RESUMEN

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive disease with poor prognosis, which is mainly due to drug resistance. The biology determining the response to chemo-radiotherapy in HNSCC is poorly understood. Using clinical samples, we found that miR124-3p and miR766-3p are overexpressed in chemo-radiotherapy-resistant (non-responder) HNSCC, as compared to responder tumors. Our study shows that inhibition of miR124-3p and miR766-3p enhances the sensitivity of HNSCC cell lines, CAL27 and FaDu, to 5-fluorouracil and cisplatin (FP) chemotherapy and radiotherapy. In contrast, overexpression of miR766-3p and miR124-3p confers a resistance phenotype in HNSCC cells. The upregulation of miR124-3p and miR766-3p is associated with increased HNSCC cell invasion and migration. In a xenograft mouse model, inhibition of miR124-3p and miR766-3p enhanced the efficacy of chemo-radiotherapy with reduced growth of resistant HNSCC. For the first time, we identified that miR124-3p and miR766-3p attenuate expression of CREBRF and NR3C2, respectively, in HNSCC, which promotes aggressive tumor behavior by inducing the signaling axes CREB3/ATG5 and ß-catenin/c-Myc. Since miR124-3p and miR766-3p affect complementary pathways, combined inhibition of these two miRNAs shows an additive effect on sensitizing cancer cells to chemo-radiotherapy. In conclusion, our study demonstrated a novel miR124-3p- and miR766-3p-based biological mechanism governing treatment-resistant HNSCC, which can be targeted to improve clinical outcomes in HNSCC.

RESUMEN

Studies suggest that the efficacy of cancer chemotherapy and immunotherapy is influenced by intestinal bacteria. However, the influence of the microbiome on radiation therapy is not as well understood, and the microbiome comprises more than bacteria. Here, we find that intestinal fungi regulate antitumor immune responses following radiation in mouse models of breast cancer and melanoma and that fungi and bacteria have opposite influences on these responses. Antibiotic-mediated depletion or gnotobiotic exclusion of fungi enhances responsiveness to radiation, whereas antibiotic-mediated depletion of bacteria reduces responsiveness and is associated with overgrowth of commensal fungi. Further, elevated intratumoral expression of Dectin-1, a primary innate sensor of fungi, is negatively associated with survival in patients with breast cancer and is required for the effects of commensal fungi in mouse models of radiation therapy.

Asunto(s)

Antifúngicos/administración & dosificación , Bacterias/clasificación , Neoplasias de la Mama/terapia , Hongos/efectos de los fármacos , Lectinas Tipo C/genética , Melanoma/terapia , Animales , Antifúngicos/farmacología , Bacterias/inmunología , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/microbiología , Terapia Combinada , Regulación hacia Abajo , Femenino , Hongos/clasificación , Hongos/inmunología , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/efectos de la radiación , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Humanos , Melanoma/inmunología , Melanoma/microbiología , Ratones , Simbiosis , Linfocitos T/metabolismo , Macrófagos Asociados a Tumores/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/efectos de la radiación , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Radiation continues to play a major role in the treatment of almost every cancer type. Traditional radiation studies focused on its ability to damage DNA, but recent evidence has demonstrated that a key mechanism driving the efficacy of radiation in vivo is the immune response triggered in irradiated tissue. Innate immune cells including macrophages, dendritic cells, and natural killer cells are key mediators of the radiation-induced immune response. They regulate the sensing of radiation-mediated damage and subsequent radiation-induced inflammation. Given the importance of innate immune cells as determinants of the post-radiation anti-tumor immune response, much research has been devoted to identify ways to both enhance the innate immune response and prevent their ability to suppress ongoing immune responses. In this review, we will discuss how the innate immune system shapes anti-tumor immunity following radiation and highlight key strategies directed at the innate immune response to enhance the efficacy of radiation.

Asunto(s)

Inmunidad Adaptativa/efectos de los fármacos , Antineoplásicos Inmunológicos/uso terapéutico , Inmunidad Innata/efectos de los fármacos , Neoplasias/terapia , Microambiente Tumoral/efectos de la radiación , Inmunidad Adaptativa/efectos de la radiación , Antineoplásicos Inmunológicos/farmacología , Quimioradioterapia/métodos , Ensayos Clínicos como Asunto , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Células Dendríticas/efectos de la radiación , Humanos , Inmunidad Innata/efectos de la radiación , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/efectos de la radiación , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/efectos de la radiación , Terapia Molecular Dirigida/métodos , Neoplasias/inmunología , Resultado del Tratamiento , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología

RESUMEN

For patients with lung cancer undergoing curative intent radiotherapy, functional lung imaging can be incorporated into treatment planning to modify the dose distribution within non-target volume lung by differentiation of lung regions that are functionally defective or viable. This concept of functional image-guided lung avoidance treatment planning has been investigated with several imaging modalities, primarily single photon emission computed tomography (SPECT), but also hyperpolarised gas magnetic resonance (MR) imaging, positron emission tomography (PET) and computed tomography (CT)-based measures of lung biomechanics. Here, we review the application of each of these modalities, review practical issues of lung avoidance implementation, including image registration and the role of both ventilation and perfusion imaging, and provide guidelines for reporting of future lung avoidance planning studies.

Asunto(s)

Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/radioterapia , Órganos en Riesgo/efectos de la radiación , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Guiada por Imagen/métodos , Humanos , Neoplasias Pulmonares/patología , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos

RESUMEN

The purpose of this work was to assess the reproducibility of percentage of ventilated lung volume (PV) measured from hyperpolarized (HP) (3)He and (1)H anatomical images acquired in the same breath-hold when compared with PV measured from (3)He and (1)H images from separate breath-holds. Volumetric (3)He ventilation and (1)H anatomical images of the same resolution were acquired during the same breath-hold. To assess reproducibility, this procedure was performed twice with a short gap between acquisitions. In addition, (1)H images were also acquired in a separate breath for comparison. PV ((3)He ventilated volume divided by (1)H total lung volume) was calculated using the single-breath-hold images (PV(single)) and the separate-breath-hold images (PV(separate)). Short-term reproducibility of PV measurement was assessed for both single- and separate-breath acquisitions. Dice similarity coefficients (DSCs) were calculated to quantify spatial overlap between (3)He and (1)H segmentations for the single- and separate-breath-hold acquisitions. The efficacy of using the separate-breath method combined with image registration was also assessed. The mean magnitude difference between the two sets of PV values (±standard deviation) was 1.49 ± 1.32% for PV(single) and 4.19 ± 4.10% for PV(separate), with a significant difference (p < 0.01). The mean magnitude difference between the two PV values for the registered separate-breath technique (PV(sep-registered)) was 2.27 ± 2.23%. Bland-Altman analysis showed that PV measured with single-breath acquisitions was more repeatable than PV measured with separate-breath acquisitions, regardless of image registration. DSC values were significantly greater (p < 0.01) for single-breath acquisition than for separate-breath acquisition. Acquisition of HP gas ventilation and (1)H anatomical images in a single breath-hold provides a more reproducible means of percentage lung ventilation volume measurement than the previously used separate-breath-hold scan approach, and reduces errors.

Asunto(s)

Helio , Mediciones del Volumen Pulmonar/métodos , Imagen por Resonancia Magnética , Protones , Ventilación Pulmonar/fisiología , Respiración , Adulto , Anciano , Humanos , Procesamiento de Imagen Asistido por Computador , Persona de Mediana Edad , Reproducibilidad de los Resultados

RESUMEN

AIM: To evaluate if diffusion-weighted imaging (DWI) is useful in characterizing liver lesions in patients with cirrhosis. MATERIALS AND METHODS: A retrospective review revealed 37 patients with cirrhosis who had 41 histologically proven hepatocellular carcinoma (HCC) lesions. Another 20 patents with cirrhosis had 29 solid nodules that remained stable for at least 12 months and were deemed to be benign hepatic nodules (BHN). Of the HCC lesions, 14 were well-differentiated (WD HCC), 20 were moderately differentiated, and seven were poorly differentiated histology. For all lesions, two reviewers analysed signal characteristics and made apparent diffusion coefficient value (ADC) measurements. RESULTS: Visual analysis of DWI was useful in that no HCC was hypointense and no BHN was hyperintense to liver. Visual analysis of DWI was not useful in separating WD HCC from higher grades. There was substantial overlap in ADC values of the HCC and BHN. Among HCC lesions, ADC values of more than 0.99 × 10(-3) mm(2)/s had sensitivity and specificity of 85% and 86% for reviewer 1, and 63% and 64% for reviewer 2 in diagnosing WD HCC. CONCLUSIONS: ADC measurements of BHN were higher than that of HCC, and the ADC values of WD HCC were higher than that of more aggressive grades of HCC. However, quantitative measurements may not help in determining the histological grade of individual cases of HCC.

Asunto(s)

Carcinoma Hepatocelular/patología , Cirrosis Hepática/patología , Neoplasias Hepáticas/patología , Adulto , Anciano , Carcinoma Hepatocelular/complicaciones , Imagen de Difusión por Resonancia Magnética/métodos , Femenino , Humanos , Cirrosis Hepática/complicaciones , Neoplasias Hepáticas/complicaciones , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Retrospectivos

RESUMEN

AIM: To assess the role of the hepatocellular phase on magnetic resonance imaging (MRI) following gadobenate in characterizing the grade of hepatocellular carcinoma (HCC) in cirrhotic patients. MATERIALS AND METHODS: A retrospective review of the MRI database from October 2004 to February 2009, performed for this Institutional Review Board-approved and Health Insurance Portability and Accountability Act (HIPAA)-complaint study, revealed 237 cirrhotic patients with focal liver lesions. Patients who had both a hepatocellular phase after gadobenate and pathological confirmation of HCC were included. Forty-six patients with 73 HCC were analysed independently by two reviewers for signal characteristics. Absolute contrast-to-noise ratio (CNR) and enhancement ratio (ER) were calculated. Univariate analysis, stepwise logistic regression analysis, and receiver operating characteristic curves (ROC) were performed. RESULTS: The mean age was 61.3 years (range 45 to 78 years). There were 11 females and 35 males, who had 22 well-differentiated (WD HCC), 35 moderately-differentiated (MD HCC), and 16 poorly-differentiated (PD HCC) hepatocellular carcinomas. On visual analysis of the hepatocellular phase, a hyperintense or isointense lesion had a sensitivity and specificity of 45% and 76%, respectively, for WD HCC. On quantitative analysis, the only significant predictor of the grade of HCC was the ER on the hepatocellular phase (p=0.019 and 0.001 for the two reviewers in logistic regression model). On ROC analysis, an ER of >13% was 47% sensitive and 89% specific in predicting WD HCC histology. CONCLUSION: Although the hepatocellular phase of gadobenate may help to differentiate some cases of WD HCC from the more aggressive grades, there is overlap between the different grades on qualitative and quantitative analysis.

Asunto(s)

Carcinoma Hepatocelular/diagnóstico , Medios de Contraste , Cirrosis Hepática/diagnóstico , Neoplasias Hepáticas/diagnóstico , Imagen por Resonancia Magnética/métodos , Meglumina/análogos & derivados , Compuestos Organometálicos , Anciano , Carcinoma Hepatocelular/patología , Diagnóstico Diferencial , Femenino , Humanos , Cirrosis Hepática/patología , Neoplasias Hepáticas/patología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos

RESUMEN

AIM: To assess the value of diffusion-weighted imaging (DWI) in evaluating parenchymal disorders following orthotopic liver transplantation (OLT). MATERIALS AND METHODS: This institutional review board-approved, retrospective study measured the hepatic apparent diffusion coefficients (ADC) in patients following OLT. Those with vascular complications or within 3 months of OLT were excluded. A single-shot echoplanar sequence with b values of 50, 400 (or 500), and 800 s/mm(2) was performed. Liver biopsy specimens [performed with a median of 17 days after magnetic resonance imaging (MRI)] were recorded for the presence and severity of parenchymal disorders, such as acute cellular rejection, and recurrence of fibrosis in all patients, and the recurrence of viral hepatitis in patients with hepatitis C. ADC values were measured blinded to histology in 41 patients (33 males) who had 56 MRI scans. RESULTS: There was a significant difference in ADC values associated with a histological abnormality seen on core biopsy [n=43, mean (SD) ADC of 0.91 (0.15)×10(-3) mm(2)/s] and those associated with no histological abnormality [n=13, mean (SD) ADC of 1.11 (0.17)×10(-3) mm(2)/s; (p=0.003)]. ADC values did not predict any of the individual parenchymal disorders on logistic regression analysis. When the ADC value was <0.99×10(-3) mm(2)/s, there was a sensitivity and specificity of 85% and 72%, respectively, in predicting a parenchymal disorder (area under ROC curve=0.84; 95% CI 0.72 to 0.92). CONCLUSION: ADC measurements may help in deciding which patients require core liver biopsy after OLT. However, ADC values are not likely to be reliable in differentiating between the various parenchymal disorders.

Asunto(s)

Carcinoma Hepatocelular/diagnóstico , Cirrosis Hepática/diagnóstico , Neoplasias Hepáticas/diagnóstico , Trasplante de Hígado/efectos adversos , Hígado/patología , Anciano , Carcinoma Hepatocelular/patología , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Cirrosis Hepática/patología , Neoplasias Hepáticas/patología , Trasplante de Hígado/patología , Masculino , Curva ROC , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad

RESUMEN

Frequency-modulation atomic force microscopy (FM-AFM) relies on an accurate tracking of the resonance frequency of a scanning probe. It is now used in environments ranging from ultrahigh vacuum to aqueous solutions, for slow and for fast imaging, with probes resonating from a few kilohertz up to several megahertz. Here we present a versatile experimental setup that detects amplitude, phase, and frequency of AFM probes for resonance frequencies up to 15 MHz and with >70 kHz maximum bandwidth for amplitude/phase detection. We provide generic parameter settings for variable-bandwidth frequency detection and test these using our setup. The signal-to-noise ratio of the frequency detector is sufficiently high to record atomic-resolution images of mica by FM-AFM in aqueous solution.

Asunto(s)

Microscopía de Fuerza Atómica/métodos , Silicatos de Aluminio/química , Diseño de Equipo , Microscopía de Fuerza Atómica/instrumentación , Ondas de Radio , Propiedades de Superficie