• Journal of Microbiology
• /
• v.44 no.2
• /
• pp.226-232
• /
• 2006

Swarming has proven to be a good in vitro model for bacterial surface adherence and colonization, and the swarming differentiation of a bacterium has been shown to be coupled with changes in the expression of virulence factors associated with its invasiveness, particularly in the early stages of infection. In this study, we attempted to determine whether the expression of vvhA, which encodes for hemolysin/cytolysin (VvhA), is either upregulated or downregulated during the swarming differentiation of V. vulnificus. The insertional inactivation of vvhA itself exerted no detectable effect on the expression of V. vulnificus swarming motility. However, in our lacZ-fused vvhA transcriptional reporter assay, vvhA expression decreased in swarming V. vulnificus as compared to non-swarming or planktonic V. vulnificus. The reduced expression of vvhA in swarming V. vulnificus increased as a result of the deletional inactivation of luxS, a gene associated with quorum sensing. These results show that vvhA expression in swarming V. vulnificus is downregulated via the activity of the LuxS quorum-sensing system, suggesting that VvhA performs no essential role in the invasiveness of V. vulnificus via the adherence to and colonization on the body surfaces required in the early stages of the infection. However, VvhA may playa significant role in the pathophysiological deterioration occurring after swarming V. vulnificus is differentiated into planktonic V. vulnificus.

• Plant Biotechnology Reports
• /
• v.5 no.1
• /
• pp.53-60
• /
• 2011

Artemisinin is effective against both chloroquine-resistant and -sensitive strains of Plasmodium species. However, the low yield of artemisinin from cultivated and wild plants is a serious limitation to the commercialization of this drug. Optimization of artemisinin yield either in vivo or in vitro is therefore highly desirable. To this end, we have overexpressed the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR) gene (hmgr) from Catharanthus roseus L. in Artemisia annua L. and analyzed its influence on artemisinin content. PCR and Southern blot analyses revealed that the transgenic plants showed stable integration of the foreign hmgr gene. The reverse transcriptase-PCR results suggested that the hmgr was expressed at the transcriptional level in transgenic lines of Artemisia annua L., while the high-performance liquid chromatography analysis showed that artemisinin content was significantly increased in a number of the transgenic lines. Artemisinin content in one of the A. annua transgenic lines was 38.9% higher than that in non-transgenic plants, and HMGR enzyme activity in transgenic A. annua L. was also higher than that in the non-transgenic lines.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.3
• /
• pp.993-1001
• /
• 2016

Type 2 diabetes mellitus patients are at increased risk of many forms of malignancies, especially of the pancreas, colon and hepatocellular cancer. Unfortunately, little is known of the possible interaction between antidiabetic drugs and anticancer agents. The present study investigates the influence of metformin (MET) and sitagliptin (SITA) on the in vitro anticancer activity of the microtubule depolymerization inhibitor agent epothilone A (EpoA). Hepatocellular liver carcinoma cell line (HepG2) viability and apoptosis were determined by the MTT test and by double staining with PO-PRO-1 and 7-aminoactinomycin D, respectively, after treatment with EpoA, metformin or sitagliptin. The levels of nuclear factor NF-${\kappa}B$ and p53 were evaluated in the presence and absence of inhibitors. While EpoA and MET inhibited HepG2 cell proliferation, SITA did not. EpoA and SITA induced higher p53 levels than MET. All tested drugs increased the level of NF-${\kappa}B$. Only MET enhanced the proapoptotic effect of EpoA. The EpoA+MET combination evoked the highest cytotoxic effect on HepG2 cells and led to apoptosis independent of p53, decreasing the level of NF-${\kappa}B$. These findings support the link between NF-${\kappa}B$ and p53 in the modulation of apoptotic effects in HepG2 cells treated by EpoA. Our studies indicate that the combination of EpoA and MET applied in subtoxic doses has a stronger cytotoxic effect on liver cancer cells than each of the compounds alone. The therapeutic advantages of the combination of EpoA with MET may be valuable in the treatment of patients with diabetes mellitus type 2 (T2DM) and liver cancer.

• BMB Reports
• /
• v.41 no.2
• /
• pp.158-163
• /
• 2008

Hepatitis B virus X protein (HBx) is essential for hepatitis B virus infection and exerts a pleiotropic effect on various cellular machineries. HBx has been also demonstrated as an indirect transcriptional transactivator of various different viral and cellular promoters. In addition, HBx is involved in the development of various liver diseases including hepatocellular carcinoma. However the mechanism of HBx in hepatocellular carcinogenesis remains largely unknown. In this study, to identify possible new cellular proteins interacting with HBx, we carried out yeast two-hybrid assay. We obtained several possible cellular partners including VBP1, a binding factor for VHL tumor suppressor protein. The direct physical interaction between HBx and VBP1 in vitro and in vivo was confirmed by immunoprecipitation assay. In addition, we found that VBP1 facilitates HBx-induced $NF{\kappa}B$ activation and cell proliferation. These results implicate the important role of HBx in the development of hepatocellular carcinoma through its interaction with VBP1.

• The Plant Pathology Journal
• /
• v.23 no.2
• /
• pp.76-89
• /
• 2007

CaCDPK4, a full-length cDNA clone encoding Capsicum annuum calcium-dependent protein kinase 4, was isolated from chili pepper (Capsicum annuum L.). Deduced amino acid sequence of CaCDPK4 shares the highest homology with tobacco NpCDPK8 and chickpea CaCDPK2 with 79% identity. Genomic blot analyses revealed that CaCDPK4 is present as a single copy in pepper genome, but it belongs to a multigene family. CaCDPK4 was highly induced when pepper plants were inoculated with an incompatible bacterial pathogen. Induced levels of CaCDPK4 transcripts were also detected in pepper leaves by the treatment of ethephon, an ethylene-inducing agent, and high-salt stress condition. The bacterial-expressed GST-CaCDPK4 protein showed to retain the autophosphorylation activity in vitro. GUS expression driven by CaCDPK4 promoter was examined in transgenic Arabidopsis containing transcriptional fusion of CaCDPK4 promoter. GUS expression under CaCDPK4 promoter was strong in the root and veins of the seedlings. GW (-1965) and D3 (-1377) promoters conferred on GUS expression in response to inoculation of an incompatible bacterial pathogen, but D4-GUS (-913) and DS-GUS (-833) did not. Taken together, our results suggest that CaCDPK4 can be implicated on signal transduction pathway of defense response against an incompatible bacterial pathogen in pepper.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.5
• /
• pp.2415-2421
• /
• 2016

E-cadherin (CDH1) genetic variations alter gene transcriptional activity of epithelial cells in vitro and may cause susceptibility to various cancers. Associations of CDH1 -160C>A polymorphism with various cancers have been widely reported. However, the results are controversial and inconsistent. To derive a more accurate estimation of the relationship, a meta-analysis was performed with regard to gastrointestinal (GI) cancer risk. Eligible studies were identified through a search of PubMed database until December 2015. Associations between the CDH1 -160C>A polymorphism and GI cancer risk was considered by odds ratios (ORs) together with their 95% confidence intervals (CIs). A total of 31 studies including 11,606 cases and 12,655 controls were involved in this meta-analysis. Overall, this meta-analysis showed no association between CDH1 -160C>A polymorphism and GI cancer risk (A vs. C: OR = 1.08, 95%CI = 0.98-1.18, P = 0.086;CA vs. CC: OR = 1.09, 95%CI = 0.97-1.22, P = 0.118; AA vs. CC: OR = 1.10, 95%CI = 0.89-1.35, P = 0.356; AA vs. CC + CA: OR = 1.06, 95%CI = 0.96-1.18, P = 0.207; CA+AA vs. CC: OR = 1.01, 95%CI = 0.84-1.22, P = 0.89). In subgroup analysis, similar results were found. In conclusion, this meta-analysis has demonstrated that there is a lack of association of the CDH1-160C>A polymorphism with GI cancer susceptibility.

• Journal of Ginseng Research
• /
• v.39 no.2
• /
• pp.141-147
• /
• 2015

Background: Adipocytes, which are the main cellular component of adipose tissue, are the building blocks of obesity. The nuclear hormone receptor $PPAR{\gamma}$ is a major regulator of adipocyte differentiation and development. Obesity, which is one of the most dangerous yet silent diseases of all time, is fast becoming a critical area of research focus. Methods: In this study, we initially aimed to investigate whether the ginsenoside Rf, a compound that is only present in Panax ginseng Meyer, interacts with $PPAR{\gamma}$ by molecular docking simulations. After we performed the docking simulation the result has been analyzed with several different software programs, including Discovery Studio, Pymol, Chimera, Ligplus, and Pose View. All of the programs identified the same mechanism of interaction between $PPAR{\gamma}$ and Rf, at the same active site. To determine the drug-like and biological activities of Rf, we calculate its absorption, distribution, metabolism, excretion, and toxic (ADMET) and prediction of activity spectra for substances (PASS) properties. Considering the results obtained from the computational investigations, the focus was on the in vitro experiments. Results: Because the docking simulations predicted the formation of structural bonds between Rf and $PPAR{\gamma}$, we also investigated whether any evidence for these bonds could be observed at the cellular level. These experiments revealed that Rf treatment of 3T3-L1 adipocytes downregulated the expression levels of $PPAR{\gamma}$ and perilipin, and also decreased the amount of lipid accumulated at different doses. Conclusion: The ginsenoside Rf appears to be promising compound that could prove useful in antiobesity treatments.

• YAKHAK HOEJI
• /
• v.54 no.2
• /
• pp.91-96
• /
• 2010

Berberine, an isoquinoline alkaloid, has a wide range of pharmacological effects, including anti-inflammation. It has been reported that berberine inhibits experimental colitis through inhibition of IL-8, and that inhibitory effect of berberine on inflammatory cytokine expression is mediated through peroxisome proliferator activated receptor (PPAR)-$\gamma$. In this study, we examined the effects and action mechanism of berberine on the tumor necrosis factor (TNF)-$\alpha$-induced monocyte adhesion to HT29 human colonic epithelial cells, which is commonly used as an in vitro model of inflammatory bowel disease (IBD). Berberine significantly inhibited the TNF-$\alpha$-induced monocyte adhesion to HT29, which is similar to the effect of PDTC, a nuclear factor (NF)-$\kappa$B inhibitor. However, ciglitazone and GW, the ligands of PPAR-$\gamma$, did not suppress the TNF-$\alpha$-induced monocyte adhesion to HT29 cells. In addition, TNF-$\alpha$-induced chemokine expression and NF-$\kappa$B transcriptional activity were significantly inhibited by berberine in a concentration-dependent manner. The results suggest that inhibitory effect of berberine on colitis is mediated through suppression of NF-$\kappa$B and NF-$\kappa$B-dependent chemokine expression.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.8 no.2
• /
• pp.169-174
• /
• 2004

Bombyx mori nucleopolyhedrovirus(BmNPV) ecdysteroid UDP-glucosyltransferase gene (egt) promoter fragments of different lengths were amplified from BmNPV ZJ-8 genomic DNA by PCR. Reporter plasmids pBmegt542-luc, pBmegt309-luc and pBmegtl59-luc with luciferase (lue) driven by egt promoters were constructed. Both in vitro and in vivo expressions showed that BmNPV egt promoter activity requires the transactivation of viral factor(s), and expression of luc was detected earliest at 24 hrs post infection (pi). BmNPV ZJ-8 homologous region 3 (hr3) increased the expression of luc by over 1,600-fold. Molting hormone of 1.0 - 2.0 $\mu\textrm{g}$/$m\ell$ can dramatically down regulate expression of luc. Juvenile hormone analogue of 0.5-2.0 ${\mu}g$/$m\ell$ increased expression of luc by 145.8% to 75.7%. Deletion assay revealed that the promoter fragment of 159 bp contains the basal promoter structure; Promoter fragments of 309 bp and 542 bp showed similar but much higher transcriptional activities than that of 159 bp, suggesting that nucleotide from -159 to -309 nt upstream the translation initiation site harbors the main cis-acting elements.

• BMB Reports
• /
• v.34 no.3
• /
• pp.237-243
• /
• 2001

Taxol, a natural product extracted from the Taxus brevifolia, is known to have significant anti-tumor activities against many common cancers, including ovarian and breast cancers. Despite the pronounced anti-tumor activity of this compound, its poor solubility in aqueous solutions hampers its clinical applications. We studied the anticancer mechanisms of the water-soluble taxol diethylenetriamine pentaacetate (DTPA) used for radiolabeling, and compared it to that of taxol. In vitro cytotoxicities of taxol and taxol-DTPA conjugate were tested in HT29 human colorectal cancer cells by the MTT method. As the result, the $IC_{50}$ value of the taxol-DTPA conjugate was about three fold higher than that of taxol. When analyzed by an agarose gel electrophoresis, the DNA ladders became evident after the incubation of cells with the taxol-DTPA conjugate for 24 h. We also found morphological changes of the cells undergoing apoptosis with electron microscopy Next, we examined the signal pathway of taxol-DTPA conjugate-induced apoptosis in HT29 cells. The activation of extracellular signal-regulated protein kinase (ERK1/2) occurred at 10, 30, 60 and 120 min after 200 nM taxol-DTPA conjugate treatment. The pretreatment of the MEK inhibitor (PD98059) completely blocked the taxol-DTPA conjugate-induced ERK1/2 activation. The activated ERK1/2 translocated into the nucleus at the same time and phosphorylated its transcriptional factor, c-Jun. These results suggest that the taxol-DTPA conjugate has an apoptotic activity in HT29 cells, and that its proapoptic activity might be related with the signal transduction via ERK1/2 and c-Jun similar to that of taxol.