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1.
Heliyon ; 8(12): e12124, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36561696

RESUMO

Background: Dermaseptins (Drs) are peptides found in the skin secretions of a variety of Hylid frogs, particularly those belonging to the Agalychnis and Phyllomedusa families. Dermaseptin B2 (Drs B2), an amphipathic, α-helical polypeptide was reported as the most active of the Dermaseptin B family. We have previously shown that Drs B2 has strong anti-proliferative activities against RD cells in vitro and thus required further evaluations for future medical applications. Aim: The aim the study was to evaluate the 14-day sub-acute and 90-day sub-chronic toxicities Drs B2 in vivo. Materials and Methods: BALB/c mice were treated with increasing concentrations of 5-25 mg/kg of Drs B2. Rats were treated with 2, 4 and 10-fold concentrations of the calculated LD50 of Drs B2 following OECD recommendations. At the end of the experimentation periods, the animals were sacrificed and dissected to collect blood and selected organs for analysis of any effects caused by Drs B2 treatment on the biochemical, haematological, and histological parameters. Results: The 14-day sub-acute toxicity tests did not cause significant alteration in the biochemical, hematological and histological parameters. The 90-day sub-chronic toxicity study showed lower ALT and AST than control at doses 1.9 mg/kg and 4.6 mg/kg, respectively. Their haematology results also showed higher platelet count than the controls but the differences were not statistically significant. Histological analysis showed increased megakaryocytes in the spleen for both the mice and the rats. Conclusion: The results of this study indicate that short term treatment of Drs B2 could be safe to the animals, however, long-term treatment can have mild effects on the liver parameters and cause an inflammatory response in the spleen.

2.
Medicine (Baltimore) ; 100(40): e27460, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622871

RESUMO

ABSTRACT: An estimated 1.5 million Kenyans are HIV-seropositive, with 1.1 million on antiretroviral therapy (ART), with the majority of them unaware of their drug resistance status. In this study, we assessed the prevalence of drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs), nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors, and the variables associated with drug resistance in patients failing treatment in Nairobi, Kenya.This cross-sectional study utilized 128 HIV-positive plasma samples obtained from patients enrolled for routine viral monitoring in Nairobi clinics between 2015 and 2017. The primary outcome was human immunodeficiency virus type 1 (HIV-1) drug resistance mutation counts determined by Sanger sequencing of the polymerase (pol) gene followed by interpretation using Stanford's HIV Drug Resistance Database. Poisson regression was used to determine the effects of sex, viral load, age, HIV-subtype, treatment duration, and ART-regimen on the primary outcome.HIV-1 drug resistance mutations were found in 82.3% of the subjects, with 15.3% of subjects having triple-class ART resistance and 45.2% having dual-class resistance. NRTI primary mutations M184 V/I and K65R/E/N were found in 28.8% and 8.9% of subjects respectively, while NNRTI primary mutations K103N/S, G190A, and Y181C were found in 21.0%, 14.6%, and 10.9% of subjects. We found statistically significant evidence (P = .013) that the association between treatment duration and drug resistance mutations differed by sex. An increase of one natural-log transformed viral load unit was associated with 11% increase in drug resistance mutation counts (incidence rate ratio [IRR] 1.11; 95% CI 1.06-1.16; P < .001) after adjusting for age, HIV-1 subtype, and the sex-treatment duration interaction. Subjects who had been on treatment for 31 to 60 months had 63% higher resistance mutation counts (IRR 1.63; 95% CI 1.12-2.43; P = .013) compared to the reference group (<30 months). Similarly, patients on ART for 61 to 90 months were associated with 133% higher mutation counts than the reference group (IRR 2.33; 95% CI 1.59-3.49; P < .001). HIV-1 subtype, age, or ART-regimen were not associated with resistance mutation counts.Drug resistance mutations were found in alarmingly high numbers, and they were associated with viral load and treatment time. This finding emphasizes the importance of targeted resistance monitoring as a tool for addressing the problem.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Adolescente , Adulto , Fatores Etários , Fármacos Anti-HIV/farmacologia , Estudos Transversais , Feminino , Genótipo , Humanos , Quênia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Carga Viral , Adulto Jovem , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética
3.
Tumour Biol ; 43(1): 37-55, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33935122

RESUMO

BACKGROUND: Green synthesized nanoparticles have been earmarked for use in nanomedicine including for the development of better anticancer drugs. OBJECTIVE: The aim of this study was to undertake biochemical evaluation of anticancer activities of green synthesized silver nanoparticles (AgNPs) from ethanolic extracts of fruits (AgNPs-F) and leaves (AgNPs-L) of Annona muricata. METHODS: Previously synthesized silver nanoparticles were used for the study. The effects of the AgNPs and 5-Fluorouracil were studied on PC3, HeLa and PNT1A cells. The resazurin, migration and colonogenic assays as well as qRT-PCR were employed. RESULTS: The AgNPs-F displayed significant antiproliferative effects against HeLa cells with an IC50 of 38.58µg/ml and PC3 cells with an IC50 of 48.17µg/ml but selectively spared normal PNT1A cells (selectivity index of 7.8), in comparison with first line drug 5FU and AgNPs-L whose selectivity index were 3.56 and 2.26 respectively. The migration assay revealed potential inhibition of the metastatic activity of the cells by the AgNPs-F while the colonogenic assay indicated the permanent effect of the AgNPs-F on the cancer cells yet being reversible on the normal cells in contrast with 5FU and AgNPs-L. CASP9 was significantly over expressed in all HeLa cells treated with the AgNPs-F (1.53-fold), AgNPs-L (1.52-fold) and 5FU (4.30-fold). CXCL1 was under expressed in HeLa cells treated with AgNPs-F (0.69-fold) and AgNPs-L (0.58-fold) and over expressed in cells treated with 5FU (4.95-fold), but the difference was not statistically significant. CXCR2 was significantly over expressed in HeLa cells treated with 5FU (8.66-fold) and AgNPs-F (1.12-fold) but under expressed in cells treated with AgNPs-L (0.76-fold). CONCLUSIONS: Here we show that biosynthesized AgNPs especially AgNPs-F can be used in the development of novel and better anticancer drugs. The mechanism of action of the AgNPs involves activation of the intrinsic apoptosis pathway through upregulation of CASP9 and concerted down regulation of the CXCL1/ CXCR2 gene axis.


Assuntos
Annona/química , Antineoplásicos/farmacologia , Caspase 9/genética , Quimiocina CXCL1/genética , Nanopartículas Metálicas , Receptores de Interleucina-8B/genética , Prata/farmacologia , Adenocarcinoma/patologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Química Verde , Humanos , Masculino , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Neoplasias da Próstata/patologia , Neoplasias do Colo do Útero/patologia
4.
Data Brief ; 26: 104442, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31528676

RESUMO

In this article, we present data on the anticancer activities of green synthesized silver nanoparticles (AgNPs) from ethanolic extracts of fruits (AgNPs-F) and leaves (AgNPs-L) of Annona muricata and standard anticancer drug 5-Fluorouracil (5-FU) on two cancer cell lines, i.e. cervical adenocarcinoma (HeLa cells) and prostate adenocarcinoma (PC3 cells) as well as on an immortalized normal prostate cell line, PNT1A. The cytotoxicity on the cells was determined by measuring the absorbance signal of resazurin dye. It has long been known that metabolically active cells change the resazurin from blue (oxidized) to red (reduced) forms, corresponding to the absorbance signals at a wavelength of 570nm (A570) and 600nm (A600) respectively, from which therefore the effects of any treatments on percentage cell viability/death can be elucidated. The raw data values of the treatments against the HeLa, PC3 and PNT1A cells are shown in the different Tables. Examples of how the data can be analyzed have been illustrated using different growth inhibition curves. The data can be used by academics, students, and researchers working on development of anticancer drugs.

5.
Data Brief ; 25: 104194, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31321276

RESUMO

In this data article, data obtained from an efficient, eco-friendly and low-cost method for the synthesis and recovery of Silver nanoparticles (AgNPs) using ethanolic extracts of Annona muricata fruits and leaves as reducing, stabilizing and capping agents has been reported. 99.7% pure silver nitrate was used as the inorganic ion source. The data was obtained using different spectroscopic and microscopic techniques. The data is presented in form of images, Microsoft excel sheets, graphs,.raw files,.dpt files, PDF files, among others. Methods of analysis and interpretation of the data have also been presented. The data can be most useful to researchers, research students, industrialists and academicians to acquire knowledge on the green synthesis of AgNPs and related applications. The data is deposited in the Mendeley Data Repository as two independent datasets accessible at https://doi.org/10.17632/jkj2x782wh.1 Gavamukulya et al., 2019 and https://doi.org/10.17632/f4mb6b488n.1 Gavamukulya et al., 2019.

6.
J Chem Ecol ; 44(11): 1030-1039, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30084041

RESUMO

Foraging parasitoids use chemical signals in host recognition and selection processes. Although, the volatiles play a relevant role in the localization by parasitoids of their hosts feeding on plants, the host identification process for acceptance occurs mainly during contact between the parasitoid and its host where host products related to feeding activities, fecal pellets and oral secretions, play a crucial role. The purpose of this study was to identify the nature of the contact kairomone(s) that mediate the acceptance for oviposition of the parasitoid Cotesia flavipes Cameron (Hymenoptera, Braconidae), which was released in Kenya in 1993 to control the invasive crambid Chilo partellus (Swinhoe). Using host and non-hosts of C. flavipes, we showed that it is mainly the oral secretions of the larvae that harbour the active compound(s) that mediate host acceptance for oviposition by C. flavipes. Using an integration of behavioral observations and biochemical approaches, the active compound of the oral secretions was identified as an α-amylase. Using synthetized α-amylases from Drosophila melanogaster (an insect model for which syntheses of active and inactive α-amylases are available), we observed that the conformation of the enzyme rather than its catalytic site as well as its substrate and its degradation product is responsible for host acceptance and oviposition mediation of C. flavipes females. The results suggest that the α-amylase from oral secretions of the caterpillar host is a good candidate for an evolutionary solution to host acceptance for oviposition in C. flavipes.


Assuntos
Vespas/fisiologia , Zea mays/parasitologia , alfa-Amilases/metabolismo , Animais , Antenas de Artrópodes/efeitos dos fármacos , Antenas de Artrópodes/fisiologia , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Interações Hospedeiro-Parasita , Proteínas de Insetos/análise , Proteínas de Insetos/metabolismo , Larva/efeitos dos fármacos , Larva/fisiologia , Oviposição , Espectrometria de Massas em Tandem , Vespas/crescimento & desenvolvimento , Zea mays/metabolismo , alfa-Amilases/farmacologia
7.
Acta Paediatr ; 106(10): 1666-1673, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28580692

RESUMO

AIM: The Helping Babies Breathe (HBB) programme is known to decrease neonatal mortality in low-resource settings but gaps in care still exist. This study describes the use of quality improvement to sustain gains in birth asphyxia-related mortality after HBB. METHODS: Tenwek Hospital, a rural referral hospital in Kenya, identified high rates of birth asphyxia (BA). They developed a goal to decrease the suspected hypoxic-ischaemic encephalopathy (SHIE) rate by 50% within six months after HBB. Rapid cycles of change were used to test interventions including training, retention and engagement for staff/trainees and improved data collection. Run charts followed the rate over time, and chi-square analysis was used. RESULTS: Ninety-six providers received HBB from September to November 2014. Over 4000 delivery records were reviewed. Ten months of baseline data showed a median SHIE rate of 14.7/1000 live births (LB) with wide variability. Ten months post-HBB, the SHIE rate decreased by 53% to 7.1/1000 LB (p = 0.01). SHIE rates increased after initial decline; investigation determined that half the trained midwives had been transferred. Presenting data to administration resulted in staff retention. Rates have after remained above goal with narrowing control limits. CONCLUSION: Focused quality improvement can sustain and advance gains in neonatal outcomes post-HBB training.


Assuntos
Asfixia Neonatal/prevenção & controle , Educação Continuada/estatística & dados numéricos , Hipóxia-Isquemia Encefálica/prevenção & controle , Asfixia Neonatal/etiologia , Humanos , Hipóxia-Isquemia Encefálica/complicações , Recém-Nascido , Quênia , Melhoria de Qualidade , Respiração Artificial
8.
J Pathol ; 217(3): 345-52, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19142888

RESUMO

A micro-array analysis using biopsies from patients with EBV-positive undifferentiated nasopharyngeal carcinoma (NPC) and from cancer-free controls revealed down-regulation of tumour suppressor genes (TSG) not previously associated with this disease; one such gene was the ataxia telangiectasia mutated (ATM) gene. Q-PCR confirmed down-regulation of ATM mRNA and ATM protein expression in tumour cells was weak or absent in almost all cases. In NPC cell lines, however, ATM was down-regulated only in the EBV-positive line, C666.1, and in none of five EBV-negative lines. In vitro infection of EBV-negative NPC cell lines with a recombinant EBV was followed by the down-regulation of ATM mRNA and protein, and only EBV-positive cells showed a defective DNA damage response following gamma-irradiation. Our data suggest that loss of ATM function could be an important step in the pathogenesis of NPC, and may have implications for the treatment of this disease.


Assuntos
Adenocarcinoma/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Neoplasias Nasofaríngeas/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Supressoras de Tumor/genética , Adenocarcinoma/virologia , Proteínas Mutadas de Ataxia Telangiectasia , Estudos de Casos e Controles , Proteínas de Ciclo Celular/análise , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/análise , Perfilação da Expressão Gênica/métodos , Herpesvirus Humano 4 , Humanos , Imuno-Histoquímica , Neoplasias Nasofaríngeas/virologia , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Serina-Treonina Quinases/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Supressoras de Tumor/análise , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/genética
9.
Blood ; 113(1): 117-26, 2009 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-18941120

RESUMO

The molecular basis of different outcomes in pediatric acute lymphoblastic leukemia (ALL) remains poorly understood. We addressed the clinical significance and mechanisms behind in vitro cellular responses to ionizing radiation (IR)-induced DNA double-strand breaks in 74 pediatric patients with ALL. We found an apoptosis-resistant response in 36% of patients characterized by failure to cleave caspase-3, -7, -9, and PARP1 by 24 hours after IR and an apoptosis-sensitive response with the cleavage of the same substrates in the remaining 64% of leukemias. Resistance to IR in vitro was associated with poor early blast clearance at day 7 or 15 and persistent minimal residual disease (MRD) at day 28 of induction treatment. Global gene expression profiling revealed abnormal up-regulation of multiple prosurvival pathways in response to IR in apoptosis-resistant leukemias and differential posttranscriptional activation of the PI3-Akt pathway was observed in representative resistant cases. Importantly, pharmacologic inhibition of selected prosurvival pathways sensitized apoptosis-resistant ALL cells to IR in vitro. We suggest that abnormal prosurvival responses to DNA damage provide one of the mechanisms of primary resistance in ALL, and that they should be considered as therapeutic targets in children with aggressive disease.


Assuntos
Quebras de DNA de Cadeia Dupla , Regulação Leucêmica da Expressão Gênica , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Apoptose/efeitos da radiação , Crise Blástica/genética , Crise Blástica/patologia , Caspase 3/metabolismo , Caspase 7/metabolismo , Caspase 9/metabolismo , Células Cultivadas , Criança , Perfilação da Expressão Gênica , Humanos , Técnicas In Vitro , Neoplasia Residual/genética , Neoplasia Residual/patologia , Neoplasia Residual/terapia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Radiação Ionizante , Transdução de Sinais
10.
Am J Med Genet A ; 146A(7): 843-53, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18324689

RESUMO

The two main causes of Prader-Willi syndrome (PWS) are a paternally derived deletion in the maternally imprinted 15q11-q13 region or UPD(15)mat. Both mechanisms result in a loss of the active paternal contribution to the region. The affective psychosis associated with PWS has been found to be mainly confined to the propositi with UPD(15)mat rather than to those with a deletion. This suggests that the psychosis may be related to the presence of two copies rather than a single copy of a gene or genes located in the distal half of the region which is paternally imprinted, but maternally active, and whose loss results in Angelman syndrome (AS). A large population-based study of PWS allowed the identification of 12 people with a 15q11-q13 deletion who had suffered psychotic episodes and four adults with UPD(15)mat who so far had not. When these people were investigated using microsatellite markers, the 12 with a deletion were found to have two maternally derived copies of a narrow region between D15S975 and D15S661 making them effectively disomic for these loci. Thus all of the people with psychosis had two active copies of any imprinted genes in the region while all non-psychotic people (including controls) had only one. Quantitative RT-PCR studies suggest that a lack of expression of FLJ33332, either as a result of or resulting in gene dysregulation, may be associated with psychosis in PWS.


Assuntos
Síndrome de Prader-Willi/genética , Transtornos Psicóticos/genética , Adulto , Estudos de Casos e Controles , Deleção Cromossômica , Cromossomos Humanos Par 15 , Etiquetas de Sequências Expressas , Feminino , Heterozigoto , Humanos , Masculino , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
J Hum Genet ; 52(4): 297-307, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17262171

RESUMO

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder associated with abnormalities of chromosome 15q11q13. The majority of cases result either from a deletion approximately 4 Mb in size, affecting chromosome 15 of paternal origin or from UPD(15)mat; these account for approximately 70 and approximately 20-25% of PWS cases, respectively. In the remaining 3-5% of PWS cases where neither the deletion nor UPD is detectable, PWS is thought to be caused either by a defect in the imprinting centre resulting in a failure to reset the paternally inherited chromosome 15 derived from the paternal grandmother or, very occasionally, from a balanced translocation involving a breakpoint in 15q11q13. Nine probands with a firm clinical diagnosis of PWS but who had neither a typical deletion in the PWS region nor UPD(15)mat were investigated for inactivating mutations in 11 genes located in the PWS region, including SNURF and SNRPN, which are associated with the imprinting centre. Other genes studied for mutations included MKRN3, NDN, IPW, HBII-85, HBII-13, HBII-436, HBII-438a, PAR1 and PAR5. A possibly inactivating mutation in the SNRPN minimal promoter region was identified. No other inactivating mutations were found in the remainder of our panel of PWS subjects with atypical genetics. Expression levels of several of the candidate genes for PWS were also investigated in this series of probands. The results indicate that PWS may result from a stochastic partial inactivation of important genes.


Assuntos
Autoantígenos/genética , Inativação Gênica , Impressão Genômica , Proteínas Nucleares/genética , Síndrome de Prader-Willi/genética , Ribonucleoproteínas Nucleares Pequenas/genética , Cromossomos Humanos Par 15/genética , Análise Mutacional de DNA , Expressão Gênica , Humanos , Mutação , Regiões Promotoras Genéticas/genética , Proteínas Centrais de snRNP
12.
Nat Genet ; 38(2): 191-6, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16415887

RESUMO

Meckel-Gruber syndrome is a severe autosomal, recessively inherited disorder characterized by bilateral renal cystic dysplasia, developmental defects of the central nervous system (most commonly occipital encephalocele), hepatic ductal dysplasia and cysts and polydactyly. MKS is genetically heterogeneous, with three loci mapped: MKS1, 17q21-24 (ref. 4); MKS2, 11q13 (ref. 5) and MKS3 (ref. 6). We have refined MKS3 mapping to a 12.67-Mb interval (8q21.13-q22.1) that is syntenic to the Wpk locus in rat, which is a model with polycystic kidney disease, agenesis of the corpus callosum and hydrocephalus. Positional cloning of the Wpk gene suggested a MKS3 candidate gene, TMEM67, for which we identified pathogenic mutations for five MKS3-linked consanguineous families. MKS3 is a previously uncharacterized, evolutionarily conserved gene that is expressed at moderate levels in fetal brain, liver and kidney but has widespread, low levels of expression. It encodes a 995-amino acid seven-transmembrane receptor protein of unknown function that we have called meckelin.


Assuntos
Anormalidades Múltiplas/genética , Mutação/genética , Proteínas/genética , Ratos Mutantes/genética , Animais , Sequência de Bases , Análise Mutacional de DNA , Modelos Animais de Doenças , Éxons/genética , Feminino , Marcadores Genéticos , Haplótipos , Humanos , Íntrons/genética , Masculino , Proteínas de Membrana , Dados de Sequência Molecular , Defeitos do Tubo Neural/genética , Linhagem , Mapeamento Físico do Cromossomo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Síndrome
13.
Cancer Res ; 65(11): 4598-606, 2005 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15930277

RESUMO

Following treatment with a demethylating agent, 5 of 11 renal cell carcinoma (RCC) cell lines showed increased expression of hepatocyte growth factor (HGF) activator inhibitor type 2 (HAI-2/SPINT2/Bikunin), a Kunitz-type protease inhibitor that regulates HGF activity. As activating mutations in the MET proto-oncogene (the HGF receptor) cause familial RCC, we investigated whether HAI-2/SPINT2 might act as a RCC tumor suppressor gene. We found that transcriptional silencing of HAI-2 in RCC cell lines was associated with promoter region methylation and HAI-2/SPINT2 protein expression was down-regulated in 30% of sporadic RCC. Furthermore, methylation-specific PCR analysis revealed promoter region methylation in 30% (19 of 64) of clear cell RCC and 40% (15 of 38) of papillary RCC, whereas mutation analysis (in 39 RCC cell lines and primary tumors) revealed a missense substitution (P111S) in one RCC cell line. Restoration of HAI-2/SPINT2 expression in a RCC cell line reduced in vitro colony formation, but the P111S mutant had no significant effect. Increased cell motility associated with HAI-2/SPINT2 inactivation was abrogated by treatment with extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) and phospholipase C-gamma inhibitors, but not by an inhibitor of atypical protein kinase C. These findings are consistent with frequent epigenetic inactivation of HAI-2/SPINT2, causing loss of RCC tumor suppressor activity and implicate abnormalities of the MET pathway in clear cell and papillary sporadic RCC. This information provides opportunities to develop novel targeted approaches to the treatment of RCC.


Assuntos
Adenocarcinoma de Células Claras/genética , Carcinoma Papilar/genética , Carcinoma de Células Renais/genética , Genes Supressores de Tumor , Neoplasias Renais/genética , Glicoproteínas de Membrana/genética , Inibidor da Tripsina de Soja de Kunitz/genética , Adenocarcinoma de Células Claras/metabolismo , Adenocarcinoma de Células Claras/patologia , Animais , Sequência de Bases , Células COS , Carcinoma Papilar/metabolismo , Carcinoma Papilar/patologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Adesão Celular/fisiologia , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Chlorocebus aethiops , Metilação de DNA , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Glicoproteínas de Membrana/biossíntese , Dados de Sequência Molecular , Células-Tronco Neoplásicas , Regiões Promotoras Genéticas , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-met , Receptores de Fatores de Crescimento/genética , Transdução de Sinais , Inibidor da Tripsina de Soja de Kunitz/biossíntese
14.
Oncogene ; 24(28): 4549-58, 2005 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-15824735

RESUMO

Upregulation of hypoxia-inducible factors HIF-1 and HIF-2 is frequent in human cancers and may result from tissue hypoxia or genetic mechanisms, in particular the inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene (TSG). Tumours with VHL inactivation are highly vascular, but it is unclear to what extent HIF-dependent and HIF-independent mechanisms account for pVHL tumour suppressor activity. As the identification of novel pVHL targets might provide insights into pVHL tumour suppressor activity, we performed gene expression microarray analysis in VHL-wild-type and VHL-null renal cell carcinoma (RCC) cell lines. We identified 30 differentially regulated pVHL targets (26 of which were 'novel') and the results of microarray analysis were confirmed in all 11 novel targets further analysed by real-time RT-PCR or Western blotting. Furthermore, nine of 11 targets were dysregulated in the majority of a series of primary clear cell RCC with VHL inactivation. Three of the nine targets had been identified previously as candidate TSGs (DOC-2/DAB2, CDKN1C and SPARC) and all were upregulated by wild-type pVHL. The significance for pVHL function of two further genes upregulated by wild-type pVHL was initially unclear, but re-expression of GNG4 (G protein gamma-4 subunit/guanine nucleotide-binding protein-4) and MLC2 (myosin light chain) in a RCC cell line suppressed tumour cell growth. pVHL regulation of CDKN1C, SPARC and GNG4 was not mimicked by hypoxia, whereas for six of 11 novel targets analysed (including DOC-2/DAB2 and MLC2) the effects of pVHL inactivation and hypoxia were similar. For GPR56 there was evidence of a tissue-specific hypoxia response. Such a phenomenon might, in part, explain organ-specific tumorigenesis in VHL disease. These provide insights into mechanisms of pVHL tumour suppressor function and identify novel hypoxia-responsive targets that might be implicated in tumorigenesis in both VHL disease and in other cancers with HIF upregulation.


Assuntos
Regulação Neoplásica da Expressão Gênica , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular/genética , Proteínas Reguladoras de Apoptose , Western Blotting , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Miosinas Cardíacas/genética , Miosinas Cardíacas/metabolismo , Hipóxia Celular/fisiologia , Inibidor de Quinase Dependente de Ciclina p57 , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/genética , Genes Supressores de Tumor , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Neoplasias Renais/genética , Neoplasias Renais/patologia , Cadeias Leves de Miosina/genética , Cadeias Leves de Miosina/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Osteonectina/genética , Oxigênio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau
15.
Nat Genet ; 37(3): 221-3, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15696165

RESUMO

Warburg Micro syndrome (WARBM1) is a severe autosomal recessive disorder characterized by developmental abnormalities of the eye and central nervous system and by microgenitalia. We identified homozygous inactivating mutations in RAB3GAP, encoding RAB3 GTPase activating protein, a key regulator of the Rab3 pathway implicated in exocytic release of neurotransmitters and hormones, in 12 families with Micro syndrome. We hypothesize that the underlying pathogenesis of Micro syndrome is a failure of exocytic release of ocular and neurodevelopmental trophic factors.


Assuntos
Mutação , Proteínas rab de Ligação ao GTP/metabolismo , Domínio Catalítico , Sistema Nervoso Central/anormalidades , Anormalidades do Olho/patologia , Genitália/anormalidades , Humanos , Dados de Sequência Molecular , Síndrome , Proteínas rab de Ligação ao GTP/genética
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