Epigallocatechin-3-gallate (EGCG) inhibits the migratory behavior of tumor bronchial epithelial cells

Background

Many studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date, most of the studies have focused on the effect of EGCG on cell proliferation or death. Since cell migration is an important mechanism involved in tumor invasion, the aim of the present work was to target another approach of the therapeutic effect of EGCG, by investigating its effect on the cell migratory behavior.

Methods

The effect of EGCG (at concentrations lower than 10 μg/ml) on the migration speed of invasive cells was assessed by using 2D and 3D models of cell culture. We also studied the effects of EGCG on proteinases expression by RT-PCR analysis. By immunocytochemistry, we analyzed alterations of vimentin organization in presence of different concentrations of EGCG.

Results

We observed that EGCG had an inhibitory effect of cell migration in 2D and 3D cell culture models. EGCG also inhibited MMP-2 mRNA and protein expression and altered the intermediate filaments of vimentin.

Conclusion

Taken together, our results demonstrate that EGCG is able to inhibit the migration of bronchial tumor cells and could therefore be an attractive candidate to treat tumor invasion and cell migration.     

Circumscription of species in the <Emphasis Type="Italic">Hodophilus foetens</Emphasis> complex (Clavariaceae,Agaricales) in Europe

Four European Hodophilus species with an odour similar to naphthalene, a strong unpleasant odour similar to that of mothballs, are recognized based on sequence and/or morphological data. The traditional concept defines Ho. foetens as the only Hodophilus species with a naphthalene odour in Europe. This name is now assigned to one of the studied species based on morphological examination of the holotype specimen. A recently collected specimen is proposed as the epitype. The other three species with a naphthalene odour are described here as new: Ho. pallidus, Ho. subfoetens and Ho. tenuicystidiatus. They are distinguishable in the field based on a combination of lamellae number and colour of basidiomata. All four species are grouped in the Ho. foetens superclade, one of two superclades, together with the Ho. micaceus superclade, in the genus Hodophilus. All are different species from North American taxa with a naphthalene-like odour recognised in a previous study. The Ho. foetens superclade also includes one species identified as Ho. atropunctus that does not have a distinctive odour. The type collection of Ho. albofloccipes, a recently described European species with a naphthalene odour, is placed together with some collections without a distinctive odour in the Ho. micaceus superclade.     

Recombination in Polymer:Fullerene Solar Cells with Open‐Circuit Voltages Approaching and Exceeding 1.0 V

Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC₆₁BM. These devices achieve open‐circuit voltages (V_oc) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V_oc’s above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage‐dependent, steady state and time‐resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of –0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V_oc values above 1.0 V and that non‐fullerene acceptor materials with large optical gaps (>1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V_oc exceeding 1.0 V.     

Low-Resolution Structure of Vaccinia Virus DNA Replication Machinery

Smallpox caused by the poxvirus variola virus is a highly lethal disease that marked human history and was eradicated in 1979 thanks to a worldwide mass vaccination campaign. This virus remains a significant threat for public health due to its potential use as a bioterrorism agent and requires further development of antiviral drugs. The viral genome replication machinery appears to be an ideal target, although very little is known about its structure. Vaccinia virus is the prototypic virus of the Orthopoxvirus genus and shares more than 97% amino acid sequence identity with variola virus. Here we studied four essential viral proteins of the replication machinery: the DNA polymerase E9, the processivity factor A20, the uracil-DNA glycosylase D4, and the helicase-primase D5. We present the recombinant expression and biochemical and biophysical characterizations of these proteins and the complexes they form. We show that the A20D4 polymerase cofactor binds to E9 with high affinity, leading to the formation of the A20D4E9 holoenzyme. Small-angle X-ray scattering yielded envelopes for E9, A20D4, and A20D4E9. They showed the elongated shape of the A20D4 cofactor, leading to a 150-Å separation between the polymerase active site of E9 and the DNA-binding site of D4. Electron microscopy showed a 6-fold rotational symmetry of the helicase-primase D5, as observed for other SF3 helicases. These results favor a rolling-circle mechanism of vaccinia virus genome replication similar to the one suggested for tailed bacteriophages.     

Detection of mitochondrial DNA deletions by a screening procedure using the Polymerase Chain Reaction

We describe an accurate procedure for a rapid diagnosis of heteroplasmic mtDNA deletions based on the polymerase chain reaction (PCR). For a selective amplification of deleted mtDNA across the breakpoints of the deletion, we used seven combinations of primers surrounding the most common deleted region between the two origins of mtDNA replication. This procedure was performed on muscle biopsies of twenty patients harboring a single mtDNA deletion and one patient with multiple mtDNA deletions. The results were compared with Southern-blotting analysis. We conclude that this PCR procedure is a sensitive and convenient screening method for the detection of mtDNA deletions. (Mol Cell Biochem 174: 221–225, 1997)     

Interaction of peanut agglutinin,a lectin specific for nonreducing terminal d-galactosyl residues,with embryonal carcinoma cells

Peanut agglutinin (PNA), a lectin specific for terminal d-galactosyl residues, was found to react with embryonal carcinoma cells, but not with their differentiated derivatives. Receptors for PNA were detectable at the surface of all cells of the quasinullipotent F9 line and on only 50% of the multipotent PCC3/A/1 line. The fraction of the PCC3/A/1 population which expresses the F9 antigen was found to be included in the subpopulation carrying the PNA receptors. PNA⁺ and PNA^? subpopulations of PCC3/A/1 were separated by a PNA-mediated reversible agglutination of PNA⁺ cells with rabbit erythrocytes. These subpopulations were essentially F9⁺ and F9^?, respectively.     

Diagnostic value of JC/BK virus antibody immunohistochemistry staining in urine samples from posttransplant immunosuppressed patients in relation to polyomavirus reactivation

OBJECTIVE: To compare the diagnostic value of cytology and immunohistochemistry staining (IHS) of urine samples for polyomavirus reactivation diagnosis. STUDY DESIGN: Sixty-eight urine samples collected from 18 immunosuppressed patients were analyzed by Papanicolaou and IHS with a JC/BK virus-specific monoclonal antibody. RESULTS: Overall, polyomavirus BK (BKV) was positive in 11 of 18 patients (61.1%) (3 of whom developed hemorrhagic cystitis) and in 23 of 68 urine samples (28%). Of 23 samples, 4 (17%) were positive by 1 of the 2 techniques, only. Of 23 samples, 19 (83%) were positive by both methods. In matching urine samples from the same patient, the number of BKV-infected positive cells detected by IHS in urine slides was higher than those detected by Papanicolaou staining (71.3%). CONCLUSION: The main advantage of LHS is that it allowed confirmation of BKV infection diagnosis in urine samples. IHS detected more BKV-infected cells in samples with few positive urothelial cells, which would have gone undetected if only Papanicolaou staining had been used as the BKV screening method. Urine samples testing for BKV by both techniques will improve diagnosis in asymptomatic patients, allowing early therapeutic intervention and a better clinical outcome.     

Therapy for chronic hepatitis C.

BACKGROUND/AIMS: in Hungary, over the past 5 years more than 900 patients with chronic hepatitis C have been examined for treatment with interferon at 16 major hepatology centres, using unified diagnostic and therapeutical criteria. Authors give an account of their experiences on the clinical features of patients with chronic hepatitis C and report the results of the interferon therapy. METHODS: a total of 993 patients--virtually the entire Hungarian hepatitis C patient population who had been referred for interferon treatment--were included in the program. Actually, the sustained efficacy of the therapy was evaluated in 724 cases. Treatment protocols (dose of interferon and duration of therapy) have changed with time from a weekly dose of 3x3 MU IFN for 6 months in the first period, to 3x3-5 MU for 12 months in the second period, and finally in the third period a combination therapy with ribavirin has also been introduced. RESULTS: in the first period, the end-of-treatment response (ETR) was 35%, sustained response (SR) 13%, the second phase schedule resulted in 42% ETR and 22% SR, while in the third period, ETR was 49% and SR 36%, respectively. Fibrosis in histology and baseline pretreatment HCV-RNA level appeared as predictors of response. The duration of treatment and the total dose of interferon exerted a moderate effect on therapeutic efficacy. Neither age nor gender influenced the outcome. CONCLUSIONS: our results-obtained in a Central East European country-are in accordance with findings of suboptimal efficacy of traditional interferon monotherapy for chronic hepatitis C reported in the West, and suggest the benefit of the combination treatment of interferon with ribavirin.     

Obtaining transgenic Solanum tuberosum potato plants with active bacterial genes xyl and T-cyt effecting the phytohormone balance]

The genetic constructions based on integrative vector pGV3850 were used to introduce bacterial genes xyl and T-cyt into potato cells. The transformation was carried out using the leaf-disc method with modifications. A special system for obtaining regenerants from explants of potato in vitro plants or calli has been designed that permitted the selection of transgenic shoots. The presence of the genes in potato genome has been proved by testing the NPTII and glucoisomerase activities. The transgenic plants expressing T-cyt gene differed from the wild type in sharp decrease of the apical dominance.