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1.
Nature ; 574(7776): 127-131, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31570881

RESUMEN

The large-scale genetic profiling of tumours can identify potentially actionable molecular variants for which approved anticancer drugs are available1-3. However, when patients with such variants are treated with drugs outside of their approved label, successes and failures of targeted therapy are not systematically collected or shared. We therefore initiated the Drug Rediscovery protocol, an adaptive, precision-oncology trial that aims to identify signals of activity in cohorts of patients, with defined tumour types and molecular variants, who are being treated with anticancer drugs outside of their approved label. To be eligible for the trial, patients have to have exhausted or declined standard therapies, and have malignancies with potentially actionable variants for which no approved anticancer drugs are available. Here we show an overall rate of clinical benefit-defined as complete or partial response, or as stable disease beyond 16 weeks-of 34% in 215 treated patients, comprising 136 patients who received targeted therapies and 79 patients who received immunotherapy. The overall median duration of clinical benefit was 9 months (95% confidence interval of 8-11 months), including 26 patients who were experiencing ongoing clinical benefit at data cut-off. The potential of the Drug Rediscovery protocol is illustrated by the identification of a successful cohort of patients with microsatellite instable tumours who received nivolumab (clinical benefit rate of 63%), and a cohort of patients with colorectal cancer with relatively low mutational load who experienced only limited clinical benefit from immunotherapy. The Drug Rediscovery protocol facilitates the defined use of approved drugs beyond their labels in rare subgroups of cancer, identifies early signals of activity in these subgroups, accelerates the clinical translation of new insights into the use of anticancer drugs outside of their approved label, and creates a publicly available repository of knowledge for future decision-making.


Asunto(s)
Antineoplásicos/uso terapéutico , Descubrimiento de Drogas/métodos , Reposicionamiento de Medicamentos/tendencias , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Femenino , Humanos , Inmunoterapia , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Neoplasias/genética , Nivolumab/uso terapéutico , Medicina de Precisión , Supervivencia sin Progresión , Proyectos de Investigación , Adulto Joven
2.
BMC Med Educ ; 23(1): 196, 2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-36991413

RESUMEN

BACKGROUND: Medical schools are reported to be less accessible to students with non-traditional backgrounds. These students face barriers when applying for and transitioning to medical school, which may be reduced by offering free preparatory activities. By equalizing access to resources, these activities are expected to reduce disparities in selection outcomes and early academic performance. In the present study, four free institutionally-provided preparatory activities were evaluated by comparing the demographic composition of participating and non-participating applicants. Additionally, the association between participation and selection outcomes and early academic performance was investigated for subgroups (based on sex, migration background and parental education). METHODS: Participants were applicants to a Dutch medical school in 2016-2019 (N = 3592). Free preparatory activities included Summer School (N = 595), Coaching Day (N = 1794), Pre-Academic Program (N = 217), and Junior Med School (N = 81), supplemented with data on participation in commercial coaching (N = 65). Demographic compositions of participants and non-participants were compared using chi-squared tests. Regression analyses were performed to compare selection outcomes (curriculum vitae [CV], selection test score, probability of enrolment) and early academic performance (first-course grade) between participants and non-participants of demographic subgroups, controlling for pre-university grades and participation in other activities. RESULTS: Generally, no differences in sociodemographic compositions of participants and non-participants were found, but males participated less often in Summer School and Coaching Day. Applicants with a non-Western background participated less often in commercial coaching, but the overall participation rate was low and participation had negligible effects on selection outcomes. Participation in Summer School and Coaching Day were stronger related with selection outcomes. In some cases, this association was even stronger for males and candidates with a migration background. After controlling for pre-university grades, none of the preparatory activities were positively associated with early academic performance. CONCLUSIONS: Free institutionally-provided preparatory activities may contribute to student diversity in medical education, because usage was similar across sociodemographic subgroups, and participation was positively associated with selection outcomes of underrepresented and non-traditional students. However, since participation was not associated with early academic performance, adjustments to activities and/or curricula are needed to ensure inclusion and retention after selection.


Asunto(s)
Educación Médica , Criterios de Admisión Escolar , Masculino , Humanos , Estudios de Cohortes , Escolaridad , Etnicidad , Facultades de Medicina
3.
Am J Physiol Endocrinol Metab ; 323(6): E492-E502, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36223522

RESUMEN

Secretion of insulin from the pancreas is pulsatile, driven by intrinsic oscillations within individual islets of Langerhans. The secretions are coordinated among the many islets distributed throughout the pancreas producing a synchronized rhythm in vivo that is essential for maintaining normal glucose levels. One hypothesized mechanism for the coordination of islet activity is negative feedback, whereby sequestration of glucose in response to elevated insulin leads to a reduction in the blood glucose level that is sensed by the islet population. This global signal of glucose then coordinates the individual islets. In this study, we tested how this coordination mechanism is affected by time delays in the negative feedback, using a microfluidic system to monitor Ca2+ levels in a small population of islets and implementing glucose control through a negative feedback system. We found that islet synchronization occurs even with time delays in the feedback of up to 7 min. We also found that a second, slower closed-loop oscillation period is produced during delayed feedback in which islet oscillations are clustered into episodes. The period of this second oscillatory mode increases with the time delay and appears to be a second stable behavior that coexists with the faster synchronized oscillation. The general conclusion is that islet coordination through negative feedback is a viable means of islet coordination that is robust to delays in the timing of the feedback, and could complement other potential coordination mechanisms such as entrainment by pancreatic ganglia.NEW & NOTEWORTHY Insulin secretion from islets of Langerhans is rhythmic, and these rhythms are coordinated to produce oscillatory plasma insulin levels. Using a combination of microfluidics and computational modeling, we demonstrate that coordination can occur through negative feedback of the type provided by the liver, even if that feedback is delayed by several minutes. We also demonstrate that a second, slower, mode of oscillations can occur when feedback is delayed where faster oscillations are grouped into episodes.


Asunto(s)
Islotes Pancreáticos , Retroalimentación , Islotes Pancreáticos/metabolismo , Secreción de Insulina , Insulina/metabolismo , Glucosa/metabolismo
4.
Neuropathol Appl Neurobiol ; 46(5): 478-492, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32072658

RESUMEN

AIMS: Methylation profiling (MP) is increasingly incorporated in the diagnostic process of central nervous system (CNS) tumours at our centres in The Netherlands and Scandinavia. We aimed to identify the benefits and challenges of MP as a support tool for CNS tumour diagnostics. METHODS: About 502 CNS tumour samples were analysed using (850 k) MP. Profiles were matched with the DKFZ/Heidelberg CNS Tumour Classifier. For each case, the final pathological diagnosis was compared to the diagnosis before MP. RESULTS: In 54.4% (273/502) of all analysed cases, the suggested methylation class (calibrated score ≥0.9) corresponded with the initial pathological diagnosis. The diagnosis of 24.5% of these cases (67/273) was more refined after incorporation of the MP result. In 9.8% of cases (49/502), the MP result led to a new diagnosis, resulting in an altered WHO grade in 71.4% of these cases (35/49). In 1% of cases (5/502), the suggested class based on MP was initially disregarded/interpreted as misleading, but in retrospect, the MP result predicted the right diagnosis for three of these cases. In six cases, the suggested class was interpreted as 'discrepant but noncontributory'. The remaining 33.7% of cases (169/502) had a calibrated score <0.9, including 7.8% (39/502) for which no class indication was given at all (calibrated score <0.3). CONCLUSIONS: MP is a powerful tool to confirm and fine-tune the pathological diagnosis of CNS tumours, and to avoid misdiagnoses. However, it is crucial to interpret the results in the context of clinical, radiological, histopathological and other molecular information.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Metilación de ADN , Sistemas de Apoyo a Decisiones Clínicas , Perfilación de la Expresión Génica/métodos , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
6.
Ann Oncol ; 28(9): 2128-2134, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28911067

RESUMEN

BACKGROUND: The phase 3 CAIRO3 study showed that capecitabine plus bevacizumab (CAP-B) maintenance treatment after six cycles capecitabine, oxaliplatin, and bevacizumab (CAPOX-B) in metastatic colorectal cancer (mCRC) patients is effective, without compromising quality of life. In this post hoc analysis with updated follow-up and data regarding sidedness, we defined subgroups according to RAS/BRAF mutation status and mismatch repair (MMR) status, and investigated their influence on treatment efficacy. PATIENTS AND METHODS: A total of 558 patients with previously untreated mCRC and stable disease or better after six cycles CAPOX-B induction treatment were randomised to either CAP-B maintenance treatment (n = 279) or observation (n = 279). Upon first progression, patients were to receive CAPOX-B reintroduction until second progression (PFS2, primary end point). We centrally assessed RAS/BRAF mutation status and MMR status, or used local results if central assessment was not possible. Intention-to-treat stratified Cox models adjusted for baseline covariables were used to examine whether treatment efficacy was modified by RAS/BRAF mutation status. RESULTS: RAS, BRAF mutations, and MMR deficiency were detected in 240/420 (58%), 36/381 (9%), and 4/279 (1%) patients, respectively. At a median follow-up of 87 months (IQR 69-97), all mutational subgroups showed significant improvement from maintenance treatment for the primary end point PFS2 [RAS/BRAF wild-type: hazard ratio (HR) 0.57 (95% CI 0.39-0.84); RAS-mutant: HR 0.74 (0.55-0.98); V600EBRAF-mutant: HR 0.28 (0.12-0.64)] and secondary end points, except for the RAS-mutant subgroup regarding overall survival. Adjustment for sidedness instead of primary tumour location yielded comparable results. Although right-sided tumours were associated with inferior prognosis, both patients with right- and left-sided tumours showed significant benefit from maintenance treatment. CONCLUSIONS: CAP-B maintenance treatment after six cycles CAPOX-B is effective in first-line treatment of mCRC across all mutational subgroups. The benefit of maintenance treatment was most pronounced in patients with RAS/BRAF wild-type and V600EBRAF-mutant tumours. CLINICALTRIALS.GOV NUMBER: NCT00442637.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bevacizumab/administración & dosificación , Capecitabina/administración & dosificación , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/genética , Neoplasias Colorrectales/patología , Reparación de la Incompatibilidad de ADN/genética , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Metástasis de la Neoplasia , Síndromes Neoplásicos Hereditarios/genética , Observación , Proteínas Proto-Oncogénicas B-raf/genética , Resultado del Tratamiento , Proteínas ras/genética
7.
BMC Cancer ; 17(1): 282, 2017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28424071

RESUMEN

BACKGROUND: The identification of four Consensus Molecular Subtypes (CMS1-4) of colorectal cancer forms a new paradigm for the design and evaluation of subtype-directed therapeutic strategies. The most aggressive subtype - CMS4 - has the highest chance of disease recurrence. Novel adjuvant therapies for patients with CMS4 tumours are therefore urgently needed. CMS4 tumours are characterized by expression of mesenchymal and stem-like genes. Previous pre-clinical work has shown that targeting Platelet-Derived Growth Factor Receptors (PDGFRs) and the related KIT receptor with imatinib is potentially effective against mesenchymal-type colon cancer. In the present study we aim to provide proof for the concept that imatinib can reduce the aggressive phenotype of primary CMS4 colon cancer. METHODS: Tumour biopsies from patients with newly diagnosed stage I-III colon cancer will be analysed with a novel RT-qPCR test to pre-select patients with CMS4 tumours. Selected patients (n = 27) will receive treatment with imatinib (400 mg per day) starting two weeks prior to planned tumour resection. To assess treatment-induced changes in the aggressive CMS4 phenotype, RNA sequencing will be performed on pre- and post-treatment tissue samples. DISCUSSION: The development of effective adjuvant therapy for primary colon cancer is hindered by multiple factors. First, new drugs that may have value in the prevention of (early) distant recurrence are almost always first tested in patients with heavily pre-treated metastatic disease. Second, measuring on-target drug effects and biological consequences in tumour tissue is not commonly a part of the study design. Third, due to the lack of patient selection tools, clinical trials in the adjuvant setting require large patient populations. Finally, the evaluation of recurrence-prevention requires a long-term follow-up. In the ImPACCT trial these issues are addressed by including newly diagnosed pre-selected patients with CMS4 tumours prior to primary tumour resection, rather than non-selected patients with late-stage disease. By making use of the pre-operative window period, the biological effect of imatinib treatment on CMS4 tumours can be rapidly assessed. Delivering proof-of-concept for drug action in early stage disease should form the basis for the design of future trials with subtype-targeted therapies in colon cancer patients. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02685046 . Registration date: February 9, 2016.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Mesilato de Imatinib/uso terapéutico , Quimioterapia Adyuvante , Ensayos Clínicos Fase II como Asunto , Neoplasias Colorrectales/patología , Humanos , Estudios Multicéntricos como Asunto , Periodo Preoperatorio , Pronóstico , Proyectos de Investigación , Resultado del Tratamiento
8.
Adv Health Sci Educ Theory Pract ; 22(2): 243-265, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27757558

RESUMEN

Situational Judgment Tests (SJTs) are increasingly used for medical school selection. Scoring an SJT is more complicated than scoring a knowledge test, because there are no objectively correct answers. The scoring method of an SJT may influence the construct and concurrent validity and the adverse impact with respect to non-traditional students. Previous research has compared only a small number of scoring methods and has not studied the effect of scoring method on internal consistency reliability. This study compared 28 different scoring methods for a rating SJT on internal consistency reliability, adverse impact and correlation with personality. The scoring methods varied on four aspects: the way of controlling for systematic error, and the type of reference group, distance and central tendency statistic. All scoring methods were applied to a previously validated integrity-based SJT, administered to 931 medical school applicants. Internal consistency reliability varied between .33 and .73, which is likely explained by the dependence of coefficient alpha on the total score variance. All scoring methods led to significantly higher scores for the ethnic majority than for the non-Western minorities, with effect sizes ranging from 0.48 to 0.66. Eighteen scoring methods showed a significant small positive correlation with agreeableness. Four scoring methods showed a significant small positive correlation with conscientiousness. The way of controlling for systematic error was the most influential scoring method aspect. These results suggest that the increased use of SJTs for selection into medical school must be accompanied by a thorough examination of the scoring method to be used.


Asunto(s)
Prueba de Admisión Académica , Juicio , Personalidad , Facultades de Medicina/normas , Adolescente , Femenino , Humanos , Masculino , Grupos Minoritarios , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Factores Socioeconómicos , Adulto Joven
9.
Dis Esophagus ; 30(9): 1-8, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28859360

RESUMEN

Survival of patients with esophageal adenocarcinoma remains poor and individual differences in prognosis remain unexplained. This study investigated whether gene mutations can explain why patients with high-risk (pT3-4, pN+) esophageal adenocarcinoma survive past 5 years after esophagectomy. Six long-term survivors (LTS) (≥5 years survival without recurrence) and six short-term survivors (STS) (<2 years survival due to recurrence) who underwent resection without neoadjuvant therapy for high-risk esophageal adenocarcinoma were included. Targeted next-generation sequencing of 16 genes related to esophageal adenocarcinoma was performed. Mutations were compared between the LTS and STS and described in comparison with literature. A total of 48 mutations in 10 genes were identified. In the LTS, the median number of mutated genes per sample was 5 (range: 0-5) and the samples together harbored 22 mutations in 8 genes: APC (n = 1), CDH11 (n = 2), CDKN2A (n = 2), FAT4 (n = 5), KRAS (n = 1), PTPRD (n = 1), TLR4 (n = 8), and TP53 (n = 2). The median number of mutated genes per sample in the STS was 4 (range: 1-8) and in total 26 mutations were found in six genes: CDH11 (n = 5), FAT4 (n = 7), SMAD4 (n = 1), SMARCA4 (n = 1), TLR4 (n = 7), and TP53 (n = 5). CDH11, CDKN2A, FAT4, TLR4, and TP53 were mutated in at least 2 LTS or STS, exceeding mutation rates in literature. Mutations across the LTS and STS were found in 10 of the 16 genes. The results warrant future studies to investigate a larger range of genes in a larger sample size. This may result in a panel with prognostic genes, to predict individual prognosis and to select effective individualized therapy for patients with esophageal adenocarcinoma.


Asunto(s)
Adenocarcinoma/genética , Neoplasias Esofágicas/genética , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Proteína de la Poliposis Adenomatosa del Colon/genética , Adulto , Anciano , Cadherinas/genética , Supervivientes de Cáncer , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Inhibidor p18 de las Quinasas Dependientes de la Ciclina/genética , ADN Helicasas/genética , Análisis Mutacional de ADN , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/cirugía , Esofagectomía , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Mutación , Estadificación de Neoplasias , Proteínas Nucleares/genética , Pronóstico , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/genética , Proteína Smad4/genética , Factores de Tiempo , Receptor Toll-Like 4/genética , Factores de Transcripción/genética , Proteína p53 Supresora de Tumor/genética , Proteínas Supresoras de Tumor/genética
11.
Dis Esophagus ; 25(7): 630-7, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22221671

RESUMEN

Barrett's esophagus (BE) is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). Risk factors for EAC overlap with those for esophageal squamous cell carcinoma (ESCC), but ESCC is surprisingly rare in BE. We report two cases of ESCC directly surrounded by BE. Both patients had a previous medical history of cancers, i.e., head and neck squamous cell carcinomas, and were using alcohol and smoking tobacco. Using immunohistochemistry for p63, CK5, CK7, and CDX2, it was confirmed that these carcinomas were pure squamous cell carcinomas, and not EACs or esophageal adenosquamous carcinomas arising from BE. Using TP53 mutation and loss of heterozygosity analysis, we established that the ESCCs in BE were not metastases of the previously diagnosed head and neck squamous cell carcinomas but de novo primary ESCCs. This study shows the strength of molecular analysis as an adjunct to the histopathologic diagnosis for distinguishing between metastases of prior cancers and primary cancers. Furthermore, these cases imply that presence of BE is not protective with regards to developing ESCC in the lower one third of the esophagus. We suggest that their ESCCs arose from islets of squamous epithelium in BE.


Asunto(s)
Esófago de Barrett/complicaciones , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/complicaciones , Neoplasias Esofágicas/complicaciones , Anciano , Esófago de Barrett/patología , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago , Humanos , Inmunohistoquímica , Masculino , Metástasis de la Neoplasia
12.
Eur J Cancer ; 171: 114-123, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35716537

RESUMEN

INTRODUCTION: In 1-3% of non-small cell lung cancer (NSCLC) human epidermal growth factor 2 (HER2) mutations are identified as a genomic driver. Nevertheless, no HER2-targeted treatment is approved for NSCLC. In the Drug Rediscovery Protocol (DRUP), patients are treated with off-label drugs based on their molecular profile. Here, we present the results of the cohort 'trastuzumab/pertuzumab for HER2 exon20 mutation positive (HER2m+) NSCLC'. METHODS: Patients with treatment refractory, advanced HER2m+ NSCLC with measurable disease (RECISTv1.1) were eligible. Treatment with intravenous trastuzumab combined with pertuzumab every 3 weeks was administered. The primary end-point was clinical benefit (CB: either objective response or stable disease ≥ 16 weeks). Patients were enrolled using a Simon-like 2-stage design, with 8 patients in stage 1 and up to 24 patients in stage 2 if at least 1 patient had CB in stage 1. At baseline, a biopsy for biomarker analysis, including whole genome sequencing, was obtained. RESULTS: Twenty-four evaluable patients were enrolled and treated between May 2017 and August 2020. CB was observed in 9 patients (38%); including an objective response rate of 8.3% (2 patients had a partial response) and 7 patients with stable disease ≥ 16 weeks. The most frequently observed HER2 mutation was p.Y772_A775dup (71%, n = 20). Median follow-up was 13 months, median progression-free survival and overall survival 4 (95% CI 3-6) and 10 months (95% CI 4 - not reached), respectively. Whole genome sequencing data (available for 67% of patients) confirmed the inclusion mutation in all cases. No unexpected toxicity was observed. CONCLUSION: Despite the fact that the study did meet its primary end-point, trastuzumab/pertuzumab was only marginally active in a subset of patients with heavily pre-treated HER2m+ NSCLC.


Asunto(s)
Neoplasias de la Mama , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Exones , Femenino , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapéutico
13.
Gut ; 57(5): 623-7, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18178612

RESUMEN

BACKGROUND/AIMS: Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder characterised by multiple gastrointestinal juvenile polyps and an increased risk of colorectal cancer. This syndrome is caused by germline mutation of either SMAD4 or BMPR1A, and possibly ENG. PTEN, originally linked to Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome, has also been associated with JPS. By direct sequencing, germline mutations are found in only 30-40% of patients with a JPS phenotype. Therefore, alternative ways of inactivation of the known JPS genes, or additional genes predisposing to JPS may be involved. In this study, a comprehensive genetic analysis of SMAD4, BMPR1A, PTEN and ENG is performed through direct sequencing and multiplex ligation-dependent probe amplification (MLPA) in JPS patients. METHODS: Archival material of 29 patients with JPS from 27 families was collected. Direct sequencing and MLPA analysis were performed to search for germline defects in SMAD4, BMPR1A, PTEN and ENG. RESULTS: A germline defect in SMAD4, BMPR1A or PTEN was found in 13 of 27 (48.1%) unrelated JPS patients. Nine mutations (33.3%) were detected by direct sequencing, including six (22.2%) SMAD4 mutations and three (11.1%) BMPR1A mutations. MLPA identified four additional patients (14.8%) with germline hemizygous large genomic deletions, including one deletion of SMAD4, one deletion of exons 10 and 11 of BMPR1A, and two unrelated patients with deletion of both BMPR1A and PTEN. No ENG gene mutations were found. CONCLUSION: Large genomic deletions of SMAD4, BMPR1A and PTEN are a common cause of JPS. Using direct sequencing and MLPA, a germline defect was detected in 48.1% of JPS patients. MLPA identified 14.8% (4/27) of these mutations. Since a substantial percentage of JPS patients carry a germline deletion and MLPA is a reliable and user-friendly technique, it is concluded that MLPA is a valuable adjunct in JPS diagnosis.


Asunto(s)
Poliposis Adenomatosa del Colon/genética , Secuencia de Bases/genética , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/genética , Fosfohidrolasa PTEN/genética , Eliminación de Secuencia/genética , Proteína Smad4/genética , Secuencia de Bases/fisiología , Análisis Mutacional de ADN/métodos , Femenino , Genoma , Genotipo , Mutación de Línea Germinal/genética , Humanos , Masculino , Linaje , Fenotipo , Eliminación de Secuencia/fisiología
14.
Virchows Arch ; 453(3): 249-55, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18688641

RESUMEN

It has been reported that interleukin-1beta (IL-1B) genes play a crucial role in the genetic predisposition to gastric cancer although there is no information about their role in different subtypes of gastric cancer. We performed single nucleotide polymorphism analysis of IL-1B in 241 gastric cancers including early onset gastric cancers (EOGC), conventional gastric cancers, and gastric stump cancers (GSCs) as well as 100 control patients, using real-time polymerase chain reaction and sequence analysis. The C allele was present in 60% of EOGCs, 59% of conventional gastric cancers, and 90% of GSCs, compared to 62% in the control group. Interestingly, there was no difference between early onset and conventional gastric cancer with respect to the IL-1B -31T>C polymorphism distribution. A statistically significant difference in the presence of the C allele compared to the control group was found in patients with gastric stump cancer (p = 0.008) with the T allele conferring protection against gastric stump cancer. In summary, we have shown that the IL-1B -31C allele promoter polymorphism is significantly associated with gastric stump cancer compared to the control group. Although several molecular differences have been identified between conventional gastric cancer and early onset gastric cancer, the IL-1B -31 allele distribution is similar between these two groups.


Asunto(s)
Muñón Gástrico , Interleucina-1beta/genética , Regiones Promotoras Genéticas , Neoplasias Gástricas/genética , Adulto , Alelos , Humanos , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Neoplasias Gástricas/complicaciones
15.
Chemosphere ; 68(10): 1976-84, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17482660

RESUMEN

WO(3) and Zn-doped WO(3) thin films were prepared on indium-tin oxide glass by a dip-coating. The composite films were characterized by UV-Vis absorption spectra, X-ray diffraction and scanning electron microscope. The effect of preparation conditions (concentration of Zn, annealing temperature, number of layers) on the photocurrent was studied. It was found that the photocurrent under visible light displayed the highest value for 2% Zn-WO(3) films annealed at 400 degrees C. The photocatalytic activity of the Zn-doped WO(3) was evaluated in terms of decay rate of nitrite ions under visible light. The influence of applied potential, initial pH and nitrite concentration on the reaction rate was studied. The experiments demonstrated that NO(2)(-) could be efficiently degraded on the doped photoanode that showed a higher activity than the undoped WO(3) especially under high anodic potential (>0.7 V). The rate of degradation was enhanced in aqueous NaCl solutions. Furthermore, it was demonstrated that the photodegradation mechanism of NO(2)(-) proceeded mainly indirectly via OH radicals. The possible reason of enhancement of reaction rate was also discussed.


Asunto(s)
Luz , Nitritos/química , Óxidos/química , Fotoquímica/métodos , Tungsteno/química , Zinc/química , Catálisis , Electrodos , Difracción de Rayos X
17.
J Clin Pathol ; 58(10): 1091-5, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16189157

RESUMEN

BACKGROUND/AIMS: LKB1 is a tumour suppressor gene that is associated with Peutz-Jeghers syndrome (PJS), a rare autosomal dominant cancer predisposition syndrome. However, germline mutations in the LKB1 gene are found in only about 60% of patients with PJS, suggesting the existence of a second PJS gene. The STRAD gene, encoding an LKB1 interacting protein that activates LKB1, which subsequently leads to polarisation of cells, is an interesting candidate for a second PJS gene and a potential tumour suppressor gene in sporadic carcinomas. METHODS: The involvement of STRAD in 42 PJS associated tumours (sporadic lung, colon, gastric, and ovarian adenocarcinomas) was studied using loss of heterozygosity (LOH) analysis of eight microsatellite markers on chromosome 17, including TP53, BRCA1, and STRAD markers. RESULTS: Loss of the marker near the STRAD locus was seen in 13 of 29 informative cases, including all gastric adenocarcinomas. Specific LOH of the STRAD marker was found in four of 29 informative cases. For these patients all exons and exon-intron boundaries of the STRAD gene were sequenced, but no somatic mutations were identified. Furthermore, no germline STRAD mutations were found in 10 patients with PJS and family members without LKB1 germline mutation. CONCLUSIONS: Despite the frequent occurrence of LOH in the STRAD region, these results indicate that inactivation of the STRAD gene is not essential in the sporadic adenocarcinomas studied, although it is possible that STRAD may be inactivated in different ways. In addition, no evidence was found for the hypothesis that STRAD is a second PJS susceptibility gene.


Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/genética , Adenocarcinoma/genética , Proteínas de Neoplasias/genética , Síndrome de Peutz-Jeghers/genética , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Adenocarcinoma/metabolismo , Cromosomas Humanos Par 17/genética , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , ADN de Neoplasias/genética , Femenino , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Humanos , Pérdida de Heterocigocidad , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Repeticiones de Microsatélite , Mutación , Proteínas de Neoplasias/metabolismo , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Síndrome de Peutz-Jeghers/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo
18.
J Phys Chem B ; 109(31): 15008-23, 2005 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-16852900

RESUMEN

In this paper, the electrochemical impedance spectroscopy (EIS) mathematical model of TiO2 photoelectrocatalytic (PEC) reactions involving charge transfer and recombination through surface states was developed. The model was used to study the kinetics of photoelectrocatalytic decomposition of salicylic acid. The model simulation results show that the appearance of two distinguishable semicircles in the EIS response depends on the charging of surface state and light intensity. The experimental results demonstrated that similar phenomena to the theoretical simulation results. The model provides a way to obtain the rate constants for the photoelectrochemical reactions of surface states mediating charge transfer and recombination. The applied potential changes not only the recombination rate constant but also the charge-transfer rate constant. Moreover, the experimental EIS results here and those previous published on PEC degradation reactions can be explained by the present model satisfactorily. The relevance of surface states was discussed briefly. The results demonstrated that EIS is a powerful tool for studying the kinetics of PEC decomposition of organic pollutants on TiO2 electrodes.

20.
J Dent Res ; 94(1): 219-28, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25391621

RESUMEN

Recent research has verified that mesenchymal stromal/stem cells (MSCs) derived from bone marrow or adipose tissues can migrate toward a variety of tumors. In this study, we explored whether human gingival-derived MSCs (G-MSCs) can migrate toward tongue squamous cell carcinoma (TSCC) and evaluated the antitumor effect of engineered G-MSCs in expressing and delivering the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). An in vitro cell migration assay with Transwell plates showed that human G-MSCs can migrate toward TSCC cell lines (Tca8113 and Cal27). Then, human G-MSCs, as a type of cell-based vehicle, were transduced with full-length TRAIL and enhanced green fluorescent protein reporter genes by the lentivirus (LV) system (G-MSCs with full-length TRAIL; G-MSCFLT). Tca8113 and Cal27 were co-cultured with G-MSCFLT, respectively, to evaluate the function of G-MSCFLT on tumor cells in vitro. This resulted in G-MSCFLT's inducing a great number of tumor cell necrosis and apoptosis. Meanwhile, in vivo antitumor assays were performed by administering G-MSCFLT to nude mice locally and systematically (mixed injection with tumor cells and tail vein injection). This showed that G-MSCFLT can reduce or even inhibit TSCC growth regardless of the method of administration, especially when the mixed injection of tumor cells and G-MSCFLT was at a ratio of 1:1, which showed no tumor formation. Furthermore, this verified that G-MSCFLT migrated toward TSCC in quantity. These data emphasize the effectiveness of G-MSCs as a vehicle for cell-based gene therapy and the antitumor activity of TRAIL-expressing G-MSCs.


Asunto(s)
Carcinogénesis/patología , Carcinoma de Células Escamosas/patología , Encía/citología , Células Madre Mesenquimatosas/fisiología , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Neoplasias de la Lengua/patología , Adipogénesis/fisiología , Animales , Apoptosis/fisiología , Carcinoma de Células Escamosas/terapia , Técnicas de Cultivo de Célula , Diferenciación Celular/fisiología , Ingeniería Celular , Línea Celular Tumoral , Movimiento Celular/fisiología , Técnicas de Cocultivo , Ingeniería Genética , Vectores Genéticos/genética , Encía/fisiología , Humanos , Lentivirus/genética , Ratones , Ratones Desnudos , Necrosis , Osteogénesis/fisiología , Distribución Aleatoria , Proteínas Recombinantes , Ligando Inductor de Apoptosis Relacionado con TNF/administración & dosificación , Neoplasias de la Lengua/terapia , Ensayos Antitumor por Modelo de Xenoinjerto
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