ObjectiveTo explore the inhibitory effect of polyphyllin Ⅰ (PPⅠ) on the proliferation of castration-resistant prostate cancer PC3 cells and its molecular mechanism.

METHODSWe cultured human prostate cancer PC3 cells in vitro and treated them with PPⅠ at the concentrations of 0 (blank group), 0.4, 0.8, 1.2, 1.6, 2.0, and 2.4 μmol/L for 24, 48, and 72 hours, respectively. Then we detected the proliferation of the cells by MTT assay, measured their apoptosis by flow cytometry, and determined the expressions of p-ERK1/2, ERK1/2, NF-κB/p65 and DNMT1 proteins as well as the level of NF-κB/p65 in the cells additionally treated with the ERK1/2 inhibitor SP600125 by Western blot.

RESULTSCompared with the blank control group, the PPⅠ-treated PC3 cells showed a concentration- and time-dependent reduction of the survival rate (1.00 ± 0.00 vs 0.85 ± 0.05, P < 0.01) at 0.4 μmol/L after 48 hours of intervention, concentration-dependent early apoptosis at 0.8 μmol/L (4.83 ± 0.95 vs 13.83 ± 2.97, P < 0.01), time-dependent increase of the expressions of p-ERK1/2 (1.00 ± 0.00 vs 1.73 ± 0.17, P < 0.01) and ERK1/2 (1.00 ± 0.00 vs 1.36 ± 0.12, P < 0.01) at 2 hours, and concentration-dependent decrease of the expressions of NF-κB/p65 and DNMT1 at 1.2 μmol/L (1.00 ± 0.00 vs 0.78 ± 0.10 and 0.63 ± 0.06, P < 0.01) and 1.6 μmol/L (1.00 ± 0.00 vs 0.67 ± 0.11 and 0.52 ± 0.09, P<0.01). Inhibition of ERK1/2 phosphorylation with PD98059 markedly reversed PPⅠ-induced decrease of the NF-κB/p65 expression as compared with that in the PPⅠ group (0.86 ± 0.18 vs 0.43 ± 0.09, P < 0.05).

CONCLUSIONSPPⅠ induces the early apoptosis and suppresses the proliferation of PC3 cells, probably by activating the ERK1/2 pathway and inhibiting the expressions of the NF-κB/p65 and DNMT1 proteins.

Apoptosis ; Cell Proliferation ; drug effects ; DNA (Cytosine-5-)-Methyltransferase 1 ; metabolism ; Diosgenin ; analogs & derivatives ; pharmacology ; Flavonoids ; metabolism ; Humans ; MAP Kinase Signaling System ; Male ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; NF-kappa B ; metabolism ; PC-3 Cells ; Phosphorylation ; Prostatic Neoplasms, Castration-Resistant ; drug therapy ; metabolism ; pathology ; Signal Transduction ; Transcription Factor RelA ; metabolism

PURPOSE: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. METHODS: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. RESULTS: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). CONCLUSION: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.
Animals ; Anoxia ; Apoptosis* ; Astrocytes ; Blotting, Western ; Caspase 3 ; DNA Nucleotidylexotransferase ; Embryonic Structures ; Erythropoietin* ; Humans ; Hypoxia-Ischemia, Brain ; MAP Kinase Signaling System ; Mice ; Mice, Inbred ICR ; Mitogen-Activated Protein Kinases ; Mortality ; Neurons ; Neuroprotection ; Neuroprotective Agents* ; p38 Mitogen-Activated Protein Kinases ; Phosphorylation ; Phosphotransferases ; Protein Kinases*

We have previously shown that the specific phosphatidylinositol 3-kinase inhibitor LY294002 (LY29), and its inactive analog LY303511 (LY30), inhibit a monocyte chemoattractant protein-1 (MCP-1) expression in human umbilical vein endothelial cells; these results suggest the potential of LY30 as an anti-inflammatory drug. In this study, we determined the effects of LY30 on the production of various inflammatory cytokines in human macrophagic THP-1 cells which were stimulated with lipopolysaccharide (LPS). LY30 selectively suppressed the mRNA expression of IL-12 p40, TNF-α, and MCP-1 without affecting the expression of IL-1α, IL-6, and IL-8. Inhibition of the production of IL-12 and TNF-α by LY30 was also demonstrated using ELISA assays. In order to elucidate the mechanisms of the action of LY30, we examined the role played by the mitogen-activated protein kinases and the key transcription factors, AP-1 and NF-κB in LPS-stimulated THP-1 cells. The results revealed that LY30 inhibited LPS-induced activation of ERK, but not p38 or JNK. Furthermore, the AP-1 DNA binding activity was suppressed by LY30 based upon the dosage, whereas NF-κB DNA binding was not affected. These results suggest that LY30 selectively inhibits cytokine production in the LPS-stimulated macrophagic THP-1 cells by downregulating the activation of ERK and AP-1.
Chemokine CCL2 ; Cytokines ; DNA ; Enzyme-Linked Immunosorbent Assay ; Human Umbilical Vein Endothelial Cells ; Humans* ; Interleukin-12 ; Interleukin-6 ; Interleukin-8 ; Mitogen-Activated Protein Kinases ; Phosphatidylinositol 3-Kinase ; RNA, Messenger ; Transcription Factor AP-1 ; Transcription Factors

OBJECTIVETo investigate the impact of NU7026 and Wortmannin, inhibitors of DNA-dependent protein kinase (DNA-PK), in HL60 cells apoptosis induced by 1, 4-benzoquinone (1, 4-BQ).

METHODSHL60 cells were divided into three groups according to the exposures: the poisoned groups which were treated with 0, 5, 10, 25 and 50 µmol/L 1, 4-BQ for 24 h, respectively, the NU7026 groups which were preincubated with 10 µmol/L NU7026 for 1h prior to the 24h treatment of 0, 5, 10, 25 and 50 µmol/L 1, 4-BQ and the Wortmannin groups which were preincubated with 25 µmol/L Wortmannin for 1h prior to the 24 h treatment of 0, 5, 10, 25 and 50 µmol/L 1, 4-BQ. Then we detected the apoptosis via flowcytometry Annexin V-FITC/PI and the DNA Ladder, respectively. We also tested the expressions of Bax mRNA with Real-Time PCR in HL60 cells which were exposed to 10 µmol/L NU7026 for 24 h, 25 µmol/L Wortmannin 24 h, 10 µmol/L 1, 4-BQ 24 h, 10 µmol/L NU7026 1h+10 µmol/L 1, 4-BQ 24 h and 25 µmol/L Wortmannin 1 h+10 µmol/L 1, 4-BQ 24 h, as well as null (control). We also examed the expressions of p53 in HL60 cells with Western blot.

RESULTSAnnexin V-FITC/PI apoptosis tests suggested that apoptosis rates of NU7026+10 µmol/L 1, 4-BQ group and Wortmannin +10 µmol/L 1, 4-BQ were 17.6±1.19% and 15.2±1.22%, respectively. Both of results were higher than that of 10 µmol/L 1, 4-BQ group (6.3±1.04%); Apoptosis of NU7026+25 µmol/L 1, 4-BQ group was 46.2±3.55%, and Wortmannin +25 µmol/L 1, 4-BQ group 26.9±2.62%. Both of results were also higher than that of 25 µmol/L 1, 4-BQ group (14.1±1.54%); Apoptosis of NU7026+50 µmol/L 1, 4-BQ group (61.8±1.78%) was higher than that of 50 µmol/L 1, 4-BQ group (35.9±4.51%). The above results were all statistically significant (P < 0.05).

RESULTSof DNA-Ladder were basically consistent with those of Annexin V-FITC/PI apoptosis tests. In addition, both NU7026 and Wortmannin pretreatment elicited the higher expression of Bax mRNA in HL60 treated by 1, 4-benzoquinone with statistically significance (P < 0.05). However, p53 protein was not detected in HL60 cells as the western blot indicated.

CONCLUSIONInhibitors of DNA-PK, NU7026 and Wortmannin, promote p53-independent apoptosis induced by 1, 4-benzoquinone in HL60 cells.

Androstadienes ; pharmacology ; Apoptosis ; drug effects ; Benzoquinones ; toxicity ; Chromones ; pharmacology ; DNA-Activated Protein Kinase ; antagonists & inhibitors ; Flow Cytometry ; HL-60 Cells ; Humans ; Morpholines ; pharmacology ; RNA, Messenger ; Tumor Suppressor Protein p53

OBJECTIVETo evaluate the effect of Zhuanggu Jianxi Decoction (, ZGJXD) on interleukin-1 β (IL-1 β)-induced degeneration of chondrocytes (CDs) as well as the activation of caveolin-p38 mitogen-activated protein kinase (MAPK) signal pathway, investigating the possible molecular mechanism that ZGJXD treats osteoarthritis.

METHODSSerum pharmacology was applied in the present study, where ZGJXD was orally administrated to New Zealand rabbits and then ZGJXD containing serum (ZGJXD-S) was collected for following in vitro experiments. CDs were isolated aseptically from New Zealand rabbits and then cultured in vitro. Upon IL-1 β stimulation, the degeneration of CDs was verified by inverted microscope, toluidine blue stain and type II collagen immunocytochemistry. After IL-1 β-stimulated CDs were intervened with blank control serum, ZGJXD-S, together with or without SB203580 (a specific inhibitor of p38 MAPK) for 48 h, caveolin-1 protein expression and the phosphorylation level of p38 were determined by Western blotting, and the mRNA expression of IL-1 β, tumor necrosis factor α (TNF-α), matrix metalloproteinase 3 (MMP-3) and MMP-13 were examined by real-time polymerase chain reaction.

RESULTSIL-1 β stimulation induced degeneration of CDs, increased caveolin-1 expression and p38 phosphorylation, up-regulated the mRNA level of IL-1 β, TNF-α, MMP-3 and MMP-13. However, the IL-1 β-induced activation of caveolin-p38 signaling and alteration in the expression of p38 downstream target genes were suppressed by ZGJXD-S and/or SB203580 in CDs.

CONCLUSIONZGJXD can prevent CDs degeneration via inhibition of caveolin-p38 MAPK signal pathway, which might be one of the mechanisms that ZGJXD treats osteoarthritis.

Animals ; Base Sequence ; Blotting, Western ; Caveolins ; metabolism ; Chondrocytes ; drug effects ; enzymology ; metabolism ; DNA Primers ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Profiling ; Interleukin-1beta ; physiology ; MAP Kinase Signaling System ; Male ; RNA, Messenger ; genetics ; Rabbits ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

OBJECTIVE: To study the expression of DNA-dependent protein kinase (DNA-PK) in human laryngeal squamous cell carcinoma (LSCC) and normal laryngeal mucosa (NLM), and to analysize the relationship between the expression and the clinicopathologic parameters of LSCC. METHOD: Immunohistochemical technique (Envision) was used to detect the expression of DNA-PK in 64 cases of LSCC and 15 cases of NLM. To investigate an investigation was conducted on the relationship between the expression and clinico-pathological features of LSCC. RESULT: DNA-PK was lowly expressed in NLM and highly expressed in LSCC,the positive rate of DNA-PK expression was 26.67% (4/15), 78.13% (50/64), respectively, and there was significant different difference between the two groups (P < 0.05). Its expression was correlated with the level of histodifferentiation (P < 0.05), but not with TNM stages and neck lymph node metastasis (P > 0.05). CONCLUSION DNA-PK may be involved in disease development of LSCC.
Aged ; Carcinoma, Squamous Cell ; enzymology ; pathology ; DNA-Activated Protein Kinase ; metabolism ; Female ; Head and Neck Neoplasms ; enzymology ; pathology ; Humans ; Laryngeal Mucosa ; enzymology ; Laryngeal Neoplasms ; enzymology ; pathology ; Larynx ; enzymology ; Lymph Nodes ; Lymphatic Metastasis ; Male ; Middle Aged ; Squamous Cell Carcinoma of Head and Neck

Benzene is an established leukotoxin and leukemogen in humans. We have previously reported that exposure of workers to benzene and to benzene metabolite hydroquinone in cultured cells induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to mediate the cellular response to DNA double strand break (DSB) caused by DNA-damaging metabolites. In this study, we used a new, small molecule, a selective inhibitor of DNA-PKcs, 2-(morpholin-4-yl)-benzo[h]chomen-4-one (NU7026), as a probe to analyze the molecular events and pathways in hydroquinone-induced DNA DSB repair and apoptosis. Inhibition of DNA-PKcs by NU7026 markedly potentiated the apoptotic and growth inhibitory effects of hydroquinone in proerythroid leukemic K562 cells in a dose-dependent manner. Treatment with NU7026 did not alter the production of reactive oxygen species and oxidative stress by hydroquinone but repressed the protein level of DNA-PKcs and blocked the induction of the kinase mRNA and protein expression by hydroquinone. Moreover, hydroquinone increased the phosphorylation of Akt to activate Akt, whereas co-treatment with NU7026 prevented the activation of Akt by hydroquinone. Lastly, hydroquinone and NU7026 exhibited synergistic effects on promoting apoptosis by increasing the protein levels of pro-apoptotic proteins Bax and caspase-3 but decreasing the protein expression of anti-apoptotic protein Bcl-2. Taken together, the findings reveal a central role of DNA-PKcs in hydroquinone-induced hematotoxicity in which it coordinates DNA DSB repair, cell cycle progression, and apoptosis to regulate the response to hydroquinone-induced DNA damage.
Apoptosis ; drug effects ; physiology ; Benzene ; toxicity ; Catalysis ; Chromones ; pharmacology ; DNA Damage ; drug effects ; genetics ; DNA Repair ; drug effects ; physiology ; DNA-Activated Protein Kinase ; antagonists & inhibitors ; metabolism ; Humans ; K562 Cells ; Morpholines ; pharmacology ; Protein Subunits

OBJECTIVETo investigate the effects of panax notoginseng saponins (PNS) on expression, regulation and phosphorylation of multiple protein kinases in mitogen activated protein kinase (MAPK) intracellular signal pathway and GATA transcription factors in hematopoietic cells, so as to explore its mechanism of proliferation and differentiation activity on hematopoiesis.

METHODSThe human granulocytic HL-60, erythrocytic K562, megakaryocytic CHRF-288 and Meg-01 cell lines were treated by PNS, the positive control of K562, CHRF-288 cells treated by recombination human erythropoietin (Epo) and thrombopoietin (Tpo) respectively. The total cell lysate and nuclei protein were extracted after being treated by PNS, subsequently, analyzed by both Western blot and immune-precipitation. Meanwhile, the nuclei extract was performed for electrophoretic mobility shift assay (EMSA) by using (32)P radio labeled double-stranded GATA consensus oligonucleotide.

RESULTSThe expression levels of kinase MEK-1, MEK-2, ERK-1, ERK-2, AKT-1, AKT-2 and PI-3K were increased by PNS treatment to different extent in four cell lines, depending on cellular heterogeneity and sensitivity to PNS, also phosphorylation of MEK-1, ERK-1 was differentially promoted by PNS respectively P<0.05, 0.01, 0.001). The expression levels of transcription factors GATA-1 and GATA-2 were increased, moreover, their DNA binding activities were raised dramatically in PNS treated K562, CHRF-288 and Meg-01 cells compared with the controls respectively (P<0.05, 0.01, 0.001). The positive control of K562, CHRF-288 cells treated by Epo or Tpo respectively also displayed up-regulation of protein kinases and GATA transcription factors respectively (P<0.05, 0.01, 0.001).

CONCLUSIONThe results indicated that intracellular signal pathway initiated by PNS was involved in MAPK pathway and transcription factors of GATA family in hematopoietic cells. PNS displayed the role to promote proliferation and differentiation, by means of increasing expression level and phosphorylation status of multiple protein kinases, also inducing synthesis of GATA transcription factors and upregulation its DNA binding activity.

Blotting, Western ; Cell Line, Tumor ; DNA ; metabolism ; Electrophoretic Mobility Shift Assay ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; GATA Transcription Factors ; metabolism ; Hematopoietic Stem Cells ; drug effects ; enzymology ; Humans ; Immunoprecipitation ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; Panax notoginseng ; chemistry ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; drug effects ; Protein Binding ; drug effects ; Protein Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Saponins ; pharmacology ; Up-Regulation ; drug effects

The study aims at cloning the CDS fragment of erk2 gene cDNA in Inner Mongolia Cashmere Goat and analyzing its tissue-specific expression, erk2 gene cDNA was cloned by RT-PCR. The nucleotide sequence was analyzed by Blast and amino acid sequence was analyzed by online softwares SMART and Psite. The tissue-specific expression pattern of erk2 was analyzed by quantitative RT-PCR. The expression of erk2 in testis of goat was detected by Immunohistochemistry. The cloned erk2 gene cDNA (GenBank Accession No. JX569765) was 1 083 bp in length, including a complete ORF encoding 360 amino acids residues. The amino acid sequence shares 100% identity with the Bos Taurus ERK2 (Bos Taurus BC133588.1). Analysis by SMART suggests that the encoded protein contained a "TEY" structure and an S-TKc domain possessing serine/threonine kinase catalytic activity. Analysis with Psite indicates one cAMP-/cGMP-dependent protein kinase phosphorylation site, 3 protein kinase C phosphorylation sites, 5 casein kinase II phosphorylation sites, 2 protein kinases ATP-binding region signatures and one serine/threonine protein kinases active-site signature in this protein. Analysis by Psort (k-NN prediction) suggestes that this protein most probably is localized in cytoplasm. The results of quantitative RT-PCR show that the expression of erk2 mRNA was higher in heart, skin and breast, whereas lower in spleen and kidney. ERK2 protein was detected in testis by immunohistochemistry.
Amino Acid Sequence ; Animals ; China ; Cloning, Molecular ; DNA, Complementary ; genetics ; Goats ; genetics ; Male ; Mitogen-Activated Protein Kinase 1 ; genetics ; metabolism ; Molecular Sequence Data ; Real-Time Polymerase Chain Reaction ; Testis ; metabolism

PURPOSE: To investigate whether the G6721T polymorphism (rs.7003908) of the non-homologous end-joining DNA repair XRCC7 gene contributes to the development of exudative age-related macular degeneration (ARMD). METHODS: The present case-control study consisted of 111 patients with exudative ARMD and 112 sex frequency-matched healthy controls that were randomly selected from unrelated volunteers in the same clinic. Genotypes were determined by the Restriction Fragment Length Polymorphism (PCR-RFLP) based method. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ARMD risk associated with polymorphism of XRCC7. In all analysis the GG genotype was considered to be the reference genotype. RESULTS: There was no significant association between genotypes of XRCC7 and susceptibility to ARMD. Considering the significant difference in age distribution between cases and controls, age was used as a covariate in further analysis. After ORs were adjusted for age, the same result was observed. In the next step we stratified our subjects into outdoor and indoor groups according to their job titles. The outdoor and indoor patients were occupationally exposed to sunlight and not exposed to sunlight, respectively. Our present study showed that among indoor subjects there was no association between XRCC7 polymorphism and susceptibility to ARMD. However, among outdoor subjects, the GT + TT genotypes compared to the GG genotype increased the risk of ARMD (OR, 3.13; 95% CI, 1.04-9.39; p = 0.042). CONCLUSIONS: Our study revealed that the T allele of the G6721T polymorphism of XRCC7 increased the risk of ARMD among outdoor subjects.
Aged ; DNA/*genetics ; DNA-Activated Protein Kinase/*genetics/metabolism ; *Environmental Exposure ; Exudates and Transudates ; Female ; Follow-Up Studies ; *Genetic Predisposition to Disease ; Genotype ; Humans ; Macular Degeneration/*genetics/metabolism ; Male ; Middle Aged ; Nuclear Proteins/*genetics/metabolism ; Polymerase Chain Reaction ; *Polymorphism, Genetic ; Retrospective Studies ; Risk Factors