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1.
Int J Mol Sci ; 25(1)2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38203214

RESUMEN

Single-agent regorafenib is approved in Canada for metastatic colorectal cancer (mCRC) patients who have failed previous lines of therapy. Identifying prognostic biomarkers is key to optimizing therapeutic strategies for these patients. In this clinical study (NCT01949194), we evaluated the safety and efficacy of single-agent regorafenib as a second-line therapy for mCRC patients who received it after failing first-line therapy with an oxaliplatin or irinotecan regimen with or without bevacizumab. Using various omics approaches, we also investigated putative biomarkers of response and resistance to regorafenib in metastatic lesions and blood samples in the same cohort. Overall, the safety profile of regorafenib seemed similar to the CORRECT trial, where regorafenib was administered as ≥ 2 lines of therapy. While the mutational landscape showed typical mutation rates for the top five driver genes (APC, KRAS, BRAF, PIK3CA, and TP53), KRAS mutations were enriched in intrinsically resistant lesions. Additional exploration of genomic-phenotype associations revealed several biomarker candidates linked to unfavorable prognoses in patients with mCRC using various approaches, including pathway analysis, cfDNA profiling, and copy number analysis. However, further research endeavors are necessary to validate the potential utility of these promising genes in understanding patients' responses to regorafenib treatment.


Asunto(s)
Neoplasias del Colon , Proteínas Proto-Oncogénicas p21(ras) , Piridinas , Humanos , Biomarcadores , Compuestos de Fenilurea/uso terapéutico
2.
Clin Transl Med ; 11(4): e401, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33931971

RESUMEN

BACKGROUND: Therapeutic resistance is the main cause of death in metastatic colorectal cancer. To investigate genomic plasticity, most specifically of metastatic lesions, associated with response to first-line systemic therapy, we collected longitudinal liver metastatic samples and characterized the copy number aberration (CNA) landscape and its effect on the transcriptome. METHODS: Liver metastatic biopsies were collected prior to treatment (pre, n = 97) and when clinical imaging demonstrated therapeutic resistance (post, n = 43). CNAs were inferred from whole exome sequencing and were correlated with both the status of the lesion and overall patient progression-free survival (PFS). We used RNA sequencing data from the same sample set to validate aberrations as well as independent datasets to prioritize candidate genes. RESULTS: We identified a significantly increased frequency gain of a unique CN, in liver metastatic lesions after first-line treatment, on chr18p11.32 harboring 10 genes, including TYMS, which has not been reported in primary tumors (GISTIC method and test of equal proportions, FDR-adjusted p = 0.0023). CNA lesion profiles exhibiting different treatment responses were compared and we detected focal genomic divergences in post-treatment resistant lesions but not in responder lesions (two-tailed Fisher's Exact test, unadjusted p ≤ 0.005). The importance of examining metastatic lesions is highlighted by the fact that 15 out of 18 independently validated CNA regions found to be associated with PFS in this study were only identified in the metastatic lesions and not in the primary tumors. CONCLUSION: This investigation of genomic-phenotype associations in a large colorectal cancer liver metastases cohort identified novel molecular features associated with treatment response, supporting the clinical importance of collecting metastatic samples in a defined clinical setting.


Asunto(s)
Neoplasias Colorrectales/genética , Variaciones en el Número de Copia de ADN/genética , Transcriptoma/genética , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Bevacizumab/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Resistencia a Antineoplásicos/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Supervivencia sin Progresión , Secuenciación del Exoma
3.
J Assoc Physicians India ; 69(2): 73-74, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33527820

RESUMEN

Pseudo-aneurysm of the brachial artery is relatively rare condition affecting the arterial vessels of the limbs. It can be due to trauma, infections or systemic vasculitis. We report a patient with aplastic anemia who developed pseudoaneurysm of the brachial artery following an episode of bacterial sepsis. Methicillin resistant Staphylococcus aureus (MRSA) was isolated on blood culture. Patient was treated with systemic antibiotics and underwent embolization of the pseudo-aneurysm. He later developed vascular insufficiency of the forearm and a stent had to be placed in the brachial artery at the site of calcified thrombus inside the pseudo-aneurysm to produce the patency of the artery and ensure adequate blood flow to forearm and hand.


Asunto(s)
Anemia Aplásica , Aneurisma Falso , Aneurisma Infectado , Staphylococcus aureus Resistente a Meticilina , Anemia Aplásica/complicaciones , Aneurisma Falso/diagnóstico por imagen , Aneurisma Falso/etiología , Aneurisma Falso/terapia , Aneurisma Infectado/diagnóstico por imagen , Aneurisma Infectado/terapia , Arteria Braquial/diagnóstico por imagen , Humanos , Masculino
4.
Plant Direct ; 3(11): e00177, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31788657

RESUMEN

MYC2 is a basic helix-loop-helix transcription factor that acts as a repressor of blue light-mediated photomorphogenic growth; however, it promotes lateral root formation. MYC2 also regulates different phytohormone-signaling pathways in crucial manner. Arabidopsis response regulator 16 (ARR16) is a negative regulator of cytokinin signaling pathways. Here, we show that MYC2 directly binds to the E-box of ARR16 minimal promoter and negatively regulates its expression in a cytokinin-dependent manner. While ARR16 and MYC2 influence jasmonic acid and cytokinin signaling, the expression of ARR16 is regulated by cry1, GBF1, and HYH, the components of light signaling pathways. The transgenic studies show that the expression of ARR16 is regulated by MYC2 at various stages of development. The mutational studies reveal that ARR16 positively regulates the hypocotyl growth in blue light, and phenotypic analysis of atmyc2 arr16 double mutant further reveals that arr16 can suppress the short hypocotyl phenotype of atmyc2. Altogether, this work highlights MYC2-mediated transcriptional repression of ARR16 in Arabidopsis seedling development.

5.
Mol Plant Microbe Interact ; 32(10): 1429-1447, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31184524

RESUMEN

Concomitant increase of auxin-responsive factors ARF16 and ARF17, along with enhanced expression of ARF10 in resistant Sinapis alba compared with that in susceptible Brassica juncea upon challenge with Alternaria brassicicola, revealed that abscisic acid (ABA)-auxin crosstalk is a critical factor for resistance response. Here, we induced the ABA response through conditional expression of ARF10 in B. juncea using the A. brassicicola-inducible GH3.3 promoter. Induced ABA sensitivity caused by conditional expression of ARF10 in transgenic B. juncea resulted in tolerance against A. brassicicola and led to enhanced expression of several ABA-responsive genes without affecting the auxin biosynthetic gene expression. Compared with ABI3 and ABI4, ABI5 showed maximum upregulation in the most tolerant transgenic lines upon pathogen challenge. Moreover, elevated expression of ARF10 by different means revealed a direct correlation between ARF10 expression and the induction of ABI5 protein in B. juncea. Through in vitro DNA-protein experiments and chromosome immunoprecipitation using the ARF10 antibody, we demonstrated that ARF10 interacts with the auxin-responsive elements of the ABI5 promoter. This suggests that ARF10 may function as a modulator of ABI5 to induce ABA sensitivity and mediate the resistance response against A. brassicicola.


Asunto(s)
Ácido Abscísico , Alternaria , Proteínas de Arabidopsis , Regulación de la Expresión Génica de las Plantas , Planta de la Mostaza , Factores de Transcripción , Alternaria/fisiología , Ácidos Indolacéticos/metabolismo , Planta de la Mostaza/genética , Planta de la Mostaza/microbiología , Factores de Transcripción/genética
6.
Mol Cancer Ther ; 18(9): 1628-1636, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31243098

RESUMEN

Rearrangements in the anaplastic lymphoma kinase (ALK) gene are found in approximately 5% of non-small cell lung carcinoma (NSCLC). Here, we present a comprehensive genomic landscape of 11 patients with ALK+ NSCLC and investigate its relationship with response to crizotinib. Using whole-exome sequencing and RNAseq data, we identified four rare ALK fusion partners (HIP1, GCC2, ERC1, and SLC16A7) and one novel partner (CEP55). At the mutation level, TP53 was the most frequently mutated gene and was only observed in patients with the shortest progression-free survival (PFS). Of note, only 4% of the genes carrying mutations are present in more than 1 patient. Analysis of somatic copy number aberrations (SCNA) demonstrated that a gain in EML4 was associated with longer PFS, and a loss of ALK or gain in EGFR was associated with shorter PFS. This study is the first to report a comprehensive view of the ALK+ NSCLC copy number landscape and to identify SCNA regions associated with clinical outcome. Our data show the presence of TP53 mutation as a strong prognostic indication of poor clinical response in ALK+ NSCLC. Furthermore, new and rare ALK fusion partners were observed in this cohort, expanding our knowledge in ALK+ NSCLC.


Asunto(s)
Quinasa de Linfoma Anaplásico/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Crizotinib/uso terapéutico , Variaciones en el Número de Copia de ADN , Genómica/métodos , Neoplasias Pulmonares/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Proteínas de Ciclo Celular/genética , Supervivencia sin Enfermedad , Femenino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Mutación , Proteínas de Fusión Oncogénica/genética , Estudios Prospectivos , Proteína p53 Supresora de Tumor/genética
7.
Plant J ; 99(6): 1080-1097, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31059179

RESUMEN

Arabidopsis MYC2 bHLH transcription factor plays a negative regulatory role in blue light (BL)-mediated seedling development. HY5 bZIP protein works as a positive regulator of multiple wavelengths of light and promotes photomorphogenesis. Both MYC2 and HY5, belonging to two different classes of transcription factors, are the integrators of multiple signaling pathways. However, the functional interrelations of these two transcription factors in seedling development remain unknown. Additionally, whereas HY5-mediated regulation of gene expression has been investigated in detail, the transcriptional regulation of HY5 itself is yet to be understood. Here, we show that HY5 and MYC2 work in an antagonistic manner in Arabidopsis seedling development. Our results reveal that HY5 expression is negatively regulated by MYC2 predominantly in BL, and at various stages of development. On the other hand, HY5 negatively regulates the expression of MYC2 at various wavelengths of light. In vitro and in vivo DNA-protein interaction studies suggest that MYC2 binds to the E-box cis-acting element of HY5 promoter. Collectively, this study demonstrates a coordinated regulation of MYC2 and HY5 in blue-light-mediated Arabidopsis seedling development.


Asunto(s)
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Plantones/genética , Antocianinas/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación , Clorofila/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Gravitropismo/genética , Luz , Microscopía Fluorescente , Mutación , Fenotipo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Regiones Promotoras Genéticas , Unión Proteica , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Transducción de Señal/genética , Transducción de Señal/efectos de la radiación , Técnicas del Sistema de Dos Híbridos
8.
Lancet Oncol ; 18(9): 1202-1210, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28729151

RESUMEN

BACKGROUND: Reduced-dose nivolumab in combination with standard-dose ipilimumab improves objective response and progression-free survival compared with standard-dose ipilimumab alone, but increases toxicity. We assessed the safety and anti-tumour activity of standard-dose pembrolizumab in combination with reduced-dose ipilimumab. METHODS: In this open-label, phase 1b trial, we recruited patients from 12 medical centres in Australia, New Zealand, and the USA. Eligible patients were aged at least 18 years, had advanced melanoma, had an Eastern Coooperative Oncology Group performance status of 0 or 1, had measurable disease according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, had adequate organ function, had resolution of toxic effects of the most recent previous chemotherapy to grade 1 or less, had no active autoimmune disease requiring systemic steroids or immunosuppressive agents, had no active non-infectious pneumonitis, had no uncontrolled thyroid dysfunction or diabetes, had no active brain metastases, and had not received previous immune checkpoint inhibitor therapy. Patients received intravenous pembrolizumab 2 mg/kg plus intravenous ipilimumab 1 mg/kg every 3 weeks for four doses, followed by intravenous pembrolizumab 2 mg/kg every 3 weeks for up to 2 years or disease progression, intolerable toxicity, withdrawal of consent, or investigator decision. The primary endpoint was safety and tolerability. The proportion of patients achieving an objective response assessed per RECIST version 1.1 by independent central review and overall survival were secondary endpoints. We also assessed progression-free survival. The primary endpoint was assessed in all patients who received at least one dose of combination therapy. Activity was assessed in all enrolled patients. This trial is registered with ClinicalTrials.gov, number NCT02089685. Enrolment into this cohort is closed, but patients are still being monitored for safety and anti-tumour activity. FINDINGS: Between Jan 13, 2015, and Sept 17, 2015, we enrolled and treated 153 patients. As of the Oct 17, 2016, cutoff date, median follow-up was 17·0 months (IQR 14·8-18·8). 110 (72%) of 153 patients received all four pembrolizumab plus ipilimumab doses; 64 (42%) remained on pembrolizumab monotherapy. 110 grade 3-4 treatment-related adverse events occurred in 69 (45%) patients. No treatment-related deaths occurred. Treatment-related adverse events led to discontinuation of pembrolizumab and ipilimumab in 22 (14%) patients, including 17 (11%) who discontinued both treatments for the same event and five (3%) who discontinued ipilimumab for one event and later discontinued pembrolizumab for another. 12 (8%) patients discontinued ipilimumab only and 14 (9%) discontinued pembrolizumab only because of treatment-related adverse events. 158 immune-mediated adverse events of any grade occurred in 92 (60%) patients, and 50 immune-mediated adverse events of grade 3-4 occurred in 42 (27%) patients; the most common immune-mediated adverse events were hypothyroidism (25 [16%]) and hyperthyroidism (17 [11%]). 93 (61% [95% CI 53-69]) patients achieved an objective response. Estimated 1 year progression-free survival was 69% (95% CI 60-75), and estimated 1 year overall survival was 89% (95% CI 83-93). INTERPRETATION: Standard-dose pembrolizumab given in combination with four doses of reduced-dose ipilimumab followed by standard-dose pembrolizumab has a manageable toxicity profile and provides robust anti-tumour activity in patients with advanced melanoma. These data suggest that standard-dose pembrolizumab plus reduced-dose ipilimumab might be a tolerable, efficacious treatment option for patients with advanced melanoma. A randomised phase 2 trial of alternative dosing strategies of this combination is underway. FUNDING: Merck & Co, Inc.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Melanoma/tratamiento farmacológico , Melanoma/secundario , Anciano , Australia , Supervivencia sin Enfermedad , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Humanos , Ipilimumab , Masculino , Melanoma/mortalidad , Persona de Mediana Edad , Nueva Zelanda , Resultado del Tratamiento , Estados Unidos
9.
Plant Physiol ; 169(4): 2922-34, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26474641

RESUMEN

Arabidopsis (Arabidopsis thaliana) Short Hypocotyl in White Light1 (SHW1) encodes a Ser-Arg-Asp-rich protein that acts as a negative regulator of photomorphogenesis. SHW1 and Constitutive Photomorphogenic1 (COP1) genetically interact in an additive manner to suppress photomorphogenesis. Elongated Hypocotyl5 (HY5) is a photomorphogenesis promoting a basic leucine zipper transcription factor that is degraded by COP1 ubiquitin ligase in the darkness. Here, we report the functional interrelation of SHW1 with COP1 and HY5 in Arabidopsis seedling development. The in vitro and in vivo molecular interaction studies show that SHW1 physically interacts with both COP1 and HY5. The genetic studies reveal that SHW1 and HY5 work in an antagonistic manner to regulate photomorphogenic growth. Additional mutation of SHW1 in hy5 mutant background is able to suppress the gravitropic root growth defect of hy5 mutants. This study further reveals that the altered abscisic acid responsiveness of hy5 mutants is modulated by additional loss of SHW1 function. Furthermore, this study shows that SHW1 promotes COP1-mediated degradation of HY5 through enhanced ubiquitylation in the darkness. Collectively, this study highlights a mechanistic view on coordinated regulation of SHW1, COP1, and HY5 in Arabidopsis seedling development.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Proteínas Nucleares/metabolismo , Plantones/metabolismo , Ácido Abscísico/farmacología , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Western Blotting , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Luz , Mutación , Proteínas Nucleares/genética , Organogénesis de las Plantas/efectos de los fármacos , Organogénesis de las Plantas/genética , Organogénesis de las Plantas/efectos de la radiación , Reguladores del Crecimiento de las Plantas/farmacología , Unión Proteica , Proteolisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Plantones/genética , Plantones/crecimiento & desarrollo , Técnicas del Sistema de Dos Híbridos , Ubiquitina-Proteína Ligasas , Ubiquitinación/efectos de los fármacos , Ubiquitinación/efectos de la radiación
10.
Acta Neuropathol ; 128(1): 111-22, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24839956

RESUMEN

Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5' arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 "hits" occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis.


Asunto(s)
ARN Helicasas DEAD-box/genética , Mutación , Neoplasias Complejas y Mixtas/genética , Neoplasias Complejas y Mixtas/patología , Neoplasias Hipofisarias/genética , Neoplasias Hipofisarias/patología , Ribonucleasa III/genética , Preescolar , Análisis Mutacional de ADN , Resultado Fatal , Mutación de Línea Germinal , Humanos , Inmunohistoquímica , Lactante , Imagen por Resonancia Magnética , Neoplasias Complejas y Mixtas/cirugía , Linaje , Neoplasias Hipofisarias/cirugía , Radiografía Torácica , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
11.
Eur J Hum Genet ; 22(4): 564-7, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24065110

RESUMEN

DICER1 is an endoribonuclease responsible for the production of mature microRNAs which are small, single-stranded RNA molecules that regulate gene expression post-transcriptionally by binding to mRNA and repressing the expression of target genes. Germ-line mutations in DICER1 are responsible for a rare cancer syndrome, including tumors that can co-occur with multinodular goiter (MNG). Using Sanger sequencing, we screened all DICER1 exons and intron boundaries in 20 suspected mutation carriers: nine with ovarian sex cord-stromal tumors (including Sertoli-Leydig cell tumors (SLCTs)), five with pleuropulmonary blastoma, one with cystic nephroma, one with nasal chondromesenchymal hamartoma and four with more than one manifestation suggestive of a germ-line DICER1 mutation. All were negative for any apparently deleterious variants. We developed a Multiplex Ligation-based Probe Amplification assay for DICER1 to screen for large deletions or duplications. Synthetic oligonucleotides were designed to cover all exons in three probe-mixes. In a child with a SLCT and MNG, and in her mother and brother (both diagnosed with MNG), we identified a heterozygous germ-line deletion of approximately 3 kilobases that eliminates exon 21 of DICER1 and two-thirds of intron 21, accompanied by an insertion of a G nucleotide at the 3' end of the deletion (c.3270-6_4051-1280delinsG). This allele is expressed in the patient's cDNA, creating an out-of-frame deletion predicted to result in a truncated protein (r.3270_4050del; p.Tyr1091Ser*28). Our novel finding of a disease-causing large deletion in DICER1 emphasizes the need to include assays that can detect rearrangements, duplications and deletions in any DICER1 screening protocol.


Asunto(s)
ARN Helicasas DEAD-box/genética , Células Germinativas/química , Reacción en Cadena de la Polimerasa Multiplex/métodos , Oligonucleótidos/química , Ribonucleasa III/genética , Eliminación de Secuencia , Alelos , Niño , Exones , Femenino , Mutación del Sistema de Lectura , Reordenamiento Génico , Mutación de Línea Germinal , Bocio Nodular/complicaciones , Bocio Nodular/genética , Humanos , Intrones , Masculino , Neoplasias Ováricas/complicaciones , Neoplasias Ováricas/genética , Linaje , Análisis de Secuencia de ADN
14.
Hum Mutat ; 32(12): 1381-4, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21882293

RESUMEN

DICER1 is crucial for embryogenesis and early development. Forty different heterozygous germline DICER1 mutations have been reported worldwide in 42 probands that developed as children or young adults, pleuropulmonary blastoma (PPB), cystic nephroma (CN), ovarian sex cord-stromal tumors (especially Sertoli-Leydig cell tumor [SLCT]), and/or multinodular goiter (MNG). We report DICER1 mutations in seven additional families that manifested uterine cervix embryonal rhabdomyosarcoma (cERMS, four cases) and primitive neuroectodermal tumor (cPNET, one case), Wilms tumor (WT, three cases), pulmonary sequestration (PS, one case), and juvenile intestinal polyp (one case). One carrier developed (age 25 years) a pleomorphic sarcoma of the thigh; another carrier had transposition of great arteries (TGA). These observations show that cERMS, cPNET, WT, PS, and juvenile polyps fall within the spectrum of DICER1-related diseases. DICER1 appears to be the first gene implicated in the etiology of cERMS, cPNET, and PS. Young adulthood sarcomas and perhaps congenital malformations such as TGA may also be associated.


Asunto(s)
Secuestro Broncopulmonar/genética , ARN Helicasas DEAD-box/genética , Poliposis Intestinal/congénito , Mutación , Tumores Neuroectodérmicos Primitivos/genética , Rabdomiosarcoma Embrionario/genética , Ribonucleasa III/genética , Neoplasias del Cuello Uterino/genética , Tumor de Wilms/genética , Adolescente , Adulto , Secuestro Broncopulmonar/patología , Niño , Preescolar , Familia , Femenino , Humanos , Poliposis Intestinal/genética , Poliposis Intestinal/patología , Masculino , Síndromes Neoplásicos Hereditarios , Tumores Neuroectodérmicos Primitivos/patología , Fenotipo , Rabdomiosarcoma Embrionario/patología , Neoplasias del Cuello Uterino/patología , Tumor de Wilms/patología
16.
Int J Biol Macromol ; 45(3): 293-7, 2009 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-19549542

RESUMEN

A water-soluble seed gum was isolated from seed endosperm of Cassia javahikai. The acid-catalyzed fragmentation, methylation, selective enzymatic degradation and periodate oxidation suggested a heteropolymeric structure for the polysaccharide. The polysaccharide was shown to have a linear chain of beta(1-->4) linked d-mannopyranosyls units with side chains of alpha(1-->6) d-galactopyranosyl units. Grafting of polyacrylamide onto the gum was performed using K(2)S(2)O(8)/ascorbic acid redox system in presence of Ag(+) as catalyst at 35+/-2 degrees C. The viscosity of the gum solution increased on grafting and the grafted gum was observed to resist biodegradation for more than 256h. Thermogravimetric analysis revealed that grafted gum was more thermally stable than native gum.


Asunto(s)
Cassia/química , Gomas de Plantas/química , Semillas/química , Conformación de Carbohidratos , Monosacáridos/química , Oligosacáridos/química , Oligosacáridos/aislamiento & purificación , Soluciones , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termogravimetría , Viscosidad
17.
FEBS Lett ; 583(7): 1096-101, 2009 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-19289122

RESUMEN

Recent studies have identified Rab35 in the endocytic pathway and as a regulator of cytokinesis; however its molecular mechanisms are currently unknown. Here, we find that Rab35 colocalizes with actin filaments and with Cdc42, Rac1 and RhoA, and that Rab35 can activate Cdc42 both in vivo and in vitro. We find activated Rab35 stimulates neurite outgrowth in PC12 and N1E-115 cells via a Cdc42-dependent pathway and that siRNA knockdown of Rab35 activity abolishes neurite outgrowth in these cell lines. We conclude that one function of Rab35 is to regulate Rho-family GTPases and that this role has consequences for neurite outgrowth.


Asunto(s)
Forma de la Célula/fisiología , Citocinesis/fisiología , Neuritas/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Actinas/genética , Actinas/metabolismo , Animales , Cricetinae , Endocitosis/fisiología , Ratones , Neuropéptidos/genética , Neuropéptidos/metabolismo , Células PC12 , Ratas , Proteína de Unión al GTP cdc42/genética , Proteína de Unión al GTP cdc42/metabolismo , Proteínas de Unión al GTP rab/genética , Proteínas de Unión al GTP rac/genética , Proteínas de Unión al GTP rac/metabolismo , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Proteína de Unión al GTP rhoA
18.
J Phys Condens Matter ; 21(9): 096001, 2009 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-21817407

RESUMEN

We have investigated the thermal properties of electron doped perovskite manganite CaMnO(3), the end member ([Formula: see text]) of the Ruddlesden-Popper (RP) calcium manganates series with cation doping at the A-site. In this paper the functional relation between the lattice distortions and the thermal properties is determined and compared to available reports. The temperature dependence of the lattice specific heat (C(v(lattice))) of Ca(1-x)Ln(x)MnO(3) (x = 0.05, 0.10, 0.15, 0.20) with Ln(= La, Ce, Pr, Nd, Th, Bi) doping at the A-site has been studied as a function of temperature (10 K≤T≤500 K) by means of a rigid ion model (RIM) after modifying its framework to incorporate the van der Waals interactions. Strong electron-phonon interactions are present in these compounds, which are responsible for the variation of the lattice specific heat with cation doping of varying size and valency. We have found that the calculated thermal properties reproduce well the corresponding experimental data, implying that modified RIM represents properly the nature of these perovskite manganite systems. We demonstrate that the electron concentration, size mismatch and Jahn-Teller (JT) effects are the dominant factors, whereas charge mismatch and buckling of Mn-O-Mn angle influence the thermal properties to a lesser degree in the ferromagnetic state. In the insulating paramagnetic state, JT distortions vary linearly and influence the thermal properties. These specific heat results can be further improved by including the ferromagnetic spin wave and charge order contributions to the specific heat.

19.
J Neurochem ; 98(6): 1746-62, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16879712

RESUMEN

NECAPs (adaptin ear-binding clathrin-associated protein) are a new family of clathrin accessory proteins identified through a proteomic analysis of clathrin-coated vesicles (CCVs) from the brain. One member of this family, NECAP 1, is found primarily in tissues from the central nervous system and has been shown to be complexed tightly with a substantial portion of adaptor protein-2 (AP-2) in brain extracts. However, the function and intracellular location of this protein is unknown. In this study, we find that endogenous and epitope-tagged NECAP 1 co-localizes well with clathrin and AP-2 in punctate structures, many of which also contain the presynaptic markers synaptophysin, synaptotagmin or synaptic vesicle protein 2 (SV2). NECAP 1 was also detected by western blot in synaptic vesicle preparations. Overexpression of a truncation mutant of NECAP 1 (BC-NECAP 1) in neurons inhibited transferrin endocytosis but not epidermal growth factor (EGF) endocytosis, and this inhibition was dependent on an AP-2-binding WVQF motif. Moreover, overexpression of BC-NECAP 1 results in inhibition of synaptotagmin endocytosis both in unstimulated neurons and in neurons stimulated with potassium chloride. This inhibition was abrogated by truncation of the WVQF domain. We conclude from these observations that NECAP 1 plays a role in clathrin-mediated neuronal endocytosis, including a role in presynaptic endocytosis.


Asunto(s)
Proteínas de la Membrana/fisiología , Neuronas/fisiología , Complejo 2 de Proteína Adaptadora/metabolismo , Animales , Biomarcadores/metabolismo , Células Cultivadas , Clatrina/metabolismo , Endocitosis/efectos de los fármacos , Factor de Crecimiento Epidérmico/metabolismo , Epítopos , Eliminación de Gen , Hipocampo/citología , Hipocampo/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Proteínas de la Membrana/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fragmentos de Péptidos/genética , Cloruro de Potasio/farmacología , Ratas , Sinapsis/metabolismo , Sinaptotagminas/metabolismo , Factores de Tiempo , Distribución Tisular , Transferrina/metabolismo
20.
J Environ Biol ; 25(1): 93-8, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15303710

RESUMEN

Duckweed (Lemna minor) a small vascular plant, grows rapidly, is sensitive to a wide variety of toxicants and is easy to culture. A method is described that measures duckweed frond growth, chlorophyll, protein and biomass content as indicator of growth inhibition. The physico-chemical analysis of anaerobically treated distillery effluent revealed high BOD (28,000 mg/l), COD (52,400 mg/l) and dark brown colour (180,000 Co. Pt.). This effluent showed high toxicity to Lemna minor after 96 h of exposure in laboratory condition. EC50 of the fronds for chlorophyll, protein and biomass was found to be 25%, however, the bacterial decolourised effluent showed reduction of BOD (87.50%), COD (84.50%) and colour (76%). Further the toxicity evaluation with Lemna minor showed toxicity reduction up to 63% for all tested parameters. The EC50 noted for chlorophyll, protein and biomass was 100% concentration of decolourised effluent.


Asunto(s)
Bacterias/metabolismo , Plantas/efectos de los fármacos , Pruebas de Toxicidad/métodos , Contaminantes del Agua/toxicidad , Animales , Biodegradación Ambiental , Bioensayo , Biomasa , Clorofila/metabolismo , Microbiología Industrial , Residuos Industriales , Pigmentos Biológicos/metabolismo , Desarrollo de la Planta , Factores de Tiempo
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