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1.
Cell Mol Life Sci ; 81(1): 256, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38866991

RESUMEN

Pulmonary hypertension (PH) is characterized by vascular remodeling predominantly driven by a phenotypic switching in pulmonary artery smooth muscle cells (PASMCs). However, the underlying mechanisms for this phenotypic alteration remain incompletely understood. Here, we identified that RNA methyltransferase METTL3 is significantly elevated in the lungs of hypoxic PH (HPH) mice and rats, as well as in the pulmonary arteries (PAs) of HPH rats. Targeted deletion of Mettl3 in smooth muscle cells exacerbated hemodynamic consequences of hypoxia-induced PH and accelerated pulmonary vascular remodeling in vivo. Additionally, the absence of METTL3 markedly induced phenotypic switching in PASMCs in vitro. Mechanistically, METTL3 depletion attenuated m6A modification and hindered the processing of pri-miR-143/145, leading to a downregulation of miR-143-3p and miR-145-5p. Inhibition of hnRNPA2B1, an m6A mediator involved in miRNA maturation, similarly resulted in a significant reduction of miR-143-3p and miR-145-5p. We demonstrated that miR-145-5p targets Krüppel-like factor 4 (KLF4) and miR-143-3p targets fascin actin-bundling protein 1 (FSCN1) in PASMCs. The decrease of miR-145-5p subsequently induced an upregulation of KLF4, which in turn suppressed miR-143/145 transcription, establishing a positive feedback circuit between KLF4 and miR-143/145. This regulatory circuit facilitates the persistent suppression of contractile marker genes, thereby sustaining PASMC phenotypic switch. Collectively, hypoxia-induced upregulation of METTL3, along with m6A mediated regulation of miR-143/145, might serve as a protective mechanism against phenotypic switch of PASMCs. Our results highlight a potential therapeutic strategy targeting m6A modified miR-143/145-KLF4 loop in the treatment of PH.


Asunto(s)
Adenosina , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel , Metiltransferasas , MicroARNs , Miocitos del Músculo Liso , Arteria Pulmonar , Factor 4 Similar a Kruppel/metabolismo , Animales , MicroARNs/genética , MicroARNs/metabolismo , Arteria Pulmonar/metabolismo , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Miocitos del Músculo Liso/metabolismo , Ratones , Adenosina/análogos & derivados , Adenosina/metabolismo , Metiltransferasas/metabolismo , Metiltransferasas/genética , Ratas , Fenotipo , Masculino , Hipertensión Pulmonar/metabolismo , Hipertensión Pulmonar/genética , Hipertensión Pulmonar/patología , Músculo Liso Vascular/metabolismo , Ratones Endogámicos C57BL , Remodelación Vascular/genética , Ratas Sprague-Dawley , Humanos
2.
Cell Mol Biol Lett ; 29(1): 69, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38741032

RESUMEN

BACKGROUND: Pulmonary hypertension (PH) is a progressive disease characterized by pulmonary vascular remodeling. Increasing evidence indicates that endothelial-to-mesenchymal transition (EndMT) in pulmonary artery endothelial cells (PAECs) is a pivotal trigger initiating this remodeling. However, the regulatory mechanisms underlying EndMT in PH are still not fully understood. METHODS: Cytokine-induced hPAECs were assessed using RNA methylation quantification, qRT-PCR, and western blotting to determine the involvement of N6-methyladenosine (m6A) methylation in EndMT. Lentivirus-mediated silencing, overexpression, tube formation, and wound healing assays were utilized to investigate the function of METTL3 in EndMT. Endothelial-specific gene knockout, hemodynamic measurement, and immunostaining were performed to explore the roles of METTL3 in pulmonary vascular remodeling and PH. RNA-seq, RNA Immunoprecipitation-based qPCR, mRNA stability assay, m6A mutation, and dual-luciferase assays were employed to elucidate the mechanisms of RNA methylation in EndMT. RESULTS: The global levels of m6A and METTL3 expression were found to decrease in TNF-α- and TGF-ß1-induced EndMT in human PAECs (hPAECs). METTL3 inhibition led to reduced endothelial markers (CD31 and VE-cadherin) and increased mesenchymal markers (SM22 and N-cadherin) as well as EndMT-related transcription factors (Snail, Zeb1, Zeb2, and Slug). The endothelial-specific knockout of Mettl3 promoted EndMT and exacerbated pulmonary vascular remodeling and hypoxia-induced PH (HPH) in mice. Mechanistically, METTL3-mediated m6A modification of kruppel-like factor 2 (KLF2) plays a crucial role in the EndMT process. KLF2 overexpression increased CD31 and VE-cadherin levels while decreasing SM22, N-cadherin, and EndMT-related transcription factors, thereby mitigating EndMT in PH. Mutations in the m6A site of KLF2 mRNA compromise KLF2 expression, subsequently diminishing its protective effect against EndMT. Furthermore, KLF2 modulates SM22 expression through direct binding to its promoter. CONCLUSIONS: Our findings unveil a novel METTL3/KLF2 pathway critical for protecting hPAECs against EndMT, highlighting a promising avenue for therapeutic investigation in PH.


Asunto(s)
Adenosina , Células Endoteliales , Transición Epitelial-Mesenquimal , Hipertensión Pulmonar , Factores de Transcripción de Tipo Kruppel , Metiltransferasas , Adenosina/análogos & derivados , Adenosina/metabolismo , Animales , Hipertensión Pulmonar/genética , Hipertensión Pulmonar/metabolismo , Humanos , Metiltransferasas/metabolismo , Metiltransferasas/genética , Ratones , Células Endoteliales/metabolismo , Transición Epitelial-Mesenquimal/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Arteria Pulmonar/metabolismo , Arteria Pulmonar/patología , Metilación , Ratones Endogámicos C57BL , Cadherinas/metabolismo , Cadherinas/genética , Masculino , Remodelación Vascular/genética , Células Cultivadas
3.
Molecules ; 28(21)2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-37959861

RESUMEN

Total synthesis of the proposed noursamycin A has been accomplished, which disproves the original structural assignments. The synthetic strategy described herein has also been employed in the first total synthesis of nicrophorusamide A, a cyclopeptide that is structurally related to noursamycin A.

4.
Am J Physiol Cell Physiol ; 320(2): C225-C239, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33206547

RESUMEN

There is growing evidence that microRNAs (miRNAs) are implicated in cellular adaptation to osmotic stress, but the underlying osmosignaling pathways are still not completely understood. In this study, we found that a passenger strand miRNA, miR-23a-5p, was significantly downregulated in response to high NaCl treatment in mouse inner medullary collecting duct cells (mIMCD3) through an miRNA profiling assay. The decrease of miR-23a-5p is hypertonicity-dependent and osmotolerant cell type-specific. Knockdown of miR-23a-5p increased cellular survival and proliferation in mIMCD3. In contrast, miR-23a-5p overexpression repressed cell viability and proliferation under hypertonic stress. RNA deep-sequencing revealed that a heat shock protein 70 (HSP70) isoform, HSP70 member 1B (HSPA1B), was significantly increased under hypertonic treatment. Based on the prediction analysis by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and TargetScan, and a further validation via a dual-luciferase assay, HSPA1B was identified as a potential target of miR-23a-5p. Overexpressed miR-23a-5p suppressed HSPA1B, whereas downregulated miR-23a-5p promoted HSPA1B expression in mIMCD3. In addition, an in vivo study demonstrated that there is a reverse correlation between the levels of miR-23a-5p and HSPA1B in mouse renal inner medulla (papilla) that is exposed to extremely high osmolality. In summary, this study elucidates that passenger strand miR-23a-5p is a novel tonicity-responsive miRNA. The downregulation of miR-23a-5p facilitates cellular adaptation to hypertonic stress in mammalian renal cells through modulating HSPA1B.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Proteínas HSP70 de Choque Térmico/metabolismo , Soluciones Hipertónicas/toxicidad , MicroARNs/metabolismo , Presión Osmótica/fisiología , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células HEK293 , Humanos , Masculino , Ratones , MicroARNs/antagonistas & inhibidores , Presión Osmótica/efectos de los fármacos
5.
PLoS Biol ; 13(4): e1002133, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25909860

RESUMEN

The authors of "Relatedness, Conflict, and the Evolution of Eusociality" respond to objections raised by Martin Nowak and Benjamin Allen.


Asunto(s)
Modelos Teóricos , Conducta Social , Animales
6.
PLoS Biol ; 13(3): e1002098, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25799485

RESUMEN

The evolution of sterile worker castes in eusocial insects was a major problem in evolutionary theory until Hamilton developed a method called inclusive fitness. He used it to show that sterile castes could evolve via kin selection, in which a gene for altruistic sterility is favored when the altruism sufficiently benefits relatives carrying the gene. Inclusive fitness theory is well supported empirically and has been applied to many other areas, but a recent paper argued that the general method of inclusive fitness was wrong and advocated an alternative population genetic method. The claim of these authors was bolstered by a new model of the evolution of eusociality with novel conclusions that appeared to overturn some major results from inclusive fitness. Here we report an expanded examination of this kind of model for the evolution of eusociality and show that all three of its apparently novel conclusions are essentially false. Contrary to their claims, genetic relatedness is important and causal, workers are agents that can evolve to be in conflict with the queen, and eusociality is not so difficult to evolve. The misleading conclusions all resulted not from incorrect math but from overgeneralizing from narrow assumptions or parameter values. For example, all of their models implicitly assumed high relatedness, but modifying the model to allow lower relatedness shows that relatedness is essential and causal in the evolution of eusociality. Their modeling strategy, properly applied, actually confirms major insights of inclusive fitness studies of kin selection. This broad agreement of different models shows that social evolution theory, rather than being in turmoil, is supported by multiple theoretical approaches. It also suggests that extensive prior work using inclusive fitness, from microbial interactions to human evolution, should be considered robust unless shown otherwise.


Asunto(s)
Evolución Biológica , Aptitud Genética/fisiología , Modelos Genéticos , Procesos de Determinación del Sexo , Conducta Social , Animales , Hormigas/fisiología , Abejas/fisiología , Conducta Animal , Genética de Población , Isópteros/fisiología , Selección Genética , Avispas/fisiología
7.
Gut ; 66(8): 1463-1473, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-27196573

RESUMEN

OBJECTIVE: Evidence suggests that CD274 (programmed death-ligand 1, B7-H1) immune checkpoint ligand repress antitumour immunity through its interaction with the PDCD1 (programmed cell death 1, PD-1) receptor of T lymphocytes in various tumours. We hypothesised that tumour CD274 expression levels might be inversely associated with T-cell densities in colorectal carcinoma tissue. DESIGN: We evaluated tumour CD274 expression by immunohistochemistry in 823 rectal and colon cancer cases within the Nurses' Health Study and Health Professionals Follow-up Study. We conducted multivariable ordinal logistic regression analyses to examine the association of tumour CD274 expression with CD3+, CD8+, CD45RO (PTPRC)+ or FOXP3+ cell density in tumour tissue, controlling for potential confounders including tumour status of microsatellite instability (MSI), CpG island methylator phenotype, long interspersed nucleotide element-1 methylation level and KRAS, BRAF and PIK3CA mutations. RESULTS: CD274 expression in tumour cells or stromal cells (including immune cells) was detected in 731 (89%) or 44 (5%) cases, respectively. Tumour CD274 expression level correlated inversely with FOXP3+ cell density in colorectal cancer tissue (outcome) (ptrend=0.0002). For a unit increase in outcome quartile categories, multivariable OR in the highest (vs lowest) CD274 expression score was 0.22 (95% CI 0.10 to 0.47). Tumour CD274 expression was inversely associated with MSI-high status (p=0.001). CD274 expression was not significantly associated with CD3+, CD8+ or CD45RO+ cell density, pathological lymphocytic reactions or patient survival prognosis. CONCLUSIONS: Tumour CD274 expression is inversely associated with FOXP3+ cell density in colorectal cancer tissue, suggesting a possible influence of CD274-expressing carcinoma cells on regulatory T cells in the tumour microenvironment.


Asunto(s)
Antígeno B7-H1/análisis , Carcinoma/química , Neoplasias del Colon/química , ADN Bacteriano/análisis , Linfocitos/química , Neoplasias del Recto/química , Anciano , Complejo CD3/análisis , Linfocitos T CD8-positivos , Carcinoma/genética , Carcinoma/patología , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Femenino , Factores de Transcripción Forkhead/análisis , Fusobacterium nucleatum , Humanos , Antígenos Comunes de Leucocito/análisis , Recuento de Linfocitos , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Receptor de Muerte Celular Programada 1/análisis , Neoplasias del Recto/genética , Neoplasias del Recto/patología , Tasa de Supervivencia
8.
N Engl J Med ; 369(12): 1095-105, 2013 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-24047059

RESUMEN

BACKGROUND: Colonoscopy and sigmoidoscopy provide protection against colorectal cancer, but the magnitude and duration of protection, particularly against cancer of the proximal colon, remain uncertain. METHODS: We examined the association of the use of lower endoscopy (updated biennially from 1988 through 2008) with colorectal-cancer incidence (through June 2010) and colorectal-cancer mortality (through June 2012) among participants in the Nurses' Health Study and the Health Professionals Follow-up Study. RESULTS: Among 88,902 participants followed over a period of 22 years, we documented 1815 incident colorectal cancers and 474 deaths from colorectal cancer. With endoscopy as compared with no endoscopy, multivariate hazard ratios for colorectal cancer were 0.57 (95% confidence interval [CI], 0.45 to 0.72) after polypectomy, 0.60 (95% CI, 0.53 to 0.68) after negative sigmoidoscopy, and 0.44 (95% CI, 0.38 to 0.52) after negative colonoscopy. Negative colonoscopy was associated with a reduced incidence of proximal colon cancer (multivariate hazard ratio, 0.73; 95% CI, 0.57 to 0.92). Multivariate hazard ratios for death from colorectal cancer were 0.59 (95% CI, 0.45 to 0.76) after screening sigmoidoscopy and 0.32 (95% CI, 0.24 to 0.45) after screening colonoscopy. Reduced mortality from proximal colon cancer was observed after screening colonoscopy (multivariate hazard ratio, 0.47; 95% CI, 0.29 to 0.76) but not after sigmoidoscopy. As compared with colorectal cancers diagnosed in patients more than 5 years after colonoscopy or without any prior endoscopy, those diagnosed in patients within 5 years after colonoscopy were more likely to be characterized by the CpG island methylator phenotype (CIMP) (multivariate odds ratio, 2.19; 95% CI, 1.14 to 4.21) and microsatellite instability (multivariate odds ratio, 2.10; 95% CI, 1.10 to 4.02). CONCLUSIONS: Colonoscopy and sigmoidoscopy were associated with a reduced incidence of cancer of the distal colorectum; colonoscopy was also associated with a modest reduction in the incidence of proximal colon cancer. Screening colonoscopy and sigmoidoscopy were associated with reduced colorectal-cancer mortality; only colonoscopy was associated with reduced mortality from proximal colon cancer. Colorectal cancer diagnosed within 5 years after colonoscopy was more likely than cancer diagnosed after that period or without prior endoscopy to have CIMP and microsatellite instability. (Funded by the National Institutes of Health and others.).


Asunto(s)
Colonoscopía , Neoplasias Colorrectales/epidemiología , Detección Precoz del Cáncer , Sigmoidoscopía , Adenoma/diagnóstico , Adenoma/epidemiología , Adenoma/mortalidad , Adenoma/prevención & control , Anciano , Estudios de Cohortes , Pólipos del Colon/genética , Pólipos del Colon/patología , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/prevención & control , ADN de Neoplasias/análisis , Femenino , Humanos , Incidencia , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Análisis Multivariante , Mutación , Estados Unidos/epidemiología
9.
Ann Surg Oncol ; 23(3): 908-17, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26577117

RESUMEN

BACKGROUND: High-level physical activity is associated with lower colorectal cancer (CRC) mortality, likely through insulin sensitization. Insulin receptor substrate 1 (IRS1) is a mediator of insulin and insulin-like growth factor (IGF) signaling pathways, and its down-regulation is associated with insulin resistance. Therefore, we hypothesized that tumor IRS1 expression status might modify cellular sensitivity to insulin and IGF, and the prognostic association of physical activity. METHODS: We assessed IRS1 expression level in 371 stage I-III rectal and colon cancers in the Nurses' Health Study and the Health Professionals Follow-up Study by immunohistochemistry. In survival analysis, Cox proportional hazards model was used to assess an interaction between post-diagnosis physical activity (ordinal scale of sex-specific quartiles Q1 to Q4) and IRS1 expression (ordinal scale of negative, low, and high), controlling for potential confounders, including microsatellite instability, CpG island methylator phenotype, long interspersed nucleotide element-1 (LINE-1) methylation level, and KRAS, BRAF, and PIK3CA mutation status. RESULTS: There was a statistically significant interaction between post-diagnosis physical activity and tumor IRS1 expression in CRC-specific mortality analysis (P interaction = 0.005). Multivariable hazard ratio (95% confidence interval) for higher post-diagnosis physical activity (Q3-Q4 vs. Q1-Q2) was 0.15 (0.02-1.38) in the IRS1-negative group, 0.45 (0.19-1.03) in the IRS1-low group, and 1.32 (0.50-3.53) in the IRS1-high group. CONCLUSIONS: The association of post-diagnosis physical activity with colorectal carcinoma patient survival may differ by tumor IRS1 expression level. If validated, tumor IRS1 expression status may serve as a predictive marker to identify subgroups of patients who might gain greater survival benefit from an increased level of exercise.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias Colorrectales/mortalidad , Terapia por Ejercicio/mortalidad , Proteínas Sustrato del Receptor de Insulina/metabolismo , Anciano , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/terapia , Metilación de ADN , Femenino , Estudios de Seguimiento , Humanos , Técnicas para Inmunoenzimas , Elementos de Nucleótido Esparcido Largo , Masculino , Inestabilidad de Microsatélites , Mutación/genética , Clasificación del Tumor , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Tasa de Supervivencia , Análisis de Matrices Tisulares
10.
Blood ; 123(9): 1412-21, 2014 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-24357730

RESUMEN

Increasing evidence across malignancies suggests that infiltrating T cells at the site of disease are crucial to tumor control. We hypothesized that marrow-infiltrating immune populations play a critical role in response to donor lymphocyte infusion (DLI), an established and potentially curative immune therapy whose precise mechanism remains unknown. We therefore analyzed marrow-infiltrating immune populations in 29 patients (22 responders, 7 nonresponders) with relapsed chronic myelogenous leukemia who received CD4(+) DLI in the pre-tyrosine kinase inhibitor era. Immunohistochemical analysis of pretreatment marrow revealed that the presence of >4% marrow-infiltrating CD8(+) (but not CD4(+)) T cells predicted DLI response, even in the setting of high leukemia burden. Furthermore, mRNA expression profiling of marrow-infiltrating T cells of a subset of responders compared with nonresponders revealed enrichment of T-cell exhaustion-specific genes in pretreatment T cells of DLI responders and significant downregulation of gene components in the same pathway in responders in conjunction with clinical response. Our data demonstrate that response to DLI is associated with quantity of preexisting marrow CD8(+) T cells and local reversal of T-cell exhaustion. Our studies implicate T-cell exhaustion as a therapeutic target of DLI and support the potential use of novel anti-PD1/PDL1 agents in lieu of DLI.


Asunto(s)
Inmunoterapia Adoptiva/métodos , Leucemia Mielógena Crónica BCR-ABL Positiva/inmunología , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Depleción Linfocítica , Transfusión de Linfocitos , Linfocitos Infiltrantes de Tumor/patología , Linfocitos T/patología , Donantes de Sangre , Células de la Médula Ósea/inmunología , Células de la Médula Ósea/patología , Estudios de Cohortes , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Recuento de Linfocitos , Transcriptoma , Resultado del Tratamiento , Carga Tumoral
11.
N Engl J Med ; 367(17): 1596-606, 2012 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-23094721

RESUMEN

BACKGROUND: Regular use of aspirin after a diagnosis of colon cancer has been associated with a superior clinical outcome. Experimental evidence suggests that inhibition of prostaglandin-endoperoxide synthase 2 (PTGS2) (also known as cyclooxygenase-2) by aspirin down-regulates phosphatidylinositol 3-kinase (PI3K) signaling activity. We hypothesized that the effect of aspirin on survival and prognosis in patients with cancers characterized by mutated PIK3CA (the phosphatidylinositol-4,5-bisphosphonate 3-kinase, catalytic subunit alpha polypeptide gene) might differ from the effect among those with wild-type PIK3CA cancers. METHODS: We obtained data on 964 patients with rectal or colon cancer from the Nurses' Health Study and the Health Professionals Follow-up Study, including data on aspirin use after diagnosis and the presence or absence of PIK3CA mutation. We used a Cox proportional-hazards model to compute the multivariate hazard ratio for death. We examined tumor markers, including PTGS2, phosphorylated AKT, KRAS, BRAF, microsatellite instability, CpG island methylator phenotype, and methylation of long interspersed nucleotide element 1. RESULTS: Among patients with mutated-PIK3CA colorectal cancers, regular use of aspirin after diagnosis was associated with superior colorectal cancer-specific survival (multivariate hazard ratio for cancer-related death, 0.18; 95% confidence interval [CI], 0.06 to 0.61; P<0.001 by the log-rank test) and overall survival (multivariate hazard ratio for death from any cause, 0.54; 95% CI, 0.31 to 0.94; P=0.01 by the log-rank test). In contrast, among patients with wild-type PIK3CA, regular use of aspirin after diagnosis was not associated with colorectal cancer-specific survival (multivariate hazard ratio, 0.96; 95% CI, 0.69 to 1.32; P=0.76 by the log-rank test; P=0.009 for interaction between aspirin and PIK3CA variables) or overall survival (multivariate hazard ratio, 0.94; 95% CI, 0.75 to 1.17; P=0.96 by the log-rank test; P=0.07 for interaction). CONCLUSIONS: Regular use of aspirin after diagnosis was associated with longer survival among patients with mutated-PIK3CA colorectal cancer, but not among patients with wild-type PIK3CA cancer. The findings from this molecular pathological epidemiology study suggest that the PIK3CA mutation in colorectal cancer may serve as a predictive molecular biomarker for adjuvant aspirin therapy. (Funded by The National Institutes of Health and others.).


Asunto(s)
Aspirina/uso terapéutico , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Fosfatidilinositol 3-Quinasas/genética , Anciano , Aspirina/farmacología , Fosfatidilinositol 3-Quinasa Clase I , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Inhibidores de la Ciclooxigenasa 2/farmacología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Modelos de Riesgos Proporcionales , Transducción de Señal/efectos de los fármacos , Análisis de Supervivencia
12.
Mol Cancer ; 13: 135, 2014 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-24885062

RESUMEN

BACKGROUND: KRAS mutations in codons 12 and 13 are established predictive biomarkers for anti-EGFR therapy in colorectal cancer. Previous studies suggest that KRAS codon 61 and 146 mutations may also predict resistance to anti-EGFR therapy in colorectal cancer. However, clinicopathological, molecular, and prognostic features of colorectal carcinoma with KRAS codon 61 or 146 mutation remain unclear. METHODS: We utilized a molecular pathological epidemiology database of 1267 colon and rectal cancers in the Nurse's Health Study and the Health Professionals Follow-up Study. We examined KRAS mutations in codons 12, 13, 61 and 146 (assessed by pyrosequencing), in relation to clinicopathological features, and tumor molecular markers, including BRAF and PIK3CA mutations, CpG island methylator phenotype (CIMP), LINE-1 methylation, and microsatellite instability (MSI). Survival analyses were performed in 1067 BRAF-wild-type cancers to avoid confounding by BRAF mutation. Cox proportional hazards models were used to compute mortality hazard ratio, adjusting for potential confounders, including disease stage, PIK3CA mutation, CIMP, LINE-1 hypomethylation, and MSI. RESULTS: KRAS codon 61 mutations were detected in 19 cases (1.5%), and codon 146 mutations in 40 cases (3.2%). Overall KRAS mutation prevalence in colorectal cancers was 40% (=505/1267). Of interest, compared to KRAS-wild-type, overall, KRAS-mutated cancers more frequently exhibited cecal location (24% vs. 12% in KRAS-wild-type; P < 0.0001), CIMP-low (49% vs. 32% in KRAS-wild-type; P < 0.0001), and PIK3CA mutations (24% vs. 11% in KRAS-wild-type; P < 0.0001). These trends were evident irrespective of mutated codon, though statistical power was limited for codon 61 mutants. Neither KRAS codon 61 nor codon 146 mutation was significantly associated with clinical outcome or prognosis in univariate or multivariate analysis [colorectal cancer-specific mortality hazard ratio (HR) = 0.81, 95% confidence interval (CI) = 0.29-2.26 for codon 61 mutation; colorectal cancer-specific mortality HR = 0.86, 95% CI = 0.42-1.78 for codon 146 mutation]. CONCLUSIONS: Tumors with KRAS mutations in codons 61 and 146 account for an appreciable proportion (approximately 5%) of colorectal cancers, and their clinicopathological and molecular features appear generally similar to KRAS codon 12 or 13 mutated cancers. To further assess clinical utility of KRAS codon 61 and 146 testing, large-scale trials are warranted.


Asunto(s)
Codón , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Mutación , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Anciano , Fosfatidilinositol 3-Quinasa Clase I , Estudios de Cohortes , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/mortalidad , Islas de CpG , Metilación de ADN , Receptores ErbB/genética , Femenino , Expresión Génica , Humanos , Elementos de Nucleótido Esparcido Largo/genética , Masculino , Persona de Mediana Edad , Fosfatidilinositol 3-Quinasas/genética , Modelos de Riesgos Proporcionales , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras) , Análisis de Supervivencia
13.
Ann Surg Oncol ; 21(13): 4164-73, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25023548

RESUMEN

BACKGROUND: Smoothened, frizzled family receptor (SMO) is an important component of the hedgehog signaling pathway, which has been implicated in various human carcinomas. However, clinical, molecular, and prognostic associations of SMO expression in colorectal cancer remain unclear. METHODS: Using a database of 735 colon and rectal cancers in the Nurse's Health Study and the Health Professionals Follow-up Study, we examined the relationship of tumor SMO expression (assessed by immunohistochemistry) to prognosis, and to clinical, pathological, and tumor molecular features, including mutations of KRAS, BRAF, and PIK3CA, microsatellite instability, CpG island methylator phenotype (CIMP), LINE-1 methylation, and expression of phosphorylated AKT and CTNNB1. RESULTS: SMO expression was detected in 370 tumors (50 %). In multivariate logistic regression analysis, SMO expression was independently inversely associated with phosphorylated AKT expression [odds ratio (OR) 0.48; 95 % confidence interval (CI) 0.34-0.67] and CTNNB1 nuclear localization (OR 0.48; 95 % CI 0.35-0.67). SMO expression was not significantly associated with colorectal cancer-specific or overall survival. However, in CIMP-high tumors, but not CIMP-low/0 tumors, SMO expression was significantly associated with better colorectal cancer-specific survival (log-rank P = 0.012; multivariate hazard ratio, 0.36; 95 % CI 0.13-0.95; P interaction = 0.035, for SMO and CIMP status). CONCLUSIONS: Our data reveal novel potential associations between the hedgehog, the WNT/CTNNB1, and the PI3K (phosphatidylinositol-4,5-bisphosphonate 3-kinase)/AKT pathways, supporting pivotal roles of SMO and hedgehog signaling in pathway networking. SMO expression in colorectal cancer may interact with tumor CIMP status to affect patient prognosis, although confirmation by future studies is needed.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Colorrectales/genética , Regulación Neoplásica de la Expresión Génica , Mutación , Receptores Acoplados a Proteínas G/genética , Anciano , Fosfatidilinositol 3-Quinasa Clase I , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Femenino , Estudios de Seguimiento , Proteínas Hedgehog/genética , Humanos , Estimación de Kaplan-Meier , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Fenotipo , Fosfatidilinositol 3-Quinasas/genética , Pronóstico , Estudios Prospectivos , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas p21(ras) , Transducción de Señal , Receptor Smoothened , Estados Unidos , beta Catenina/genética , Proteínas ras/genética
14.
RSC Adv ; 14(20): 13694-13702, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38681839

RESUMEN

Currently, the photostability of photosensitizer curcumin is the main bottleneck limiting their application, reducing the bioavailability of curcumin. Studying the effect of different light sources on the photostabilities of curcumin and loading it onto polydopamine nanocarriers with better biocompatibility will help improve its light utilization efficiency. In this study, we investigated the photostabilities of curcumin and a polydopamine-based nanoparticle (polydopamine-curcumin composite nanoparticles, PDA-Cur NPs) loaded with curcumin through in vitro and in vivo experiments to achieve better antitumor effects. The results demonstrated that curcumin has good photostability in dark, but with significant photodegradation rates in both red and blue light. Blue light has a faster effect on the photodegradation of curcumin, with a degradation rate of 42.1% after 10 minutes, which is about 1.7 times that of the red light. Our study successfully synthesized PDA-Cur NPs, demonstrating its ability to stably load and release curcumin, with a loading percentage of 65.7% after 2 hours and 41.9% release in 8 hours (pH 6.0). Compared with single curcumin treatments, the photodegradation rates of PDA-Cur NPs in red and blue light treatments were reduced by 46% and 50%, respectively. Meanwhile, PDA-Cur NPs exhibited remarkable antitumor efficacy due to PDT and promote apoptosis in cancer cells, which both better than that of single curcumin treatments. Moreover, in MCF-7 tumor-bearing mice, the PDA-Cur NPs led to significant tumor growth inhibition effects, without causing evident systemic damage in vivo. The findings highlight the potential of PDA-Cur NPs as anticancer photosensitizer with greatly increased utilization of curcumin in PDT.

15.
Complement Ther Med ; 82: 103051, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38761869

RESUMEN

BACKGROUND: Acupuncture stands out as a prominent complementary and alternative medicine therapy employed for functional dyspepsia (FD). We conducted a Bayesian meta-analysis to ascertain both the relative effectiveness and safety of various acupuncture methods in the treatment of functional dyspepsia. METHODS: We systematically searched eight electronic databases, spanning from their inception to April 2023. The eligibility criteria included randomized controlled trials investigating acupuncture treatments for FD. Study appraisal was conducted using the Cochrane risk of bias tool. Pairwise and network meta-analyses were conducted using RevMan 5.3 and ADDIS V.1.16.6 software. Bayesian network meta-analysis was performed to compare and rank the efficacy of different acupuncture therapies for FD symptoms. RESULTS: This study found that combining different acupuncture methods or using acupuncture in conjunction with Western medicine is more effective in improving symptoms of functional dyspepsia compared to using Western medicine alone. According to the comprehensive analysis results, notably, the combination of Western medicine and acupuncture exhibited superior efficacy in alleviating early satiation and postprandial fullness symptoms. For ameliorating epigastric pain, acupuncture combined with moxibustion proved to be the most effective treatment, while moxibustion emerged as the optimal choice for addressing burning sensations. Warming needle was identified as the preferred method for promoting motilin levels. CONCLUSION: The findings of this study demonstrate that acupuncture, both independently and in conjunction with other modalities, emerged as a secure and effective treatment option for patients with functional dyspepsia.


Asunto(s)
Terapia por Acupuntura , Teorema de Bayes , Dispepsia , Humanos , Terapia por Acupuntura/métodos , Dispepsia/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto
16.
Am J Epidemiol ; 178(1): 84-100, 2013 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-23788674

RESUMEN

The effect of duration of cigarette smoking cessation on colorectal cancer risk by molecular subtypes remains unclear. Using duplication-method Cox proportional-hazards regression analyses, we examined associations between duration of smoking cessation and colorectal cancer risk according to status of CpG island methylator phenotype (CIMP), microsatellite instability, v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation, or DNA methyltransferase-3B (DNMT3B) expression. Follow-up of 134,204 individuals in 2 US nationwide prospective cohorts (Nurses' Health Study (1980-2008) and Health Professionals Follow-up Study (1986-2008)) resulted in 1,260 incident rectal and colon cancers with available molecular data. Compared with current smoking, 10-19, 20-39, and ≥40 years of smoking cessation were associated with a lower risk of CIMP-high colorectal cancer, with multivariate hazard ratios (95% confidence intervals) of 0.53 (0.29, 0.95), 0.52 (0.32, 0.85), and 0.50 (0.27, 0.94), respectively (Ptrend = 0.001), but not with the risk of CIMP-low/CIMP-negative cancer (Ptrend = 0.25) (Pheterogeneity = 0.02, between CIMP-high and CIMP-low/CIMP-negative cancer risks). Differential associations between smoking cessation and cancer risks by microsatellite instability (Pheterogeneity = 0.02), DNMT3B expression (Pheterogeneity = 0.03), and BRAF (Pheterogeneity = 0.10) status appeared to be driven by the associations of CIMP-high cancer with microsatellite instability-high, DNMT3B-positive, and BRAF-mutated cancers. These molecular pathological epidemiology data suggest a protective effect of smoking cessation on a DNA methylation-related carcinogenesis pathway leading to CIMP-high colorectal cancer.


Asunto(s)
Neoplasias Colorrectales/epidemiología , Cese del Hábito de Fumar/estadística & datos numéricos , Anciano , Neoplasias Colorrectales/etiología , Neoplasias Colorrectales/genética , Islas de CpG/genética , ADN (Citosina-5-)-Metiltransferasas/genética , Epigénesis Genética/genética , Femenino , Humanos , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Fenotipo , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Proteínas Proto-Oncogénicas B-raf/genética , Factores de Riesgo , Factores Sexuales , Fumar/efectos adversos , Factores de Tiempo , ADN Metiltransferasa 3B
17.
JAMA ; 309(24): 2563-71, 2013 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-23800934

RESUMEN

IMPORTANCE: Aspirin use reduces the risk of colorectal carcinoma. Experimental evidence implicates a role of RAF kinases in up-regulation of prostaglandin-endoperoxide synthase 2 (PTGS2, cyclooxygenase 2), suggesting that BRAF-mutant colonic cells might be less sensitive to the antitumor effects of aspirin than BRAF-wild-type neoplastic cells. OBJECTIVE: To examine whether the association of aspirin intake with colorectal cancer risk differs according to status of tumor BRAF oncogene mutation. DESIGN AND SETTING: We collected biennial questionnaire data on aspirin use and followed up participants in the Nurses' Health Study (from 1980) and the Health Professionals Follow-up Study (from 1986) until July 1, 2006, for cancer incidence and until January 1, 2012, for cancer mortality. Duplication-method Cox proportional cause-specific hazards regression for competing risks data was used to compute hazard ratios (HRs) for colorectal carcinoma incidence according to BRAF mutation status. MAIN OUTCOMES AND MEASURES: Incidence of colorectal cancer cases according to tumor BRAF mutation status. RESULTS: Among 127,865 individuals, with 3,165,985 person-years of follow-up, we identified 1226 incident rectal and colon cancers with available molecular data. Compared with nonuse, regular aspirin use was associated with lower BRAF-wild-type cancer risk (multivariable HR, 0.73; 95% CI, 0.64 to 0.83; age-adjusted incidence rate difference [RD], -9.7; 95% CI, -12.6 to -6.7 per 100,000 person-years). This association was observed irrespective of status of tumor PTGS2 expression or PIK3CA or KRAS mutation. In contrast, regular aspirin use was not associated with a lower risk of BRAF-mutated cancer (multivariable HR, 1.03; 95% CI, 0.76 to 1.38; age-adjusted, incidence RD, 0.7; 95% CI, -0.3 to 1.7 per 100,000 person-years: P for heterogeneity = .037, between BRAF-wild-type vs BRAF-mutated cancer risks). Compared with no aspirin use, aspirin use of more than 14 tablets per week was associated with a lower risk of BRAF-wild-type cancer (multivariable HR, 0.43; 95% CI, 0.25 to 0.75; age-adjusted incidence RD, -19.8; 95% CI, -26.3 to -13.3 per 100,000 person-years). The relationship between the number of aspirin tablets per week and colorectal cancer risk differed significantly by BRAF mutation status (P for heterogeneity = .005). CONCLUSIONS AND RELEVANCE: Regular aspirin use was associated with lower risk of BRAF-wild-type colorectal cancer but not with BRAF-mutated cancer risk. These findings suggest that BRAF-mutant colon tumor cells may be less sensitive to the effect of aspirin. Given the modest absolute risk difference, further investigations are necessary to determine clinical implications of our findings.


Asunto(s)
Aspirina/administración & dosificación , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/prevención & control , Antagonistas de Prostaglandina/administración & dosificación , Proteínas Proto-Oncogénicas B-raf/genética , Anciano , Aspirina/farmacología , Neoplasias Colorrectales/epidemiología , Ciclooxigenasa 2/metabolismo , Femenino , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Mutación , Antagonistas de Prostaglandina/farmacología , Riesgo , Análisis de Supervivencia , Regulación hacia Arriba
18.
Gut ; 61(6): 847-54, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22427238

RESUMEN

OBJECTIVE: Colorectal cancer is typically classified into proximal colon, distal colon and rectal cancer. Tumour genetic and epigenetic features differ by tumour location. Considering a possible role of bowel contents (including microbiome) in carcinogenesis, this study hypothesised that tumour molecular features might gradually change along bowel subsites, rather than change abruptly at splenic flexure. DESIGN: Utilising 1443 colorectal cancers in two US nationwide prospective cohort studies, the frequencies of molecular features (CpG island methylator phenotype (CIMP), microsatellite instability (MSI), LINE-1 methylation and BRAF, KRAS and PIK3CA mutations) were examined along bowel subsites (rectum, rectosigmoid junction, sigmoid, descending colon, splenic flexure, transverse colon, hepatic flexure, ascending colon and caecum). The linearity and non-linearity of molecular relations along subsites were statistically tested by multivariate logistic or linear regression analysis. RESULTS: The frequencies of CIMP-high, MSI-high and BRAF mutations gradually increased from the rectum (<2.3%) to ascending colon (36-40%), followed by falls in the caecum (12-22%). By linearity tests, these molecular relations were significantly linear from rectum to ascending colon (p<0.0001), and there was little evidence of non-linearity (p>0.09). Caecal cancers exhibited the highest frequency of KRAS mutations (52% vs 27-35% in other sites; p<0.0001). CONCLUSIONS: The frequencies of CIMP-high, MSI-high and BRAF mutations in cancer increased gradually along colorectum subsites from the rectum to ascending colon. These novel data challenge the common conception of discrete molecular features of proximal versus distal colorectal cancers, and have a substantial impact on clinical, translational and epidemiology research, which has typically been performed with the dichotomous classification of proximal versus distal tumours.


Asunto(s)
Neoplasias Colorrectales/genética , Anciano , Neoplasias del Ciego/genética , Neoplasias del Ciego/patología , Fosfatidilinositol 3-Quinasa Clase I , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Islas de CpG/genética , Metilación de ADN/genética , ADN de Neoplasias/genética , Femenino , Humanos , Elementos de Nucleótido Esparcido Largo/genética , Masculino , Inestabilidad de Microsatélites , Mutación/genética , Tasa de Mutación , Fosfatidilinositol 3-Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras) , Neoplasias del Recto/genética , Neoplasias del Recto/metabolismo , Neoplasias del Recto/patología , Neoplasias del Colon Sigmoide/genética , Neoplasias del Colon Sigmoide/patología , Proteínas ras/genética
19.
Adv Sci (Weinh) ; 10(29): e2303517, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37541670

RESUMEN

The functionalization of the ß-carbon of enals with electrophiles is a signature umpolung reactivity of N-heterocyclic carbene (NHC) derived homoenolates. However, only a limited number of electrophiles are shown to be compatible, with most of them being π-electrophiles. In this study, the successful enantioselective ß-alkylation of homoenolates is reported using Csp3 electrophiles through an SN 2 strategy. The protocol shows a broad scope regarding alkyl electrophiles, delivering good yields, and excellent enantioselectivities (up to 99% ee). It enables the installation of drug-like structural motifs in either enals or alkylating agents, demonstrating its potential as a valuable tool for late-stage modification. Furthermore, a concise synthetic route is presented to chiral pyrroloindoline-type skeletons. Preliminary mechanistic studies support a direct SN 2 mechanism.

20.
Int J Cancer ; 131(5): 1169-78, 2012 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-22038927

RESUMEN

Inactivation of the TP53 (p53) pathway by TP53 mutations is one of key steps in colorectal carcinogenesis. TP53 also plays an important role in cellular energy metabolism. We hypothesized that TP53-altered tumor cells might behave aggressively independent of energy balance, while progression of TP53-intact cells might depend on excess energy balance. Utilizing a database of 1,060 colon and rectal cancer patients in two prospective cohort studies, we evaluated TP53 expression by immunohistochemistry. Among 1,060 colorectal cancers, 457 (43%) tumors were positive for TP53. Cox proportional hazards model was used to compute mortality hazard ratio (HR), adjusting for clinical and tumoral features, including microsatellite instability, the CpG island methylator phenotype, LINE-1 methylation, KRAS, BRAF and PIK3CA. TP53 positivity was not significantly associated with cancer-specific survival in univariate analysis with HR of 1.16 [95% confidence interval (CI)=0.92-1.45], which became significant after stage adjustment (multivariate HR=1.30; 95% CI=1.02-1.65). Notably, we found a possible modifying effect of patient's body mass index (BMI) on tumor TP53. In non-obese patients (BMI<30 kg/m2), TP53 positivity was associated with shorter cancer-specific survival (multivariate HR=1.53; 95% CI=1.17-2.00), while TP53 positivity was not significantly associated with survival among obese patients (BMI≥30 kg/m2). Effect of TP53 positivity on cancer-specific survival significantly differed by BMI (pinteraction=0.0051). The adverse effect of obesity on patient mortality was limited to TP53-negative patients. These molecular pathological epidemiology data may support a dual role of TP53 alterations in cell-cycle deregulation and cell autonomy with respect to energy balance status.


Asunto(s)
Índice de Masa Corporal , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Metilación de ADN , Inestabilidad de Microsatélites , Anciano , Composición Corporal , Fosfatidilinositol 3-Quinasa Clase I , Neoplasias Colorrectales/metabolismo , Islas de CpG , ADN de Neoplasias/genética , Femenino , Estudios de Seguimiento , Humanos , Técnicas para Inmunoenzimas , Masculino , Minnesota/epidemiología , Mutación/genética , Obesidad/genética , Fosfatidilinositol 3-Quinasas/genética , Reacción en Cadena de la Polimerasa , Pronóstico , Estudios Prospectivos , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras) , Tasa de Supervivencia , Proteínas ras/genética
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