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1.
J Cell Biochem ; 125(4): e30534, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38358025

RESUMO

Missense mutations in the DNA binding domain of p53 are observed frequently in esophageal squamous cell carcinoma (ESCC). Recent studies have revealed the potentially oncogenic transcriptional networks regulated by mutant p53 proteins. However, majority of these studies have focused on common "hotspot" p53 mutations while rarer mutations are poorly characterized. In this study, we report the characterization of rare, "non-hotspot" p53 mutations from ESCC. In vitro tumorigenic assays performed following ectopic-expression of certain "non-hotspot" mutant p53 proteins caused enhancement of oncogenic properties in squamous carcinoma cell lines. Genome-wide transcript profiling of ESCC tumor samples stratified for p53 status, revealed several genes exhibiting elevated transcript levels in tumors harboring mutant p53. Of these, ARF6, C1QBP, and TRIM23 were studied further. Reverse transcription-quantitative PCR (RT-qPCR) performed on RNA isolated from ESCC tumors revealed significant correlation of TP53 transcript levels with those of the three target genes. Ectopic expression of wild-type and several mutant p53 forms followed by RT-qPCR, chromatin affinity-purification (ChAP), and promoter-luciferase assays indicated the exclusive recruitment of p53 mutants-P190T and P278L, to the target genes leading to the activation of expression. Several functional assays following knockdown of the target genes revealed a significant suppression of tumorigenicity in squamous carcinoma cell lines. Rescue experiments confirmed the specificity of the knockdown. The tumorigenic effects of the genes were confirmed in nude mice xenograft assays. This study has therefore identified novel oncogenic targets of "non-hotspot" mutant p53 proteins relevant for ESCC besides validating the functional heterogeneity of the spectrum of tumor-specific p53 mutations.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Animais , Camundongos , Humanos , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Neoplasias Esofágicas/patologia , Camundongos Nus , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Proliferação de Células , Proteínas de Ligação ao GTP/genética , Proteínas de Transporte/genética , Proteínas Mitocondriais/genética
2.
J Cell Physiol ; 235(5): 4559-4570, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31637714

RESUMO

Though primarily a tumor suppressor, TP53 harboring specific missense mutations located in the region encoding the DNA binding domain exhibits a gain of function by transcriptional activation of oncogenes. We performed microarray-based messenger RNA profiling of squamous cell carcinoma of the oral tongue (SCCOT) and identified significant elevation of SMARCD1 in samples exhibiting p53 nuclear stabilization. Activation of SMARCD1 by mutant p53 was confirmed by evaluation of additional tongue cancer samples as well as The Cancer Genome Atlas expression datasets. SMARCD1 knockdown in HNSCC cells resulted in a significant reduction in several tumorigenic characteristics including cell viability, ability to form colonies in liquid and solid media and cell migration. We identified significantly increased SMARCD1 transcript levels in tumor versus matched normal samples in SCCOT as well as in other cancer types. Increased SMARCD1 expression predicted poor survival in HNSCC tumors harboring missense p53 mutations. Our results suggest SMARCD1 to be a novel transcriptional target of mutant p53.


Assuntos
Proteínas Cromossômicas não Histona/genética , Mutação , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Transcrição Gênica , Proteína Supressora de Tumor p53/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Proteínas Cromossômicas não Histona/metabolismo , Bases de Dados Genéticas , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Bucais/genética , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Proteína Supressora de Tumor p53/metabolismo
3.
Mol Carcinog ; 54(12): 1807-14, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25420488

RESUMO

Lynch syndrome (LS), the most common form of familial CRC predisposition that causes tumor onset at a young age, is characterized by the presence of microsatellite instability (MSI) in tumors due to germline inactivation of mismatch repair (MMR) system. Two MMR genes namely MLH1 and MSH2 account for majority of LS cases while MSH6 and PMS2 may account for a minor proportion. In order to identify MMR genes causing LS in India, we analyzed MSI and determined expression status of the four MMR genes in forty eight suspected LS patient colorectal tumor samples. Though a majority exhibited MSI, only 58% exhibited loss of MMR expression, a significantly low proportion compared to reports from other populations. PCR-DNA sequencing and MLPA-based mutation and exonic deletion/duplication screening respectively, revealed genetic lesions in samples with and without MMR gene expression. Interestingly, tumor samples with and without MMR expression exhibited significant differences with respect to histological (mucin content) and molecular (instability exhibited by mononucleotide microsatellites) features. The study has revealed for the first time a significant proportion of LS tumors not exhibiting loss of MMR expression.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/genética , Expressão Gênica/genética , Adulto , Idoso , Neoplasias Colorretais/genética , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Mutação/genética
4.
Proc Natl Acad Sci U S A ; 109(5): E252-9, 2012 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-22233809

RESUMO

Defining the molecular genetic alterations underlying pancreatic cancer may provide unique therapeutic insight for this deadly disease. Toward this goal, we report here an integrative DNA microarray and sequencing-based analysis of pancreatic cancer genomes. Notable among the alterations newly identified, genomic deletions, mutations, and rearrangements recurrently targeted genes encoding components of the SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex, including all three putative DNA binding subunits (ARID1A, ARID1B, and PBRM1) and both enzymatic subunits (SMARCA2 and SMARCA4). Whereas alterations of each individual SWI/SNF subunit occurred at modest-frequency, as mutational "hills" in the genomic landscape, together they affected at least one-third of all pancreatic cancers, defining SWI/SNF as a major mutational "mountain." Consistent with a tumor-suppressive role, re-expression of SMARCA4 in SMARCA4-deficient pancreatic cancer cell lines reduced cell growth and promoted senescence, whereas its overexpression in a SWI/SNF-intact line had no such effect. In addition, expression profiling analyses revealed that SWI/SNF likely antagonizes Polycomb repressive complex 2, implicating this as one possible mechanism of tumor suppression. Our findings reveal SWI/SNF to be a central tumor suppressive complex in pancreatic cancer.


Assuntos
Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/fisiologia , Genes Supressores de Tumor , Neoplasias Pancreáticas/metabolismo , Fatores de Transcrição/fisiologia , Proteínas Cromossômicas não Histona/genética , Perfilação da Expressão Gênica , Humanos , Mutação , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fatores de Transcrição/genética , Transcriptoma
5.
J Cell Biochem ; 115(3): 566-74, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24130151

RESUMO

Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by mutational inactivation of the phenylalanine hydroxylase (PAH) gene. Missense mutations are the most common PAH mutation type detected in PKU patients worldwide. We performed PAH mutation analysis in 27 suspected Indian PKU families (including 7 from our previous study) followed by structure and function analysis of specific missense and splice/insertion-deletion/nonsense mutations, respectively. Of the 27 families, disease-causing mutations were detected in 25. A total of 20 different mutations were identified of which 7 "unique" mutations accounted for 13 of 25 mutation positive families. The unique mutations detected exclusively in Indian PKU patients included three recurrent mutations detected in three families each. The 20 mutations included only 5 missense mutations in addition to 5 splice, 4 each nonsense and insertion-deletion mutations, a silent variant in coding region and a 3'UTR mutation. One deletion and two nonsense mutations were characterized to confirm significant reduction in mutant transcript levels possibly through activation of nonsense mediated decay. All missense mutations affected conserved amino acid residues and sequence and structure analysis suggested significant perturbations in the enzyme activity of respective mutant proteins. This is probably the first report of identification of a significantly low proportion of missense PAH mutations from PKU families and together with the presence of a high proportion of splice, insertion-deletion, and nonsense mutations, points to a unique PAH mutation profile in Indian PKU patients.


Assuntos
Códon sem Sentido/genética , Mutação INDEL/genética , Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Alelos , Povo Asiático/genética , Análise Mutacional de DNA , Feminino , Humanos , Índia , Masculino , Linhagem , Fenilalanina Hidroxilase/metabolismo , Fenilcetonúrias/etiologia , Fenilcetonúrias/patologia , Sítios de Splice de RNA/genética
6.
Dalton Trans ; 52(16): 5297-5311, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-36988241

RESUMO

Hydrogen fuel plays a ubiquitous role in empowering the sustainable green energy economy. As an eco-friendly production method for hydrogen, photo-assisted water splitting is accepted to be the most reliable. However, the fabrication of stable and efficient photocatalysts is challenging. To overcome this difficulty, here we present a novel and inexpensive oxidant-promoted ultrasonic-assisted liquid phase layer exfoliation technique to fabricate a CdS/H-MoS2 nano hybrid. The newly fabricated CdS/H-MoS2 shows a hydrogen evolution rate of 162.4 mmol g-1h-1, which is 16 times higher compared to that of CdS/Pt and 67 times higher compared to that of bare CdS. Theoretical results clearly demonstrate a built-in electrostatic potential in the heterostructure junction, and that a shift in water reduction potential plays a key role in the enhancement of hydrogen production rate. We believe that the proposed experimental strategies and theoretical studies will open up a new avenue to develop new photocatalysts with high hydrogen evolution efficiency.

7.
J Cell Biochem ; 113(10): 3122-32, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22593002

RESUMO

Maple Syrup Urine Disease is a rare metabolic disorder caused by reduced/absent activity of the branched chain α-Ketoacid dehydrogenase enzyme complex. Mutations in BCKDHA, BCKDHB, and DBT, that encode important subunits of the enzyme complex namely E1α, E1ß, and E2, are the primary cause for the disease. We have performed the first molecular genetic analysis of MSUD from India on nine patients exhibiting classical MSUD symptoms. BCKDHA and BCKDHB mutations were identified in four and five patients, respectively including seven novel mutations namely the BCKDHA c.1249delC, c.1312T>C, and c.1561T>A and the BCKDHB c.401T>A, c.548G>A, c.964A>G, and c.1065delT. The BCKDHB c.970C>T (p.R324X) mutation was shown to trigger nonsense mediated decay-based degradation of the transcript. Seven of the total 11 mutations resulted in perturbations in the E1α or E1ß C-termini either through altered termination or through an amino acid change; these are expected to result in disruption of E1 enzyme complex assembly. Our study has therefore revealed that BCKDHA and BCKDHB mutations might be primarily responsible for MSUD in the Indian population.


Assuntos
3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/química , Doença da Urina de Xarope de Bordo/genética , Complexos Multienzimáticos/química , Mutação de Sentido Incorreto , Regiões 3' não Traduzidas , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética , Sequência de Aminoácidos , Aminoácidos/química , Sequência de Bases , Códon sem Sentido/química , Códon sem Sentido/genética , Análise Mutacional de DNA , Feminino , Testes Genéticos , Genoma Humano , Genótipo , Humanos , Índia , Lactente , Recém-Nascido , Masculino , Doença da Urina de Xarope de Bordo/diagnóstico , Dados de Sequência Molecular , Complexos Multienzimáticos/genética , Estabilidade de RNA , Alinhamento de Sequência , Análise de Sequência de Proteína , Deleção de Sequência
8.
Mol Cell Biochem ; 360(1-2): 373-82, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21959974

RESUMO

Familial Hypertrophic Cardiomyopathy (FHC) is an autosomal dominant disorder affecting the cardiac muscle and exhibits varied clinical symptoms because of genetic heterogeneity. Several disease causing genes have been identified and most code for sarcomere proteins. In the current study, we have carried out clinical and molecular analysis of FHC patients from India. FHC was detected using echocardiography and by analysis of clinical symptoms and family history. Disease causing mutations in the ß-cardiac myosin heavy chain (MYH7) and Myosin binding protein C3 (MYBPC3) genes were identified using Polymerase Chain Reaction-Deoxyribose Nucleic Acid (PCR-DNA) sequencing. Of the 55 patient samples screened, mutations were detected in only nineteen in the two genes; MYBPC3 mutations were identified in 12 patients while MYH7 mutations were identified in five, two patients exhibited double heterozygosity. All four MYH7 mutations were missense mutations, whereas only 3/9 MYPBC3 mutations were missense mutations. Four novel mutations in MYBPC3 viz. c.456delC, c.2128G>A (p.E710K), c.3641G>A (p.W1214X), and c.3656T>C (p.L1219P) and one in MYH7 viz. c.965C>T (p.S322F) were identified. A majority of missense mutations affected conserved amino acid residues and were predicted to alter the structure of the corresponding mutant proteins. The study has revealed a greater frequency of occurrence of MYBPC3 mutations when compared to MYH7 mutations.


Assuntos
Miosinas Cardíacas/genética , Cardiomiopatia Hipertrófica Familiar/genética , Proteínas de Transporte/genética , Mutação de Sentido Incorreto , Cadeias Pesadas de Miosina/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Miosinas Cardíacas/química , Pré-Escolar , Sequência Conservada , Feminino , Estudos de Associação Genética , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Cadeias Pesadas de Miosina/química , Peptidil Dipeptidase A/genética , Estrutura Terciária de Proteína , Análise de Sequência de DNA , Adulto Jovem
9.
Hemoglobin ; 36(5): 497-503, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22734501

RESUMO

ß-Thalassemia (ß-thal) is a common single gene autosomal recessive disorder resulting in severe anemia due to reduced or absent ß-globin polypeptide synthesis. The disease is caused by mutations in the ß-globin gene; eight common mutations are proposed to cause the majority of ß-thal in India. However, the occurrence of a region-specific mutation spectrum in India has also been suggested. We had earlier carried out analyses of the ß-globin gene mutation spectrum from southern Indian states of Andhra Pradesh and Karnataka. In the current study, we have analyzed three of 73 transfusion-dependent patients visiting a referral hospital in Karnataka State, South India, who did not carry any of the 22 common ß-globin gene mutations as determined by reverse dot-blot analysis. The IVS-II-837 (T>G) (ß(+)) (HBB:c.316-14TG) mutation was detected in two of the three patients analyzed suggesting a higher occurrence of the mutation in ß-thal patients in Karnataka when compared to other regions of India. The rare polyadenylation (poly A) site (T>C) (AATAAA>AACAAA; ß(+)) mutation was detected in the third patient. The IVS-II-837 mutation was also identified in asymptomatic carrier parents during routine high performance liquid chromatography (HPLC)-based Hb A(1c) screening in suspected diabetes patients. This is the first report of the identification of ß-thal trait through HPLC-based diabetes screening in India, revealing the importance of linking diabetes screening with screening for thalassemia.


Assuntos
Mutação , Globinas beta/genética , Talassemia beta/genética , Adolescente , Adulto , Criança , Feminino , Genótipo , Geografia , Humanos , Índia/epidemiologia , Masculino , Adulto Jovem , Talassemia beta/epidemiologia
10.
Dalton Trans ; 51(48): 18693-18707, 2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36448739

RESUMO

Solar-driven hydrogen generation using single-semiconductor photocatalysts for hydrogen evolution seems to be challenging due to their poor solar to fuel conversion efficiency because of their fast charge carrier recombination. The ternary heterostructure was prepared by an advanced approach to suppress the recombination of photogenerated charge carriers and has contributed a new platform for designing highly efficient photocatalytic systems. Herein, we fabricated a ternary heterojunction with ultrathin WS2-SnS2 nanosheets and CdS nanorods, and the photocatalytic activity was studied. The optimized CdS/SnS2-WS2 (6 wt%) nanostructures were found to be highly stable and exhibited the highest hydrogen evolution rate of 232.45 mmol g-1 h-1, which was almost 93-fold higher than that of the pristine CdS nanorods. Also, Density Functional Theory (DFT) calculations confirmed that the favorable band alignment for charge transport and superior catalytic activity of the newly fabricated ternary nanostructures make them a potential candidate for solar-driven hydrogen production.

11.
Synapse ; 65(7): 592-600, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21484878

RESUMO

UNLABELLED: [F-18]Mefway was developed to provide an F-18 labeled positron emission tomography (PET) neuroligand with high affinity for the serotonin 5-HT(1A) receptor to improve the in vivo assessment of the 5-HT(1A) system. The goal of this work was to compare the in vivo kinetics of [F-18]mefway, [F-18]MPPF, and [C-11]WAY100635 in the rhesus monkey. METHODS: Each of four monkeys were given bolus injections of [F-18]mefway, [C-11]WAY100635, and [F-18]MPPF and scans were acquired with a microPET P4 scanner. Arterial blood was sampled to assay parent compound throughout the time course of the PET experiment. Time activity curves were extracted in the high 5-HT(1A) binding areas of the anterior cingulate cortex (ACG), mesial temporal cortex, raphe nuclei, and insula cortex. Time activity curves were also extracted in the cerebellum, which was used as a reference region. The in vivo kinetics of the radiotracers were compared based on the nondisplaceable distribution volume (V(ND) ) and binding potential (BP(ND) ). RESULTS: At 30 min, the fraction of radioactivity in the plasma due to parent compound was 19%, 28%, and 29% and cleared from the arterial plasma at rates of 0.0031, 0.0078, and 0.0069 (min⁻¹) ([F-18]mefway, [F-18]MPPF, [C-11]WAY100635). The BP(ND) in the brain regions were mesial temporal cortex: 7.4 ± 0.6, 3.1 ± 0.4, 7.0 ± 1.2, ACG: 7.2 ± 1.2, 2.1 ± 0.2, 7.9 ± 1.2; raphe nuclei: 3.7 ± 0.6, 1.3 ± 0.3, 3.3 ± 0.7; and insula cortex: 4.2 ± 0.6, 1.2 ± 0.1, 4.7 ± 1.0 for [F-18]mefway, [F-18]MPPF, and [C-11]WAY100635 respectively. CONCLUSIONS: In the rhesus monkey, [F-18]mefway has similar in vivo kinetics to [C-11]WAY100635 and yields greater than 2-fold higher BP(ND) than [F-18]MPPF. These properties make [F-18]mefway a promising radiotracer for 5-HT(1A) assay, providing higher counting statistics and a greater dynamic range in BP(ND).


Assuntos
Encéfalo/diagnóstico por imagem , Piperazinas/farmacocinética , Piridinas/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Animais , Radioisótopos de Carbono/farmacocinética , Radioisótopos de Flúor/farmacocinética , Macaca mulatta , Tomografia por Emissão de Pósitrons/métodos
12.
Synapse ; 65(12): 1309-18, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21674627

RESUMO

OBJECTIVE: [F-18]Nifene is a PET radioligand developed to image α4ß2* nicotinic acetylcholine receptors (nAChR) in the brain. This work assesses the in vivo binding and imaging characteristics of [F-18]nifene in rhesus monkeys for the development of PET experiments examining nAChR binding. METHODS: Dynamic PET imaging experiments with [F-18]nifene were acquired in four anesthetized Macaca mulatta (rhesus) monkeys using a microPET P4 scanner. Data acquisition was initiated with a bolus injection of 109 ± 17 MBq [F-18]nifene and the time course of the radioligand in the brain was measured for up to 120 min. For two experiments, a displacement dose of (-)nicotine (0.03 mg kg(-1) , i.v.) was given 45-60 min post injection and followed 30 min later with a second [F-18]nifene injection to measure radioligand nondisplaceable uptake. Time activity curves were extracted in the regions of the antereoventral thalamus (AVT), lateral geniculate nucleus region (LGN), frontal cortex, and the cerebellum (CB). RESULTS: The highest levels of [F-18]nifene uptake were observed in the AVT and LGN. Target-to-CB ratios reached maximum values of 3.3 ± 0.4 in the AVT and 3.2 ± 0.3 in the LGN 30-45 min postinjection. Significant binding of [F-18]nifene was observed in the subiculum, insula cortex, temporal cortex, cingulate gyrus, frontal cortex, striatum, and midbrain areas. The (-)nicotine displaced bound [F-18]nifene to near background levels within 15 min postdrug injection. No discernable displacement was observed in the CB, suggesting its potential as a reference region. Logan graphical estimates using the CB as a reference region yielded binding potentials of 1.6 ± 0.2 in the AVT and 1.3 ± 0.1 in the LGN. The postnicotine injection displayed uniform nondisplaceable uptake of [F-18]nifene throughout gray and white brain matter. CONCLUSIONS: [F-18]Nifene exhibits rapid equilibration and a moderately high target to background binding profile in the α4ß2* nAChR rich regions of the brain, thus providing favorable imaging characteristics as a PET radiotracer for nAChR assay.


Assuntos
Piridinas/metabolismo , Pirróis/metabolismo , Receptores Nicotínicos/metabolismo , Animais , Sítios de Ligação/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Feminino , Macaca mulatta , Masculino , Neuroimagem/métodos , Tomografia por Emissão de Pósitrons/métodos , Ligação Proteica/fisiologia
14.
PLoS Genet ; 4(5): e1000081, 2008 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-18535672

RESUMO

Pancreatobiliary cancers have among the highest mortality rates of any cancer type. Discovering the full spectrum of molecular genetic alterations may suggest new avenues for therapy. To catalogue genomic alterations, we carried out array-based genomic profiling of 31 exocrine pancreatic cancers and 6 distal bile duct cancers, expanded as xenografts to enrich the tumor cell fraction. We identified numerous focal DNA amplifications and deletions, including in 19% of pancreatobiliary cases gain at cytoband 18q11.2, a locus uncommonly amplified in other tumor types. The smallest shared amplification at 18q11.2 included GATA6, a transcriptional regulator previously linked to normal pancreas development. When amplified, GATA6 was overexpressed at both the mRNA and protein levels, and strong immunostaining was observed in 25 of 54 (46%) primary pancreatic cancers compared to 0 of 33 normal pancreas specimens surveyed. GATA6 expression in xenografts was associated with specific microarray gene-expression patterns, enriched for GATA binding sites and mitochondrial oxidative phosphorylation activity. siRNA mediated knockdown of GATA6 in pancreatic cancer cell lines with amplification led to reduced cell proliferation, cell cycle progression, and colony formation. Our findings indicate that GATA6 amplification and overexpression contribute to the oncogenic phenotypes of pancreatic cancer cells, and identify GATA6 as a candidate lineage-specific oncogene in pancreatobiliary cancer, with implications for novel treatment strategies.


Assuntos
Neoplasias do Sistema Biliar/genética , Fator de Transcrição GATA6/genética , Amplificação de Genes , Neoplasias Pancreáticas/genética , Animais , Neoplasias do Sistema Biliar/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Cromossomos Humanos Par 18/genética , Fator de Transcrição GATA6/metabolismo , Perfilação da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Camundongos , Neoplasias Pancreáticas/metabolismo , Transplante Heterólogo/patologia , Transplante Heterólogo/veterinária
15.
Mol Genet Metab ; 100(1): 96-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20188615

RESUMO

Analysis of seven Indian phenylketonuria families has revealed four novel mutations in the phenylalanine hydroxylase gene; two affected consensus splice sequence and the 3' UTR, respectively, while the other two were single base insertion and deletion mutations, respectively. A novel 3' splice site mutation c.168-2A>G resulted in the activation of a cryptic 3' splice site that generated a premature termination codon leading to very low levels of the mutant transcript, probably due to activation of the nonsense-mediated decay (NMD) pathway. This is probably the first report of PKU caused by the activation of NMD.


Assuntos
Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Mutação , Fenilcetonúrias/enzimologia , Sítios de Splice de RNA , Deleção de Sequência
16.
Mater Today Proc ; 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33520674

RESUMO

The epic Covid sickness 2019 (COVID-19) has turned into the significant danger to humankind in year 2020. The pandemic COVID-19 flare-up has influenced more than 2.7 million individuals and caused around 187 thousand fatalities worldwide [1] inside scarcely any months of its first appearance in Wuhan city of China and the number is developing quickly in various pieces of world. As researcher everywhere on the world are battling to discover the fix and treatment for COVID-19, the urgent advance fighting against COVID-19 is the screening of immense number of associated cases for disconnection and isolate with the patients. One of the key methodologies in screening of COVID-19 can be chest radiological imaging. The early investigations on the patients influenced by COVID-19 shows the attributes variations from the norm in chest radiography pictures. This introduced a chance to utilize distinctive counterfeit clever (AI) frameworks dependent on profound picking up utilizing chest radiology pictures for the recognition of COVID-19 and numerous such framework were proposed indicating promising outcomes. In this paper, we proposed a profound learning based convolution neural organization to characterize COVID-19, Pneumonia and Normal cases from chest radiology pictures. The proposed convolution neural organization (CNN) grouping model had the option to accomplish exactness of 94.85% on test dataset. The trial was completed utilizing the subset of information accessible in GitHub and Kaggle.

17.
Neuroimage ; 47(4): 1230-6, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19505582

RESUMO

UNLABELLED: The length polymorphism of the serotonin (5-HT) transporter gene promoter region has been implicated in altered 5-HT function and, in turn, neuropsychiatric illnesses, such as anxiety and depression. The nonhuman primate has been used as a model to study anxiety-related mechanisms in humans based upon similarities in behavior and the presence of a similar 5-HT transporter gene polymorphism. Stressful and threatening contexts in the nonhuman primate model have revealed 5-HT transporter genotype dependent differences in regional glucose metabolism. Using the rhesus monkey, we examined the extent to which serotonin transporter genotype is associated with 5-HT transporter binding in brain regions implicated in emotion-related pathology. METHODS: Genotype data and high resolution PET scans were acquired in 29 rhesus (Macaca mulatta) monkeys. [C-11]DASB dynamic PET scans were acquired for 90 min in the anesthetized animals and images of distribution volume ratio (DVR) were created to serve as a metric of 5-HT transporter binding for group comparison based on a reference region method of analysis. Regional and voxelwise statistical analysis were performed with corrections for anatomical differences in gray matter probability, sex, age and radioligand mass. RESULTS: There were no significant differences when comparing l/l homozygotes with s-carriers in the regions of the brain implicated in anxiety and mood related illnesses (amygdala, striatum, thalamus, raphe nuclei, temporal and prefrontal cortex). There was a significant sex difference in 5-HT transporter binding in all regions with females having 18%-28% higher DVR than males. CONCLUSIONS: Because these findings are consistent with similar genotype findings in humans, this further strengthens the use of the rhesus model for studying anxiety-related neuropathologies.


Assuntos
Compostos de Anilina/farmacocinética , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Sulfetos/farmacocinética , Animais , Radioisótopos de Carbono/farmacocinética , Feminino , Genótipo , Humanos , Macaca mulatta , Masculino , Ligação Proteica , Compostos Radiofarmacêuticos/farmacocinética , Distribuição Tecidual
18.
RSC Adv ; 9(59): 34158-34165, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-35530013

RESUMO

The temperature dependence of the stability of bulk BaZrO3 (BZO) and of the vacancies in this material are investigated by considering phonon contributions to the free energy. The stability diagram of BZO is determined for different chemical environments. With increasing temperature the stability region becomes smaller which is particularly caused by the strong temperature dependence of the chemical potential of gaseous oxygen. The free formation energy of Ba, Zr, and O vacancies in BZO is calculated for all possible charge states and for different atomic reservoirs. While the free formation energy of Zr vacancies is strongly influenced by temperature a weaker dependence is found for Ba and O vacancies. This also has an effect on the charge transition levels at different temperatures. The present results demonstrate that O poor reservoir conditions and a Fermi level close to the valence band maximum favour a high concentration of doubly positively charged O vacancies which is a prerequisite to get a large number of protonic defects and good proton conductivity. In such a chemical environment the number of Ba and Zr vacancies is low so that Ba and Zr deficiencies are not an important issue and BZO remains sufficiently stable.

19.
Sci Rep ; 8(1): 8005, 2018 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-29789634

RESUMO

Recently the solar energy, an inevitable part of green energy source, has become a mandatory topics in frontier research areas. In this respect, non-centrosymmetric ferroelectric perovskites with open circuit voltage (VOC) higher than the bandgap, gain tremendous importance as next generation photovoltaic materials. Here a non-toxic co-doped Ba1-x(Bi0.5Li0.5) x TiO3 ferroelectric system is designed where the dopants influence the band topology in order to enhance the photovoltaic effect. In particular, at the optimal doping concentration (x opt ~ 0.125) the sample reveals a remarkably high photogenerated field EOC = 320 V/cm (VOC = 16 V), highest ever reported in any bulk polycrystalline non-centrosymmetric systems. The band structure, examined through DFT calculations, suggests that the shift current mechanism is key to explain the large enhancement in photovoltaic effect in this family.

20.
J Mol Med (Berl) ; 96(2): 135-146, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29124284

RESUMO

Our previous extensive analysis revealed a significant proportion of early-onset colorectal tumors from India to be localized to the rectum in younger individuals and devoid of deregulated Wnt/ß-catenin signaling. In the current study, we performed a comprehensive genome-wide analysis of clinically well-annotated microsatellite stable early-onset sporadic rectal cancer (EOSRC) samples. Results revealed extensive DNA copy number alterations in rectal tumors in the absence of deregulated Wnt/ß-catenin signaling. More importantly, transcriptome profiling revealed a (non-Wnt/ß-catenin, non-MSI) genetic signature that could efficiently and specifically identify Wnt- rectal cancer. The genetic signature included a significant representation of genes belonging to Ca2+/NFAT signaling pathways that were validated in additional samples. The validated NFAT target genes exhibited significantly higher expression levels than canonical Wnt/ß-catenin targets in Wnt- samples, an observation confirmed in other CRC expression data sets as well. We confirmed the validated genes to be transcriptionally regulated by NFATc1 by (a) evaluating their respective transcript levels and (b) performing promoter-luciferase and chromatin immunoprecipitation assays following ectopic expression as well as knockdown of NFATc1 in CRC cells. NFATc1 and its targets RUNX2 and GSN could drive increased migration in CRC cells. Finally, the validated genes were associated with poor survival in the cancer genome atlas CRC expression data set. This study is the first comprehensive molecular characterization of EOSRC that appears to be driven by noncanonical tumorigenesis pathways. KEY MESSAGES: Early-onset sporadic rectal cancer exhibits DNA gain and loss without Wnt activation. Ca2+/NFAT signaling appears to be activated in the absence of Wnt activation. An eight-gene genetic signature distinguishes Wnt+ and Wnt- rectal tumors. NFAT and its target genes regulate tumorigenic properties in CRC cells.


Assuntos
Cálcio/metabolismo , Fatores de Transcrição NFATC/metabolismo , Neoplasias Retais/metabolismo , Proteínas Wnt/metabolismo , Adulto , Idade de Início , Células HCT116 , Humanos , Índia , Pessoa de Meia-Idade , Neoplasias Retais/genética , Transdução de Sinais , Adulto Jovem
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