Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 143
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Int J Cancer ; 153(12): 1978-1987, 2023 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-37555819

RESUMEN

Evidence suggests that aspirin use reduces the occurrence of colorectal neoplasia. Few studies have investigated the association among Black Americans, who are disproportionately burdened by the disease. We assessed aspirin use in relation to colorectal adenoma among Black women. The Black Women's Health Study is a prospective cohort of self-identified Black American women established in 1995. Participants reported regular aspirin use on baseline and follow-up questionnaires. Beginning in 1999, participants reported undergoing a colonoscopy or sigmoidoscopy, the only procedures through which colorectal adenomas can be diagnosed. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between aspirin use and colorectal adenoma among 34 397 women who reported at least 1 colonoscopy or sigmoidoscopy. From 1997 through 2018, 1913 women were diagnosed with an adenoma. Compared to nonaspirin users, regular users had 14% (OR = 0.86, 95% CI: 0.78-0.95) lower odds of adenoma. The odds of adenoma decreased with increasing duration of aspirin use (≥10 years: OR = 0.80, 95% CI: 0.66-0.96). Initiating aspirin at a younger age was associated with a reduced adenoma occurrence (age < 40 years at initiation: OR = 0.69, 95% CI: 0.55-0.86). Regular aspirin use was associated with a decreased odds of colorectal adenoma in our study of Black women. These findings support evidence demonstrating a chemopreventive impact of aspirin on colorectal neoplasia and suggest that aspirin may be a useful prevention strategy among US Black women.


Asunto(s)
Adenoma , Antiinflamatorios no Esteroideos , Aspirina , Negro o Afroamericano , Neoplasias Colorrectales , Adulto , Femenino , Humanos , Acetaminofén , Adenoma/epidemiología , Adenoma/etnología , Adenoma/prevención & control , Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/uso terapéutico , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/prevención & control , Neoplasias Colorrectales/tratamiento farmacológico , Estudios Prospectivos , Estados Unidos/epidemiología
2.
Gastrointest Endosc ; 94(1): 60-67.e1, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33385462

RESUMEN

BACKGROUND AND AIMS: Portal pressure can be used to identify patients with chronic liver disease who have progressed to cirrhosis. Portal pressure can also provide accurate prognostication for patients with cirrhosis. However, there are no practical means for assessment of portal pressure. Although it is well established that the gastric mucosal blood supply increases in patients with cirrhosis, this has been difficult to quantify reproducibly. Our group has developed a novel spectroscopic technology called spatially resolved subdiffuse reflectance spectroscopy (SRSRS), which enables quantification of mucosal microcirculation. We aim to ascertain if quantification of the gastric mucosal microcirculation with SRSRS correlates with clinical evidence of portal hypertension. METHODS: Patients undergoing EGD for clinical indications had 10 measurements taken in the endoscopically normal gastric fundus via SRSRS probe to assess the microcirculation. Cases were defined as patients with cirrhosis (n = 18), and controls were those without evidence of liver disease (n = 18); this was corroborated with transient elastography. RESULTS: The blood volume fraction (P = .06) and subdiffuse reflectance (P = .02) from a shallow depth in the gastric fundus were higher in patients with cirrhosis than those without. These markers were combined to yield an overall optical marker that can differentiate patients with cirrhosis from controls with a sensitivity of 72% and specificity of 94% (area under receiver operating curve, 0.82). CONCLUSIONS: Spectroscopic quantification of gastric fundal mucosal microcirculation is a promising surrogate of clinical correlates of portal hypertension. This approach may represent a less-intrusive surrogate biomarker for liver disease prognostication and potentially response to therapy.


Asunto(s)
Hipertensión Portal , Biomarcadores , Mucosa Gástrica , Humanos , Hipertensión Portal/diagnóstico por imagen , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico por imagen , Microcirculación , Análisis Espectral
3.
Liver Int ; 41(8): 1901-1908, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33969607

RESUMEN

BACKGROUND: Fresh frozen plasma (FFP) transfusion is often used in the management of acute variceal haemorrhage (AVH) despite best practice advice suggesting otherwise. OBJECTIVE: We investigated if FFP transfusion affects clinical outcomes in AVH. DESIGN, SETTING AND PATIENTS: We performed a retrospective cohort study of 244 consecutive, eligible patients admitted to five tertiary health care centres between 2013 and 2018 with AVH. MAIN OUTCOME MEASUREMENTS: Multivariable regression analyses were used to study the association of FFP transfusion with mortality at 42 days (primary outcome) and failure to control bleeding at 5 days and length of stay (secondary outcomes). RESULTS: Patients who received FFP transfusion (n = 100) had higher mean Model for End Stage Liver Disease (MELD) score and more severe variceal bleeding than those who did not received FFP transfusion (n = 144). Multivariable analysis showed that FFP transfusion was associated with increased odds of mortality at 42 days (odds ratio [OR] 9.41, 95% confidence interval [CI] 3.71-23.90). FFP transfusion was also associated with failure to control bleeding at 5 days (OR 3.87, 95% CI 1.28-11.70) and length of stay >7 days (adjusted OR 1.88, 95% CI 1.03-3.42). The independent association of FFP transfusion with mortality at 42 days persisted when the cohort was restricted to high-risk patients and in patients without active bleeding. LIMITATIONS AND CONCLUSIONS: Fresh frozen plasma transfusion in AVH is independently associated with poor clinical outcomes. As this an observational study, there may be residual bias due to confounding; however, we demonstrate no benefit and potential harm with FFP transfusions in AVH.


Asunto(s)
Enfermedad Hepática en Estado Terminal , Várices Esofágicas y Gástricas , Transfusión de Componentes Sanguíneos , Estudios de Cohortes , Várices Esofágicas y Gástricas/complicaciones , Várices Esofágicas y Gástricas/terapia , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/terapia , Humanos , Plasma , Estudios Retrospectivos , Índice de Severidad de la Enfermedad
4.
Int J Colorectal Dis ; 36(7): 1515-1524, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33934174

RESUMEN

PURPOSE: The United States Preventive Services Task Force (USPSTF) newly drafted recommendations for colorectal cancer (CRC) screening age in average-risk individuals decreased to 45 years from 50 years. This study evaluates the change in the incidence of CRC, compares the demographic characteristics, characteristics of CRC, survival, and factors affecting the survival of younger (< 50 years) with the older (> 50 years) CRC-diagnosed population of Boston Medical Center (BMC). Also tailors the screening recommendations of CRC based on subpopulations. METHODS: A retrospective cohort study was conducted from 2004 to 2019 at BMC who underwent colonoscopy, to see newly diagnosed CRC. The analysis was done in R studio version 1.2.5033. RESULTS: The incidence rate of CRC is increasing in the younger population. The CRC in younger population was 350 and older was 2019. The most prevalent site among the younger population was rectum (33.33%), and most of the CRC were diagnosed at an advanced stage. Hispanics were less likely to be diagnosed with CRC in older age group (OR= 0.468, 95% CI 0.285, 0.796). Lower BMI was associated with a higher risk of mortality (p= 0.012). There was no difference in survival in younger and older populations. CONCLUSIONS: CRC is increasing in the younger population, and Hispanics are diagnosed with CRC usually at a younger age. Early screening in young populations with average risk and even earlier screening in high-risk populations like Hispanics is warranted for timely recognition for prevention, early management, and reduction of mortality.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Anciano , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Humanos , Incidencia , Tamizaje Masivo , Estudios Retrospectivos , Estados Unidos
5.
Aging Clin Exp Res ; 32(10): 2141-2158, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32876941

RESUMEN

OBJECTIVES: We present evidence for a possible role of Vitamin D (VitD) deficiency in unregulated cytokine production and inflammation leading to complications in COVID-19 patients. DESIGN: The time-adjusted case mortality ratio (T-CMR) was estimated as the ratio of deceased patients on day N to the confirmed cases on day N-8. The adaptive average of T-CMR (A-CMR) was calculated as a metric of COVID-19 associated mortality. A model based on positivity change (PC) and an estimated prevalence of COVID-19 was used to determine countries with similar screening strategies. A possible association of A-CMR with the mean concentration of 25-hydroxyvitamin D (25(OH)D) in elderly individuals in countries with similar screening strategy was investigated. We considered high C-reactive protein (CRP) in severe COVID-19 patients (CRP ≥ 1 mg/dL) as a surrogate of a cytokine storm. We considered high-sensitivity CRP (hs-CRP) in healthy subjects as hs-CRP ≥ 0.2 mg/dL. RESULTS: A link between 25(OH)D and A-CMR in countries with similar screening strategy is evidence for VitD's possible role in reducing unregulated cytokine production and inflammation among patients with severe COVID-19. We observed an odds ratio (OR) of 1.8 with 95% confidence interval (95% CI) (1.2 to 2.6) and an OR of 1.9 with 95% CI (1.4 to 2.7) for hs-CRP in VitD deficient elderly from low-income families and high-income families, respectively. COVID-19 patient-level data show an OR of 3.4 with 95% CI (2.15 to 5.4) for high CRP in severe COVID-19 patients. CONCLUSION: We conclude that future studies on VitD's role in reducing cytokine storm and COVID-19 mortality are warranted.


Asunto(s)
Infecciones por Coronavirus/inmunología , Citocinas/inmunología , Inflamación/inmunología , Neumonía Viral/inmunología , Vitamina D/inmunología , Anciano , Betacoronavirus/inmunología , Betacoronavirus/patogenicidad , Proteína C-Reactiva/análisis , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/epidemiología , Neumonía Viral/mortalidad , SARS-CoV-2 , Vitamina D/uso terapéutico
6.
Proc Natl Acad Sci U S A ; 113(42): E6372-E6381, 2016 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-27702891

RESUMEN

The organization of chromatin is a regulator of molecular processes including transcription, replication, and DNA repair. The structures within chromatin that regulate these processes span from the nucleosomal (10-nm) to the chromosomal (>200-nm) levels, with little known about the dynamics of chromatin structure between these scales due to a lack of quantitative imaging technique in live cells. Previous work using partial-wave spectroscopic (PWS) microscopy, a quantitative imaging technique with sensitivity to macromolecular organization between 20 and 200 nm, has shown that transformation of chromatin at these length scales is a fundamental event during carcinogenesis. As the dynamics of chromatin likely play a critical regulatory role in cellular function, it is critical to develop live-cell imaging techniques that can probe the real-time temporal behavior of the chromatin nanoarchitecture. Therefore, we developed a live-cell PWS technique that allows high-throughput, label-free study of the causal relationship between nanoscale organization and molecular function in real time. In this work, we use live-cell PWS to study the change in chromatin structure due to DNA damage and expand on the link between metabolic function and the structure of higher-order chromatin. In particular, we studied the temporal changes to chromatin during UV light exposure, show that live-cell DNA-binding dyes induce damage to chromatin within seconds, and demonstrate a direct link between higher-order chromatin structure and mitochondrial membrane potential. Because biological function is tightly paired with structure, live-cell PWS is a powerful tool to study the nanoscale structure-function relationship in live cells.


Asunto(s)
Microscopía/métodos , Imagen Molecular/métodos , Animales , Células CHO , Cromatina/química , Cricetulus , Células HeLa , Células Endoteliales de la Vena Umbilical Humana , Humanos , Sustancias Macromoleculares/química , Orgánulos/química
7.
Gastroenterology ; 163(3): 537-538, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35711114
8.
BMC Cancer ; 18(1): 814, 2018 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-30103733

RESUMEN

BACKGROUND: The present study aimed to investigate the role of blood supply in early tumorigenesis in colorectal cancer. We leveraged the renin angiotensin system (RAS) to alter colonic blood supply and determine the effect on tumor initiation and progression. METHODS: To test the effect of blood supply on tumorigenesis, 53 male A/J mice were randomly assigned to one of three RAS modulation groups and one of two AOM treatments. The RAS modulation groups were I) water (RAS-unmodulated) as a control group, II) angiotensin-II and III) the angiotensin receptor blocker, Losartan. The mice in each group were then randomly split into either the saline control condition or the AOM-treated condition in which tumors were induced with a standard protocol of serial azoxymethane (AOM) injections. To monitor microvascular changes in the rectal mucosa during the study, we used confocal laser endomicroscopy (CLE) with FITC-Dextran for in-vivo imaging of vessels and polarization-gated spectroscopy (PGS) to quantify rectal hemoglobin concentration ([Hb]) and blood vessel radius (BVR). RESULTS: At 12 weeks post-AOM injections and before tumor formation, CLE images revealed many traditional hallmarks of angiogenesis including vessel dilation, loss of co-planarity, irregularity, and vessel sprouting in the pericryptal capillaries of the rectal mucosa in AOM-Water tumor bearing mice. PGS measurements at the same time-point showed increased rectal [Hb] and decreased BVR. At later time points, CLE images showed pronounced angiogenic features including irregular networks throughout the colon. Notably, the AOM-Losartan mice had significantly lower tumor multiplicity and did not exhibit the same angiogenic features observed with CLE, or the increase in [Hb] or decrease in BVR measured with PGS. The AOM-AngII mice did not have any significant trends. CONCLUSION: In-vivo PGS measurements of rectal colonic blood supply as well as CLE imaging revealed angiogenic disruptions to the capillary network prior to tumor formation. Losartan demonstrated an effective way to mitigate the changes to blood supply during tumorigenesis and reduce tumor multiplicity. These effects can be used in future studies to understand the early vessel changes observed.


Asunto(s)
Carcinogénesis/efectos de los fármacos , Colon/irrigación sanguínea , Neoplasias del Colon/irrigación sanguínea , Neoplasias del Colon/tratamiento farmacológico , Animales , Azoximetano/toxicidad , Vasos Sanguíneos/efectos de los fármacos , Vasos Sanguíneos/patología , Carcinogénesis/genética , Colon/efectos de los fármacos , Colon/patología , Neoplasias del Colon/sangre , Neoplasias del Colon/inducido químicamente , Dextranos/sangre , Modelos Animales de Enfermedad , Fluoresceína-5-Isotiocianato/análogos & derivados , Hemoglobinas/metabolismo , Humanos , Ratones , Microscopía Confocal , Sistema Renina-Angiotensina/efectos de los fármacos , Sistema Renina-Angiotensina/genética
9.
Dig Dis Sci ; 63(5): 1123-1138, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29572615

RESUMEN

Colorectal cancer (CRC) accounts for ~9% of all cancers in the Veteran population, a fact which has focused a great deal of the attention of the VA's research and development efforts. A field-based meeting of CRC experts was convened to discuss both challenges and opportunities in precision medicine for CRC. This group, designated as the VA Colorectal Cancer Cell-genomics Consortium (VA4C), discussed advances in CRC biology, biomarkers, and imaging for early detection and prevention. There was also a discussion of precision treatment involving fluorescence-guided surgery, targeted chemotherapies and immunotherapies, and personalized cancer treatment approaches. The overarching goal was to identify modalities that might ultimately lead to personalized cancer diagnosis and treatment. This review summarizes the findings of this VA field-based meeting, in which much of the current knowledge on CRC prescreening and treatment was discussed. It was concluded that there is a need and an opportunity to identify new targets for both the prevention of CRC and the development of effective therapies for advanced disease. Also, developing methods integrating genomic testing with tumoroid-based clinical drug response might lead to more accurate diagnosis and prognostication and more effective personalized treatment of CRC.


Asunto(s)
Neoplasias Colorrectales , Medicina de Precisión/métodos , Salud de los Veteranos , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/terapia , Terapia Combinada , Detección Precoz del Cáncer/métodos , Humanos , Pronóstico
11.
Gut ; 66(2): 285-292, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-26503631

RESUMEN

OBJECTIVE: A major impediment to translating chemoprevention to clinical practice has been lack of intermediate biomarkers. We previously reported that rectal interrogation with low-coherence enhanced backscattering spectroscopy (LEBS) detected microarchitectural manifestations of field carcinogenesis. We now wanted to ascertain if reversion of two LEBS markers spectral slope (SPEC) and fractal dimension (FRAC) could serve as a marker for chemopreventive efficacy. DESIGN: We conducted a multicentre, prospective, randomised, double-blind placebo-controlled, clinical trial in subjects with a history of colonic neoplasia who manifested altered SPEC/FRAC in histologically normal colonic mucosa. Subjects (n=79) were randomised to 325 mg aspirin or placebo. The primary endpoint changed in FRAC and SPEC spectral markers after 3 months. Mucosal levels of prostaglandin E2 (PGE2) and UDP-glucuronosyltransferase (UGT)1A6 genotypes were planned secondary endpoints. RESULTS: At 3 months, the aspirin group manifested alterations in SPEC (48.9%, p=0.055) and FRAC (55.4%, p=0.200) with the direction towards non-neoplastic status. As a measure of aspirin's pharmacological efficacy, we assessed changes in rectal PGE2 levels and noted that it correlated with SPEC and FRAC alterations (R=-0.55, p=0.01 and R=0.57, p=0.009, respectively) whereas there was no significant correlation in placebo specimens. While UGT1A6 subgroup analysis did not achieve statistical significance, the changes in SPEC and FRAC to a less neoplastic direction occurred only in the variant consonant with epidemiological evidence of chemoprevention. CONCLUSIONS: We provide the first proof of concept, albeit somewhat underpowered, that spectral markers reversion mirrors antineoplastic efficacy providing a potential modality for titration of agent type/dose to optimise chemopreventive strategies in clinical practice. TRIAL NUMBER: NCT00468910.


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/uso terapéutico , Neoplasias del Colon/prevención & control , Análisis Espectral/métodos , Anciano , Antiinflamatorios no Esteroideos/efectos adversos , Aspirina/efectos adversos , Biomarcadores de Tumor , Quimioprevención , Dinoprostona/metabolismo , Método Doble Ciego , Femenino , Genotipo , Glucuronosiltransferasa/genética , Humanos , Mucosa Intestinal/metabolismo , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recto/metabolismo
12.
Curr Opin Gastroenterol ; 33(1): 47-52, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27798442

RESUMEN

PURPOSE OF REVIEW: Despite the large investment of resources from screening, the fact that colorectal cancer remains the second leading cause of cancer deaths among Americans underscores the need for alternative strategies. Thus, a major clinical and research imperative is personalize clinical care, while focusing on risk stratification for screening, surveillance, chemoprevention, and therapeutic intervention. RECENT FINDINGS: A complicating factor that colorectal cancer is biologically heterogeneous for at least four consensus molecular subtypes presents clear challenges for developing robust molecular biomarkers. SUMMARY: The purpose of the review is to discuss the genetics and molecular biology of colonic neoplasia, high and low penetrance, and racial disparities in colonic neoplasia. Finally, we put forth the emerging concept of greater genomic landscape and the idea of chromatin protection therapy as a novel adjuvant to chemotherapy.


Asunto(s)
Neoplasias del Colon/genética , Neoplasias Colorrectales/genética , Disparidades en el Estado de Salud , Neoplasias del Colon/fisiopatología , Predisposición Genética a la Enfermedad , Humanos , Penetrancia
13.
Biophys J ; 109(11): 2218-26, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26636933

RESUMEN

Chromatin organization has a fundamental impact on the whole spectrum of genomic functions. Quantitative characterization of the chromatin structure, particularly at submicron length scales where chromatin fractal globules are formed, is critical to understanding this structure-function relationship. Such analysis is currently challenging due to the diffraction-limited resolution of conventional light microscopy. We herein present an optical approach termed inverse spectroscopic optical coherence tomography to characterize the mass density fractality of chromatin, and we apply the technique to observe chromatin decompaction in live cells. The technique makes it possible for the first time, to our knowledge, to sense intracellular morphology with length-scale sensitivity from ∼30 to 450 nm, thus primarily probing the higher-order chromatin structure, without resolving the actual structures. We used chromatin decompaction due to inhibition of histone deacytelases and measured the subsequent changes in the fractal dimension of the intracellular structure. The results were confirmed by transmission electron microscopy and confocal fluorescence microscopy.


Asunto(s)
Cromatina/química , Cromatina/metabolismo , Fractales , Supervivencia Celular , Cromatina/efectos de los fármacos , Células HT29 , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Tomografía Óptica , Ácido Valproico/farmacología
14.
J Biol Chem ; 288(23): 16274-16281, 2013 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-23603907

RESUMEN

Forkhead transcription factor FOXO3 plays a critical role in suppressing tumor growth, in part, by increasing the cell cycle inhibitor p27kip1, and Foxo3 deficiency in mice results in marked colonic epithelial proliferation. Here, we show in Foxo3-deficient colonic epithelial cells a striking increase in intracytoplasmic lipid droplets (LDs), a dynamic organelle recently observed in human tumor tissue. Although the regulation and function of LDs in non-adipocytes is unclear, we hypothesize that the anti-proliferative effect of FOXO3 was dependent on lowering LD density, thus decreasing fuel energy in both normal and colon cancer cells. In mouse colonic tumors, we found an increased expression of LD coat protein PLIN2 compared with normal colonic epithelial cells. Stimulation of LD density in human colon cancer cells led to a PI3K-dependent loss of FOXO3 and a decrease in the negative regulator of lipid metabolism in Sirtuin6 (SIRT6). Foxo3 deficiency also led to a decrease in SIRT6, revealing the existence of LD and FOXO3 feedback regulation in colonic cells. In parallel, LD-dependent loss of FOXO3 led to its dissociation from the promoter and decreased expression of the cell cycle inhibitor p27kip1. Stimulation of LD density promoted proliferation in colon cancer cells, whereas silencing PLIN2 or overexpression of FOXO3 inhibited proliferation. Taken together, FOXO3 and LDs might serve as new targets for therapeutic intervention of colon cancer.


Asunto(s)
Proliferación Celular , Colon/metabolismo , Neoplasias del Colon/metabolismo , Células Epiteliales/metabolismo , Factores de Transcripción Forkhead/metabolismo , Mucosa Intestinal/metabolismo , Metabolismo de los Lípidos , Proteínas de Neoplasias/metabolismo , Animales , Línea Celular Tumoral , Colon/patología , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Neoplasias del Colon/terapia , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Células Epiteliales/patología , Proteína Forkhead Box O3 , Factores de Transcripción Forkhead/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Mucosa Intestinal/patología , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , Ratones , Proteínas de Neoplasias/genética , Perilipina-2 , Regiones Promotoras Genéticas , Sirtuinas/genética , Sirtuinas/metabolismo
15.
BMC Cancer ; 14: 189, 2014 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-24629088

RESUMEN

BACKGROUND: Nuclear alterations are a well-known manifestation of cancer. However, little is known about the early, microscopically-undetectable stages of malignant transformation. Based on the phenomenon of field cancerization, the tissue in the field of a tumor can be used to identify and study the initiating events of carcinogenesis. Morphological changes in nuclear organization have been implicated in the field of colorectal cancer (CRC), and we hypothesize that characterization of chromatin alterations in the early stages of CRC will provide insight into cancer progression, as well as serve as a biomarker for early detection, risk stratification and prevention. METHODS: For this study we used transmission electron microscopy (TEM) images of nuclei harboring pre-neoplastic CRC alterations in two models: a carcinogen-treated animal model of early CRC, and microscopically normal-appearing tissue in the field of human CRC. We quantify the chromatin arrangement using approaches with two levels of complexity: 1) binary, where chromatin is separated into areas of dense heterochromatin and loose euchromatin, and 2) grey-scale, where the statistics of continuous mass-density distribution within the nucleus is quantified by its spatial correlation function. RESULTS: We established an increase in heterochromatin content and clump size, as well as a loss of its characteristic peripheral positioning in microscopically normal pre-neoplastic cell nuclei. Additionally, the analysis of chromatin density showed that its spatial distribution is altered from a fractal to a stretched exponential. CONCLUSIONS: We characterize quantitatively and qualitatively the nanoscale structural alterations preceding cancer development, which may allow for the establishment of promising new biomarkers for cancer risk stratification and diagnosis. The findings of this study confirm that ultrastructural changes of chromatin in field carcinogenesis represent early neoplastic events leading to the development of well-documented, microscopically detectable hallmarks of cancer.


Asunto(s)
Adenoma/patología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/ultraestructura , Ensamble y Desensamble de Cromatina , Neoplasias Colorrectales/patología , Animales , Cromatina/patología , Cromatina/ultraestructura , Humanos , Microscopía Electrónica de Transmisión , Ratas
16.
Gastrointest Endosc ; 80(5): 786-93.e1-2, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24861243

RESUMEN

BACKGROUND: According to the field effect theory, by detecting microvasculature changes such as early increase in blood supply (EIBS) in the surrounding tissue, neoplastic lesions can be identified from a distance. OBJECTIVE: To determine the feasibility and efficacy of a fiberoptic probe containing novel polarization gating spectroscopy technology to identify patients with pancreatic adenocarcinoma (PAC) by the field effect theory. DESIGN: Prospective cohort (pilot) study. SETTING: Outpatient tertiary care center. PATIENTS: Adult (≥ 18 years) patients undergoing EGD-EUS were screened. Patients with PAC were included in the "cancer" group and patients without PAC were included in the "control" group. We excluded patients with other known malignancies and gastroduodenal premalignant lesions. INTERVENTIONS AND MAIN OUTCOME MEASURES: Spectroscopic measurements of EIBS variables, such as deoxyhemoglobin concentration (DHb) and mean blood vessel radius (BVR), were obtained from 5 periampullary locations. The Mann-Whitney rank sum test was used for the statistical analysis (P ≤ .05). RESULTS: Fourteen patients (mean age 72 years, 79% male) in the cancer group and 15 patients (mean age 63 years, 60% male) in the control group were included in the final analysis. At the ampullary site, both DHb (P = .001) and BVR (P = .03) were higher in PAC patients than in the control subjects. The DHb alone (92% sensitivity, 86% specificity) or in combination with BVR (92% sensitivity, 79% specificity) can differentiate PAC from control subjects with high accuracy. LIMITATIONS: Small sample size, unmatched control subjects. CONCLUSIONS: Spectroscopic measurements of EIBS by fiberoptic probes are feasible. Preliminary evidence suggests that in vivo measurement of normal-appearing duodenal tissue can differentiate PAC patients from a distance with high accuracy.


Asunto(s)
Adenocarcinoma/diagnóstico , Ampolla Hepatopancreática/irrigación sanguínea , Duodeno/irrigación sanguínea , Mucosa Intestinal/irrigación sanguínea , Microvasos/patología , Neoplasias Pancreáticas/diagnóstico , Anciano , Anciano de 80 o más Años , Ampolla Hepatopancreática/metabolismo , Estudios de Casos y Controles , Estudios de Cohortes , Duodeno/metabolismo , Endoscopía del Sistema Digestivo/métodos , Endosonografía , Estudios de Factibilidad , Femenino , Hemoglobinas/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Proyectos Piloto , Estudios Prospectivos , Análisis Espectral/métodos
18.
Sci Rep ; 14(1): 7808, 2024 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-38565871

RESUMEN

Colonoscopy is accurate but inefficient for colorectal cancer (CRC) prevention due to the low (~ 7 to 8%) prevalence of target lesions, advanced adenomas. We leveraged rectal mucosa to identify patients who harbor CRC field carcinogenesis by evaluating chromatin 3D architecture. Supranucleosomal disordered chromatin chains (~ 5 to 20 nm, ~1 kbp) fold into chromatin packing domains (~ 100 to 200 nm, ~ 100 to 1000 kbp). In turn, the fractal-like conformation of DNA within chromatin domains and the folding of the genome into packing domains has been shown to influence multiple facets of gene transcription, including the transcriptional plasticity of cancer cells. We deployed an optical spectroscopic nanosensing technique, chromatin-sensitive partial wave spectroscopic microscopy (csPWS), to evaluate the packing density scaling D of the chromatin chain conformation within packing domains from rectal mucosa in 256 patients with varying degrees of progression to colorectal cancer. We found average packing scaling D of chromatin domains was elevated in tumor cells, histologically normal-appearing cells 4 cm proximal to the tumor, and histologically normal-appearing rectal mucosa compared to cells from control patients (p < 0.001). Nuclear D had a robust correlation with the model of 5-year risk of CRC with r2 = 0.94. Furthermore, rectal D was evaluated as a screening biomarker for patients with advanced adenomas presenting an AUC of 0.85 and 85% sensitivity and specificity. artificial intelligence-enhanced csPWS improved diagnostic performance with AUC = 0.90. Considering the low sensitivity of existing CRC tests, including liquid biopsies, to early-stage cancers our work highlights the potential of chromatin biomarkers of field carcinogenesis in detecting early, significant precancerous colon lesions.


Asunto(s)
Adenoma , Neoplasias Colorrectales , Humanos , Inteligencia Artificial , Detección Precoz del Cáncer , Carcinogénesis/patología , Colonoscopía , Cromatina/genética , Biomarcadores , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Adenoma/diagnóstico , Adenoma/genética , Adenoma/patología
19.
Cancer Lett ; 587: 216704, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38360138

RESUMEN

Despite significant advancements in prevention and treatment, colorectal cancer (CRC) remains the third leading cause of cancer-related deaths. Animal models, including xenografts, syngeneic, and genetically engineered, have emerged as indispensable tools in cancer research. These models offer a valuable platform to address critical questions regarding molecular pathogenesis and test therapeutic interventions before moving on to clinical trials. Advancements in CRC animal models have also facilitated the advent of personalized and precision medicine. Patient-derived xenografts and genetically engineered mice that mirror features of human tumors allow for tailoring treatments to specific CRC subtypes, improving treatment outcomes and quality of life. To overcome the limitations of individual model systems, recent studies have employed a multi-modal approach, combining different animal models, 3D organoids, and in vitro studies. This integrative approach provides a comprehensive understanding of CRC biology, including the tumor microenvironment and therapeutic responses, driving the development of more effective and personalized therapeutic interventions. This review discusses the animal models used for CRC research, including recent advancements and limitations of these animal models.


Asunto(s)
Neoplasias Colorrectales , Ratones , Humanos , Animales , Neoplasias Colorrectales/patología , Calidad de Vida , Modelos Animales de Enfermedad , Microambiente Tumoral
20.
Int J Cancer ; 133(5): 1143-52, 2013 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-23436651

RESUMEN

Ovarian cancer ranks fifth in cancer fatalities among American women. Although curable at early stages with surgery, most women are diagnosed with symptoms of late-stage metastatic disease. Moreover, none of the current diagnostic techniques are clinically recommended for at-risk women as they preferentially target low-grade tumors (which do not affect longevity) and fail to capture early signatures of more lethal serous tumors which originate in the fimbrae region of the fallopian tubes. Hence, the early detection of ovarian cancer is challenging given the current strategy. Recently, our group has developed a novel optical imaging technique, partial wave spectroscopic (PWS) microscopy, that can quantify the nanoscale macromolecular density fluctuations within biological cells via a biomarker, disorder strength (Ld ). Using the concept of field carcinogenesis, we propose a method of detecting ovarian cancer by PWS assessment of endometrial and endocervical columnar cells. The study includes 26 patients (controls = 15, cancer = 11) for endometrium and 23 (controls = 13, cancer = 10) for endocervix. Our results highlight a significant increase in Ld (% fold-increase > 50%, p-value < 0.05) for columnar epithelial cells obtained from cancer patients compared to controls for both endocervix and endometrium. Overall, the quantification of field carcinogenic events in the endometrium and the novel observation of its extension to the cervix are unique findings in the understanding of ovarian field carcinogenesis. We further show independent validation of the presence of cervical field carcinogenesis with micro-RNA expression data.


Asunto(s)
Transformación Celular Neoplásica , Cuello del Útero/patología , Endometrio/patología , Neoplasias Ováricas/patología , Anciano , Células Epiteliales/patología , Femenino , Humanos , Persona de Mediana Edad , Nanotecnología , Neoplasias Ováricas/etiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA