RESUMEN
Breast cancer is the second most commonly diagnosed malignancy among women globally. Past MRI studies have linked a high animal fat diet (HAFD) to increased mammary cancer risk in the SV40Tag mouse model of triple-negative breast cancer. Here, serial MRI examines tumor progression and measures the arterial blood volume feeding mammary glands in low fat diet (LFD) or HAFD fed mice. Virgin female C3(1)SV40Tag mice (n = 8), weaned at 3 weeks old, were assigned to an LFD (n = 4, 3.7 kcal/g, 17.2% kcal from vegetable oil) or an HAFD (n = 4, 5.3 kcal/g, 60% kcal from lard) group. From ages 8 to 12 weeks, weekly fast spin echo MR images and time-of-flight (TOF) MR angiography of inguinal mammary glands were acquired at 9.4 T. Following in vivo MRI, mice were sacrificed. Inguinal mammary glands were excised and fixed for ex vivo MRI and histology. Tumor, blood, and mammary gland volumes for each time point were measured from manually traced regions of interest; tumors were classified as invasive by histopathology-blinded observers. Our analysis confirmed a strong correlation between total tumor volume and blood volume in the mammary gland. Tumor growth rates from weeks 8-12 were twice as high in HAFD-fed mice (0.42 ± 0.14/week) as in LFD-fed mice (0.21 ± 0.03/week), p < 0.004. Mammary gland blood volume growth rate was 2.2 times higher in HAFD mice (0.29 ± 0.11/week) compared with LFD mice (0.13 ± 0.06/week), p < 0.02. The mammary gland growth rate of HAFD-fed mice (0.071 ± 0.011/week) was 2.7 times larger than that of LFD-fed mice (0.026 ± 0.009/week), p < 0.01. This is the first non-invasive, in vivo MRI study to demonstrate a strong correlation between an HAFD and increased cancer burden and blood volume in mammary cancer without using contrast agents, strengthening the evidence supporting the adverse effects of an HAFD on mammary cancer. These results support the potential future use of TOF angiography to evaluate vasculature of suspicious lesions.
Asunto(s)
Arterias/diagnóstico por imagen , Carcinogénesis/patología , Dieta Alta en Grasa , Conducta Alimentaria , Angiografía por Resonancia Magnética , Neoplasias de la Mama Triple Negativas/diagnóstico por imagen , Neoplasias de la Mama Triple Negativas/patología , Animales , Modelos Animales de Enfermedad , Femenino , Imagenología Tridimensional , Glándulas Mamarias Animales/diagnóstico por imagen , Glándulas Mamarias Animales/patología , Neoplasias Mamarias Animales/diagnóstico por imagen , Neoplasias Mamarias Animales/patología , Ratones , Invasividad Neoplásica , Tamaño de los Órganos , Flujo Sanguíneo Regional , Carga TumoralRESUMEN
MAIN CONCLUSION: The nucleotide sequence of a BAHD hydroxycinnamoyltransferase was amplified from Actaea racemosa (Ranunculaceae) and expressed in E. coli. The protein catalysed the formation of cimicifugic acids and thus is named hydroxycinnamoyl-CoA:piscidic acid hydroxycinnamoyltransferase (ArHPT1; cimicifugic acid synthase). Actaea racemosa (syn. Cimicifuga racemosa) is known to contain triterpene lactone glycosides and cimicifugic acids. The latter are esters of various hydroxycinnamic or benzoic acids with piscidic or fukiic acid. Amplification of a nucleotide sequence from A. racemosa, that was already known as HCT1 from an EST approach, and its expression in E. coli resulted in a protein that was able to catalyse the formation of several cimicifugic acids. For the characterisation of this hydroxycinnamoyltransferase (hydroxy)cinnamoyl-coenzyme A thioesters were synthesised as donor substrates and piscidic acid isolated as acceptor substrate. The lowest Km-value with 6.8 µM was determined for p-coumaroyl-CoA. More than 30 possible acceptor substrates were tested, but only piscidic acid and putatively fukiic acid were accepted. The apparent Km-value for piscidic acid was 32.3 µM. High expression of the hydroxycinnamoyltransferase gene was found in roots, but the content of cimicifugic acids was higher in leaves and flowers than in roots. This work describes for the first time a biosynthetic step in the formation of cimicifugic acids catalysed by a so far uncharacterised hydroxycinnamoyltransferase accepting piscidic acid as acceptor substrate thus being a hydroxycinnamoyl-CoA:piscidic acid hydroxycinnamoyltransferase (ArHPT1; cimicifugic acid synthase).
Asunto(s)
Aciltransferasas/metabolismo , Ácidos Cafeicos/metabolismo , Cimicifuga/enzimología , Fenilacetatos/metabolismo , Aciltransferasas/genética , Catálisis , Cimicifuga/química , Cimicifuga/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Glicósidos/metabolismo , Hidroxibenzoatos/metabolismo , Fenilpropionatos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/química , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Succinatos/metabolismo , Triterpenos/metabolismoRESUMEN
BACKGROUND AND PURPOSE: Although the assessment of cervical motion is routinely performed in clinical practice, no standard protocol for this procedure has ever been established formally. The specific aim of the present study was to select from four different measurement protocols the one which was most stable in terms of reproducibility and was appropriate for clinical and/or medicolegal applications. METHOD: A repeated measurement, test-retest of cervical motion study design using an ultrasound-based system for three-dimensional (3D) motion analysis; cervical range of motion was measured along the six primary directions: flexion; extension; right and left rotation; and right and left lateral flexion, in 20 healthy subjects who were tested twice over a period of lasting from one to four weeks. 'Protocol A' (reciprocal--intermittent testing) consisted of moving the head along a given primary direction, return to the neutral position, a pause and then motion to the opposite primary direction and return to neutral position. These movements were repeated three times. 'Protocol B' (reciprocal--continuous testing) was identical to Protocol A, but without the pause between the primary directions. 'Protocol C' consisted of three repetitions of the same primary direction with a break between two consecutive primary directions. Three sets of six randomly ordered primary directions constituted 'Protocol D'. RESULTS: Protocol D was associated with a significantly smaller range of motion and with the least intra-test reproducibility, as indicated by the coefficient of variation. The differences between the other protocols were largely negligible. CONCLUSION: In routine clinical practice, either of protocols A, B or C may be applied.