N-acetyltransferase 1 and 2 gene sequence variants and risk of head and neck cancer

Polymorphisms that alter the function of genes involved in the activation or detoxification of carcinogenic compounds can influence an individuals risk of developing cancer. Polymorphic changes modulating the acetylation capacity of the N-acetyltransferase (NAT) genes have been implicated in the risk of developing cancer. In this study the role of genetically determined individual NAT1 and NAT2 genotypes, haplotypes and haplotype combinations in the predisposition to head and neck cancer was investigated. Polymorphic regions of the NAT1 and NAT2 genes were analyzed in patients with head and neck cancer and healthy individuals by polymerase chain reaction-restriction fragment length polymorphism. Distribution of the genotypes, allele frequencies, diplotypes and haplotypes and correlation with clinical characteristics were evaluated. No association was observed between the NAT1*3, NAT1*10, NAT1*11, NAT2*5 and NAT2*6 genotypes and risk of head and neck cancer. The NAT2*7 slow genotype was associated with reduced risk of disease. A significant association was observed between the fast acetylator NAT2*4/NAT1*10 diplotype and risk of head and neck cancer. Combined haplotypes harboring the T1088A and C1095A variants characterizing the NAT1*10 allele were associated with increased risk. Our results suggest that NAT1 and NAT2 gene combinations may influence the risk of developing head and neck cancer.     

Genotypic and Phenotypic Characterization of P23H Line 1 Rat Model

Rod-cone dystrophy, also known as retinitis pigmentosa (RP), is the most common inherited degenerative photoreceptor disease, for which no therapy is currently available. The P23H rat is one of the most commonly used autosomal dominant RP models. It has been created by incorporation of a mutated mouse rhodopsin (Rho) transgene in the wild-type (WT) Sprague Dawley rat. Detailed genetic characterization of this transgenic animal has however never been fully reported. Here we filled this knowledge gap on P23H Line 1 rat (P23H-1) and provide additional phenotypic information applying non-invasive and state-of-the-art in vivo techniques that are relevant for preclinical therapeutic evaluations. Transgene sequence was analyzed by Sanger sequencing. Using quantitative PCR, transgene copy number was calculated and its expression measured in retinal tissue. Full field electroretinography (ERG) and spectral domain optical coherence tomography (SD-OCT) were performed at 1-, 2-, 3- and 6-months of age. Sanger sequencing revealed that P23H-1 rat carries the mutated mouse genomic Rho sequence from the promoter to the 3’ UTR. Transgene copy numbers were estimated at 9 and 18 copies in the hemizygous and homozygous rats respectively. In 1-month-old hemizygous P23H-1 rats, transgene expression represented 43% of all Rho expressed alleles. ERG showed a progressive rod-cone dysfunction peaking at 6 months-of-age. SD-OCT confirmed a progressive thinning of the photoreceptor cell layer leading to the disappearance of the outer retina by 6 months with additional morphological changes in the inner retinal cell layers in hemizygous P23H-1 rats. These results provide precise genotypic information of the P23H-1 rat with additional phenotypic characterization that will serve basis for therapeutic interventions, especially for those aiming at gene editing.     

Immobilization of a thermostable α-amylase, Termamyl, onto nitrocellulose membrane by Cibacron Blue F3GA dye binding

Highly porous nitrocellulose membranes were prepared by a solvent casting technique for the first time to immobilize α-amylase. An affinity dye, namely Cibacron Blue F3GA (CB), was incorporated covalently within the structure. The nitrocellulose–CB derivatized membranes were used for the immobilization of a starch degrading enzyme, α-amylase. Optimum conditions of immobilization for highest apparent activity were determined as pH 6.0, temperature 50°C and initial enzyme concentration 0.317 KNU/l. Under these optimum conditions, maximum enzyme immobilization yield was around 21% of the initial amount of the enzyme in the solution. Performance of free and immobilized enzymes at the same amount was compared for repeated runs. Up to the third use, immobilized enzyme showed higher activity than that of free enzyme mainly due to higher enzyme concentration in the membrane structure, then the apparent activity decreased gradually. However, when regenerated by switching pH to cause contraction/expansion of the structure, the membrane showed the highest activity, almost 2.5 times than that of the free enzyme. This unusual feature along with inexpensive cost may well make the nitrocellulose membrane an economical material for industrial application in glucose syrup production.     

Reverse micelles of dipalmitoyl phosphatidyl choline in chloroform and their interactions with dapsone.

1H NMR studies of DiPalmitoyl Phosphatidyl Choline (DPPC) in CDCl3 at various concentrations indicate that DPPC exists as reverse micelles for concentrations beyond 6 mM. The chemical environments of the two acyl chains of DPPC are inequivalent and the inequivalence decreases with increasing DPPC concentration. At low concentrations of DPPC (less than 1.0 mM) intramolecular interactions predominate, whereas at high concentrations, intermolecular interactions predominate. Addition of water to this system, at high concentrations of the phospholipid, reduces the intermolecular interactions. In the presence of the antileprotic drug, Diamino Diphenyl Sulfone (DDS or Dapsone), significant shifts were observed only in the choline resonances of DPPC and the amino resonance of the drug, showing that the amino group of DDS interacts with the head group of DPPC.     

Effects of exotic and translocated fish species in the inland waters of Turkey

Throughout the world a number of problems have arisen following the introduction of new fish species; impacts of introductions are not limited to biological and ecological effects but may also have socioeconomic implications. Exotic and translocated fish species have become established in various parts of the inland waters of Turkey since the 1950s. The present paper reviewed ecological and economical effects of introduced freshwater fish of Turkey.     

Synthesis of novel mono and bis-indole conduritol derivatives and their α/β-glycosidase inhibitory effects

Here we synthesized four novel indole conduritol derivatives 1–4 for the first time in the literature and probed their biological activities with the α and β-glucosidases. The compounds showed quite effective glucosidase inhibitory action. IC₅₀ values of the compounds were compared with the known glucosidase inhibitor acarbose and it was determined that newly synthesized indole conduritols had more powerful effect against β-glucosidase in addition to exhibiting moderate influence against α-glucosidase. Our molecules thus constitute an important starting point for the design and exploitation of novel glucosidase inhibitors since glucosidase inhibitors have widespread applications in the treatment of diabetes, viral infections, lysosomal storage diseases and cancers.     

Disruption of the protein interaction between FAK and IGF-1R inhibits melanoma tumor growth

FAK (focal adhesion kinase) and IGF-1R (insulin-like growth factor receptor-1) directly interact with each other and thereby activate crucial signaling pathways that benefit cancer cells. Inhibition of FAK and IGF-1R function has been shown to significantly decrease cancer cell proliferation and increase sensitivity to chemotherapy and radiation treatment. As a novel approach in human melanoma, we evaluated the effect of a small-molecule compound that disrupts the protein interaction of FAK and IGF-1R. Previously, using virtual screening and functional testing, we identified a lead compound (INT2–31) that targets the known FAK-IGF-1R protein interaction site. We studied the ability of this compound to disrupt FAK-IGF-1R protein interactions, inhibit downstream signaling, decrease human melanoma cell proliferation, alter cell cycle progression, induce apoptosis and decrease tumor growth in vivo. INT2–31 blocked the interaction of FAK and IGF-1R in vitro and in vivo in melanoma cells and tumor xenografts through precluding the activation of IRS-1, leading to reduced phosphorylation of AKT upon IGF-1 stimulation. As a result, INT2–31 significantly inhibited cell proliferation and viability (range 0.05–10 μM). More importantly, 15 mg/kg of INT2–31 given for 21 d via intraperitoneal injection disrupted the interaction of FAK and IGF-1R and effectively decreased phosphorylation of tumor AKT, resulting in significant melanoma tumor regression in vivo. Our data suggest that the FAK-IGF-1R protein interaction is an important target, and disruption of this interaction with a novel small molecule (INT2–31) has potential anti-neoplastic therapeutic effects in human melanoma.     

Addressable self-immobilization of lactate dehydrogenase across multiple length scales

Successful nanobiotechnology implementation largely depends on control over the interfaces between inorganic materials and biological molecules. Controlling the orientations of biomolecules and their spatial arrangements on the surface may transform many technologies including sensors, to energy. Here, we demonstrate the self-organization of L -lactate dehydrogenase (LDH), which exhibits enhanced enzymatic activity and stability on a variety of gold surfaces ranging from nanoparticles to electrodes, by incorporating a gold-binding peptide tag (AuBP2) as the fusion partner for Bacillus stearothermophilus LDH (bsLDH). Binding kinetics and enzymatic assays verified orientation control of the enzyme on the gold surface through the genetically incorporated peptide tag. Finally, redox catalysis efficiency of the immobilized enzyme was detected using cyclic voltammetry analysis in enzyme-based biosensors for lactate detection as well as in biofuel cell energy systems as the anodic counterpart. Our results demonstrate that the LDH enzyme can be self-immobilized onto different gold substrates using the short peptide tag under a biologically friendly environment. Depending on the desired inorganic surface, the proposed peptide-mediated path could be extended to any surface to achieve single-step oriented enzyme immobilization for a wide range of applications.