Design, synthesis, and anticancer activity of phosphonic acid diphosphate derivative of adenine-containing butenolide and its water-soluble derivatives of paclitaxel with high antitumor activity

Synthesis of adenine derivative of triphosphono-gamma-(Z)-ethylidene-2,3-dimethoxybutenolide 4 was accomplished by treatment of phosphonate 3 with 5-phosphoribosyl 1-pyrophosphate in the presence of 5-phosphoribosyl 1-pyrophosphate synthetase. It was found that triphosphonate 4 functions as an irreversible stoichiometric inactivator of the Escherichia coli ribonucleoside diphosphate reductase (RDPR). Triphosphonate 4 exhibited potent inhibitory activity against murine leukemias (L1210 and P388), breast carcinoma (MCF7), and human T-lymphoblasts (Molt4/C8 and CEM/0) cell lines. Paclitaxel ester derivatives of adenine-containing triphosphono-gamma-(Z)-ethylidene-2,3-dimethoxybutenolide 8-10 were also synthesized. Like triphosphonate 4, compound 8 exhibited inhibitory property toward RDPR. It also induced microtubule assembly similar to paclitaxel (5). The structure of the chlorodiester linker in 8 was found to account for this dual property. After treatment of MCF7 cells with compounds 4, 5, and 8, fluorescence microscope examination demonstrated the presence of nucleus shrinkage or segmentation. Bifunctional prodrug 8 exhibited higher lipophilicity than 4 and higher water-solubility than 5. Pro-dual-drug 8 exhibited more pronounced anticancer activity relative to that of the triphosphonate 4 and paclitaxel (5). In contrast, compound 9, resulting from the linkage of triphosphonate 4 and paclitaxel (5) through a diester unit, was only found to function as a highly water-soluble prodrug for paclitaxel (5). It induced microtubule assembly in vitro, but did not show inhibitory property toward RDPR. On the other hand, compound 10, an aggregate of triphosphonate 4 and paclitaxel (5), neither functioned as an inhibitor of RDPR nor exhibited microtubule assembly stimulating activity in vitro.     

Fusobacterium nucleatum secretes amyloid‐like FadA to enhance pathogenicity

Fusobacterium nucleatum (Fn) is a Gram‐negative oral commensal, prevalent in various human diseases. It is unknown how this common commensal converts to a rampant pathogen. We report that Fn secretes an adhesin (FadA) with amyloid properties via a Fap2‐like autotransporter to enhance its virulence. The extracellular FadA binds Congo Red, Thioflavin‐T, and antibodies raised against human amyloid β42. Fn produces amyloid‐like FadA under stress and disease conditions, but not in healthy sites or tissues. It functions as a scaffold for biofilm formation, confers acid tolerance, and mediates Fn binding to host cells. Furthermore, amyloid‐like FadA induces periodontal bone loss and promotes CRC progression in mice, with virulence attenuated by amyloid‐binding compounds. The uncleaved signal peptide of FadA is required for the formation and stability of mature amyloid FadA fibrils. We propose a model in which hydrophobic signal peptides serve as “hooks” to crosslink neighboring FadA filaments to form a stable amyloid‐like structure. Our study provides a potential mechanistic link between periodontal disease and CRC and suggests anti‐amyloid therapies as possible interventions for Fn‐mediated disease processes.     

Induction of meiotic gynogenesis in ship sturgeon Acipenser nudiventris using UV-irradiated heterologous sperm

Diploid gynogenesis was induced in ship sturgeon Acipenser nudiventris using UV-irradiated sperm from Siberian sturgeon Acipenser baerii. The optimal condition for the retention of the second polar body in ship sturgeon was determined to be 10 min after activation/fertilization in experiments. The temperature of cold shock and its duration were 2.5 °C and 30 min, respectively. A total of 30 gynogens of known parentage from experimental treatments were screened using microsatellite DNA analysis, and uniparental transmission in meiogens was confirmed. The results show that heterologous Siberian sturgeon sperm is applicable as UV-irradiated sperm for the induction of gynogenesis in ship sturgeon. This technique may recover the critically endangered sturgeon species that are becoming extinct.     

Cholestasis induced nephrotoxicity: The role of endogenous opioids

AimsElevated levels of endogenous opioids play a pivotal role in several deleterious consequences of cholestasis. Renal dysfunction occurs in cholestasis but its exact mechanism is still unknown. In this study, we investigated the role of endogenous opioids in cholestasis induced nephrotoxicity.Main methodsThirty-five rats were divided into five groups. In groups 1 and 2 BDL rats received either daily subcutaneous 20 mg/kg of naltrexone or its vehicle, for 7 days after BDL. In groups 3 and 4, BDL or Sham rats received no injections. In group 5, normal rats received subcutaneous injections of 20 mg/kg/day of naltrexone for 7 days. At the 7th day, 24 h urine was collected to measure urinary N-acetyl-β-D-glucosaminidase (NAG) as an early marker of renal tubular injury. Kidney samples were then collected for light and electron microscopic studies.Key findingsBDL significantly increased NAG activity compared to sham groups. Naltrexone significantly reversed NAG activity to normal levels in BDL animals. Naltrexone treatment in BDL animals also significantly reversed ALT and AST to their normal levels. In light and electron microscopic studies, there were significant structural alterations in BDL samples, which were mostly prevented in naltrexone treated BDL animals.SignificanceSignificant changes in urinary NAG activity and renal morphology of cholestatic rats were reversed by naltrexone treatment. These results suggest a possible role for endogenous opioids in inducing cholestatic nephrotoxicity.     

P-9A COMPARISON OF THE REPORTING MORPHOLOGICAL FEATURES OF GLANDULAR NEOPLASIA FOR CONVENTIONAL AND LIQUID BASED CYTOLOGY FOR CERVICAL SAMPLES

Cervical cancer accounts for approximately 15% of cancer diagnosed in women worldwide with up to 190 000 deaths per annum. One of the major causes of cervical cancer is the infection of human papillomavirus (HPV), a DNA virus. This virus is epidermotropic; there are over 75 subtypes and subtypes 16, 18, 31 and 33 are associated with cervical intraepithelial neoplasia (CIN) and carcinomas. Since the start of the cervical screening in mid 1960s, the cervical cancer rate has decreased. There are two techniques used for slide preparation and staining: conventional cytology and liquid based cytology (LBC). Due to the differences in sample collection and preparation, certain aspects of cell morphology, architecture and patterns will present differently from each other on the slide. The study was conducted in a County Hospital. Twenty conventional slides and eight LBC slides already reported as ? Glandular neoplasia were reviewed and assessed with regards to their morphological features. Moreover, conventional slides were compared with LBC slides to determine the differences in their cell morphology, sensitivity and specificity. Furthermore, a semi-quantitative method was used and also true-positive and false-positive rates were evaluated using positive predictive value (PPV). The findings indicated that despite the differences in cell morphology there are many similarities between the two techniques. The study also showed that it was difficult to distinguish between abnormal glandular cells and abnormal squamous cells, which may end in a false positive result and over reporting of glandular neoplasia. Finally, it showed that LBC slides were easier to screen and also had a higher positive predictive value (PPV) resulting in higher sensitivity and specificity. In conclusion, the LBC technique is more accurate and conversion to this technique is the positive step in the screening program.     

Induced pluripotent stem cells (iPSCs) as game-changing tools in the treatment of neurodegenerative disease: Mirage or reality?

Based on investigations, there exist tight correlations between neurodegenerative diseases' incidence and progression and aberrant protein aggregreferates in nervous tissue. However, the pathology of these diseases is not well known, leading to an inability to find an appropriate therapeutic approach to delay occurrence or slow many neurodegenerative diseases' development. The accessibility of induced pluripotent stem cells (iPSCs) in mimicking the phenotypes of various late-onset neurodegenerative diseases presents a novel strategy for in vitro disease modeling. The iPSCs provide a valuable and well-identified resource to clarify neurodegenerative disease mechanisms, as well as prepare a promising human stem cell platform for drug screening. Undoubtedly, neurodegenerative disease modeling using iPSCs has established innovative opportunities for both mechanistic types of research and recognition of novel disease treatments. Most important, the iPSCs have been considered as a novel autologous cell origin for cell-based therapy of neurodegenerative diseases following differentiation to varied types of neural lineage cells (e.g. GABAergic neurons, dopamine neurons, cortical neurons, and motor neurons). In this review, we summarize iPSC-based disease modeling in neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and Huntington's disease. Moreover, we discuss the efficacy of cell-replacement therapies for neurodegenerative disease.     

Constructing circular phylogenetic networks from weighted quartets using simulated annealing

In this paper, we present a heuristic algorithm based on the simulated annealing, SAQ-Net, as a method for constructing phylogenetic networks from weighted quartets. Similar to QNet algorithm, SAQ-Net constructs a collection of circular weighted splits of the taxa set. This collection is represented by a split network. In order to show that SAQ-Net performs better than QNet, we apply these algorithm to both the simulated and actual data sets containing salmonella, Bees, Primates and Rubber data sets. Then we draw phylogenetic networks corresponding to outputs of these algorithms using SplitsTree4 and compare the results. We find that SAQ-Net produces a better circular ordering and phylogenetic networks than QNet in most cases. SAQ-Net has been implemented in Matlab and is available for download at http://bioinf.cs.ipm.ac.ir/softwares/saq.net.     

Galactosylated nanostructured lipid carriers for delivery of 5-FU to hepatocellular carcinoma

The aim of the present study was to design a targeted delivery system of 5-fluorouracil (5-FU) for hepatocellular carcinoma (HCC). Lactobionic acid (LB) was conjugated to stearyl amine (SA) by a chemical reaction. The nanostructured lipid carriers (NLCs), containing LB conjugate, lecithin, glyceryl monostearate, oil [oleic acid (OA) or Labrafac 5 or 10%], and 5-FU, were dissolved in alcohol/acetone, the oil phase was added to the aqueous phase containing Tween 80 or Solutol(?) HS15 (0.25 or 0.5%), and NLCs were prepared by an emulsification-solvent diffusion method. Physical properties and drug release were studied in NLCs. The thiazolyl blue tetrazolium bromide assay was used to study the cytotoxicity of NLCs on HepG(2) cells, and the cellular uptake of NLCs was determined by flow cytometry. Fourier transform infrared spectroscopy and (1)H-NMR spectra confirmed the successful conjugation of LB and SA. The optimized NLCs consisted of 0.5% Solutol HS15 and 10% OA oil. The particle size of these nanoparticles was 139.2 nm, with a zeta potential of -18 mV, loading efficiency of 34.2%, release efficiency after 2 hours of the release test was 72.6%, and crystallinity was 0.63%. The galactosylated NLCs of 5-FU were cytotoxic on the HepG(2) cell line in a half concentration of 5-FU and seems promising in reducing 5-FU dose in HCC.