Search results for "BC"

An Artificial Bee Colony Approach for Classification of Remote Sensing Imagery

2018

This paper presents a novel Artificial Bee Colony (ABC) approach for supervised classification of remote sensing images. One proposes to apply an ABC algorithm to optimize the coefficients of the set of polynomial discriminant functions. We have experimented the proposed ABC-based classifier algorithm for a Landsat 7 ETM+ image database, evaluating the influence of the ABC model parameters on the classifier performances. Such ABC model parameters are: numbers of employed/onlooker/scout bees, number of epochs, and polynomial degree. One has compared the best ABC classifier Overall Accuracy (OA) with the performances obtained using a set of benchmark classifiers (NN, NP, RBF, and SVM). The re…

Ancient cattle genomics, origins, and rapid turnover in the Fertile Crescent

2019

Cattle were domesticated ∼10,000 years ago, but analysis of modern breeds has not elucidated their origins. Verdugo et al. performed genome-wide analysis of 67 ancient Near Eastern Bos taurus DNA samples. Several populations of ancient aurochs were progenitors of domestic cows. These genetic lineages mixed ∼4000 years ago in a region around the Indus Valley. Interestingly, mitochondrial analysis indicated that genetic material likely derived from arid-adapted Bos indicus (zebu) bulls was introduced by introgression.Science, this issue p. 173Genome-wide analysis of 67 ancient Near Eastern cattle, Bos taurus, remains reveals regional variation that has since been obscured by admixture in mode…

Betulinic Acid Exerts Cytotoxic Activity Against Multidrug-Resistant Tumor Cells via Targeting Autocrine Motility Factor Receptor (AMFR).

2018

Betulinic acid (BetA) is a naturally occurring pentacyclic triterpene isolated from the outer bark of white-barked birch trees and many other medicinal plants. Here, we studied betulinic acid's cytotoxic activity against drug-resistant tumor cell lines. P-glycoprotein (MDR1/ABCB1) and BCRP (ABCG2) are known ATP-binding cassette (ABC) drug transporters that mediating MDR. ABCB5 is a close relative to ABCB1, which also mediates MDR. Constitutive activation of the EGF receptor is tightly linked to the development of chemotherapeutic resistance. BetA inhibited P-gp, BCRP, ABCB5 and mutation activated EGFR overexpressing cells with similar efficacy as their drug-sensitive parental counterparts. …

2018

ABC (ATP binding cassette) transporters, ubiquitous in all kingdoms of life, carry out essential substrate transport reactions across cell membranes. Their transmembrane domains bind and translocate substrates and are connected to a pair of nucleotide binding domains, which bind and hydrolyze ATP to energize import or export of substrates. Over four decades of investigations into ABC transporters have revealed numerous details from atomic-level structural insights to their functional and physiological roles. Despite all these advances, a comprehensive understanding of the mechanistic principles of ABC transporter function remains elusive. The human multidrug resistance transporter ABCB1, al…

Phosphorylation of CENP-A on serine 7 does not control centromere function.

2019

CENP-A is the histone H3 variant necessary to specify the location of all eukaryotic centromeres via its CENP-A targeting domain and either one of its terminal regions. In humans, several post-translational modifications occur on CENP-A, but their role in centromere function remains controversial. One of these modifications of CENP-A, phosphorylation on serine 7, has been proposed to control centromere assembly and function. Here, using gene targeting at both endogenous CENP-A alleles and gene replacement in human cells, we demonstrate that a CENP-A variant that cannot be phosphorylated at serine 7 maintains correct CENP-C recruitment, faithful chromosome segregation and long-term cell viab…

Indicaxanthin from Opuntia Ficus Indica (L. Mill) impairs melanoma cell proliferation, invasiveness, and tumor progression.

2018

Abstract Background: A strong, reciprocal crosstalk between inflammation and melanoma has rigorously been demonstrated in recent years, showing how crucial is a pro-inflammatory microenvironment to drive therapy resistance and metastasis. Purpose: We investigated on the effects of Indicaxanthin, a novel, anti-inflammatory and bioavailable phytochemical from Opuntia Ficus Indica fruits, against human melanoma both in vitro and in vivo. Study Design and Methods: The effects of indicaxanthin were evaluated against the proliferation of A375 human melanoma cell line and in a mice model of cutaneous melanoma. Cell proliferation was assessed by MTT assay, apoptosis by Annexin V-Fluorescein Isothio…

Melatonin Targets Metabolism in Head and Neck Cancer Cells by Regulating Mitochondrial Structure and Function.

2021

This study was funded by grants from the Ministerio de Economia, Industria y Competitividad y por el Fondo de Desarrollo Regional FEDER, Spain nº SAF2013-49019, SAF2017-85903-P, and from the Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía (P07- CTS- 03135, P10- CTS- 5784, and CTS- 101), Spain. J.F. and L.M. have FPU fellowships from the Ministerio de Educación Cultura y Deporte, Spain. C.R.S. was a schorlarship holder from the Plan Propio de Investigación of the University of Granada.

AMPA receptor complex constituents: Control of receptor assembly, membrane trafficking and subcellular localization

2018

Fast excitatory transmission at synapses of the central nervous system is mainly mediated by AMPA receptors (AMPARs). Synaptic AMPAR number and function correlates with synaptic strength. AMPARs are thus key proteins of activity-dependent plasticity in neuronal communication. Up- or down-regulation of synaptic AMPAR number is a tightly controlled dynamic process that involves export of receptors from the endoplasmic reticulum (ER) and Golgi apparatus, exocytosis and endocytosis as well as lateral diffusion of the receptors in the cell membrane. The four AMPAR subunits are embedded into a dynamic network of more than 30 interacting proteins. Many of these proteins are known to modulate recep…

Genomic and transcriptomic profiling of resistant CEM/ADR-5000 and sensitive CCRF-CEM leukaemia cells for unravelling the full complexity of multi-fa…

2016

AbstractWe systematically characterised multifactorial multidrug resistance (MDR) in CEM/ADR5000 cells, a doxorubicin-resistant sub-line derived from drug-sensitive, parental CCRF-CEM cells developed in vitro. RNA sequencing and network analyses (Ingenuity Pathway Analysis) were performed. Chromosomal aberrations were identified by array-comparative genomic hybridisation (aCGH) and multicolour fluorescence in situ hybridisation (mFISH). Fifteen ATP-binding cassette transporters and numerous new genes were overexpressed in CEM/ADR5000 cells. The basic karyotype in CCRF-CEM cells consisted of 47, XX, der(5)t(5;14) (q35.33;q32.3), del(9) (p14.1), +20. CEM/ADR5000 cells acquired additional aber…

Cytotoxicity of sesquiterpene alkaloids from Nuphar plants toward sensitive and drug-resistant cell lines.

2018

Multi-drug resistance (MDR) is a critical problem in cancer chemotherapy. MDR causes the overexpression of ATP-binding cassette (ABC) transporters and mutations in tumor suppressor genes and oncogenes. To tackle this issue, in this study, we focused on Nuphar plants, which have been traditionally used as food. Sesquiterpene alkaloids (1–3) were isolated from N. japonicum and dimeric sesquiterpene thioalkaloids (4–10) were isolated from N. pumilum. P-glycoprotein-overexpressing CEM/ADR5000 cells were cross-resistant to 6,6′-dihydroxythiobinupharidine (10). Using in silico molecular docking, we calculated the binding energies and simulated the interactions of these compounds with the correspo…