Search results for: symbiosis receptor kinase (SYMRK)
595 Trastuzumab Decorated Bioadhesive Nanoparticles for Targeted Breast Cancer Therapy
Authors: Kasi Viswanadh Matte, Abhisheh Kumar Mehata, M.S. Muthu
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Brest cancer, up-regulated with human epidermal growth factor receptor type-2 (HER-2) led to the concept of developing HER-2 targeted anticancer therapeutics. Docetaxel-loaded D-α-tocopherol polyethylene glycol succinate 1000 conjugated chitosan (TPGS-g-chitosan) nanoparticles were prepared with or without Trastuzumab decoration. The particle size and entrapment efficiency of conventional, non-targeted and targeted nanoparticles were found to be in the range of 126-186 nm and 74-78% respectively. In-vitro, MDA-MB-231 cells showed that docetaxel-loaded non-targeted and HER-2 receptor targeted TPGS-g-chitosan nanoparticles have enhanced the cellular uptake and cytotoxicity with a promising bioadhesion property, in comparison to conventional nanoparticles. The IC50 values of non-targeted and targeted nanoparticles from cytotoxic assay were found to be 43 and 223 folds higher than DocelTM. The in-vivo pharmacokinetic study showed 2.33, and 2.82-fold enhancement in relative bioavailability of docetaxel for non-targeted and HER-2 receptor targeted nanoparticles, respectively than DocelTM, and after i.v administration, non-targeted and targeted nanoparticle achieved 3.48 and 5.94 times prolonged half-life in comparison to DocelTM. The area under the curve (AUC), relative bioavailability (FR) and mean residence time (MRT) were found to be higher for non-targeted and targeted nanoparticles compared to DocelTM. Further, histopathology results of non-targeted and targeted nanoparticles showed less toxicity on vital organs such as lungs, liver, and kidney compared to DocelTM.Keywords: breast cancer, HER-2 receptor, targeted nanomedicine, chitosan, TPGS
Procedia PDF Downloads 237594 Enhancement Effect of Compound 4-Hydroxybenzoic Acid from Petung Bamboo (Dendrocalamus Asper) Shoots on α1β2γ2S of GABA (A) Receptor Expressed in Xenopus laevis Oocytes- Preliminary Study on Its Anti-Epileptic Potential
Authors: Muhammad Bilal, Amelia Jane Llyod, Habsah Mohamad, Jia Hui Wong, Abdul Aziz Mohamed Yusoff, Jafri Malin Abdullah, Jingli Zhang
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Epilepsy is one of the major brain afflictions occurs with uncontrolled excitation of cortex; disturbed 50 million of world’s population. About 25 percent of patients subjected to adverse effects from antiepileptic drugs (AEDs) such as depression, nausea, tremors, gastrointestinal symptoms, osteoporosis, dizziness, weight change, drowsiness, fatigue are commonly observed indications; therefore, new drugs are required to cure epilepsy. GABA is principle inhibitory neurotransmitter, control excitation of the brain. Mutation or dysfunction of GABA receptor is one of the primary causes of epilepsy, which is confirmed from many acquired models of epilepsy like traumatic brain injury, kindling, and status epilepticus models of epilepsy. GABA receptor has 3 distinct types such as GABA (A), GABA (B), GABA(C).GABA (A) receptor has 20 different subunits, α1β2γ2 subunits composition of GABA (A) receptor is the most used combination of subunits for screening of compounds against epilepsy. We expressed α1β2γ2s subunits of GABA (A) Receptor in Xenopus leavis oocytes and examined the enhancement potential of 4-Hydroxybenzoic acid compound on GABA (A) receptor via two-electrode voltage clamp current recording technique. Bamboo shoots are the young, tender offspring of bamboo, which are usually harvested after a cultivating period of 2 weeks. Proteins, acids, fat, starch, carbohydrate, fatty acid, vitamin, dietary fiber, and minerals are the major constituent found systematically in bamboo shoots. These shoots reported to have anticancer, antiviral, antibacterial activity, also possess antioxidant properties due to the presence of phenolic compounds. Student t-test analysis suggested that 4- hydroxybenzoic acid positively allosteric GABA (A) receptor, increased normalized current amplitude to 1.0304±0.0464(p value 0.032) compared with vehicle. 4-Hydrobenzoic acid, a compound from Dendrocalamus Asper bamboo shoot gives new insights for future studies on bamboo shoots with motivation for extraction of more compounds to investigate their effects on human and rodents against epilepsy, insomnia, and anxiety.Keywords: α1β2γ2S, antiepileptic, bamboo shoots, epilepsy GABA (A) receptor, two-microelectrode voltage clamp, xenopus laevis oocytes
Procedia PDF Downloads 396593 Immunohistochemical Expression of β-catenin and Epidermal Growth Factor Receptor in Adamantinomatous Craniopharyngioma
Authors: Ghada Esheba, Fatimah Alturkistani, Arwa Obaid, Ahdab Bashehab, Moayad Alturkistani
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Introduction: Craniopharyngiomas (CPs) are rare epithelial tumors located mainly in the sellar/parasellar region. CPs have been classified histopathologically, genetically, clinically and prognostically into two distinctive subtypes: adamantinomatous and papillary variants. Aim: To examine the pattern of expression of both the β-catenin and epidermal growth factor receptor (EGFR) in surgically resected samples of adamantinomatous CP, and to asses for the possibility of using anti-EGFR in the management of ACP patients. Materials and methods: β-catenin and EGFR immunostaining was performed on paraffin-embedded tissue sections of 18 ACP cases. Result: 17 out of 18 cases (94%) of ACP exhibited strong nuclear/cytoplasmic expression of β-catenin, 15 (83%) of APC cases were positive for EGFR. Conclusion: Nuclear accumulation of β-catenin is a diagnostic hallmark of ACP. EGFR positivity in most cases of ACP could qualify the use of anti-EGFR therapy.Keywords: craniopharyngioma, adamantinomatous, papillary, epidermal growth factor receptor, B-catenin
Procedia PDF Downloads 221592 Camptothecin Promotes ROS-Mediated G2/M Phase Cell Cycle Arrest, Resulting from Autophagy-Mediated Cytoprotection
Authors: Rajapaksha Gedara Prasad Tharanga Jayasooriya, Matharage Gayani Dilshara, Yung Hyun Choi, Gi-Young Kim
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Camptothecin (CPT) is a quinolone alkaloid which inhibits DNA topoisomerase I that induces cytotoxicity in a variety of cancer cell lines. We previously showed that CPT effectively inhibited invasion of prostate cancer cells and also combined treatment with subtoxic doses of CPT and TNF-related apoptosis-inducing ligand (TRAIL) potentially enhanced apoptosis in a caspase-dependent manner in hepatoma cancer cells. Here, we found that treatment with CPT caused an irreversible cell cycle arrest in the G2/M phase. CPT-induced cell cycle arrest was associated with a decrease in protein levels of cell division cycle 25C (Cdc25C) and increased the level of cyclin B and p21. The CPT-induced decrease in Cdc25C was blocked in the presence of proteasome inhibitor MG132, thus reversed the cell cycle arrest. In addition to that treatment of CPT-increased phosphorylation of Cdc25C was the resulted of activation of checkpoint kinase 2 (Chk2), which was associated with phosphorylation of ataxia telangiectasia-mutated. Interestingly CPT induced G2/M phase of the cell cycle arrest is reactive oxygen species (ROS) dependent where ROS inhibitors NAC and GSH reversed the CPT-induced cell cycle arrest. These results further confirm by using transient knockdown of nuclear factor-erythroid 2-related factor 2 (Nrf2) since it regulates the production of ROS. Our data reveal that treatment of siNrf2 increased the ROS level as well as further increased the CPT induce G2/M phase cell cycle arrest. Our data also indicate CPT-enhanced cell cycle arrest through the extracellular signal-regulated kinase (ERK) and the c-Jun N-terminal kinase (JNK) pathway. Inhibitors of ERK and JNK more decreased the Cdc25C expression and protein expression of p21 and cyclin B. These findings indicate that Chk2-mediated phosphorylation of Cdc25C plays a major role in G2/M arrest by CPT.Keywords: camptothecin, cell cycle, checkpoint kinase 2, nuclear factor-erythroid 2-related factor 2, reactive oxygen species
Procedia PDF Downloads 428591 The Incidence of Acetylcholine Receptor Antibody Positive Myasthenia Gravis in South Africa
Authors: Mombaur Busisiwe, Lesosky Maia, Liebenberg Lisa, Heckmann Jeannine
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Introduction: To assess age- and gender-specific incidence rates (IR) of acetylcholine receptor (AChR)-antibody positive myasthenia gravis (MG) in South Africa, and geographical variation in incidence. Methods: IRs were calculated from positive AChR antibody laboratory data between 2011 and 2012, using 2011 population census data. Results:890 individuals were seropositive, for an annual IR of 8.5 per million. Age-standardized IR for early- (< 50) and late-onset (≥ 50) MG were 4.1 and 24 per million, respectively, and for juveniles, 4.3 per million. The IR between provinces ranged from 1 to 19 per million. Conclusions: In this Southern hemisphere African population, the overall IR and peak IR (in older men) for seropositive MG is comparable to that in Europe and North America, arguing against environmental factors. However, IRs may be higher among children with African genetic ancestry. Geographical variation in incidence underscores the importance of outreach programs for regions with limited resources.Keywords: incidence rates (IR), acetylcholine receptor (AChR), myasthenia gravis (MG), South Africa
Procedia PDF Downloads 488590 Trans-Activator of Transcription-Tagged Active AKT1 Variants for Delivery to Mammalian Cells
Authors: Tarana Siddika, Ilka U. Heinemann, Patrick O’Donoghue
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Protein kinase B (AKT1) is a serine/threonine kinase and central transducer of cell survival pathways. Typical approaches to study AKT1 biology in cells rely on growth factor or insulin stimulation that activates AKT1 via phosphorylation at two key regulatory sites (Threonine308, Serine473), yet cell stimulation also activates many other kinases and fails to differentiate the effect of the two main activating sites of AKT1 on downstream substrate phosphorylation and cell growth. While both AKT1 activating sites are associated with disease and used as clinical markers, in some cancers, high levels of Threonine308 phosphorylation are associated with poor prognosis while in others poor survival correlates with high Serine473 levels. To produce cells with specific AKT1 activity, a system was developed to deliver active AKT1 to human cells. AKT1 phospho-variants were produced from Escherichia coli with programmed phosphorylation by genetic code expansion. Tagging of AKT1 with an N-terminal cell penetrating peptide tag derived from the human immunodeficiency virus trans-activator of transcription (TAT) helped to enter AKT1 proteins in mammalian cells. The TAT-tag did not alter AKT1 kinase activity and was necessary and sufficient to rapidly deliver AKT1 protein variants that persisted in human cells for 24 h without the need to use transfection reagents. TAT-pAKT1T308, TAT-pAKT1S473 and TAT-pAKT1T308S473 proteins induced selective phosphorylation of the known AKT1 substrate GSK-3αβ, and downstream stimulation of the AKT1 pathway as evidenced by phosphorylation of ribosomal protein S6 at Serine240/244 in transfected cells. Increase in cell growth and proliferation was observed due to the transfection of different phosphorylated AKT1 protein variants compared to cells with TAT-AKT1 protein. The data demonstrate efficient delivery of AKT1 with programmed phosphorylation to human cells, thus establishing a cell-based model system to investigate signaling that is dependent on specific AKT1 activity and phosphorylation.Keywords: cell penetrating peptide, cell signaling, protein kinase b (AKT1), phosphorylation
Procedia PDF Downloads 110589 The Effects of pH on p53 Phosphorylation by Ataxia Telangiectasia Mutated Kinase
Authors: Serap Pektas
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Ataxia telangiectasia mutated (ATM) is a serine-threonine kinase, which is the major regulator of the DNA damage response. ATM is activated upon the formation of DNA double-strand breaks (DSBs) in the cells. ATM phosphorylates the proteins involved in apoptotic responses, cell cycle checkpoint control, DNA repair, etc. Tumor protein p53, known as p53 is one of these proteins that phosphorylated by ATM. Phosphorylation of p53 at Ser15 residue leads to p53 stabilization in the cells. Often enzymes activity is affected by hydrogen ion concentration (pH). In order to find the optimal pH range for ATM activity, steady-state kinetic assays were performed at acidic and basic pH ranges. Ser15 phosphorylation of p53 is determined by using ELISA. The results indicated that the phosphorylation rate was better at basic pH range compared with the acidic pH range. This could be due to enzyme stability, or enzyme-substrate interaction is pH dependent.Keywords: ataxia telangiectasia mutated, DNA double strand breaks, DNA repair, tumor protein p53
Procedia PDF Downloads 122588 The Overexpression of Horsegram MURLK Improves Regulation of Cell Death and Defense Responses to Microbial Pathogens
Authors: Shikha Masand, Sudesh Kumar Yadav
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Certain protein kinases have been shown to be crucial for plant cell signaling pathways associated with plant immune responses. Here we identified a horsegram [Macrotyloma uniflorum (Lam.) Verdc.] malectin-like leucine rich receptor-like protein kinase (RLK) gene MuRLK. The functional MuRLK protein preferentially binds to mannose and N-acetyl glucosamine residues. MuRLK exists in the cytoplasm and also localizes to the plasma membrane of plant cells via its N-terminus. Over-expression of MuRLK in Arabidopsis enhances the basal resistance to infection with Pseudomonas syringae pv. tomato, Alternaria brassicicola and Hyaloperonospora arabidopsidis, are associated with elevated ROS bursts, MAPK activation, thus ultimately leading to hypersensitive cell death. Moreover, salicylic acid-dependent and jasmonic acid-dependent defense responses are also enhanced in the MuRLK-overexpressed plants that lead to HR-induced cell death. Together, these results suggest that MuRLK plays a key role in the regulation of plant cell death, early and late defense responses after the recognition of microbial pathogens.Keywords: horsegram, Pseudomonas syringae pv. tomato, MuRLK, ROS burst, cell death, plant defense
Procedia PDF Downloads 244587 Cardiolipin-Incorporated Liposomes Carrying Curcumin and Nerve Growth Factor to Rescue Neurons from Apoptosis for Alzheimer’s Disease Treatment
Authors: Yung-Chih Kuo, Che-Yu Lin, Jay-Shake Li, Yung-I Lou
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Curcumin (CRM) and nerve growth factor (NGF) were entrapped in liposomes (LIP) with cardiolipin (CL) to downregulate the phosphorylation of mitogen-activated protein kinases for Alzheimer’s disease (AD) management. AD belongs to neurodegenerative disorder with a gradual loss of memory, yielding irreversible dementia. CL-conjugated LIP loaded with CRM (CRM-CL/LIP) and that with NGF (NGF-CL/LIP) were applied to AD models of SK-N-MC cells and Wistar rats with an insult of β-amyloid peptide (Aβ). Lipids comprising 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (Avanti Polar Lipids, Alabaster, AL), 1',3'-bis[1,2- dimyristoyl-sn-glycero-3-phospho]-sn-glycerol (CL; Avanti Polar Lipids), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N- [methoxy(polyethylene glycol)-2000] (Avanti Polar Lipids), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethylene glycol)-2000] (Avanti Polar Lipids) and CRM (Sigma–Aldrich, St. Louis, MO) were dissolved in chloroform (J. T. Baker, Phillipsburg, NJ) and condensed using a rotary evaporator (Panchum, Kaohsiung, Taiwan). Human β-NGF (Alomone Lab, Jerusalem, Israel) was added in the aqueous phase. Wheat germ agglutinin (WGA; Medicago AB, Uppsala, Sweden) was grafted on LIP loaded with CRM for (WGA-CRM-LIP) and CL-conjugated LIP loaded with CRM (WGA-CRM-CL/LIP) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (Sigma–Aldrich) and N-hydroxysuccinimide (Alfa Aesar, Ward Hill, MA). The protein samples of SK-N-MC cells (American Type Tissue Collection, Rockville, MD) were used for sodium dodecyl sulfate (Sigma–Aldrich) polyacrylamide gel (Sigma–Aldrich) electrophoresis. In animal study, the LIP formulations were administered by intravenous injection via a tail vein of male Wistar rats (250–280 g, 8 weeks, BioLasco, Taipei, Taiwan), which were housed in the Animal Laboratory of National Chung Cheng University in accordance with the institutional guidelines and the guidelines of Animal Protection Committee under the Council of Agriculture of the Republic of China. We found that CRM-CL/LIP could inhibit the expressions of phosphorylated p38 (p-p38), p-Jun N-terminal kinase (p-JNK), and p-tau protein at serine 202 (p-Ser202) to retard the neuronal apoptosis. Free CRM and released CRM from CRM-LIP and CRM-CL/LIP were not in a straightforward manner to effectively inhibit the expression of p-p38 and p-JNK in the cytoplasm. In addition, NGF-CL/LIP enhanced the quantities of p-neurotrophic tyrosine kinase receptor type 1 (p-TrkA) and p-extracellular-signal-regulated kinase 5 (p-ERK5), preventing the Aβ-induced degeneration of neurons. The membrane fusion of NGF-LIP activated the ERK5 pathway and the targeting capacity of NGF-CL/LIP enhanced the possibility of released NGF to affect the TrkA level. Moreover, WGA-CRM-LIP improved the permeation of CRM across the blood–brain barrier (BBB) and significantly reduced the Aβ plaque deposition and malondialdehyde level and increased the percentage of normal neurons and cholinergic function in the hippocampus of AD rats. This was mainly because the encapsulated CRM was protected by LIP against a rapid degradation in the blood. Furthermore, WGA on LIP could target N-acetylglucosamine on endothelia and increased the quantity of CRM transported across the BBB. In addition, WGA-CRM-CL/LIP could be effective in suppressing the synthesis of acetylcholinesterase and reduced the decomposition of acetylcholine for better neurotransmission. Based on the in vitro and in vivo evidences, WGA-CRM-CL/LIP can rescue neurons from apoptosis in the brain and can be a promising drug delivery system for clinical AD therapy.Keywords: Alzheimer’s disease, β-amyloid, liposome, mitogen-activated protein kinase
Procedia PDF Downloads 328586 Efficacy of Pisum sativum and Arbuscular Mycorrhizal Symbiosis for Phytoextraction of Heavy Metalloids from Soil
Authors: Ritu Chaturvedi, Manoj Paul
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A pot experiment was conducted to investigate the effect of Arbuscular mycorrhizal fungus (AMF) on metal(loid) uptake and accumulation efficiency of Pisum sativum along with physiological and biochemical response. Plants were grown in soil spiked with 50 and 100 mg kg-1 Pb, 25 and 50 mg kg-1 Cd, 50 and 100 mg kg-1 As and a combination of all three metal(loid)s. A parallel set was maintained and inoculated with arbuscular mycorrhizal fungus for comparison. After 60 days, plants were harvested and analysed for metal(loid) content. A steady increase in metal(loid) accumulation was observed on increment of metal(loid) dose and also on AMF inoculation. Plant height, biomass, chlorophyll, carotenoid and carbohydrate content reduced upon metal(loid) exposure. Increase in enzymatic (CAT, SOD and APX) and nonenzymatic (Proline) defence proteins was observed on metal(loid) exposure. AMF inoculation leads to an increase in plant height, biomass, chlorophyll, carotenoids, carbohydrate and enzymatic defence proteins (p≤0.001) under study; whereas proline content was reduced. Considering the accumulation efficiency and adaptive response of plants and alleviation of stress by AMF, this symbiosis can be applied for on-site remediation of Pb and Cd contaminated soil.Keywords: heavy metal, mycorrhiza, pea, phyroremediation
Procedia PDF Downloads 225585 Plant Mediated RNAi Approach to Knock Down Ecdysone Receptor Gene of Colorado Potato Beetle
Authors: Tahira Hussain, Ilhom Rahamkulov, Muhammad Aasim, Ugur Pirlak, Emre Aksoy, Mehmet Emin Caliskan, Allah Bakhsh
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RNA interference (RNAi) has proved its usefulness in functional genomic research on insects recently and is considered potential strategy in crop improvement for the control of insect pests. The different insect pests incur significant losses to potato yield worldwide, Colorado Potato Beetle (CPB) being most notorious one. The present study focuses to knock down highly specific 20-hydroxyecdysone hormone-receptor complex interaction by using RNAi approach to silence Ecdysone receptor (EcR) gene of CPB in transgenic potato plants expressing dsRNA of EcR gene. The partial cDNA of Ecdysone receptor gene of CPB was amplified using specific primers in sense and anti-sense orientation and cloned in pRNAi-GG vector flanked by an intronic sequence (pdk). Leaf and internodal explants of Lady Olympia, Agria and Granola cultivars of potato were infected with Agrobacterium strain LBA4404 harboring plasmid pRNAi-CPB, pRNAi-GFP (used as control). Neomycin phosphotransferase (nptII) gene was used as a plant selectable marker at a concentration of 100 mg L⁻¹. The primary transformants obtained have shown proper integration of T-DNA in plant genome by standard molecular analysis like polymerase chain reaction (PCR), real-time PCR, Sothern blot. The transgenic plants developed out of these cultivars are being evaluated for their efficacy against larvae as well adults of CPB. The transgenic lines are expected to inhibit expression of EcR protein gene, hindering their molting process, hence leading to increased potato yield.Keywords: plant mediated RNAi, molecular strategy, ecdysone receptor, insect metamorphosis
Procedia PDF Downloads 166584 Importance of E-Participation by U-Society in the Development of the U-City
Authors: Jalaluddin Abdul Malek, Mohd Asruladlyi Ibrahim, Zurinah Tahir
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This paper is to reveal developments in the areas of urban technology in Malaysia. Developments occur intend to add value intelligent city development to the ubiquitous city (U-city) or smart city. The phenomenon of change is called the development of post intelligent cities. U-City development discourse is seen from the perspective of the philosophy of the virtuous city organized by al-Farabi. The prosperity and perfection of a city is mainly caused by human personality factors, as well as its relationship with material and technological aspects of the city. The question is, to what extent to which human factors are taken into account in the concept of U-City as an added value to the intelligent city concept to realize the prosperity and perfection of the city? Previously, the intelligent city concept was developed based on global change and ICT movement, while the U-city added value to the development of intelligent cities and focused more on the development of information and communications technology (ICT). Value added is defined as the use of fiber optic technology that is wired to the use of wireless technology, such as wireless broadband. In this discourse, the debate on the concept of U-City is to the symbiosis between the U-City and the importance of local human e-participation (U-Society) for prosperity. In the context of virtuous city philosophy, it supports the thought of symbiosis so the concept of U-City can achieve sustainability, prosperity and perfection of the city.Keywords: smart city, ubiquitous city, u-society, e-participation, prosperity
Procedia PDF Downloads 268583 Study of Demographic, Hematological Profile and Risk Stratification in Chronic Myeloid Leukemia Patients
Authors: Rajandeep Kaur, Rajeev Gupta
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Background: Chronic myeloid leukemia (CML) is the most common leukaemia in India. The annual incidence of chronic myeloid leukemia in India was originally reported to be 0.8 to 2.2 per 1,00,000 population. CML is a clonal disorder that is usually easily diagnosed because the leukemic cells of more than 95% of patients have a distinctive cytogenetic abnormality, the Philadelphia chromosome (Ph1). The approval of tyrosine kinase inhibitors (TKIs), which target BCR-ABL1 kinase activity, has significantly reduced the mortality rate associated with chronic myeloid leukemia (CML) and revolutionized treatment. Material and Methods: 80 diagnosed cases of CML were taken. Investigations were done. Bone marrow and molecular studies were also done and with EUTOS, patients were stratified into low and high-risk groups and then treatment with Imatinib was given to all patients and the molecular response was evaluated at 6 months and 12 months follow up with BCR-ABL by RT-PCR quantitative assay. Results: In the study population, out of 80 patients in the study population, 40 were females and 40 were males, with M: F is 1:1. Out of total 80 patients’ maximum patients (54) were in 31-60 years age group. Our study showed a most common symptom of presentation is abdominal discomfort followed by fever. Out of the total 80 patients, 25 (31.3%) patients had high EUTOS scores and 55 (68.8%) patients had low EUTOS scores. On 6 months follow up 36.3% of patients had Complete Molecular Response, 16.3% of patients had Major Molecular Response and 47.5% of patients had No Molecular Response but on 12 months follow up 71.3% of patients had Complete Molecular Response, 16.25% of patients had Major Molecular Response and 12.5% patients had No Molecular Response. Conclusion: In this study, we found a significant correlation between EUTOS score and Molecular response at 6 months and 12 months follow up after Imatinib therapy.Keywords: chronic myeloid leukemia, European treatment and outcome study score, hematological response, molecular response, tyrosine kinase inhibitor
Procedia PDF Downloads 96582 Application of Computational Chemistry for Searching Anticancer Derivatives of 2-Phenazinamines as Bcr-Abl Tyrosine Kinase Inhibitors
Authors: Gajanan M. Sonwane
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The computational studies on 2-phenazinamines with their protein targets have been carried out to design compounds with potential anticancer activity. This strategy of designing compounds possessing selectivity over specific tyrosine kinase has been achieved through G-QSAR and molecular docking studies. The objective of this research has been to design newer 2-phenazinamine derivatives as Bcr-Abl tyrosine kinase inhibitors by G-QSAR, molecular docking studies followed by wet-lab studies along with evaluation of their anticancer potential. Computational chemistry was done by using VLife MDS 4.3 and Autodock 4.2 followed by wet-lab experiments for synthesizing 2-phenazinamine derivatives. The chemical structures of ligands in 2D were drawn by employing Chemdraw 2D Ultra 8.0 and were converted into 3D. These were optimized by using a semi-empirical method called MOPAC. The protein structure was retrieved from RCSC protein data bank as a PDB file. The binding interactions of protein and ligands were done by using PYMOL. The molecular properties of the designed compounds were predicted in silico by using Osiris property explorer. The parent compound 2-phenazinamine was synthesized by reduction of 2, 4-dinitro-N-phenyl-benzenamine in the presence of tin chloride followed by cyclization in the presence of nitrobenzene and magnesium sulfate. The derivatization at the amino function of 2-phenazinamine was performed by treating parent compound with various aldehydes in the presence of dicyclohexylcarbodiimide (DCC) and urea to afford 2-(2-chlorophenyl)-3-(phenazine-2-yl) thiazolidine-4-one. Synthesized 39 novel derivatives of 2-phenazinamine and performed antioxidant activity, anti antiproliferative on the bulb of onion and anticancer activity on cell line showing significant competition with marked blockbuster drug imatinib.Keywords: computer-aided drug design, tyrosin kinases, anticancer, docking
Procedia PDF Downloads 129581 Antitrypanosomal Activity of Stigmasterol: An in silico Approach
Authors: Mohammed Auwal Ibrahim, Aminu Mohammed
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Stigmasterol has previously been reported to possess antitrypanosomal activity using in vitro and in vivo models. However, the mechanism of antitrypanosomal activity is yet to be elucidated. In the present study, molecular docking was used to decipher the mode of interaction and binding affinity of stigmasterol to three known antitrypanosomal drug targets viz; adenosine kinase, ornithine decarboxylase and triose phosphate isomerase. Stigmasterol was found to bind to the selected trypanosomal enzymes with minimum binding energy of -4.2, -6.5 and -6.6 kcal/mol for adenosine kinase, ornithine decarboxylase, and triose phosphate isomerase respectively. However, hydrogen bond was not involved in the interaction of stigmasterol with all the three enzymes, but hydrophobic interaction seemed to play a vital role in the binding phenomenon which was predicted to be non-competitive like type of inhibition. It was concluded that binding to the three selected enzymes, especially triose phosphate isomerase, might be involved in the antitrypanosomal activity of stigmasterol but not mediated via a hydrogen bond interaction.Keywords: antitrypanosomal, in silico, molecular docking, stigmasterol
Procedia PDF Downloads 268580 SOCS3 Reverses Multidrug Resistance by Inhibiting MDR1 in Mammary Cell Carcinoma
Authors: S. Pradhan, D. Pradhan, G. Tripathy, T. Dasmohapatra
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Suppressors of cytokine signalling (SOCS3), a newly indentified anti-apoptotic molecule is a downstream effecter of the receptor tyrosine kinase-Ras signalling pathway. Current study has uncovered that SOCS3 may have wide and imperative capacities, particularly because of its close correlation with malignant tumors. To investigate the impact of SOCS3 on MDR, we analyzed the expression of P-gp and SOCS3 by immune-histochemistry and found there was positive correlation between them. At that point we effectively interfered with RNA translation by the contamination of siRNA of SOCS3 into MCF7/ADM breast cancer cell lines through a lentivirus, and the expression of the target gene was significantly inhibited. After RNAi the drug resistance was reduced altogether and the expression of MDR1 mRNA and P-gp in MCF7/ADM cell lines demonstrated a significant decrease. Likewise the expression of P53 protein increased in a statistically significant manner (p ≤ 0.01) after RNAi exposure. Moreover, flowcytometry analysis uncovers that cell cycle and anti-apoptotic enhancing capacity of cells changed after RNAi treatment. These outcomes proposed SOCS3 may take part in breast cancer MDR by managing MDR1 and P53 expression, changing cell cycle and enhancing the anti-apoptotic ability.Keywords: SOCS3gene, breast cancer, multidrug resistance, MDR1 gene, RNA interference
Procedia PDF Downloads 329579 Effect of TPA and HTLV-1 Tax on BRCA-1 and ERE Controlled Genes Expression
Authors: Azhar Jabareen, Mahmoud Huleihel
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BRCA-1 is a multifunctional tumor suppressor, whose expression is activated by the estrogen (E2)-liganded ERα receptor. The activated ERα is a transcriptional factor which activates various genes either by direct binding to the DNA at E2-responsive elements (EREs) and indirectly associated with a range of alternative non-ERE elements. Interference with BRCA-1 expression and/or functions leads to high risk of breast or/and ovarian cancer. Our lab investigated the involvement of Human T-cell leukemia Virus Type 1 (HTLV-1) in breast cancer, since HTLV-1 Tax was found to strongly inhibit BRCA-1 expression. In addition, long exposure of 12-O-tetradecanoylphorbol-13-acetate (TPA), which is one of the stress-inducing agents activated the HTLV-1 promoter. So here the involvement of TPA in breast cancer had been examined by testing the effect of TPA on BRCA-1 and ERE expression. The results showed that TPA activated both BRCA-1 and ERE expression. In the 12 hours TPA activated the tow promoters more than others time, and after 24 hours the level of the tow promoters was decreased. Tax inhibited BRCA-1 expression but did not succeed to inhibit the effect of TPA. Then the activation of the two promoters was not through ERα pathway because TPA had no effect on ERα binding to the two promoters of the BRCA-1 and ERE. Also, the activation was not via nuclear factor kappa B (NF-κB) pathway because when the inhibitory of NF-κB had been added to the TPA, it still activated the tow promoters. However, it seems that 53BP1 may be involved in TPA activation of these promoters because ectopic high expression of 53BP1 significantly reduced the TPA activity. In addition, in the presence of Bisindolylmaleimide-I (BI)- the inhibitor of Protein Kinase C (PKC)- there was no activation for the two promoters, so the PKC is agonized BRCA-1 and ERE activation.Keywords: BRCA-1, ERE, HTLV-1, TPA
Procedia PDF Downloads 243578 Anticancer Lantadene Derivatives: Synthesis, Cytotoxic and Docking Studies
Authors: A. Monika, Manu Sharma, Hong Boo Lee, Richa Dhingra, Neelima Dhingra
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Nuclear factor-κappa B serve as a molecular lynchpin that links persistent infections and chronic inflammation to increased cancer risk. Inflammation has been recognized as a hallmark and cause of cancer. Natural products present a privileged source of inspiration for chemical probe and drug design. Herbal remedies were the first medicines used by humans due to the many pharmacologically active secondary metabolites produced by plants. Some of the metabolites like Lantadene (pentacyclic triterpenoids) from the weed Lantana camara has been known to inhibit cell division and showed anti-antitumor potential. The C-3 aromatic esters of lantadenes were synthesized, characterized and evaluated for cytotoxicity and inhibitory potential against Tumor necrosis factor alpha-induced activation of Nuclear factor-κappa B in lung cancer cell line A549. The 3-methoxybenzoyloxy substituted lead analogue inhibited kinase activity of the inhibitor of nuclear factor-kappa B kinase in a single-digit micromolar concentration. At the same time, the lead compound showed promising cytotoxicity against A549 lung cancer cells with IC50 ( half maximal inhibitory concentration) of 0.98l µM. Further, molecular docking of 3-methoxybenzoyloxy substituted analogue against Inhibitor of nuclear factor-kappa B kinase (Protein data bank ID: 3QA8) showed hydrogen bonding interaction involving oxygen atom of 3-methoxybenzoyloxy with the Arginine-31 and Glutamine-110. Encouraging results indicate the Lantadene’s potential to be developed as anticancer agents.Keywords: anticancer, lantadenes, pentacyclic triterpenoids, weed
Procedia PDF Downloads 154577 Rice Serine/Threonine Kinase 1 Is Required for the Stimulation of OsNug2 GTPase Activity
Authors: Jae Bok Heo, Yun Mi Lee, Hee Rang Yun
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Several GTPases are required for ribosome biogenesis and assembly. We recently characterized rice (Oryza sativa) nuclear/nucleolar GTPase 2 (OsNug2), belonging to the YlqF/YawG family of GTPases, as playing a role in pre-60S ribosomal subunit maturation. To investigate the potential factors involved in regulating the function of OsNug2, yeast two-hybrid screens were carried out using OsNug2 as bait. Rice serine/threonine kinase 1 (OsSTK1) was identified as a potential interacting protein candidate. In vitro pull down and bimolecular fluorescence complementation assays confirmed the interaction between OsNug2 and OsSTK1, and like green fluorescent protein-tagged OsNug2, green fluorescent protein-tagged OsSTK1 was targeted to the nucleus of Arabidopsis protoplasts. OsSTK1 was not found to affect the GTP-binding activity of OsNug2; however, when recombinant OsSTK1 was included in OsNug2 assay reaction mixtures, OsSTK1 increased the GTPase activity of OsNug2. To test whether OsSTK1 phosphorylates OsNug2 in vitro, a kinase assay was performed. OsSTK1 was found to have weak autophosphorylation activity and strongly phosphorylated serine 209 of OsNug2. Yeast complementation testing resulted in a GAL::OsNug2(S209N) mutant-harboring yeast strain exhibiting a growth-defective phenotype on galactose medium at 39°C, divergent from that of a yeast strain harboring GAL::OsNug2. The intrinsic GTPase activity of mutant OsNug2(S209N) was found to be similar to that of OsNug2, was not fully enhanced upon weak binding of OsSTK1. Our findings reported here indicate that OsSTK1 functions as a positive regulator protein of OsNug2 by enhancing the GTPase activity of OsNug2, and that the phosphorylation of serine 209 of OsNug2 is essential for the complete function of OsNug2 in ribosome biogenesis.Keywords: OsSTK1, OsNug2, GTPase activity, GTP binding activity, phosphorylation
Procedia PDF Downloads 369576 GABARAPL1 (GEC1) mRNA Expression Levels in Patients with Alzheimer's Disease
Authors: Ali Bayram, Burak Uz, Ilhan Dolasik, Remzi Yiğiter
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The GABARAP (GABAA-receptor-associated protein) family consists of GABARAP, GABARAPL1 (GABARAP-like 1) and GABARAPL2 (GABARAP-like 2). GABARAPL1, like GABARAP, was described to interact with both GABAA receptor and tubulin, and to be involved in intracellular GABAA receptor trafficking and promoting tubulin polymerization. In addition, GABARAPL1 is thought to be involved in various physiological (autophagosome closure, regulation of circadian rhythms) and/or pathological mechanisms (cancer, neurodegeneration). Alzheimer’s disease (AD) is a progressive neuro degenerative disorder characterized with impaired cognitive functions. Disruption of the GABAergic neuro transmission as well as cholinergic and glutamatergic interactions, may also be involved in the pathogenesis of AD. GABARAPL1 presents a regulated tissue expression and is the most expressed gene among the GABARAP family members in the central nervous system. We, herein, conducted a study to investigate the GABARAPL1 mRNA expression levels in patients with AD. 50 patients with AD and 49 control patients were enrolled to the present study. Messenger RNA expression levels of GABARAPL1 were detected by real-time polymerase chain reaction. GABARAPL1 mRNA expression in AD / control patients was 0,495 (95% confidence interval: 0,404-0,607), p= 0,00000002646. Reduced activity of GABARAPL1 gene might play a role, at least partly, in the pathophysiology of AD.Keywords: Alzheimer’s disease, GABARAPL1, mRNA expression, RT-PCR
Procedia PDF Downloads 453575 SOCS1 Inhibits MDR1 in Mammary Cell Carcinoma Reverses Multidrug Resistance
Authors: Debasish Pradhan, Shaktiprasad Pradhan, Rakesh Kumar Pradhan, Gitanjali Tripathy
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Suppressors of cytokine signalling (SOCS1), a newly indentified antiapoptotic molecule is a downstream effector of the receptor tyrosine kinase-Ras signalling pathway. The current study has uncovered that SOCS1 may have wide and imperative capacities, particularly because of its close correlation with malignant tumors. To investigate the impact of SOCS1 on MDR, we analyzed the expression of P-gp and SOCS1 by immunohistochemistry and found there was a positive correlation between them. At that point, we effectively interfered with RNA translation by the contamination of siRNA of SOCS1 into MCF7/ADM breast cancer cell lines through a lentivirus, and the expression of the target gene was significantly inhibited. After RNAi, the drug resistance was reduced altogether and the expression of MDR1 mRNA and P-gp in MCF7/ADM cell lines demonstrated a significant decrease. Likewise, the expression of P53 protein increased in a statistically significant manner (p ≤ 0.01) after RNAi exposure. Moreover, flow cytometry analysis uncovers that cell cycle and anti-apoptotic enhancing capacity of cells changed after RNAi treatment. These outcomes proposed SOCS1 may take part in breast cancer MDR by managing MDR1 and P53 expression, changing cell cycle and enhancing the anti-apoptotic ability.Keywords: breast cancer, multidrug resistance, SOCS1 gene, MDR1 gene, RNA interference
Procedia PDF Downloads 352574 Aptamers: A Potential Strategy for COVID-19 Treatment
Authors: Mohamad Ammar Ayass, Natalya Griko, Victor Pashkov, Wanying Cao, Kevin Zhu, Jin Zhang, Lina Abi Mosleh
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Respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for coronavirus disease 2019 (COVID-19). Early evidence pointed at the angiotensin-converting enzyme 2 (ACE-2) expressed on the epithelial cells of the lung as the main entry point of SARS-CoV-2 into the cells. The viral entry is mediated by the binding of the Receptor Binding Domain (RBD) of the spike protein that is expressed on the surface of the virus to the ACE-2 receptor. As the number of SARS-CoV-2 variants continues to increase, mutations arising in the RBD of SARS-CoV-2 may lead to the ineffectiveness of RBD targeted neutralizing antibodies. To address this limitation, the objective of this study is to develop a combination of aptamers that target different regions of the RBD, preventing the binding of the spike protein to ACE-2 receptor and subsequent viral entry and replication. A safe and innovative biomedical tool was developed to inhibit viral infection and reduce the harms of COVID-19. In the present study, DNA aptamers were developed against a recombinant trimer S protein using the Systematic Evolution of Ligands by Exponential enrichment (SELEX). Negative selection was introduced at round number 7 to select for aptamers that bind specifically to the RBD domain. A series of 9 aptamers (ADI2010, ADI2011, ADI201L, ADI203L, ADI205L, ADIR68, ADIR74, ADIR80, ADIR83) were selected and characterized with high binding affinity and specificity to the RBD of the spike protein. Aptamers (ADI25, ADI2009, ADI203L) were able to bind and pull down endogenous spike protein expressed on the surface of SARS-CoV-2 virus in COVID-19 positive patient samples and determined by liquid chromatography- tandem mass spectrometry analysis (LC-MS/MS). LC-MS/MS data confirmed that aptamers can bind to the RBD of the spike protein. Furthermore, results indicated that the combination of the 9 best aptamers inhibited the binding of the purified trimer spike protein to the ACE-2 receptor found on the surface of Vero E6 cells. In the same experiment, the combined aptamers displayed a better neutralizing effect than antibodies. The data suggests that the selected aptamers could be used in therapy to neutralize the effect of the SARS-CoV-2 virus by inhibiting the interaction between the RBD and ACE-2 receptor, preventing viral entry into target cells and therefore blocking viral replication.Keywords: aptamer, ACE-2 receptor, binding inhibitor, COVID-19, spike protein, SARS-CoV-2, treatment
Procedia PDF Downloads 180573 Targeting the EphA2 Receptor Tyrosine Kinases in Melanoma Cancer, both in Humans and Dogs
Authors: Shabnam Abdi, Behzad Toosi
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Background: Melanoma is the most lethal type of malignant skin cancer in humans and dogs since it spreads rapidly throughout the body. Despite significant advances in treatment, cancer at an advanced stage has a poor prognosis. Hence, more effective treatments are needed to enhance outcomes with fewer side effects. Erythropoietin-producing hepatocellular receptors are the largest family of receptor tyrosine kinases and are divided into two subfamilies, EphA and EphB, both of which play a significant role in disease, especially cancer. Due to their association with proliferation and invasion in many aggressive types of cancer, Eph receptor tyrosine kinases (Eph RTKs) are promising cancer therapy molecules. Because these receptors have not been studied in canine melanoma, we investigated how EphA2 influences survival and tumorigenicity of melanoma cells. Methods: Expression of EphA2 protein in canine melanoma cell lines and human melanoma cell line was evaluated by Western blot. Melanoma cells were transduced with lentiviral particles encoding Eph-targeting shRNAs or non-silencing shRNAs (control) for silencing the expression of EphA2 receptor, and silencing was confirmed by Western blotting and immunofluorescence. The effect of siRNA treatment on cellular proliferation, colony formation, tumorsphere assay, invasion was analyzed by Resazurin assay Matrigel invasion assay, respectively. Results: Expression of EphA2 was detected in canine and human melanoma cell lines. Moreover, stably silencing EphA2 by specific shRNAs significantly and consistently decreased the expression of EphA2 protein in both human and canine melanoma cells. Proliferation, colony formation, tumorsphere and invasion of melanoma cells were significantly decreased in EphA2 siRNA-treated cells compared to control. Conclusion: Our data provide the first functional evidence that the EphA2 receptor plays a critical role in the malignant cellular behavior of melanoma in both human and dogs.Keywords: ephA2, targeting, melanoma, human, canine
Procedia PDF Downloads 52572 Melatonin Rescue Fungicide Induced Behavioral and Reproductive Abnormalities through Changes of Dopaminergic Activity in the Brain of Catfish, Mystus cavasisu
Authors: Muhammad Badruzzaman, Alif Hasan, Md. Shahjahan
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Propiconazole is a triazole fungicide extensively used in agriculture which can harm to non-target organisms in aquatic environment through runoff. Chronic exposure to environmental pesticides turn to behavioral impairment in vertebrates including teleosts. However, the potential effect of this fungicide on neurobehavioral impairment and release from it in vertebrates has not been fully explored. In this work, we examined the role of melatonin to rescue fungicide induced neurobehavioral and reproductive alternation and its connection with changes in dopaminergic activity in the brain of Mystus cavasius. After fish were exposed to water containing propiconazole at 0, 0.1, 5, and 250 µg/L for 3 days, significant increases of DA, 3,4-dihydroxyphenylacetic acid (DOPAC; a DA metabolite), and their ratio (DOPAC/DA) were observed in whole brain at 250 µg/L concentration. When fish were treated with propiconazole at 250 µg/L for 3 days, there was a significant elevation of DA, DOPAC and DOPAC/DA in diencephalon and pituitary, and only DA in the telencephalon, compared with control fish. Besides, it induced a reduction in extracellular serotonin and had an anxiolytic-like effect, supported by a decrease in cortisol production. Increased locomotor activity, anxiety and aggressiveness, decreased gonadosomatic index with few vitellogenic oocytes in ovaries after propiconazole treatment. When fish were treated with melatonin, D1 (SCH-23390) or D2 (Haloperidol) dopamine receptor antagonists and combined of melatonin and D1/D2 receptor antagonist and was observed melatonin + D2 receptor antagonist rescued fungicide induced all behavioral changes in fish. These results indicate that propiconazole increases locomotor activity, anxiety and aggressiveness and decreases reproductive activity, which was rescued by combined treatment of melatonin and dopamine receptor antagonist.Keywords: behavior, catfish, dopamine, fungicide, melatonin
Procedia PDF Downloads 111571 Genome-Wide Significant SNPs Proximal to Nicotinic Receptor Genes Impact Cognition in Schizophrenia
Authors: Mohammad Ahangari
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Schizophrenia is a psychiatric disorder with symptoms that include cognitive deficits and nicotine has been suggested to have an effect on cognition. In recent years, the advents of Genome-Wide Association Studies(GWAS) has evolved our understanding about the genetic causes of complex disorders such as schizophrenia and studying the role of genome-wide significant genes could potentially lead to the development of new therapeutic agents for treatment of cognitive deficits in schizophrenia. The current study identified six Single Nucleotide Polymorphisms (SNP) from schizophrenia and smoking GWAS that are located on or in close proximity to the nicotinic receptor gene cluster (CHRN) and studied their association with cognition in an Irish sample of 1297 cases and controls using linear regression analysis. Further on, the interaction between CHRN gene cluster and Dopamine receptor D2 gene (DRD2) during working memory was investigated. The effect of these polymorphisms on nicotinic and dopaminergic neurotransmission, which is disrupted in schizophrenia, have been characterized in terms of their effects on memory, attention, social cognition and IQ as measured by a neuropsychological test battery and significant effects in two polymorphisms were found across global IQ domain of the test battery.Keywords: cognition, dopamine, GWAS, nicotine, schizophrenia, SNPs
Procedia PDF Downloads 332570 Prognostic Value of Tumor Markers in Younger Patients with Breast Cancer
Authors: Lola T. Alimkhodjaeva, Lola T. Zakirova, Soniya S. Ziyavidenova
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Background: Breast cancer occupies the first place among the cancer in women in the world. It is urgent today to study the role of molecular markers which are capable of predicting the dynamics and outcome of the disease. The aim of this study is to define the prognostic value of the content of estrogen receptor (ER), progesterone receptor (PgR), and amplification of HER-2 / neu oncoprotein by studying 3 and 5-year overall and relapse-free survival in 470 patients with primary operable and 280 patients with locally–advanced breast cancer. Materials and methods: Study results of 3 and 5-year overall and relapse-free survival, depending on the content of RE, PgR in primary operable patients showed that ER positive (+) and PgR (+) survival was 100 (96.2%) and 97.3 (94.6%), for ER negative (-) and PgR (-) - 69.2 (60.3%) and 65.4 (57.7%), for ER positive (+) and negative PgR (-) 87.4 (80.1%) and 81.5 (79.3%), for ER negative (-) and positive PgR (+) - 97.4 (93.4%) and 90.4 (88.5%), respectively. Survival results depended also on the level of HER-2 / neu expression. In patients with HER-2 / neu negative the survival rates were as follows: 98.6 (94.7%) and 96.2 (92.3%). In group of patients with the level of HER-2 / neu (2+) expression these figures were: 45.3 (44.3%) and 45.1 (40.2%), and in group of patients with the level of HER-2 / neu (3+) expression - 41.2 (33.1%) and 34.3 (29.4%). The combination of ER negative (-), PgR (-), HER-2 / neu (-) they were 27.2 (25.4%) and 19.5 (15.3%), respectively. In patients with locally-advanced breast cancer the results of 3 and 5-year OS and RFS for ER (+) and PgR (+) were 76.3 (69.3%) and 62.2 (61.4%), for ER (-) and RP (-) 29.1 (23.7%) and 18.3 (12.6%), for ER (+) and PgR (-) 61.2 (47.2%) and 39.4 (25.6%), for ER (-) and PgR (+) 54.3 (43.1%) and 41.3 (18.3%), respectively. The level of HER-2 / neu expression also affected the survival results. Therefore, in HER-2/ neu negative patients the survival rate was 74.1 (67.6%) and 65.1 (57.3%), with the level of expression (2+) 20.4 (14.2%) and 8.6 (6.4%), with the level of expression (3+) 6.2 (3.1%) and 1.2 (1.5%), respectively. The combination for ER, PgR, HER-2 / neu negative was 22.1 (14.3%) and 8.4 (1.2%). Conclusion: Thus, the presence of steroid hormone receptors in breast tumor tissues at primary operable and locally- advanced process as the lack of HER-2/neu oncoprotein correlates with the highest rates of 3- and 5-year overall and relapse-free survival. The absence of steroid hormone receptors as well as of HER-2/neu overexpression in malignant breast tissues significantly degrades the 3- and 5-year overall and relapse-free survival. Tumors with ER, PgR and HER-2/neu negative have the most unfavorable prognostics.Keywords: breast cancer, estrogen receptor, oncoprotein, progesterone receptor
Procedia PDF Downloads 178569 Receptor-Independent Effects of Endocannabinoid Anandamide on Contractility and Electrophysiological Properties of Rat Ventricular Myocytes
Authors: Lina T. Al Kury, Oleg I. Voitychuk, Ramiz M. Ali, Sehamuddin Galadari, Keun-Hang Susan Yang, Frank Christopher Howarth, Yaroslav M. Shuba, Murat Oz
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A role for anandamide (N-arachidonoyl ethanolamide; AEA), a major endocannabinoid, in the cardiovascular system in various pathological conditions has been reported in earlier studies. In the present work, we have hypothesized that the antiarrhythmic effects reported for AEA are due to its negative inotropic effect and altered action potential (AP) characteristics. Therefore, we tested the effects of AEA on contractility and electrophysiological properties of rat ventricular myocytes. Video edge detection was used to measure myocyte shortening. Intracellular Ca2+ was measured in cells loaded with the fluorescent indicator fura-2 AM. Whole-cell patch-clamp technique was employed to investigate the effect of AEA on the characteristics of APs. AEA (1 μM) caused a significant decrease in the amplitudes of electrically-evoked myocyte shortening and Ca2+ transients and significantly decreased the duration of AP. The effect of AEA on myocyte shortening and AP characteristics was not altered in the presence of pertussis toxin (PTX, 2 µg/ml for 4 h), AM251 and SR141716 (cannabinoid type 1 receptor antagonists) or AM630 and SR 144528 (cannabinoid type 2 receptor antagonists). Furthermore, AEA inhibited voltage-activated inward Na+ (INa) and Ca2+ (IL,Ca) currents; major ionic currents shaping the APs in ventricular myocytes, in a voltage and PTX-independent manner. Collectively, the results suggest that AEA depresses ventricular myocyte contractility, by decreasing the action potential duration (APD), and inhibits the function of voltage-dependent Na+ and L-type Ca2+ channels in a manner independent of cannabinoid receptors. This mechanism may be importantly involved in the antiarrhythmic effects of anandamide.Keywords: action potential, anandamide, cannabinoid receptor, endocannabinoid, ventricular myocytes
Procedia PDF Downloads 350568 Combined Treatment of Estrogen-Receptor Positive Breast Microtumors with 4-Hydroxytamoxifen and Novel Non-Steroidal Diethyl Stilbestrol-Like Analog Produces Enhanced Preclinical Treatment Response and Decreased Drug Resistance
Authors: Sarah Crawford, Gerry Lesley
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This research is a pre-clinical assessment of anti-cancer effects of novel non-steroidal diethyl stilbestrol-like estrogen analogs in estrogen-receptor positive/ progesterone-receptor positive human breast cancer microtumors of MCF 7 cell line. Tamoxifen analog formulation (Tam A1) was used as a single agent or in combination with therapeutic concentrations of 4-hydroxytamoxifen, currently used as a long-term treatment for the prevention of breast cancer recurrence in women with estrogen receptor positive/ progesterone receptor positive malignancies. At concentrations ranging from 30-50 microM, Tam A1 induced microtumor disaggregation and cell death. Incremental cytotoxic effects correlated with increasing concentrations of Tam A1. Live tumor microscopy showed that microtumos displayed diffuse borders and substrate-attached cells were rounded-up and poorly adherent. A complete cytotoxic effect was observed using 40-50 microM Tam A1 with time course kinetics similar to 4-hydroxytamoxifen. Combined treatment with TamA1 (30-50 microM) and 4-hydroxytamoxifen (10-15 microM) induced a highly cytotoxic, synergistic combined treatment response that was more rapid and complete than using 4-hydroxytamoxifen as a single agent therapeutic. Microtumors completely dispersed or formed necrotic foci indicating a highly cytotoxic combined treatment response. Moreover, breast cancer microtumors treated with both 4-hydroxytamoxifen and Tam A1 displayed lower levels of long-term post-treatment regrowth, a critical parameter of primary drug resistance, than observed for 4-hydroxytamoxifen when used as a single agent therapeutic. Tumor regrowth at 6 weeks post-treatment with either single agent 4-hydroxy tamoxifen, Tam A1 or a combined treatment was assessed for the development of drug resistance. Breast cancer cells treated with both 4-hydroxytamoxifen and Tam A1 displayed significantly lower levels of post-treatment regrowth, indicative of decreased drug resistance, than observed for either single treatment modality. The preclinical data suggest that combined treatment involving the use of tamoxifen analogs may be a novel clinical approach for long-term maintenance therapy in patients with estrogen-receptor positive/progesterone-receptor positive breast cancer receiving hormonal therapy to prevent disease recurrence. Detailed data on time-course, IC50 and tumor regrowth assays post- treatment as well as a proposed mechanism of action to account for observed synergistic drug effects will be presented.Keywords: 4-hydroxytamoxifen, tamoxifen analog, drug-resistance, microtumors
Procedia PDF Downloads 62567 Parathyroid Hormone Receptor 1 as a Prognostic Indicator in Canine Osteosarcoma
Authors: Awf A. Al-Khan, Michael J. Day, Judith Nimmo, Mourad Tayebi, Stewart D. Ryan, Samantha J. Richardson, Janine A. Danks
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Osteosarcoma (OS) is the most common type of malignant primary bone tumour in dogs. In addition to their critical roles in bone formation and remodeling, parathyroid hormone-related protein (PTHrP) and its receptor (PTHR1) are involved in progression and metastasis of many types of tumours in humans. The aims of this study were to determine the localisation and expression levels of PTHrP and PTHR1 in canine OS tissues using immunohistochemistry and to investigate if this expression is correlated with survival time. Formalin-fixed, paraffin-embedded tissue samples from 44 dogs with known survival time that had been diagnosed with primary osteosarcoma were analysed for localisation of PTHrP and PTHR1. Findings showed that both PTHrP and PTHR1 were present in all OS samples. The dogs with high level of PTHR1 protein (16%) had decreased survival time (P<0.05) compared to dogs with less PTHR1 protein. PTHrP levels did not correlate with survival time (P>0.05). The results of this study indicate that the PTHR1 is expressed differently in canine OS tissues and this may be correlated with poor prognosis. This may mean that PTHR1 may be useful as a prognostic indicator in canine OS and could represent a good therapeutic target in OS.Keywords: dog, expression, osteosarcoma, parathyroid hormone receptor 1 (PTHR1), parathyroid hormone-related protein (PTHrP), survival
Procedia PDF Downloads 265566 Isolation and Characterisation of Novel Environmental Bacteriophages Which Target the Escherichia coli Lamb Outer Membrane Protein
Authors: Ziyue Zeng
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Bacteriophages are viruses which infect bacteria specifically. Over the past decades, phage λ has been extensively studied, especially its interaction with the Escherichia coli LamB (EcLamB) protein receptor. Nonetheless, despite the enormous numbers and near-ubiquity of environmental phages, aside from phage λ, there is a paucity of information on other phages which target EcLamB as a receptor. In this study, to answer the question of whether there are other EcLamB-targeting phages in the natural environment, a simple and convenient method was developed and used for isolating environmental phages which target a particular surface structure of a particular bacterium; in this case, the EcLamB outer membrane protein. From the enrichments with the engineered bacterial hosts, a collection of EcLamB-targeting phages (ΦZZ phages) were easily isolated. Intriguingly, unlike phage λ, an obligate EcLamB-dependent phage in the Siphoviridae family, the newly isolated ΦZZ phages alternatively recognised EcLamB or E. coli OmpC (EcOmpC) as a receptor when infecting E. coli. Furthermore, ΦZZ phages were suggested to represent new species in the Tequatrovirus genus in the Myoviridae family, based on phage morphology and genomic sequences. Most phages are thought to have a narrow host range due to their exquisite specificity in receptor recognition. With the ability to optionally recognise two receptors, ΦZZ phages were considered relatively promiscuous. Via the heterologous expression of EcLamB on the bacterial cell surface, the host range of ΦZZ phages was further extended to three different enterobacterial genera. Besides, an interesting selection of evolved phage mutants with a broader host range was isolated, and the key mutations involved in their evolution to adapt to new hosts were investigated by genomic analysis. Finally, and importantly, two ΦZZ phages were found to be putative generalised transducers, which could be exploited as tools for DNA manipulations.Keywords: environmental microbiology, phage, microbe-host interactions, microbial ecology
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