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1.
BMC Cancer ; 24(1): 878, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39039514

RESUMEN

PURPOSE: Oxaliplatin-containing adjuvant chemotherapy yields a significant survival benefit in stage III colon cancer and is the standard of care. Simultaneously, it causes dose-dependent peripheral neuropathy that may increase the risk of fall-related injury (FRI) such as fracture and laceration. Because these events carry significant morbidity and the global burden of colon cancer is on the rise, we examined the association between treatment with a full versus shortened course of adjuvant chemotherapy and post-treatment FRI and fracture. METHODS: In this overlap propensity score weighted, retrospective cohort study, we included patients aged ≥ 18 years with resected stage III colon cancer diagnosed 2007-2019 and treated with oxaliplatin-containing adjuvant chemotherapy (oxaliplatin plus a fluoropyrimidine; capecitabine [CAPOX] or 5-fluorouracil and leucovorin [FOLFOX]). Propensity score methods facilitate the separation of design from analysis and comparison of baseline characteristics across the weighted groups. Treatment groups were defined as 50% (4 cycles CAPOX/6 cycles FOLFOX) and > 85% (7-8 cycles CAPOX/11-12 cycles FOLFOX) of a maximal course of adjuvant chemotherapy to approximate the treatment durations received in the IDEA collaboration. The main outcomes were time to any FRI and time to fracture. We determined the subdistribution hazard ratios (sHR) estimating the association between FRI/fracture and treatment group, accounting for the competing risk of death. RESULTS: We included 3,461 patients; 473 (13.7%) received 50% and 2,988 (86.3%) received > 85% of a maximal course of adjuvant therapy. For post-treatment FRI, median follow-up was 4.6 years and total follow-up was 17,968 person-years. There were 508 FRI, 301 fractures, and 692 deaths. Treatment with > 85% of a maximal course of therapy conferred a sHR of 0.84 (95% CI 0.62-1.13) for post-treatment FRI and a sHR of 0.72 (95% CI 0.49-1.06) for post-treatment fracture. CONCLUSION: For patients with stage III colon cancer undergoing treatment with oxaliplatin-containing adjuvant chemotherapy, any potential neuropathy associated with longer durations of treatment was not found to result in greater rates of FRI and fracture. Within the limits of this retrospective study, our findings suggest concern about FRI, while mechanistically plausible, ought not to determine treatment duration.


Asunto(s)
Accidentes por Caídas , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias del Colon , Fluorouracilo , Leucovorina , Estadificación de Neoplasias , Oxaliplatino , Humanos , Estudios Retrospectivos , Femenino , Masculino , Quimioterapia Adyuvante/métodos , Quimioterapia Adyuvante/efectos adversos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Neoplasias del Colon/mortalidad , Persona de Mediana Edad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Oxaliplatino/administración & dosificación , Oxaliplatino/efectos adversos , Oxaliplatino/uso terapéutico , Anciano , Accidentes por Caídas/estadística & datos numéricos , Leucovorina/uso terapéutico , Leucovorina/efectos adversos , Leucovorina/administración & dosificación , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Fluorouracilo/uso terapéutico , Fracturas Óseas/etiología , Fracturas Óseas/epidemiología , Capecitabina/administración & dosificación , Puntaje de Propensión , Adulto , Compuestos Organoplatinos
2.
Malar J ; 21(1): 60, 2022 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-35193585

RESUMEN

BACKGROUND: Cerebral malaria is still a major cause of death in children in sub-Saharan Africa. Among survivors, debilitating neurological sequelae can leave children with permanent cognitive impairments and societal stigma, resulting in taxing repercussions for their families. This study investigated the effect of delay in presentation to medical care on outcome in children with cerebral malaria in Malawi. METHODS: This retrospective study included participants enrolled in a longstanding study of cerebral malaria between 2001 and 2021 and considered coma duration prior to arrival at hospital (with or without anti-malarial treatment), HIV status, blood lactate levels at admission and age as factors that could affect clinical outcome. Outcomes were categorized as full recovery, sequelae at the time of discharge, or death. A multinomial regression was fit and run controlling for coma duration, HIV status, lactate levels and age, to determine the association between each explanatory variable and outcome. RESULTS: A total of 1663 children with cerebral malaria, aged 6 months to 14 years were included. Longer coma duration (in hours) was associated with greater odds of developing sequelae (OR = 1.023, 95% CI 1.007-1.039, p = 0.006) but not death (OR = 1.00, 95% CI 0.986-1.015, p = 0.961). Younger age (in months) was also correlated with higher rates of sequelae, (OR = 0.990, 95% CI 0.983-0.997, p = 0.004) but not with increased mortality (OR = 0.998, 95% CI 0.993-1.003, p = 0.335). Blood lactate levels on admission were correlated with mortality (OR = 1.125, 95% CI 1.090-1.161, p < 0.001) but not associated with increased rates of sequelae (OR = 1.016, 95% CI 0.973-1.060, p = 0.475). Positive HIV status and treatment with an anti-malarial (artemisinin or non-artemisinin-based) prior to arrival at the hospital were not significantly associated with either adverse outcome. CONCLUSIONS: In Malawian children with cerebral malaria, higher rates of sequelae were significantly associated with extended coma duration prior to admission and younger age. Mortality rates were correlated with increased lactate levels on admission. The differential effects of variables on clinical outcomes suggest that there may be different pathogenic pathways leading to sequelae and death. Actions taken by parents and health care professionals are critical in defining when patients arrive at hospital and determining their ultimate outcome.


Asunto(s)
Antimaláricos , Malaria Cerebral , Antimaláricos/uso terapéutico , Niño , Hospitales , Humanos , Lactante , Malaria Cerebral/tratamiento farmacológico , Malaui/epidemiología , Estudios Retrospectivos
3.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-35163100

RESUMEN

CD26 has been reported as a marker for colorectal cancer stem cells endowed with tumor-initiating properties and capable of colorectal cancer (CRC) metastasis. In this study, we investigated the functional effect of CD26 on CRC angiogenesis and metastasis, and the potential underlying mechanism. The functional effects of CD26 overexpression or repression were determined by a wound healing experiment, and cell migration and invasion assays in vitro and in mouse models. Differentially expressed genes regulated by CD26 were identified by genome-wide mRNA expression array and validated by quantitative PCR. CD26 functionally regulated CRC cell migration and invasion in vitro and angiogenesis and metastasis in vivo. Genome-wide mRNA expression array and qPCR showed that MMP1 was up-regulated in CD26+ subpopulation, and a subsequent experiment demonstrated the regulatory effect of CD26 on MMP1 in CRC cell lines with CD26 repression or overexpression. Furthermore, overexpression of CAV1 abrogated the CD26-regulated MMP1 induction in CRC cell lines. This study demonstrated the functional roles of CD26 in inducing CRC migration, invasion, angiogenesis and metastasis and identified the potential involvement of MMP1 and CAV1 in such process. CD26 is an attractive therapeutic target for combating tumor progression to improve the prognosis of CRC patients.


Asunto(s)
Caveolina 1/metabolismo , Neoplasias Colorrectales/irrigación sanguínea , Neoplasias Colorrectales/patología , Dipeptidil Peptidasa 4/metabolismo , Regulación Neoplásica de la Expresión Génica , Metaloproteinasa 1 de la Matriz/metabolismo , Neovascularización Patológica/patología , Animales , Apoptosis , Caveolina 1/genética , Movimiento Celular , Proliferación Celular , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Dipeptidil Peptidasa 4/genética , Humanos , Metaloproteinasa 1 de la Matriz/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Metástasis de la Neoplasia , Neovascularización Patológica/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
4.
CMAJ ; 193(21): E753-E760, 2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-34035055

RESUMEN

BACKGROUND: Reduced use of the emergency department during the COVID-19 pandemic may result in increased disease acuity when patients do seek health care services. We sought to evaluate emergency department visits for common abdominal and gynecologic conditions before and at the beginning of the pandemic to determine whether changes in emergency department attendance had serious consequences for patients. METHODS: We conducted a population-based analysis using administrative data to evaluate the weekly rate of emergency department visits pre-COVID-19 (Jan. 1-Mar. 10, 2020) and during the beginning of the COVID-19 pandemic (Mar. 11-June 30, 2020), compared with a historical control period (Jan. 1-July 1, 2019). All residents of Ontario, Canada, presenting to the emergency department with appendicitis, cholecystitis, ectopic pregnancy or miscarriage were included. We evaluated weekly incidence rate ratios (IRRs) of emergency department visits, management strategies and clinical outcomes. RESULTS: Across all study periods, 39 691 emergency department visits met inclusion criteria (40.2 % appendicitis, 32.1% miscarriage, 21.3% cholecystitis, 6.4% ectopic pregnancy). Baseline characteristics of patients presenting to the emergency department did not vary across study periods. After an initial reduction in emergency department visits, presentations for cholecystitis and ectopic pregnancy quickly returned to expected levels. However, presentations for appendicitis and miscarriage showed sustained reductions (IRR 0.61-0.80), with 1087 and 984 fewer visits, respectively, after the start of the pandemic, relative to 2019. Management strategies, complications and mortality rates were similar across study periods for all conditions. INTERPRETATION: Although our study showed evidence of emergency department avoidance in Ontario during the first wave of the COVID-19 pandemic, no adverse consequences were evident. Emergency care and outcomes for patients were similar before and during the pandemic.


Asunto(s)
Apendicitis , COVID-19 , Colecistitis , Servicio de Urgencia en Hospital/tendencias , Utilización de Instalaciones y Servicios/tendencias , Enfermedades de los Genitales Femeninos , Aceptación de la Atención de Salud/estadística & datos numéricos , Aborto Espontáneo/diagnóstico , Aborto Espontáneo/epidemiología , Aborto Espontáneo/terapia , Adulto , Anciano , Apendicitis/diagnóstico , Apendicitis/epidemiología , Apendicitis/terapia , COVID-19/epidemiología , COVID-19/psicología , Colecistitis/diagnóstico , Colecistitis/epidemiología , Colecistitis/terapia , Estudios Transversales , Femenino , Enfermedades de los Genitales Femeninos/diagnóstico , Enfermedades de los Genitales Femeninos/epidemiología , Enfermedades de los Genitales Femeninos/terapia , Humanos , Masculino , Persona de Mediana Edad , Ontario/epidemiología , Pandemias , Embarazo , Embarazo Ectópico/diagnóstico , Embarazo Ectópico/epidemiología , Embarazo Ectópico/terapia , Índice de Severidad de la Enfermedad
5.
Colorectal Dis ; 23(8): 2127-2136, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33973319

RESUMEN

AIM: Clinical trials suggest that hyaluronate carboxymethylcellulose (HA/CMC) prevents adhesion-related complications after intra-abdominal surgery, but at a high upfront cost. This study evaluated the cost-effectiveness of HA/CMC for patients undergoing curative-intent open colorectal cancer surgery. METHODS: Using a Markov Monte Carlo microsimulation model, we conducted a cost-utility analysis comparing the cost-effectiveness of HA/CMC at curative-intent open colorectal cancer surgery versus standard management. We considered a scenario where HA/CMC was used at the index operation only, as well as where it was used at the index operation and any subsequent operations. The perspective was that of the third-party payer. Costs and utilities were discounted 1.5% annually, with a 1-month cycle length and 5-year time horizon. Model input data were obtained from a literature review. Outcomes included cost, quality-adjusted life-years (QALYs), small bowel obstructions (SBOs) and operations for SBO. RESULTS: Using HA/CMC at the index operation results in an incremental cost increase of CA$316 and provides 0.001 additional QALYs, for an incremental cost-effectiveness ratio of CA$310,000 per QALY compared to standard management. In our simulated cohort of 10,000 patients, HA/CMC prevented 460 SBOs and 293 surgeries for SBO. Probabilistic sensitivity analysis found that HA/CMC was cost-effective in 18.5% of iterations, at a cost-effectiveness threshold of CA$50,000 per QALY. Results of the scenario analysis where HA/CMC was used at the index operation and any subsequent operations were similar. CONCLUSIONS: Hyaluronate carboxymethylcellulose prevents adhesive bowel obstruction after open colorectal cancer surgery but is unlikely to be cost-effective given minimal long-term impact on healthcare costs and QALYs.


Asunto(s)
Adhesivos , Carboximetilcelulosa de Sodio , Carboximetilcelulosa de Sodio/uso terapéutico , Análisis Costo-Beneficio , Humanos , Años de Vida Ajustados por Calidad de Vida , Adherencias Tisulares
6.
Healthc Q ; 24(3): 76-81, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34792453

RESUMEN

Canada's healthcare sector produces the third highest healthcare-related emissions per capita globally. However, Canada has no national strategy toward environmentally sustainable healthcare. Transforming Canada's health systems to be environmentally sustainable requires leadership from many stakeholders and collaboration between trainees and health leaders. This article provides an overview of student and trainee leadership among health-related fields in response to the climate crisis and highlights the formation of a trainee-led organization focused on building capacity among emerging leaders in healthcare. We share key lessons learned by this group that are essential for all leaders seeking to leverage interdisciplinary action toward sustainable health systems in Canada.


Asunto(s)
Programas de Gobierno , Liderazgo , Canadá , Atención a la Salud , Sector de Atención de Salud , Humanos
7.
J Org Chem ; 84(21): 13565-13571, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31512872

RESUMEN

The mechanism and origins of syn and anti selectivity of cross-benzoin reactions between furfural and α-amino aldehydes, catalyzed by a triazolium-based NHC, were investigated using density functional theory calculations. N-Boc-α-amino aldehydes were found to react with anti selectivity, while N-Bn-N-Boc-α-amino aldehydes react with syn selectivity. We find that the anti product is more thermodynamically favored than the syn product for reactions with N-Boc-α-amino aldehydes, and that the formation of the syn product for reactions involving N-Bn-N-Boc-α-amino aldehydes is kinetically favored. The switch in selectivity is a result of an intramolecular hydrogen bond in the N-Boc-α-amino aldehyde, whereas switching to N-Bn-N-Boc-α-amine removes the hydrogen bond. The steric and electronic interactions in the transition state are rationalized by a Felkin-Anh model.

8.
Int J Mol Sci ; 18(6)2017 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-28545226

RESUMEN

Colorectal cancer results from genetic aberrations which accumulate over a long period of time, with malignant and metastatic properties acquired at a relatively late stage. A subpopulation of CD26+ colorectal cancer stem cells are known to be implicated in metastasis. We quantified CD26+ cancer cells in 11 primary tumor samples by flow cytometry, and showed that tumors having confirmed or suspected metastases harbored a relatively high CD26+ level in these samples. We hypothesized that this subpopulation of cancer stem cells arises in the late stage of carcinogenesis from the bulk of tumor daughter cells which are CD26-. The manipulation of PIK3CA and TP53, two genes commonly deregulated in the late stage, had an effect on the maintenance of the CD26+ cell population. When CD26- tumor daughter cells were sorted and cultured, the emergence of tumor spheres containing CD26+ cells occurred. These findings shed light to the origin of colorectal cancer stem cells with metastatic properties, which has an implication on conventional treatments by surgery or adjuvant chemotherapy for tumor debulking.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinogénesis/metabolismo , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Dipeptidil Peptidasa 4/metabolismo , Células Madre Neoplásicas/metabolismo , Anciano , Anciano de 80 o más Años , Carcinogénesis/patología , Femenino , Humanos , Masculino
9.
Nat Methods ; 10(4): 354-60, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23474465

RESUMEN

An inability to reliably predict quantitative behaviors for novel combinations of genetic elements limits the rational engineering of biological systems. We developed an expression cassette architecture for genetic elements controlling transcription and translation initiation in Escherichia coli: transcription elements encode a common mRNA start, and translation elements use an overlapping genetic motif found in many natural systems. We engineered libraries of constitutive and repressor-regulated promoters along with translation initiation elements following these definitions. We measured activity distributions for each library and selected elements that collectively resulted in expression across a 1,000-fold observed dynamic range. We studied all combinations of curated elements, demonstrating that arbitrary genes are reliably expressed to within twofold relative target expression windows with ∼93% reliability. We expect the genetic element definitions validated here can be collectively expanded to create collections of public-domain standard biological parts that support reliable forward engineering of gene expression at genome scales.


Asunto(s)
Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica , Factores Procarióticos de Iniciación/metabolismo , Transcripción Genética , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Biblioteca de Genes , Ingeniería Genética , Genoma Bacteriano , Factores Procarióticos de Iniciación/genética , Regiones Promotoras Genéticas/genética , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo
10.
Nat Methods ; 10(4): 347-53, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23474467

RESUMEN

The practice of engineering biology now depends on the ad hoc reuse of genetic elements whose precise activities vary across changing contexts. Methods are lacking for researchers to affordably coordinate the quantification and analysis of part performance across varied environments, as needed to identify, evaluate and improve problematic part types. We developed an easy-to-use analysis of variance (ANOVA) framework for quantifying the performance of genetic elements. For proof of concept, we assembled and analyzed combinations of prokaryotic transcription and translation initiation elements in Escherichia coli. We determined how estimation of part activity relates to the number of unique element combinations tested, and we show how to estimate expected ensemble-wide part activity from just one or two measurements. We propose a new statistic, biomolecular part 'quality', for tracking quantitative variation in part performance across changing contexts.


Asunto(s)
Bioingeniería/métodos , Escherichia coli/metabolismo , Factores de Iniciación de Péptidos/metabolismo , Animales , Proteínas Bacterianas , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Biblioteca de Genes , Iniciación de la Cadena Peptídica Traduccional , Factores Procarióticos de Iniciación/metabolismo , Transcripción Genética
11.
Hepatobiliary Pancreat Dis Int ; 15(5): 493-498, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27733318

RESUMEN

BACKGROUND: Chemoembolization with doxorubucin-eluting beads (DEB) has been used to treat hepatocellular carcinoma (HCC) since 2007. This study compared the efficacy and survival between transarterial chemoembolization (TACE) with DEB and conventional approach (cTACE) in HCC treatment. METHODS: This retrospective case-control study compared the overall survival and tumor response of HCC patients to cTACE (n=190) and DEB (n=143) by the reassessment of computed tomography and serum alpha-fetoprotein (AFP). Multivariate analysis was used to determine the factors affecting tumor response. RESULTS: The median post-treatment to pre-treatment AFP level was 0.8 for a DEB session (n=258) and 1.0 for a cTACE session (n=452), showing a significantly greater decrease in AFP after DEB (P<0.05). More patients in the DEB group achieved objective response (complete and partial) compared with those in the cTACE group (P<0.05). Objective tumor response after DEB vs cTACE was 34.8% vs 15.4% in 0-3 months (P=0.001), 37.1% vs 20.0% in 3-6 months (P<0.05), and 50.0% vs 30.0% in 6-12 months (P=0.093). DEB predicted a 3.604 times odds of achieving at least one objective tumor response in a patient when compared to cTACE (P<0.0001). The median survival from first transcatheter therapy of patients having undergone at least once DEB was 12.53 months, while those having received cTACE only was 10.53 months (P=0.086). A tendency of improved survival appeared to maintain until >80 months after the first TACE session in the DEB group. CONCLUSION: DEB is a safe alternative to cTACE in HCC patients with better therapeutic efficacy.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica , Doxorrubicina/administración & dosificación , Neoplasias Hepáticas/terapia , Anciano , Antibióticos Antineoplásicos/efectos adversos , Carcinoma Hepatocelular/sangre , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/patología , Quimioembolización Terapéutica/efectos adversos , Distribución de Chi-Cuadrado , Doxorrubicina/efectos adversos , Femenino , Hong Kong , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/sangre , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Estudios Retrospectivos , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Carga Tumoral , alfa-Fetoproteínas/metabolismo
12.
Mol Cancer ; 14: 80, 2015 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-25884645

RESUMEN

BACKGROUND: In colorectal carcinoma (CRC), activation of the Raf/MEK/ERK signaling pathway is commonly observed. In addition, the commonly used 5FU-based chemotherapy in patients with metastatic CRC was found to enrich a subpopulation of CD26(+) cancer stem cells (CSCs). As activation of the Raf/MEK/ERK signaling pathway was also found in the CD26(+) CSCs and therefore, we hypothesized that an ATP-competitive pan-Raf inhibitor, Raf265, is effective in eliminating the cancer cells and the CD26(+) CSCs in CRC patients. METHODS: HT29 and HCT116 cells were treated with various concentrations of Raf265 to study the anti-proliferative and apoptotic effects of Raf265. Anti-tumor effect was also demonstrated using a xenograft model. Cells were also treated with Raf265 in combination with 5FU to demonstrate the anti-migratory and invasive effects by targeting on the CD26(+) CSCs and the anti-metastatic effect of the combined treatment was shown in an orthotopic CRC model. RESULTS: Raf265 was found to be highly effective in inhibiting cell proliferation and tumor growth through the inhibition of the RAF/MEK/ERK signaling pathway. In addition, anti-migratory and invasive effect was found with Raf265 treatment in combination with 5FU by targeting on the CD26(+) cells. Finally, the anti-tumor and anti-metastatic effect of Raf265 in combination with 5FU was also demonstrated. CONCLUSIONS: This preclinical study demonstrates the anti-tumor and anti-metastatic activity of Raf265 in CRC, providing the basis for exploiting its potential use and combination therapy with 5FU in the clinical treatment of CRC.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias Colorrectales/metabolismo , Imidazoles/farmacología , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Piridinas/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Autorrenovación de las Células , Neoplasias Colorrectales/patología , Evaluación Preclínica de Medicamentos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fluorouracilo/farmacología , Células HCT116 , Células HT29 , Humanos , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Proto-Oncogénicas B-raf/metabolismo , Transducción de Señal/efectos de los fármacos
13.
Nucleic Acids Res ; 41(9): 5139-48, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23511967

RESUMEN

The reliable forward engineering of genetic systems remains limited by the ad hoc reuse of many types of basic genetic elements. Although a few intrinsic prokaryotic transcription terminators are used routinely, termination efficiencies have not been studied systematically. Here, we developed and validated a genetic architecture that enables reliable measurement of termination efficiencies. We then assembled a collection of 61 natural and synthetic terminators that collectively encode termination efficiencies across an ∼800-fold dynamic range within Escherichia coli. We simulated co-transcriptional RNA folding dynamics to identify competing secondary structures that might interfere with terminator folding kinetics or impact termination activity. We found that structures extending beyond the core terminator stem are likely to increase terminator activity. By excluding terminators encoding such context-confounding elements, we were able to develop a linear sequence-function model that can be used to estimate termination efficiencies (r = 0.9, n = 31) better than models trained on all terminators (r = 0.67, n = 54). The resulting systematically measured collection of terminators should improve the engineering of synthetic genetic systems and also advance quantitative modeling of transcription termination.


Asunto(s)
Modelos Genéticos , Regiones Terminadoras Genéticas , Terminación de la Transcripción Genética , Escherichia coli/genética , Pliegue del ARN
14.
Hepatology ; 58(2): 667-79, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23504997

RESUMEN

UNLABELLED: Early reports suggested that actopaxin, a member of the focal adhesion proteins, regulates cell migration. Here we investigated whether actopaxin is involved in hepatocellular carcinoma (HCC) progression and metastasis. We examined actopaxin expression in human HCC samples using immunohistochemistry and western blotting. The functional and molecular effect of actopaxin was studied in vitro by overexpression in a nonmetastatic HCC cell line, as well as repression in a metastatic cell line. The in vivo effect of actopaxin repression was studied in nonobese diabetic and severe combined immunodeficient mice. We found that actopaxin was frequently overexpressed in human HCC patients and its overexpression positively correlated with tumor size, stage, and metastasis. Actopaxin expression also correlated with the metastatic potential of HCC cell lines. Actopaxin overexpression induced the invasion and migration ability of nonmetastatic HCC cells, whereas down-regulation of actopaxin reverted the invasive phenotypes and metastatic potential of metastatic HCC cells through regulating the protein expression of certain focal adhesion proteins including ILK, PINCH, paxillin, and cdc42, as well as regulating the epithelial-mesenchymal transition pathway. Furthermore, there was a close association between actopaxin and CD29. HCC cells with stronger CD29 expression showed a higher actopaxin level, whereas actopaxin repression attenuated CD29 activity. Finally, actopaxin down-regulation enhanced the chemosensitivity of HCC cells towards oxaliplatin treatment by way of a collective result of suppression of survivin protein, ß-catenin, and mammalian target of rapamycin pathways and up-regulation of p53. CONCLUSION: This study provides concrete evidence of a significant role of actopaxin in HCC progression and metastasis, by way of regulation of cell invasiveness and motility, an epithelial-mesenchymal transition process, and chemosensitivity to cytotoxic drugs.


Asunto(s)
Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/fisiopatología , Movimiento Celular/fisiología , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/fisiopatología , Proteínas de Microfilamentos/antagonistas & inhibidores , Metástasis de la Neoplasia/fisiopatología , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Carcinoma Hepatocelular/mortalidad , Línea Celular Tumoral , Células Cultivadas , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal/fisiología , Femenino , Xenoinjertos , Humanos , Técnicas In Vitro , Integrina beta1/fisiología , Neoplasias Hepáticas/mortalidad , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas de Microfilamentos/efectos de los fármacos , Proteínas de Microfilamentos/fisiología , Persona de Mediana Edad , Invasividad Neoplásica/patología , Invasividad Neoplásica/fisiopatología , Metástasis de la Neoplasia/patología , Compuestos Organoplatinos/farmacología , Oxaliplatino , ARN Interferente Pequeño/farmacología , Tasa de Supervivencia
16.
Curr Oncol ; 30(7): 6508-6532, 2023 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-37504338

RESUMEN

PURPOSE: Few studies have examined the relationship between duration of oxaliplatin-containing adjuvant chemotherapy for stage III colon cancer and mortality in routine practice. We examined the association between treatment with 50% versus >85% of a maximal course of adjuvant therapy (eight cycles of CAPOX, twelve cycles of FOLFOX) and mortality in stage III colon cancer. METHODS: Using linked databases, we identified Ontarians aged ≥18 years at diagnosis of stage III colon cancer between 2007 and 2019. In the primary comparison, we compared patients who received 50% or >85% of a maximal course of adjuvant therapy; in a secondary comparison, we evaluated a dose effect across patients who received FOLFOX in one-cycle increments from six to ten cycles against >85% (more than ten cycles) of a maximal course of FOLFOX. The main outcomes were overall and cancer-specific mortality. Follow-up began 270 days after adjuvant treatment initiation and terminated at the first of the outcome of interest, loss of eligibility for Ontario's Health Insurance Program, or study end. Overlap propensity score weights accounted for baseline between-group differences. We determined the hazard ratio, estimating the association between mortality and treatment. Non-inferiority was concluded in the primary comparison for either outcome if the upper limit of the two-sided 95% CI was ≤1.11, which is the margin used in the International Duration Evaluation of Adjuvant Chemotherapy Collaboration. RESULTS: We included 3546 patients in the analysis of overall mortality; 486 (13.7%) received 50% and 3060 (86.3%) received >85% of a maximal course of therapy. Median follow-up was 5.4 years, and total follow-up was 20,510 person-years. There were 833 deaths. Treatment with 50% of a maximal course of adjuvant therapy was associated with a hazard ratio of 1.13 (95% CI 0.88 to 1.47) for overall mortality and a subdistribution hazard ratio of 1.31 (95% CI 0.91 to 1.87) for cancer-specific mortality versus >85% of a maximal course of therapy. In the secondary comparison, there was a trend toward higher overall mortality in patients treated with shorter durations of therapy, though confidence intervals overlapped considerably. CONCLUSION: We could not conclude that treatment with 50% of a maximal course is non-inferior to >85% of a maximal course of adjuvant therapy for mortality in stage III colon cancer. Clinicians and patients engaging in decision-making around treatment duration in this context should carefully consider the trade-off between treatment effectiveness and adverse effects of treatment.


Asunto(s)
Neoplasias del Colon , Fluorouracilo , Humanos , Adolescente , Adulto , Oxaliplatino/uso terapéutico , Fluorouracilo/uso terapéutico , Capecitabina , Estudios Retrospectivos , Supervivencia sin Enfermedad , Protocolos de Quimioterapia Combinada Antineoplásica , Leucovorina/uso terapéutico , Estadificación de Neoplasias , Compuestos Organoplatinos/uso terapéutico , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Quimioterapia Adyuvante
17.
Clin Colorectal Cancer ; 22(4): 431-441.e9, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37648568

RESUMEN

INTRODUCTION: The International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration in 2017 established 3 months of adjuvant therapy as an alternative to 6 months of therapy for stage III colon cancer. We determined the association between the IDEA publication, changes in clinical practice, and prescriber variation. PATIENTS AND METHODS: Using linked databases, we identified Ontarians aged ≥18 years at diagnosis of stage III colon cancer between 2007 and 2019 who received oxaliplatin-containing adjuvant therapy. The outcome was duration of therapy, categorized as ≤25%, >25% to ≤50%, >50% to ≤75%, and >75% of a 6-month course of therapy to approximate treatment durations in the IDEA collaboration. We examined trends in duration over time using an interrupted time series regression model. We analyzed treatment duration after accounting for patient and prescriber characteristics, using multivariable mixed effects logistic regression models to quantify between-prescriber variation. RESULTS: We included 4695 patients with stage III colon cancer who received oxaliplatin-containing adjuvant chemotherapy, of whom 77.5% initiated treatment pre-IDEA and 22.5% initiated treatment post-IDEA. Post-IDEA, there was a 16.4% (95% CI, 12.5%-20.3%) absolute increase in the proportion of patients treated with ≤50% of a maximal course of therapy. This trend was greatest among patients with low-risk tumors. Prescriber variation increased pre-IDEA to 15.6% post-IDEA (variance partition coefficient 5.4% pre-IDEA and 15.6% post-IDEA). CONCLUSION: The publication of IDEA was associated with increases in short duration adjuvant therapy and prescriber-level practice variation for stage III colon cancer. Clinicians should be better supported to make consistent recommendations about adjuvant duration under conditions of uncertainty and trade-offs.


Asunto(s)
Neoplasias del Colon , Fluorouracilo , Humanos , Adolescente , Adulto , Oxaliplatino , Estudios Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias del Colon/patología , Quimioterapia Adyuvante/efectos adversos , Estadificación de Neoplasias
18.
BMJ Open Gastroenterol ; 10(1)2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37277204

RESUMEN

BACKGROUND AND AIMS: Non-pharmacological interventions to improve patient-reported outcomes of colonoscopy may be effective at mitigating negative experiences and perceptions of the procedure, but research to characterise the extent and features of studies of these interventions is limited. METHODS: We conducted a scoping review searching multiple databases for peer-reviewed publications of randomised controlled trials conducted in adults investigating a non-pharmacological intervention to improve patient-reported outcomes of colonoscopy. Study characteristics were tabulated and summarised narratively and graphically. RESULTS: We screened 5939 citations and 962 full texts, and included 245 publications from 39 countries published between 1992 and 2022. Of these, 80.8% were full publications and 19.2% were abstracts. Of the 41.9% of studies reporting funding sources, 11.4% were unfunded. The most common interventions were carbon dioxide and/or water insufflation methods (33.9%), complementary and alternative medicines (eg, acupuncture) (20.0%), and colonoscope technology (eg, magnetic scope guide) (21.6%). Pain was as an outcome across 82.0% of studies. Studies most often used a patient-reported outcome examining patient experience during the procedure (60.0%), but 42.9% of studies included an outcome without specifying the time that the patient experienced the outcome. Most intraprocedural patient-reported outcomes were measured retrospectively rather than contemporaneously, although studies varied in terms of when outcomes were assessed. CONCLUSION: Research on non-pharmacological interventions to improve patient-reported outcomes of colonoscopy is unevenly distributed across types of intervention and features high variation in study design and reporting, in particular around outcomes. Future research efforts into non-pharmacological interventions to improve patient-reported outcomes of colonoscopy should be directed at underinvestigated interventions and developing consensus-based guidelines for study design, with particular attention to how and when outcomes are experienced and measured. PROSPERO REGISTRATION NUMBER: 42020173906.


Asunto(s)
Colonoscopía , Adulto , Humanos , Estudios Retrospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto
19.
Mol Carcinog ; 51(5): 422-32, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21678496

RESUMEN

The role of X chromosome-linked inhibitor of apoptosis protein (XIAP)-associated factor 1 (XAF1) in mediating apoptosis has been reported but the underlying mechanism remains unclear. The present study was designed to examine the putative interaction between XAF1 and p53 and the functional importance of this interaction in regulation of apoptosis in human gastric and colon cancer cells. We first identified XAF1 as a novel target gene of p53 by the chromatin immunoprecipitation (CHIP) assay and demonstrated that wild-type p53, but not mutant p53, down-regulated XAF1 at both mRNA and protein levels, which acted mostly under the condition of high expression of XAF1 and was associated with the physical interaction between p53 and the XAF1 promoter. We also found that the over-expression of XAF1 led to activation of wild-type p53 via post-translational modification in cells with or without DNA damage, which resulting in p53 nuclear accumulation and its increased transcriptional activity and enhancing p53-dependent apoptosis. These findings suggest that a potential novel feedback loop exists between XAF1 and wild-type p53.


Asunto(s)
Apoptosis/genética , Neoplasias del Colon/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Proteínas Reguladoras de la Apoptosis , Línea Celular Tumoral , Neoplasias del Colon/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas de Neoplasias/genética , Regiones Promotoras Genéticas , Procesamiento Proteico-Postraduccional/genética , Neoplasias Gástricas/genética , Proteína p53 Supresora de Tumor/genética
20.
Curr Oncol ; 29(11): 8609-8625, 2022 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-36421332

RESUMEN

Outcome disparities between adults <50 with colorectal cancer (CRC) and older adults may be explained by clinical delays. This study synthesized the literature comparing delays and outcomes between younger and older adults with CRC. Databases were searched until December 2021. We included studies published after 1990 reporting delay in adults <50 that made comparisons to older adults. Comparisons were described narratively and stage between age groups was meta-analyzed. 39 studies were included representing 185,710 younger CRC patients and 1,422,062 older patients. Sixteen delay intervals were compared. Fourteen studies (36%) found significantly longer delays among younger adults, and nine (23%) found shorter delays among younger patients. Twelve studies compared time from symptom onset to diagnosis (N younger = 1538). Five showed significantly longer delays for younger adults. Adults <50 years also had higher odds of advanced stage (16 studies, pooled OR for Stage III/IV 1.76, 95% CI 1.52-2.03). Ten studies compared time from diagnosis to treatment (N younger = 171,726) with 4 showing significantly shorter delays for younger adults. All studies showing longer delays for younger adults examined pre-diagnostic intervals. Three studies compared the impact of delay on younger versus older adult. One showed longer delays were associated with advanced stage and worse survival in younger but not older adults. Longer delays among younger adults with CRC occur in pre-diagnostic intervals.


Asunto(s)
Neoplasias Colorrectales , Humanos , Anciano , Bases de Datos Factuales , Neoplasias Colorrectales/terapia , Neoplasias Colorrectales/diagnóstico
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