OBJECTIVE: To investigate the regulatory role of miRNA-26a in vascular smooth muscle cell (VSMC) calcification by regulating connective tissue growth factor (CTGF). METHODS: Rat thoracic aorta VSMCs (A7r5 cells) with induced calcification were treated with AR234960 agonist or transfected with miR-26a mimic, or with both treatments. Alizarin red staining was used to determine calcium deposition, and phosphatase (ALP) activity in the cells was measured. The mRNA and protein expressions of miR-26a, OPG, OPN, BMP-2 and collagen Ⅱ were detected using qPCR and Western blotting. The binding of miR-26a to CTGF was verified using dual luciferase reporter gene assay. RESULTS: After induced calcification, A7r5 cells showed gradually decreased miR-26a expression (P < 0.05) and progressively increased CTGF expression (P < 0.05) with the extension of induction time. Treatment of the cells with AR234960 obviously increased calcification in the cells, while transfection with miR-26a mimic significantly reduced cell calcification. The calcifying cells showed significantly increased ALP activity and expressions of OPN, BMP-2 and collagen Ⅱ (P < 0.05) and lowered OPG expression (P < 0.05), and treatment with AR234960 did not produce obvious effects on these changes (P > 0.05). Transfection with miR-26a mimic resulted in significantly decreased ALP activity and expressions OPN, BMP-2 and collagen Ⅱ expression (P < 0.05) and increased OPG expression (P < 0.05) in the calcifying cells. These effects of miR-26a mimic was significantly attenuated by treatment of the cells with AR234960 (P < 0.05). The result of luciferase reporter gene assay confirmed the binding of miR-26a to CTGF. CONCLUSION miRNA-26a can effectively alleviate vascular calcification by lowering the level of CTGF, reducing ALP activity and the expressions of OPN, BMP-2 and collagen Ⅱ, and increasing the expression of OPG.
Animals ; Calcium/metabolism* ; Cells, Cultured ; Connective Tissue Growth Factor/pharmacology* ; MicroRNAs/metabolism* ; Muscle, Smooth, Vascular ; Myocytes, Smooth Muscle ; Phosphoric Monoester Hydrolases/pharmacology* ; RNA, Messenger/metabolism* ; Rats ; Sulfones ; Vascular Calcification

This study was aimed to investigate the effects of bortezomib combined with 5-azacytidine on the apoptosis of K562 cells and expressiom of SHIP mRNA. The K562 cells were cultured and treated with different concentrations of bortezomib, 5-azacytidine or their combination for 24 hours. Then, the expression of SHIP mRNA was detected by RT-PCR,the cell proliferation was analyzed by using MTT assay and flow cytometry. The results showed that 5-20 nmol/L bortezomib could effectively inhibit the proliferation of K562 and this inhibitory effect gradually enhanced along with the increase of bortezomib concentration, the group of bortezomib combined with 5-azacytidine showed more inhibitory effect on K562 cells than that of bortezomib or 5-azacytidine alone.The bortezomib could promote the apoptosis of K562 cells in a dose-dependent manner,and this apoptotic effect was higher in group of bortezomib combined with 5-azacytidine than that in group of bortezomib or 5-azacytidine alone.Bortezomib could down-regulated the expression of SHIP mRNA in a dose-dependent manner,and this down-requlated effect was higher in group of bortezomib combined with 5-azacytidine than that in group of bortezomib or 5-azacytidine alone.It is concluded that bortezomib and 5-azacytidine can induce apoptosis by inhibiting the expression of SHIP mRNA in K562 cells.The combination of bortezomib with 5-azacytidine displays a synergetic effect.
Apoptosis ; drug effects ; Azacitidine ; pharmacology ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Proliferation ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; Phosphoric Monoester Hydrolases ; genetics ; Pyrazines ; pharmacology ; RNA, Messenger ; biosynthesis

This study was aimed to investigate the effects of proteasome inhibitor bortezomib on proliferation, apoptosis and the SHIP expression of K562 cells. K562 cells were treated with bortezomib of different concentrations. Cell proliferation was analyzed by MTT assay, cell apoptosis was detected by flow cytometry and SHIP mRNA expression was assayed by RT-PCR.The results showed that after being treated with 10, 20, 50 and 100 nmol/L bortezomib for 24 h, the inhibitory rates of K562 cells were (5.76 ± 1.47)%, (10.55 ± 1.59)%, (17.14 ± 2.05)% and (27.69 ± 3.57)% respectively, and were higher than that in control (1.30 ± 0.10); when K562 cells were treated with 20 nmol/L bortezomib for 24, 48 and 72 h, the inhibitory rates of cell proliferation were (10.55 ± 1.59)%, (16.33 ± 2.53)% and (19.78 ± 1.56)% respectively, there was statistic difference of cell proliferation rate between 24 h group and 48 h group (P < 0.05). After being treated with 10,20,50,100 nmol/L bortezomib for 24 h, the apoptotic rates of K562 cells were (12.7 ± 0.6)%, (26.9 ± 0.9)%, (32.6 ± 1.2)% and (72.5 ± 1.5)% respectively,and all higher than that in control (1.0 ± 0.5)% (P < 0.05). According to results of RT-PCR detection, the expression level of SHIP mRNA was obviously up-regulated after treatment with bortezomib, and showed statistical difference in comparison with control. It is concluded that bortezomib inhibits proliferation of K562 cells in time and concentration-dependent manner and induces apoptosis through up-regulation of SHIP gene.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Proliferation ; drug effects ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; Phosphoric Monoester Hydrolases ; genetics ; metabolism ; Proteasome Inhibitors ; pharmacology ; Pyrazines ; pharmacology

AIMTo elucidate the genetic basis for the pronounced resistance that the oral pathogen, Porphyromonas gingivalis (P. gingivalis), exhibits towards the cationic antimicrobial peptide, polymyxin B.

METHODOLOGYA genetic screen of P. gingivalis clones generated by a Tn4400'-based random insertion mutagenesis strategy was performed to identify bacteria harboring novel genetic mutations that render P. gingivalis susceptible to killing by the cationic antimicrobial peptide, polymyxin B (PMB, 50 microg x mL(-1)).

RESULTSP. gingivalis (ATCC 33277) is unusually resistant to the cationic antimicrobial peptide, PMB at relatively high concentrations (200 microg x mL(-1)). Approximately 2,700 independent Tn4400'-derived mutants of P. gingivalis were examined for increased sensitivity to PMB killing at a relatively low dose (50 microg x mL(-1)). A single PMB-sensitive mutant was obtained in this phenotypic screen. We determined that the Tn4400' transposon was integrated into the gene encoding the lipid A 4'-phosphatase, PGN_0524, demonstrating that this insertion event was responsible for its increased susceptibility of this clone to PMB-dependent killing. The resulting mutant strain, designated 0524-Tn4400', was highly sensitive to PMB killing relative to wild-type P. gingivalis, and exhibited the same sensitivity as the previously characterized strain, 0524KO, which bears a genetically engineered deletion in the PGN_0524 locus. Positive ion mass spectrometric structural (MALDI-TOF MS) analyses revealed that lipid A isolates from 0524-Tn4400' and 0524KO strains displayed strikingly similar MALDI-TOF MS spectra that were substantially different from the wildtype P. gingivalis lipid A spectrum. Finally, intact 0524-Tn4400' and 0524KO mutant bacteria, as well as their corresponding LPS isolates, were significantly more potent in stimulating Toll-like receptor 4 (TLR4)-dependent E-selectin expression in human endothelial cells relative to intact wild-type P. gingivalis or its corresponding LPS isolate.

CONCLUSIONThe combined molecular evidence provided in this report suggests that PGN_0524, a lipid A 4'-phosphatase, is the sole genetic element conferring the ability of the periodontopathogen, P. gingivalis, to evade the killing activity of cationic antimicrobial peptides, such as PMB. These data strongly implicate PGN_0524 as a critical virulence factor for the ability of P. gingivalis to evade front-line host innate defenses that are dependent upon cationic antimicrobial peptide activity and TLR 4 sensing.

Anti-Bacterial Agents ; pharmacology ; Chromosome Mapping ; DNA Transposable Elements ; genetics ; Drug Resistance, Bacterial ; genetics ; E-Selectin ; analysis ; immunology ; Endothelial Cells ; immunology ; microbiology ; Gene Deletion ; Humans ; Lipid A ; analysis ; immunology ; Lipopolysaccharides ; analysis ; immunology ; Mutagenesis, Insertional ; genetics ; Open Reading Frames ; genetics ; Phosphoric Monoester Hydrolases ; genetics ; physiology ; Polymyxin B ; pharmacology ; Porphyromonas gingivalis ; enzymology ; genetics ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Toll-Like Receptor 4 ; analysis ; immunology ; Virulence Factors ; physiology

PURPOSE: The purpose of this study was to identify differences in signal transduction gene expression between normal and diabetic keratocytes stimulated with interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha). METHODS: Normal and diabetic keratocytes were primarily cultured and treated with 20 ng/ml IL-1alpha and TNF-alpha for 6 h. cDNA was hybridized to an oligonucleotide microarray. Genes identified by the microarray were further evaluated by real-time PCR. RESULTS: Diabetic keratocytes over-expressed components of the MAPK and Notch pathways, and under-expressed components of the insulin, calcium, and TGF-beta pathways. Cytokine treated diabetic keratocytes differentially expressed components of the TGF-beta and MAPK pathways. After IL-1alpha and TNF-alpha treatment, nine genes were under-expressed, falling in the insulin, TGF-beta, and Toll-like receptor pathways. Real-time PCR showed a significant decrease in the IL-6 and TGF-beta2 genes and a significant increase in the Ppm1a gene. CONCLUSIONS: There were some differences in gene expression between normal and diabetic keratocytes related to signal transduction pathways, such as the insulin, MAPK, calcium, and TGF-beta pathways. In addition, IL-1alpha and TNF-alpha stimulating the insulin, TGF-beta, and Toll-like receptor signaling pathways may have different effects in diabetic keratocytes.
Animals ; Apoptosis ; Cells, Cultured ; Cornea/drug effects/*metabolism/pathology ; DNA/*genetics ; Diabetes Mellitus, Experimental/*genetics/pathology ; Gene Expression Profiling ; Insulin/genetics ; Interleukin-1alpha/pharmacology ; Mitogen-Activated Protein Kinase Kinases/genetics ; Nuclear Proteins/genetics ; Oligonucleotide Array Sequence Analysis/*methods ; Phosphoric Monoester Hydrolases/genetics ; Polymerase Chain Reaction ; Prolactin/genetics ; Rats ; Rats, Long-Evans ; Receptors, Notch/genetics ; Signal Transduction/drug effects/*genetics ; Transforming Growth Factor beta/genetics ; Tumor Necrosis Factor-alpha/pharmacology ; Ubiquitin-Protein Ligases/genetics

Apoptosis ; Cell Line, Tumor ; Colorectal Neoplasms ; drug therapy ; pathology ; HT29 Cells ; Humans ; PPAR gamma ; genetics ; physiology ; PTEN Phosphohydrolase ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; Phosphoric Monoester Hydrolases ; analysis ; Prostaglandin D2 ; analogs & derivatives ; pharmacology ; Protein-Serine-Threonine Kinases ; analysis ; Proto-Oncogene Proteins ; analysis ; Proto-Oncogene Proteins c-akt ; Thiazolidinediones ; pharmacology ; Tumor Suppressor Proteins ; analysis ; Up-Regulation

OBJECTIVETo investigate the apoptosis inducing effect of tea polyphenols (TPP) on human lung cancer cell (LCC) and its associative mechanism.

METHODSThe apoptosis inducing effect of TPP on LCC in vitro, and its influence on expression of the related gene were determined by MTT assay, laser scanning confocal microscopy and flow cytometry.

RESULTSTPP in different concentration (50,100,200 and 400 microg/ml) had dose-dependent inhibitory effect on LCC, the inhibitory rate was 28.69+/-1.27% ,46. 19+/-1.79% ,64.61+/-1.29%, 75.90+/-1.96%, respectively. The inhibited LCC were blocked in (G0/G1 phase, and could not transferred to S and G2/ M phase of cell cycle. Meanwhile, TPP could induce apoptosis of LCC, the apoptotic rate being 4.76+/-0.11 %, 5.78+/-0.38 %, 10.06+/-0.67 %, 24.44+/-0.44 %, respectively. Morphologic changes of cells were seen in laser scanning confocal microscopy observation. Compared to the control group, intracellular Ca2+ concentration, Annexin V expression, phospatase and tensin homologe deleted on chromosome ten (PTEN) protein and expression gradually increased, while Cyclin D1 protein expression gradually decreased in the TPP treated groups along with the increasing of TPS concentration.

CONCLUSIONTTP can induce LCC apoptosis, the mechanism is related to the change of intracellular Ca2+ concentration, PTEN protein and Cyclin D1 protein expression.

Annexin A5 ; biosynthesis ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cyclin D1 ; biosynthesis ; Dose-Response Relationship, Drug ; Flavonoids ; pharmacology ; Humans ; Lung Neoplasms ; pathology ; PTEN Phosphohydrolase ; Phenols ; pharmacology ; Phosphoric Monoester Hydrolases ; biosynthesis ; Polyphenols ; Tea ; chemistry ; Tumor Cells, Cultured ; Tumor Suppressor Proteins ; biosynthesis

Phospholipase C-gamma1, containing two SH2 and one SH3 domains which participate in the interaction between signaling molecules, plays a significant role in the growth factor-induced signal transduction. However, the role of the SH domains in the growth factor-induced PLC-gamma1 regulation is unclear. By peptide-mass fingerprinting analysis, we have identified SHIP1 as the binding protein for the SH3 domain of PLC-gamma1. SHIP1 was co-immunoprecipitated with PLC-gamma1 and potentiated EGF-induced PLC-gamma1 activation. However, inositol 5'-phosphatase activity of SHIP1 was not required for the potentiation of EGF-induced PLC-gamma1 activation. Taken together, these results suggest that SHIP1 may function as an adaptor protein which can potentiate EGF-induced PLC-gamma1 activation without regards to its inositol 5'-phosphatase activity.
Adaptor Proteins, Signal Transducing ; Amino Acid Sequence ; Animals ; COS Cells/enzymology ; Cercopithecus aethiops ; Enzyme Activation ; Epidermal Growth Factor/*pharmacology ; Immunoprecipitation ; Inositol 1,4,5-Trisphosphate/metabolism ; Molecular Sequence Data ; Phospholipase C/chemistry/*metabolism ; Phosphoric Monoester Hydrolases/chemistry/*metabolism ; Protein Binding ; Signal Transduction ; src Homology Domains/*physiology

OBJECTIVEThe SH2 domain containing inositol 5'-phosphatase (SHIP) is predominately expressed in hematopoietic cells, and is a crucial negative regulator in the development of hematopoietic cells. This paper is to evaluate the role of the SHIP gene in human leukemogenesis.

METHODSExpression of SHIP gene in bone marrow and/or peripheral blood from 32 patients with acute myeloid leukemia (AML), 9 with acute lymphoblastic leukemia (ALL), as well as human hematopoietic cell lines was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and DNA sequencing.

RESULTSRT-PCR showed that all samples expressed SHIP gene. Mutations of SHIP gene were detected in 7 (22%) of 32 AML patients and one (12%) of 9 ALL patients. Interestingly, two missense mutations that had been observed in a AML patient at diagnosis disappeared after complete remission (CR). In addition, in vitro Akt phosphorylation was prolonged and increased following IL-3 stimulation of this patient's cells.

CONCLUSIONOur data demonstrate for the first time the mutation of SHIP gene in acute leukemia and suggest a possible role of the mutation of this gene in the development of acute leukemia. SHIP may serve as a tumor suppressor by negatively regulating the PI3K/Akt signaling pathway in hematopoietic cells.

Blotting, Western ; Cell Line, Tumor ; DNA Mutational Analysis ; HL-60 Cells ; Humans ; Inositol Polyphosphate 5-Phosphatases ; Interleukin-3 ; pharmacology ; K562 Cells ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Mutation ; Oncogene Protein v-akt ; metabolism ; Phosphoric Monoester Hydrolases ; genetics ; metabolism ; Phosphorylation ; drug effects ; Polymorphism, Single-Stranded Conformational ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; U937 Cells

OBJECTIVETo evaluate the inhibitory effect of tumor suppressor PTEN on cell growth of endometrial carcinoma.

METHODSThe exogenous wild PTEN cDNA via an adenoviral vector (Ad-PTEN) was introduced into Ishikawa cells. The expression of PTEN protein was detected by Western blot. The growth of Ishikawa cells was evaluated by trypan blue exclusion method and MTT.

RESULTSThe expression of PTEN protein was induced on day 1, and greatly increasing on day 3 - 5 after Ad-PTEN infection. The expression of PTEN significantly inhibited the growth of Ishikawa cells, and also significantly inhibited the growth of Ishikawa cells induced by IGF-II.

CONCLUSIONAdenovirus-mediated introduction of exogenous PTEN into human endometrial carcinoma cells can induce growth suppression. PTEN gene may be a novel therapeutic agent for endometrial carcinoma.

Adenoviridae ; genetics ; Cell Proliferation ; Endometrial Neoplasms ; metabolism ; pathology ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Insulin-Like Growth Factor II ; pharmacology ; PTEN Phosphohydrolase ; Phosphoric Monoester Hydrolases ; biosynthesis ; genetics ; physiology ; Recombination, Genetic ; Transfection ; Tumor Suppressor Proteins ; biosynthesis ; genetics ; physiology