Hypoxia occurs in chronic and acute vascular diseases and tumor formation. The ability of tumor cells to maintain a balance between an adaptation to hypoxia and cell death is regulated by a family of transcription factors called hypoxia-inducible factor 1 (HIF-1). Tumor hypoxia mediated by HIF-1 would facilitate the likelihood of resistance to chemotherapy and radiotherapy, proliferation, metastasis and the invasive potential; all of which culminate in a decrease in patient survival. And HIF-1 alpha subunit decides the activity of HIF-1, which is regulated by oxygen. So understanding the role of HIF in signal pathway, drug resistance mechanism and its feature is crucial for developing novel anticancer therapies. In recent years, more attentions have focused on HIF-1 alpha inhibitors. It is expected that development of more potent and selective HIF inhibitors will provide an effective treatment of cancer and other HIF-related diseases. So we will focus on the biological characteristics and mechanism of HIF-1 to review currently studied HIF-1 inhibitors.
Cell Death ; Humans ; Hypoxia-Inducible Factor 1 ; antagonists & inhibitors ; metabolism ; Hypoxia-Inducible Factor 1, alpha Subunit ; antagonists & inhibitors ; metabolism ; Neoplasms ; drug therapy ; Oxygen ; metabolism ; Signal Transduction

Hypoxia is a general characteristic of most solid malignancies and intimately related to cancer progression. Homeostatic response to hypoxia is primarily mediated by hypoxia inducible factor-1alpha (HIF-1alpha) that elicits transcriptional activity through recruitment P300 coactivator. Targeting the interaction of HIF- alpha and P300 would thus constitute a novel approach for cancer treatment by suppressing tumor angiogenesis and metastasis. Here, a screening assay was developed for inhibitors targeting the interaction between HIF-1alpha and P300. The nucleotide sequence of human HIF-1alpha and P300 were cloned into pBIND and pACT vectors, named pBIND-HIF1alpha and pACT-P300. The interaction of HIF-1alpha and P300 was identified in HEK293 cell using mammalian two-hybrid system. And compound chetomin decreased their interaction in this mammalian two-hybrid system. We further verified HIF-1 inhibition effect of chetomin in U251-HRE cells. Therefore, we established a screening assay combined HIF-1alpha and P300 mammalian two-hybrid system and U251-HRE reporter assay for HIF-1 selective inhibitors.
Cell Hypoxia ; Disulfides ; pharmacology ; Drug Screening Assays, Antitumor ; E1A-Associated p300 Protein ; antagonists & inhibitors ; HEK293 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; antagonists & inhibitors ; Indole Alkaloids ; pharmacology ; Two-Hybrid System Techniques

Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor on hypoxia responses in mammalian tissues. HIF-1 plays as a positive factor in solid tumor and leads to hypoxia-driven responses that enhance its downstream gene expression for tumor growth and survival. LXY6099 was obtained by the structural modification and optimization of manassantin A (MA) as a high potent HIF-1 inhibitor. Antitumor activity of LXY6099 was observed in this study. LXY6099 with an IC50 value of 2.46 x 10(-10) mol x L(-1) showed more sensitive inhibition activity to HIF-1 than that of MA detected by reporter gene assay (> 100 folds). It showed strong inhibition on the growth of human solid tumor cell lines. Furthermore, LXY6099 exhibited significant antitumor activity against established human tumor xenografts in nu/nu mice with treatment of MX-1 breast cancer. Thus, LXY6099 as a novel HIF-1 inhibitor could be further developed into anti-cancer agents.
Animals ; Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; metabolism ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Heterografts ; Humans ; Hypoxia-Inducible Factor 1 ; metabolism ; Lignans ; pharmacology ; Mice, Nude

The effect of amygdalin joint hydroxysafflor yellow A (HSYA) on the endplate chondrocytes derived from intervertebral discs of rats induced by IL-1beta and the possible mechanism were studied and explored. Chondrocytes were obtained from endplate of one-month SD rat intervertebral discs and cultured primary endplate chondrocytes. After identification, they were divided into normal group, induced group, amygdalin group, HSYA group and combined group. CCK-8 kit was adopted to detect the proliferation of the endplate chondrocytes. FCM was measured to detect the apoptosis. Real-time PCR method was adopted to observe the mRNA expression of Aggrecan, Col 2 alpha1, Col 10 alpha1, MMP-13 and the inflammatory cytokines IL-1beta. The protein expression of Col II, Col X was tested through immunofluorescence. Compared with the normal group, the proliferation of the endplate chondrocytes decreased while the apoptosis increased (P < 0.05). With down regulation of the mRNA expressions of Aggrecan, Col 2 alpha1 and up regulation of the mRNA expressions of Col 10 alpha1, MMP-13, IL-1beta (P < 0.05), the protein expression of Col II decreased while the protein expression of Col X increased. Compared with the induced group, amygdalin group, HSYA group, the combined group could inhibit the apoptosis and promote the proliferation (P < 0.05). They could increase the mRNA expressions of Aggrecan and Col 2 alpha1 while decrease the mRNA expressions of Col 10 alpha1, MMP-13 and IL-1beta (P < 0.05). They could also enhance the protein expression of Col II while reduce the protein expression of Col X. The effect of the combined group was significantly better than that of amygdalin and HSYA. Amygdalin joint HSYA could inhibit the degeneration of the endplate chondrocytes derived from intervertebral discs of rats induced by IL-1beta and better than the single use of amygdalin or HSYA.
Amygdalin ; pharmacology ; Animals ; Apoptosis ; Cells, Cultured ; Chalcone ; analogs & derivatives ; pharmacology ; Chondrocytes ; drug effects ; Collagen ; metabolism ; Drug Synergism ; Interleukin-1beta ; Intervertebral Disc ; cytology ; Quinones ; pharmacology ; Rats

The purpose of this study is to investigate the activity and mechanism of a new anti-tumor agent T03. MTT and colony formation assay were performed to determine anti-proliferation activity of T03 in vitro. Antitumor activity was observed by Renca xenograft model in vivo. The effect of T03 on cell cycle and apoptosis were measured by FCM analysis. Western blotting was performed to investigate the expression level of proteins in HepG2 cell lines treated with T03. T03 had anti-tumor activity by inhibiting tumor cell growth and colony formation in vitro, especially on hepatocellular carcinoma cells (HCC). At the concentration of 10 micromol x L(-1), T03 induced cell apoptosis and cell cycle arrest in HCC. Moreover, it proved that T03 reduced the tumor weight with the rate of 42.30% without any obviously side effect in Renca xenograft model. At the concentration of 2.0 micromol x L(-1), T03 was able to reduce the level of p-c-Raf (Ser259), and thus blocked Raf/MEK/ERK and AKT signaling in HepG2 cell lines. The result suggested that T03 has the potential to inhibit cell proliferation and induce cell apoptosis both in vitro and in vivo, particularly active against HCC, indicating T03 and its analogues may serve as a new anti-cancer drug against hepatocellular carcinoma.
Animals ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Cycle Checkpoints ; drug effects ; Cell Proliferation ; drug effects ; Hep G2 Cells ; drug effects ; Humans ; Liver Neoplasms ; pathology ; Signal Transduction ; drug effects ; Xenograft Model Antitumor Assays

N-acyl-homoserine lactones (AHLs), are widely conserved signal molecules present in quorum-sensing systems of many Gram-negative bacteria. AHLs molecules mediate the expression of virulence genes of a range of bacterial pathogens. Recently, it has been reported that AiiA protein, which widely exists in Bacillus species, can inactivate the AHLs by hydrolyzing the lactone bond of AHLs, thus attenuate the diseases caused by the expression of virulence genes of bacterial pathogens. Bacillus thuringiensis, a type of Gram-positive bacteria, has been used extensively as a microbial insecticide in the last few decades. However, most of important insecticidal B. thuringiensis strains have not been exploited for bacterial disease control because they usually do not produce antibiotics that are effective against bacteria and fungi. The discovery of AiiA protein in B. thuringiensis shows the application potential of B. thuringiensis on biocontrol against bacterial diseases. In this study, in order to construct the B. thuringiensis recombinant strain that has high expression of AiiA protein, the promoter of insecticidal crystal protein coding gene cry3Aa of B. thuringiensis was selected. The promoter of gene cry3Aa is a non-sporulation promoter, it promotes the transcription earlier and longer than the promoters of other cry genes. The promoter of AiiA protein coding gene aiiA was replaced with the promoter of gene cry3Aa by overlapping PCR, resulting fusion gene pro3A-aiiA. The gene pro3A-aiiA was inserted into shuttle vector pHT304 at site BamH I / Sph I , resulting recombinant plasmid pBMB686. The plasmid pBMB686 was introduced into B. thuringiensis acrystalliferous strain BMB171, the resulting strain BMB686 had a higher and more stable expression level of protein AiiA comparing with the parental strain BMB171. Furthermore, the strain BMB686 exhibited stronger ability of AHLs inactivation and much more effective restraint to the potato's soft rot disease caused by Erwinia carotovora than those of the parental strain BMB171. From these results, it was concluded that the B. thuringiensis strain harvesting the fusion gene pro3A-aiiA may be utilized in the future to control bacterial diseases which are mediated by the AHL quorum-sensing signals.
Acyl-Butyrolactones ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Daucus carota ; microbiology ; Endotoxins ; genetics ; metabolism ; Hemolysin Proteins ; genetics ; metabolism ; Metalloendopeptidases ; genetics ; metabolism ; Models, Genetic ; Pectobacterium carotovorum ; pathogenicity ; Plant Diseases ; microbiology ; prevention & control ; Promoter Regions, Genetic ; genetics ; Recombinant Proteins ; genetics ; metabolism

The resolution recognization sites of transposon Tn4430 of Bacillus thuringiensis was inserted into cloning vector pRSET B and pUC19, resulting recombinant plasmids pBMB1201 and pBMB1202. Both of the mini res fragments, BamHI/HindIII fragment in pBMB1201 and EcoRI/HindIII fragment in pBMB1202, were ligated to the 3.3 kb EcoRI/HindIII fragment of shuttle vector pHT3101, which contained the ori. Ec, ampr and emr antibiotic resistant genes, resulting recombinant plasmid pBMB1203. After deleted the BamHI and EcoRI sites which located ouside the two res sites, resolution vector pBMB1204 was resulted. There are multiple cloning sites between two copies of resolution sites which have the same direction. The plasmid replication origin ori44, which come from B. thuringiensis sub sp. kurstaki strain YBT-1520, was inserted into the multiple cloning sites of pBMB1204 and then resolution shuttle vector pBMB1205 was obtained. With spectinomycin resistant gene as target, it was found that the resolution rate is 100% and the stability of the resolved plasmid is 93%. Using this shuttle vector, antibiotic resistance markers and other non-B. thuringiensis DNA can be selectively eliminated after the selection of transformants by antibiotic resistance marker. This vector is very useful to solve the gene safety problem while has no effect on target gene expression.
Bacillus thuringiensis ; genetics ; DNA Transposable Elements ; Genetic Vectors ; Plasmids ; Replicon

OBJECTIVETo study the relation between the nitric-oxide synthase (NOS) expression and nitric oxide (NO) content in the skeletal muscles and the injury condition of soft tissue in the 3rd lumbar vertebrae syndrome model rats, and to observe the effect of acupotomology therapy.

METHODSOne hundred and twenty-eight adult SD rats were allocated to 4 groups randomly: normal group, model group, aminoguanidin group and acupotomology treatment group, 32 rats in each group. NOS expression, NO content and injury of the soft tissue in the 3rd lumbar vertebra were observed on the 1st, 3rd, 7th and 14th day after the acupotomology treatment and aminoguanidine intervention.

RESULTS1) Inducible NOS (iNos) activity and NO content in model group was significantly higher (F = 522.860, P < 0.01), in acupotomology group and aminoguanidine group was significantly lower than the model group (FiNOS = 28.894, P < 0.01), and iNOS activity and NO content in all groups was in competence with the condition of soft tissue injuries. 2) Endothelium NOS (eNOS) expression raised in model group and acupotomology group, and achieve peak on the 7th day. There was significant difference between the eNOS expression in acupotomology group and the model group (FeNOS = 3.454, P < 0.05). 3) The expression of neuron NOS (nNOS) in the model group, aminoguanidine group and acupotomology group had no significant (FnNOS = 0.962, P > 0.05).

CONCLUSIONAcupotomology treatment can restrain the development of high content NO, release the inflammatory reaction and injury condition, improve microcirculation, prevent the development of scar tissue of the injured soft tissue, and has significant recovering effectiveness in the soft tissue injured model rats.

Animals ; Disease Models, Animal ; Gene Expression Regulation, Enzymologic ; Guanidines ; therapeutic use ; Lumbar Vertebrae ; drug effects ; metabolism ; pathology ; surgery ; Male ; Muscle, Skeletal ; drug effects ; metabolism ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Syndrome ; Time Factors

OBJECTIVETo observe the relationship between protein sythesis and cardiomyocyte viability in neonatal rats.

METHODSThe protein sythesis in neonatal rat cardiomyocytes was measured according to Brandford's method, the absorbance at 490 nm (A(490 nm)) of the cells was measured with MTT assay and the cell viability evaluated by the ratio of A(490 nm) to the total cell number.

RESULTSET-1 increased cardiomyocyte protein synthesis dose-dependently, and this effect was attenuated by the application of lacidipine and tetramethylpyrazines Higher doses of ET-1 resulted in lower A(490 nm)/total cell number ratio, which was further lowered by larcidipine and tetramethylpyrazine.

CONCLUSIONThe status of protein synthesis is not associated with the viability of neonatal rat cardiomyocytes.

Animals ; Animals, Newborn ; Calcium Channel Blockers ; pharmacology ; Cell Survival ; drug effects ; Cells, Cultured ; Dihydropyridines ; pharmacology ; Dose-Response Relationship, Drug ; Endothelin-1 ; pharmacology ; Myocytes, Cardiac ; cytology ; drug effects ; metabolism ; Protein Biosynthesis ; Pyrazines ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo develop a method for evaluating the feasibility of prenatal screening using local median value and determining the cut-off value.

METHODSWith receiver operating characteristic curve (ROC) analysis, results of second trimester prenatal screening calculated by a local median value in a new model and the built-in median value in 2T software were compared. The cut-off value was set by serial analysis of true and false positive rates and other relevant data.

RESULTSThe ROC curve has accurately estimated the difference in the screening efficacy between a local median value and that embedded in the 2T model, and established a reasonable cut-off value for the laboratory based on false positive rate and detection rate.

CONCLUSIONThe method of ROC curve can be used to evaluate the performance of local median value in prenatal screening and to test the rationality of cut-off value established in the laboratory. As the result, a better cut-off value may be derived.

China ; epidemiology ; Down Syndrome ; diagnosis ; epidemiology ; genetics ; Female ; Humans ; Male ; Pregnancy ; Pregnancy Trimester, Second ; genetics ; Prenatal Diagnosis ; instrumentation ; methods ; standards ; ROC Curve ; Software