46 research outputs found

    Discovery of novel class of histone deacetylase inhibitors as potential anticancer agents

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    Selective inhibition of histone deacetylases (HDACs) is an important strategy in the field of anticancer drug discovery. However, lack of inhibitors that possess high selectivity toward certain HDACs isozymes is associated with adverse side effects that limits their clinical applications. We have initiated a collaborative initiatives between multi-institutions aimed at the discovery of novel and selective HDACs inhibitors. To this end, a phenotypic screening of an in-house pilot library of about 70 small molecules against various HDAC isozymes led to the discovery of five compounds that displayed varying degrees of HDAC isozyme selectivity. The anticancer activities of these molecules were validated using various biological assays including transcriptomic studies. Compounds 15, 14, and 19 possessed selective inhibitory activity against HDAC5, while 28 displayed selective inhibition of HDAC1 and HDAC2. Compound 22 was found to be a selective inhibitor for HDAC3 and HDAC9. Importantly, we discovered a none-hydroxamate based HDAC inhibitor, compound 28, representing a distinct chemical probe of HDAC inhibitors. It contains a trifluoromethyloxadiazolyl moiety (TFMO) as a non-chelating metal-binding group. The new compounds showed potent anti-proliferative activity when tested against MCF7 breast cancer cell line, as well as increased acetylation of histones and induce cells apoptosis. The new compounds apoptotic effects were validated through the upregulation of proapoptotic proteins caspases3 and 7 and downregulation of the antiapoptotic biomarkers C-MYC, BCL2, BCL3 and NFĸB genes. Furthermore, the new compounds arrested cell cycle at different phases, which was confirmed through downregulation of the CDK1, 2, 4, 6, E2F1 and RB1 proteins. Taken together, our findings provide the foundation for the development of new chemical probes as potential lead drug candidates for the treatment of cancer

    Isolation of a 97-kb Minimal Essential MHC B Locus from a New Reverse-4D BAC Library of the Golden Pheasant

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    The bacterial artificial chromosome (BAC) system is widely used in isolation of large genomic fragments of interest. Construction of a routine BAC library requires several months for picking clones and arraying BACs into superpools in order to employ 4D-PCR to screen positive BACs, which might be time-consuming and laborious. The major histocompatibility complex (MHC) is a cluster of genes involved in the vertebrate immune system, and the classical avian MHC-B locus is a minimal essential one, occupying a 100-kb genomic region. In this study, we constructed a more effective reverse-4D BAC library for the golden pheasant, which first creates sub-libraries and then only picks clones of positive sub-libraries, and identified several MHC clones within thirty days. The full sequencing of a 97-kb reverse-4D BAC demonstrated that the golden pheasant MHC-B locus contained 20 genes and showed good synteny with that of the chicken. The notable differences between these two species were the numbers of class II B loci and NK genes and the inversions of the TAPBP gene and the TAP1-TAP2 region. Furthermore, the inverse TAP2-TAP1 was unique in the golden pheasant in comparison with that of chicken, turkey, and quail. The newly defined genomic structure of the golden pheasant MHC will give an insight into the evolutionary history of the avian MHC

    Spatial and Sex-Specific Variation in Growth of Albacore Tuna (Thunnus alalunga) across the South Pacific Ocean

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    Spatial variation in growth is a common feature of demersal fish populations which often exist as discrete adult sub-populations linked by a pelagic larval stage. However, it remains unclear whether variation in growth occurs at similar spatial scales for populations of highly migratory pelagic species, such as tuna. We examined spatial variation in growth of albacore Thunnus alalunga across 90° of longitude in the South Pacific Ocean from the east coast of Australia to the Pitcairn Islands. Using length-at-age data from a validated ageing method we found evidence for significant variation in length-at-age and growth parameters (L∞ and k) between sexes and across longitudes. Growth trajectories were similar between sexes up until four years of age, after which the length-at-age for males was, on average, greater than that for females. Males reached an average maximum size more than 8 cm larger than females. Length-at-age and growth parameters were consistently greater at more easterly longitudes than at westerly longitudes for both females and males. Our results provide strong evidence that finer spatial structure exists within the South Pacific albacore stock and raises the question of whether the scale of their “highly migratory” nature should be re-assessed. Future stock assessment models for South Pacific albacore should consider sex-specific growth curves and spatial variation in growth within the stock

    The New Zealand gravimetric quasigeoid model 2017 that incorporates nationwide airborne gravimetry

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    A one arc-minute resolution gravimetric quasigeoid model has been computed for New Zealand, covering the region (Formula presented.)–(Formula presented.) and (Formula presented.)–(Formula presented.). It was calculated by Wong and Gore modified Stokes integration using the remove–compute–restore technique with the EIGEN-6C4 global gravity model as the reference field. The gridded gravity data used for the computation consisted of 40,677 land gravity observations, satellite altimetry-derived marine gravity anomalies, historical shipborne marine gravity observations and, importantly, approximately one million new airborne gravity observations. The airborne data were collected with the specific intention of reinforcing the shortcomings of the existing data in areas of rough topography inaccessible to land gravimetry and in coastal areas where shipborne gravimetry cannot be collected and altimeter-derived gravity anomalies are generally poor. The new quasigeoid has a nominal precision of (Formula presented.) on comparison with GPS-levelling data, which is approximately (Formula presented.) less than its predecessor NZGeoid09

    Persistent torticollis, facial asymmetry, grooved tongue, and dolicho-odontoid process in connection with atlas malformation complex in three family subjects

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    Congenital clefts and other malformations of the atlas are incidental findings identified while investigating the cervical spine following trauma. A persistent bifid anterior and posterior arch of the atlas beyond the age of 3–4 years is observed in skeletal dysplasias, Goldenhar syndrome, Conradi syndrome, and Down’s syndrome. There is a high incidence of both anterior and posterior spina bifida of the atlas in patients with metabolic disorders, such as Morquio’s syndrome [Baraitser and Winter in London dysmorphology database, Oxford University Press, 2005; Torriani, Lourenco in Rev Hosp Clin Fac Med Sao Paulo 53: 73–76, 2002]. We report two siblings and their mother, with congenital, persistent torticollis, plagiocephaly, facial asymmetry, grooved tongues, and asymptomatic “dolicho-odontoid process”. All are of normal intelligence. No associated Neurological dysfunction, paresis, apnoea, or failures to thrive were encountered. Radiographs of the cervical spine were non-contributory, but 3D CT scanning of this area allowed further visualisation of the cervico–cranial malformation complex in this family and might possibly explain the sudden early juvenile mortality. Agenesis of the posterior arch of the atlas and bifidity/clefting of anterior arch of the atlas associated with asymptomatic “dolicho-odontoid process” were the hallmark in the proband and his female sibling. Some of the features were present in the mother. All the family subjects were investigated. To the best of our knowledge the constellation of malformation complex in this family has not been previously reported
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