those in negative controls. There was dose-effect relationship between the concentration of MTBE and hepatocytes DNA migration lengths in mice (r = 0.997, P = 0.003). MTBE of 1,440 and 4,968 mg/m(3) contributed to a rise in MDA of renal homogenates in female mice (P < 0.05). MTBE above 0.050 mmol/L caused greater DNA migration in cultured rat type II pneumocytes and rat hepatocytes in vitro (P < 0.05), and also with dose-effect relationship (r(lung) = 0.967, r(liver) = 0.963, P < 0.05)). In UDS assay, DNA synthesis of rat type II pneumocytes and rat hepatocytes were increased at the concentration of 5.0 mmol/L and 10.0 mmol/L of MTBE.

CONCLUSIONMTBE has some genotoxicity on DNA, and the single strand breaks of cell and lipid peroxidation may be one of the possible mechanism of MTBE-induced hepatic and renal tumors of animal.

Alveolar Epithelial Cells ; drug effects ; Animals ; Cells, Cultured ; Comet Assay ; DNA Damage ; drug effects ; Female ; Hepatocytes ; drug effects ; Kidney ; metabolism ; pathology ; Liver ; metabolism ; pathology ; Male ; Methyl Ethers ; toxicity ; Mice ; Rats

Adenosine Triphosphate ; metabolism ; Animals ; Animals, Newborn ; Cantharidin ; pharmacokinetics ; Cell Hypoxia ; drug effects ; Enzyme Inhibitors ; pharmacology ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Flow Cytometry ; Kidney Tubules ; drug effects ; metabolism ; pathology ; Swine