OBJECTIVETo study aberrant DNA methylation potentially resulting in changes in the expression of cancer-related genes as a possible epigenetic mechanism for cadmium carcinogenesis.

METHODSGenomic DNA isolated from CdCl(2)-transformed BALB/c-3T3 cells was digested with Mse1 (methylation non-sensitive) alone or with Mse1 and BstU1 (methylation sensitive). The resulting DNA was analyzed for aberrant methylation using PCR-based technique-Methylation-Sensitive Restriction Fingerprinting (MSRF). Several DNA fragments differentially methylated in the transformed cells identified by MSRF were confirmed by Southern hybridization analysis using the aberrantly methylated DNA fragments as the probes.

RESULTSAberrant DNA methylation was identified in the transformed cells. DNA sequencing and sequence similarity analysis identified one of the aberrantly methylated DNA fragments as the p16 tumor suppressor gene.

CONCLUSIONDNA hypermethylation is known to result in gene silencing, it appears that hypermethylation of p16 gene may represent a possible epigenetic mechanism for Cd-induced cell transformation and carcinogenesis.

Animals ; BALB 3T3 Cells ; Blotting, Southern ; Cadmium ; toxicity ; Cell Transformation, Neoplastic ; CpG Islands ; DNA Methylation ; Genes, p16 ; Mice ; Restriction Mapping

Nanosilver antibiotic devices for gynecological external use are the third-class products of medical devices, whose biological safety and efficiency should be strictly controlled. But there is not yet the national standard or industry standard for the products to control the production process, so their testing method of biological evaluation mainly refers to GB/T16886 "The Guide to Implementation of Biological Evaluation of Medical Devices". To control the biological safety effectively, it's necessary to work out the testing items and methods of the biological evaluation for such products.
Animals ; Anti-Bacterial Agents ; toxicity ; BALB 3T3 Cells ; Equipment and Supplies ; adverse effects ; Female ; Male ; Mice ; Nanostructures ; Rabbits ; Silver ; toxicity ; Toxicity Tests ; methods

BACKGROUNDThe genome of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) includes sequences encoding the putative protein X4 (ORF8, ORF7a), consisting of 122 amino acids. The deduced sequence contains a probable cleaved signal peptide sequence and a C-terminal transmembrane helix, indicating that protein X4 is likely to be a type I membrane protein. This study was conducted to demonstrate whether the protein X4 was expressed and its essential function in the process of SARS-CoV infection.

METHODSThe prokaryotic and eukaryotic protein X4-expressing plasmids were constructed. Recombinant soluble protein X4 was purified from E. coli using ion exchange chromatography, and the preparation was injected into chicken for rising specific polyclonal antibodies. The expression of protein X4 in SARS-CoV-infected Vero E6 cells and lung tissues from patients with SARS was performed using immunofluorescence assay and immunohistochemistry technique. The preliminary function of protein X4 was evaluated by treatment with and over-expression of protein X4 in cell lines. Western blot was employed to evaluate the expression of protein X4 in SARS-CoV particles.

RESULTSWe expressed and purified soluble recombinant protein X4 from E.coli, and generated specific antibodies against protein X4. Western blot proved that the protein X4 was not assembled in the SARS-CoV particles. Indirect immunofluorescence assays revealed that the expression of protein X4 was detected at 8 hours after infection in SARS-CoV-infected Vero E6 cells. It was also detected in the lung tissues from patients with SARS. Treatment with and overexpression of protein X4 inhibited the growth of Balb/c 3T3 cells as determined by cell counting and MTT assays.

CONCLUSIONThe results provide the evidence of protein X4 expression following SARS-CoV infection, and may facilitate further investigation of the immunopathological mechanism of SARS.

Amino Acid Sequence ; Animals ; BALB 3T3 Cells ; Cercopithecus aethiops ; Growth Inhibitors ; analysis ; physiology ; HeLa Cells ; Humans ; Immunohistochemistry ; Lung ; chemistry ; Mice ; Molecular Sequence Data ; SARS Virus ; chemistry ; Severe Acute Respiratory Syndrome ; metabolism ; Vero Cells ; Viral Structural Proteins ; analysis ; physiology

The immunomodulatory and antitumor effects of lactic acid bacteria (LABs) were investigated. Cytoplasmic fraction of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium longum were tested for the antiproliferative activity in vitro to SNUC2A, SNU1, NIH/3T3 and Jurkat cell lines by crystal violet assay. All cytoplasmic fraction suppressed proliferation of tumor cells, though L. casei and B. longum were more effective. From these results, cytoplasmic fraction of L. casei and B. longum with Y400 as a control were administered as dietary supplements to Balb/c mice for 2, and 4 consecutive wks. Administration for 4 wks enhanced the number of total T cells, NK cells and MHC class II+ cells, and CD4-CD8+ T cells in flow cytometry analysis. To determine of antitumor activity of LABs preparation in vivo, F9 teratocarcinoma cells were inoculated on mice at 14th day. Body weight was decreased with increased survival rate in all groups with the cytoplasm of LABs. Our results showed that cytoplasmic fraction of LABs had direct antiproliferative effects on tumor cell lines in vitro, effects on immune cells in vivo, and antitumor effects on tumor-bearing mice with prolonged survival periods.
3T3 Cells ; Animals ; *Bifidobacterium ; Body Weight ; Cell Division/physiology ; Cytotoxicity, Immunologic ; Flow Cytometry ; Humans ; Immunophenotyping ; Jurkat Cells ; Killer Cells, Natural/immunology ; *Lactobacillus casei ; Male ; Mice ; Mice, Inbred BALB C ; Neoplasms, Experimental/immunology/*therapy ; Probiotics/*pharmacology ; Survival Analysis ; T-Lymphocytes/immunology

OBJECTIVETo construct a eukaryotic expression vector for alpha-1-antitrypsin (AAT) and detect its expression and localization in NIH 3T3 cells.

METHODSThe total RNA was extracted from the liver tissue of BALB/c mice, and the corresponding coding sequences for mouse AAT (GenBank accession No. NM_009243) were amplified by RT-PCR and cloned into hemagglutinin (HA)-tagged vector pcDNA3-HA. The construct was then transfected into NIH 3T3 cells, which were observed under fluorescence microscope.

RESULTSThe recombinant plasmid was verified by PCR, enzyme digestion and sequence analysis, and the fusion protein was highly expressed in NIH 3T3 cells. Under fluorescence microscope, the fusion protein was found to distribute mainly in the cytoplasm.

CONCLUSIONThe expression vector for AAT-HA fusion protein has been successfully constructed and effectively expressed in mammalian cells to allow future functional study of AAT in mammalian cells.

Animals ; Genetic Vectors ; biosynthesis ; genetics ; Hemagglutinins ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; NIH 3T3 Cells ; Plasmids ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; alpha 1-Antitrypsin ; biosynthesis ; genetics

OBJECTIVETo prepare a monoclonal antibody (mAb) against extracellular domain of B7-H4 and to investigate the expression of B7-H4 in pancreatic cancer tissue with the prepared mAb.

METHODSBalb/c mice were immunized with 3T3-B7-H4 cells and the splenic cells of the immunized mice were fused with Sp2/0 myeloma cells by conventional hybridoma techniques. An indirect ELISA method using 3T3-B7-H4 lysate as antigen was established to screen antibody-producing hybridoma cell lines. Western blott, immunoprecipitation (IP), and immunohistochemistry (IHC) were applied to characterize the mAb. Immunohistochemical staining was used to detect the expression of B7-H4 in human pancreatic cancer tissue. The correlation of B3-H4 expressions and pathological features of pancreatic cancer was analyzed.

RESULTSA hybridoma cell line secreting mAb against B7-H4 was obtained. The subclass of this mAb was IgM, and the light chain was Kappa. Western blot and IP showed that the mAb specifically recognized B7-H4. IHC staining revealed that the mAb stained in a predominantly diffuse plasmalemmal or cytoplasmic pattern when applied to certain tumor tissues. The B7-H4 was diffusely expressed in the cytoplasma and/or membrane of pancreatic cancer tissue, which was much higher than that expressed in normal pancreatic tissue (4.00 ± 1.44 compared with 1.12 ± 0.78, P ± 0.01). The expression of B7-H4 was higher in pancreatic cancer tissues with higher pathological grade or with lymph node metastasis as compared with that in pancreatic cancer tissues with lower grade or with no lymph mode metastasis (6.10 ± 0.72 compared with 3.55 ± 1.12,P<0.01: 6.14 ± 0.66 compared with 3.70 ± 1.25,P<0.01). The expression level of B7-H4 was not related to patients'age and gender.

CONCLUSIONMonoclonal antibody against B7-H4 with high activity and specificity has been prepared successfully. The expression of B7-H4 in pancreatic cancer tissue is up-regulated,which is closely related to the tumor grade and lymph node metastasis in pancreatic cancer.

3T3 Cells ; Animals ; Antibodies, Monoclonal ; biosynthesis ; Cell Line, Tumor ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Mice ; Mice, Inbred BALB C ; Neoplasm Grading ; Pancreatic Neoplasms ; metabolism ; pathology ; V-Set Domain-Containing T-Cell Activation Inhibitor 1 ; metabolism

PURPOSE: IRF-5 is a direct transducer of virus-mediated and TLR-mediated signaling pathways for the expression of cytokines and chemokines which form homodimers or heterodimers with IRF-7. However, direct IRF-5-specific monoclonal antibodies (mAbs) are not available at present. These could be used to further evaluate the functions of IRF-5. In this study, we produced and characterized three mouse mAbs to human IRF-5. The binding of IRF-5 to nuclear import proteins was first identified using a mAb. MATERIALS AND METHODS: His-tagged human IRF-5 protein spanning amino acid residues 193- 257 was used as an antigen and three mAbs were produced. The mAbs were tested with ELISA, Western blot analysis (WB), immunofluorescent staining (IF), and immunoprecipitation (IP). In addition, the nuclear import protein which carried phosphorylated IRF-5 was identified using one of these mAbs. RESULTS: MAbs 5IRF8, 5IRF10 and 5IRF24 which reacted with the recombinant His-IRF-5(193-257) protein were produced. All mAbs bound to human IRF-5, but not to IRF-3 or IRF-7. They could be used for WB, IF, and IP studies. The binding of phosphorylated IRF-5 to karyopherin-alpha1 and -beta1 was also identified. CONCLUSION: Human IRF-5-specific mAbs are produced for studying the immunologic roles related to IRF-5. Phosphorylated IRF-5 is transported to the nucleus by binding to nuclear import proteins karyopherin-alpha1 and -beta1.
Animals ; *Antibodies, Monoclonal ; Base Sequence ; Cell Line ; Cross Reactions ; DNA Primers/genetics ; Humans ; Interferon Regulatory Factors/genetics/*immunology/*metabolism ; Mice ; Mice, Inbred BALB C ; NIH 3T3 Cells ; Protein Binding ; Recombinant Proteins/genetics/immunology/metabolism ; alpha Karyopherins/*metabolism ; beta Karyopherins/*metabolism

OBJECTIVETo establish a mouse fibroblastic cell line stably transfected with PC-1 gene, and using such cell line to investigate tumor development and progression imposed by the ectopic expression of PC-1 gene.

METHODSEukaryotic expression vector pcDNA3.1(-)/myc-his-pc-1 was transfected into mouse fibroblast cell line NIH3T3 by lipofectamine. Stable transfectants were selected by G418. The integration and expression of ectopic PC-1 gene were analyzed by PCR and RT-PCR. Cytomorphological analysis, MTT, soft agar colony formation and nude mice tumorigenesis assay were used to evaluate the effects of PC-1 gene expression on tumor development and progression.

RESULTSNIH 3T3 cell lines stably expressing PC-1 gene were successfully established and confirmed by PCR and RT-PCR analyses of the integration and expression of ectopic PC-1 gene. Comparing with the parental cell line and cells transfected with control vector, the PC-1 gene transfectants acquired several phenotypes of transformed cells: increasing growth rate, ability to grow and form cell colonies on soft agar, and becoming tumorigenic in nude mice.

CONCLUSIONEctopic expression of PC-1 gene in NIH3T3 cells can induce malignant transformation of mouse fibroblastic cells both in vitro and in vivo.

Animals ; Cell Line, Transformed ; Cell Transformation, Neoplastic ; Gene Expression ; Genes, Neoplasm ; physiology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; NIH 3T3 Cells ; Neoplasm Proteins ; biosynthesis ; genetics ; physiology ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Transfection

The present study was designed to determine the effects of Puer tea and green tea on blood glucose level. Male BALB/c mice were administered green tea extract (GTE) or Puer tea extract (PTE), either intragastrically or in their drinking water. The major components of these teas are epigallocatechin gallate (EGCG) and caffeine, respectively. Blood glucose measurement results showed that mice fed intragastrically or mice that drank GTE, PTE or caffeine showed significantly lower blood glucose levels compared to the control group. However, EGCG exhibited no influence on the blood glucose levels. When caffeine was eliminated from the GTE and PTE, the effect on the blood glucose levels was abolished, but the effect was recovered when caffeine was re-introduced into the extracts. Evaluation of hematological and biochemical indices at the time of the greatest caffeine-induced decrease in blood glucose levels showed that the effect of caffeine was specific. Microarray analyses were performed in 3T3-L1 preadipocytes and mature adipocytes treated with 0.1 mg · mL(-1) caffeine to identify factors that might be involved in the mechanisms underlying these effects. The results showed that few genes were changed after caffeine treatment in adipocytes, and of them only phospholipid transfer protein (PLTP) may be ralated to blood glucose. In conclusion, this study indicates that caffeine may be the key constituent of tea that decreases blood glucose levels, and it may be used to treat type 2 diabetes.
3T3-L1 Cells ; Adipocytes ; drug effects ; metabolism ; Animals ; Blood Glucose ; metabolism ; Caffeine ; pharmacology ; Camellia sinensis ; chemistry ; Hypoglycemic Agents ; pharmacology ; Male ; Mice ; Mice, Inbred BALB C ; Phospholipid Transfer Proteins ; metabolism ; Plant Extracts ; pharmacology ; Tea

SIP24/24p3 is a secreted murine acute phase protein which has been speculated to play an anti-inflammatory role in vivo. Recently SIP24/24p3 has been found to be able to specifically induce apoptosis in leukocytes. By using (35)S metabolic labeling method, we studied the regulation of SIP24/24p3 by glucocorticoid and pro-inflammatory cytokines IL-6 and TNF-alpha in cultured Balb/c 3T3 and BNL cells. The following results were observed: (1) dexamethasone induced the expression of SIP24/24p3 in both Balb/c 3T3 and BNL cells, the induction was more significant in BNL cells; (2) dexamethasone and IL-6 synergistically induced the expression of SIP24/24p3 in both Balb/c 3T3 and BNL cells; (3) in Balb/c 3T3 cells dexamethasone and TNF-alpha acted synergistically to induce the expression of SIP24/24p3, whereas in BNL cells dexamethasone and TNF-alpha induced the expression of SIP24/24p3 in an additive manner; (4) dexamethasone and IL-6/TNF-alpha acted synergistically in Balb/c 3T3 cells and additively in BNL cells to induce the expression of SIP24/24p3. The inducibility of SIP24/24p3 by multiple factors will help to explain its highly specific expression in vivo. The difference in the expression patterns of SIP24/24p3 in different cell types is also suggestive to its expression and regulation in hepatic and extrahepatic tissues. Finally, the fact that SIP24/24p3 protein can be induced by both pro-inflammatory as well as anti-inflammatory factors is indicative of the important role of SIP24/24p3 in the entire acute phase response process.
Acute-Phase Proteins ; biosynthesis ; genetics ; Animals ; BALB 3T3 Cells ; Carrier Proteins ; biosynthesis ; genetics ; Cytokines ; pharmacology ; Dexamethasone ; pharmacology ; Drug Synergism ; Gene Expression Regulation ; Interleukin-6 ; pharmacology ; Lipocalin-2 ; Lipocalins ; Mice ; Mice, Inbred BALB C ; Oncogene Proteins ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Tumor Necrosis Factor-alpha ; pharmacology