Objective To study the effect of pioglitazone(PIO) on AdipoR1 and cholesterol ester(CE) in foam cells derived from THP-1-derived macrophages.Methods THP-1-derived macrophages were incubated with increasing concentrations of PIO for 24 hours.After co-cultured with low density lipoprotein(LDL),the accumulation of cholesterol in macrophages was measured by fluorescence spectrophotometric method.The lipid peroxide within cells was detected by TBARS method,the foam cells were observed by oil red staining.AdipoR1 levels were determined by Western blot.Results Compared with the ox-LDL group (0 μmol/L),oil red O-positive cells of the PIO protective groups were greatly reduced.TC,CE,MDA of the PIO protective groups were also obviously decreased.TC (53.6 ± 1.2) μg/mg,CE (30.2 ± 3.6) μg/mg,MDA (3.42 ± 0.06) μg/mg of 5 μμ mol/L PIO group were lower than those of 0μmol/L PIO group[(98.2 ± 3.5),(65.5 ± 6.5),(8.50 ± 1.21)] μg/mg (P ＜ 0.05).TC (25.6 ± 1.8) μg/mg,CE (22.5 ± 4.5) μg/mg,MDA (1.90 ± 0.42) μg/mg of 50 μmol/L PIO group.TC (16.8 ± 2.2) μg/mg,CE(5.9 ± 1.4) μg/mg,MDA (0.65 ± 0.05) μg/mg of 100μmol/L PIO group.Concomitantly,PIO significantly increased AdipoR1 protein expresion,AdipoR1 of 5μmol/L PIO group(0.06±0.05) was higher than that of 0μmol/L PIO group(0.03 ±0.07).AdipoR1 of 50μmol/L PIO group(0.11 ±0.07) was higher than that of 5μmol/L PIO group (0.06 ± 0.05).AdipoR1 of 100 μmol/L PIO group (0.40 ± 0.05) was obviously higher than that of 50 μ mol/L PIO group (0.11 ± 0.07).Conclusion PIO inhibited THP-1-derived formation by up-regulation the expression of AdipoR1,which may play an important role in the development and progression of atherosclerosis.

BACKGROUNDIt has been proved that tumor development and metastasis are dependent on angiogenesis. Suppression of tumor angiogenesis can inhibit tumor growth and metastasis. Collagen X VIII/endostatin is one of the most effective inhibitors of angiogenesis at present. The aim of this study is to study the relationship between transcription expression of endostatin mRNA and clinical and pathophysiological characteristics in non-small cell lung cancer (NSCLC).

METHODSThe transcription expression of endostatin mRNA was detected in 46 lung cancer tissues and paracancerous lung tissues, 14 benign pulmonary lesion tissues as control by RT-PCR method.

RESULTS(1)The transcription expression of endostatin mRNA in lung cancer tissues (0.872±0.071) was significantly higher than that in paracancerous tissues (0.717±0.073) and benign pulmonary lesion tissues (0.611±0.026) (P < 0.001).(2)The transcription expression of endostatin mRNA in lung cancer tissues was closely related to P-TNM stages, distant metastasis, grade of cell differentiation and size of the primary tumors (P < 0.05), but not to location of tumor, lymph node status, histological classification, age and sex of the patients and smoking or not (P > 0.05).

CONCLUSIONSThe transcription expression of endostatin mRNA in NSCLC tissues is significantly higher than that in paracancerous tissues and benign pulmonary lesion tissues, and is closely related to P-TNM stages, distant metastasis, grade of cell differentiation and size of the primary tumors, hence it might be helpful to evaluate the biological behavior of lung cancer.

nm23-H1 is a proven tumor metastasis suppressive gene, tumor metastasis phenotype could be reversed by transfected nm23-H1 cDNA. This study was conducted to transfect nm23-H1 cDNA into L9981 cells and to explore the function of nm23-H1 in reversing the malignant phenotype of L9981 cells. The plasmid of pLXSN-nm23-H1-EGFP was constructed by gene clone technique, and the transfected nm23-H1 cDNA cell lines of L9981-nm23-H1 was established. The protein expression of nm23-H1 was detected by Western blot. The biologic features of L9981-nm23-H1 cells were studied in vitro and in vivo. The results showed that the fusion protein of nm23-H1-EGFP was stable, continuous and expressed with high efficiency in L9981-nm23-H1 cells. The cell proliferation, colon formation and invasive ability are significantly lowered in L9981 cells transfected nm23-H1 cDNA (P < 0.01); the tumorgenesis and the lung metastasis incidence was lower in tranfected nm23-H1 cells than in L9981 and L9981-Plxsn in nude mice (P < 0.01); the rate for inhibiting tumorgenesis of nm23 -H1 was 82.56%. These data suggest that the malignant phenotype could be reversed by wild nm23-H1 gene in L9981 cells.
Animals ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Lung Neoplasms ; pathology ; Mice ; Mice, Nude ; NM23 Nucleoside Diphosphate Kinases ; genetics ; Neoplasm Metastasis ; Neoplasm Transplantation ; Recombinant Fusion Proteins ; genetics ; Transfection ; Tumor Suppressor Proteins ; genetics

BACKGROUNDnm23-H1 gene is a well-known tumor metastasis suppression gene. Our previous study has found that transfection of wild type nm23-H1 gene can significantly downregulate the ERK1/2 activity of human high-metastatic large cell lung cancer cell line L9981. The aim of this study is to investigate the influence of nm23-H1 and exogenous ERK1/2 pathway inhibitor U0126 on the extracellular signal-regulated kinase (ERK1/2) of human high-metastatic large cell lung cancer cell line L9981 and its malignant biological behaviors.

METHODSThe expressive levels of total-ERK1/2, dually phosphorylated ERK1/2 and ERK1/2 relative activity of the human high-metastatic large cell lung cancer cell lines, L9981 (parent cell line with nm23-H1 gene hetero-deletion), L9981-nm23-H1 (transfected with nm23-H1 gene ) and L9981-PLXSN (transfected with vector) were detected by Western blot and immunoprecipitation technique after treating with U0126 (40μmol/L for 20 minutes). The in vitro proliferative and invasive abilities among the above three lung cancer cell lines were determined by MTT and improved Boyden chamber methods.

RESULTSThe phosphorylated ERK1/2 expression level and relative activity in L9981-nm23-H1 lung cancer cell line were remarkably lower than those in L9981 and L9981-PLXSN lung cancer cell lines after being treated with U0126 (P < 0.01), but there was no significant difference between L9981 and L9981-PLXSN lung cancer cell lines. No significant difference of total ERK1/2 expression level was observed among the three lung cancer cell lines (P > 0.05) after being treated with U0126. The in vitro proliferation and invasion of L9981-nm-23H1 lung cancer cell line were remarkably lower than those of L9981 and L9981-PLXSN lung cancer cell lines (P < 0.01 ), but no significant difference was found between L9981 and L9981-PLXSN lung cancer cell lines (P > 0.05 ); U0126 could significantly down-regulate the in vitro proliferation and invasion of L9981 lung cancer cell line (P < 0.01).

CONCLUSIONSBlocking the activity of ERK1/2 in L9981 lung cancer cell line and transfecting the nm23-H1 gene into the L9981 lung cancer cell line may produce similar cell biological behavior changes, namely the significant reduction of in vitro proliferation and invasion of L9981 lung cancer cell line. These results indicate that the molecular mechanism which nm23-H1 gene reverses invasion and proliferation of the human high-metastatic large cell lung cancer cell line may be related to its effects of down-regulating the activity of the key kinase ERK1/2 of Ras-to-MAPK signal transduction pathway.

BACKGROUNDIt has been known that oncogenesis and development of lung can- cer is a complex process regulated many genes and involved in multistages. Recent studies have demonstrated that signal transduction abnormality may play a very important role in these procedures. The aim of this study is to investigate the influence of exogenous MEK1/2 pathway inhibitor U0126 on the expression and activity of extracellular signal-regulated kinase (ERK1/2) of human high-metastatic large cell lung cancer cell line L9981 and its malignant biological behaviors.

METHODSThe expressive levels of total-ERK1/2, dually phosphorylated ERK1/2 and ERK1/2 relative activity of the human high-metastatic large cell lung cancer cell line L9981 (parent cell line with nm23-H1 gene hetero-deletion ) were detected by Western blot and immuno-precipitation technique after treating with different doses of U0126. The in vitro proliferative and invasive abilities of the lung cancer cell line were determined by MTT and modified Boyden chamber methods.

RESULTSThe ERK1/2 relative activity of L9981 gradually decreased accompanied with increase of U0126 doses, and a highly significant difference of phosphorylated ERK1/2 expression level existed among the different concentration groups of U0126 (P < 0.01), but no significant difference of total ERK1/2 expression was found among the different concentration groups of U0126 (P=0.387). After treatment with same concentration of U0126 for different time, the ERK1/2 relative activity of L9981 gradually decreased as the treatment time of U0126 prolonging, and a highly significant difference of phosphorylated ERK1/2 expression level was observed among different treatment time groups (P < 0.01). But no significant difference of total ERK1/2 expression level was found among different time groups (P=0.689). The inhibition of ERK1/2 pathway by MEK1/2 specific inhibitor U0126 targeting the ERK1/2 pathway of L9981 was dose- and time-dependent. After treatment with different concentration of U0126, the proliferation of L9981 gradually decreased accompanied with increase of U0126 concentration and a highly significant difference existed among different groups of U0126 concentration (P < 0.001). The in vitro invasion of L9981 gradually decreased accompanied with increase of U0126 concentration. No significant difference of in vitro invasion of L9981 was found among 0, 10 and 20μmol/l of U0126 (P > 0.05). A highly significant difference was observed when U0126 concentration increased to 40 and 60μmol/l compared with 0, 10 and 20μmol/l of U0126 (P < 0.001).

CONCLUSIONSThe inhibition of Ras-to-MAPK pathway by Ras-to-MAPK specific inhibitor U0126 targeting the Ras-to-MAPK pathway of the human high-metastatic large cell lung cancer cell line L9981 is dose-dependent and time-dependent. Suppressing or blocking of Ras-to-MAPK signal transduction pathway can reverse the invasive and metastatic phenotype of the human high-metastatic large cell lung cancer cell line L9981. These results suggest that the key kinase MEK1/2 of the ERK1/2 pathway may be a potent therapeutic target for human lung cancer.

BACKGROUNDTo investigate the influence of the tumor metastasis suppressor gene nm23 H1 on the activity of extracellular signal-regulated protein kinase (ERK) in human high metastasis large cell lung cancer cell line L9981.

METHODSThe levels of total ERK1/2 and phospho-pERK1/2 were determined with p44/42 MAP kinase antibody and dually phosphospecific phospho-44/42 MAP kinase antibody in human high-metastasis large cell lung cancer cell lines L9981 (cell line with nm23-H1 gene deletion), L9981-nm23-H1 (cell line with nm23-H1 transfected ) and L9981-PLXSN (cell line with vector transfected) by Western blot method, respectively. The activity of phospho-ERK1/2 was determined with an ERK1/2 assay kit by immunopreciptation and Western blot analysis.

RESULTSThe expression levels of phospho-ERK1/2 kinase and the activity of phospho-ERK1/2 in the lung cancer cell line L9981-nm23-H1 were remarkably higher than those of the L9981 cell line and L9981-PLXSN cell line ( P < 0.01), but no significant difference in both the phospho-ERK1/2 expression and phospho-ERK1/2 activity was observed between the L9981 and L9981-PLXSN cell lines ( P > 0.05). There was no significant difference in the total ERK1/2 level among the three cell lines.

CONCLUSIONSnm23-H1 gene can obviously targetly suppress the activity of ERK1/2 in human high metastasis large cell lung cancer cell line L9981. This suggest that the mechanisms of nm23-H1 gene as a tumor metastasis suppressor gene may be related to its suppression to the MAPK/ERK signal transduction pathway.

OBJECTIVETo explore the role of fragile histidine triad(FHIT) gene in the proliferation, apoptosis and tumorigenesis of human lung cancer cells.

METHODSFHIT gene packaged with lipofectin was transfected into the cells of a human lung adenocarcinoma cell line (A549), which stably expressed ectogenous FHIT gene. The FHIT mRNA and protein expression of A549-FHIT, A549-vector and A549 cell were detected by reverse transcription-PCR(RT-PCR), Western blot and immunocytochemical methods. The cell cycle pattern and apoptosis were assayed by using flow cytometry.

RESULTSAfter transfection of FHIT gene, cell growth was obviously inhibited (P<0.01). The apoptosis index of A549-FHIT (8.42%) was significantly higher than that of A549-vector (5.45%) and A549 cells (5.71%)(P<0.01). The clone-formation rate of A549-FHIT cell (21.84%) was significantly lower than that of A549-vector (28.70%) and A549 cells (31.68%, P<0.01). Compared with control cell lines, larger scale of A549-FHIT cells accumulated in G0/G1, presenting that the proportion of the cells in G0/G1 phase was obviously increased from 67.78 % to 82.35 %. Tumorigenicity of the A549 cells in nude mice was greatly inhibited by expression of ectogenous FHIT gene, the weight and volume of A549-FHIT(1.61 g/1.37 cm(3)) were significantly lower than that of A549-vector (2.45 g/1.99cm(3)) and A549 cells (2.77 g/2.27 cm(3))(P<0.05).

CONCLUSIONExpression of ectogenous FHIT gene can obviously inhibit the proliferation and tumorigenesis of A549 cells, and can induce A549 cells into programmed cell death. The result of this study suggests that FHIT gene may be a tumor suppressor gene in human lung cancer cells.

Acid Anhydride Hydrolases ; Adenocarcinoma ; genetics ; pathology ; physiopathology ; Animals ; Apoptosis ; physiology ; Cell Cycle ; physiology ; Cell Division ; physiology ; Female ; Genes, Tumor Suppressor ; physiology ; Humans ; Lung Neoplasms ; genetics ; pathology ; physiopathology ; Male ; Mice ; Mice, Nude ; Neoplasm Proteins ; genetics ; physiology ; Neoplasm Transplantation ; Phenotype ; Transfection ; Transplantation, Heterologous ; Tumor Cells, Cultured

Antiviral Agents ; chemistry ; metabolism ; Crystallography, X-Ray ; Ligands ; Protein Binding ; Protein Structure, Tertiary ; RNA Helicases ; chemistry ; classification ; metabolism ; Static Electricity ; Viral Proteins ; chemistry ; classification ; metabolism ; Zika Virus ; enzymology

The recent explosive outbreak of Zika virus (ZIKV) infection has been reported in South and Central America and the Caribbean. Neonatal microcephaly associated with ZIKV infection has already caused a public health emergency of international concern. No specific vaccines or drugs are currently available to treat ZIKV infection. The ZIKV helicase, which plays a pivotal role in viral RNA replication, is an attractive target for therapy. We determined the crystal structures of ZIKV helicase-ATP-Mn(2+) and ZIKV helicase-RNA. This is the first structure of any flavivirus helicase bound to ATP. Comparisons with related flavivirus helicases have shown that although the critical P-loop in the active site has variable conformations among different species, it adopts an identical mode to recognize ATP/Mn(2+). The structure of ZIKV helicase-RNA has revealed that upon RNA binding, rotations of the motor domains can cause significant conformational changes. Strikingly, although ZIKV and dengue virus (DENV) apo-helicases share conserved residues for RNA binding, their different manners of motor domain rotations result in distinct individual modes for RNA recognition. It suggests that flavivirus helicases could have evolved a conserved engine to convert chemical energy from nucleoside triphosphate to mechanical energy for RNA unwinding, but different motor domain rotations result in variable RNA recognition modes to adapt to individual viral replication.
Crystallography, X-Ray ; Protein Domains ; RNA Helicases ; chemistry ; RNA, Viral ; chemistry ; Viral Proteins ; chemistry ; Zika Virus ; enzymology