He Dianning, Mustafi Devkumar, Fan Xiaobing, Fernandez Sully, Markiewicz Erica, Zamora Marta, Mueller Jeffrey, Sachleben Joseph R, Brady Matthew J, Conzen Suzanne D, Karczmar Gregory S
Department of Radiology, The University of Chicago, Chicago, Illinois, United States of America.
Sino-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, China.
PLoS One. 2018 Jan 11;13(1):e0190929. doi: 10.1371/journal.pone.0190929. eCollection 2018.
The effects of consumption of different diets on the fatty acid composition in the mammary glands of SV40 T-antigen (Tag) transgenic mice, a well-established model of human triple-negative breast cancer, were investigated with magnetic resonance spectroscopy and spectroscopic imaging. Female C3(1) SV40 Tag transgenic mice (n = 12) were divided into three groups at 4 weeks of age: low fat diet (LFD), high animal fat diet (HAFD), and high fructose diet (HFruD). MRI scans of mammary glands were acquired with a 9.4 T scanner after 8 weeks on the diet. 1H spectra were acquired using point resolved spectroscopy (PRESS) from two 1 mm3 boxes on each side of inguinal mammary gland with no cancers, lymph nodes, or lymph ducts. High spectral and spatial resolution (HiSS) images were also acquired from nine 1-mm slices. A combination of Gaussian and Lorentzian functions was used to fit the spectra. The percentages of poly-unsaturated fatty acids (PUFA), mono-unsaturated fatty acids (MUFA), and saturated fatty acids (SFA) were calculated from each fitted spectrum. Water and fat peak height images (maps) were generated from HiSS data. The results showed that HAFD mice had significantly lower PUFA than both LFD (p < 0.001) and HFruD (p < 0.01) mice. The mammary lipid quantity calculated from 1H spectra was much larger in HAFD mice than in LFD (p = 0.03) but similar to HFruD mice (p = 0.10). The average fat signal intensity over the mammary glands calculated from HiSS fat maps was ~60% higher in HAFD mice than in LFD (p = 0.04) mice. The mean or median of calculated parameters for the HFruD mice were between those for LFD and HAFD mice. Therefore, PRESS spectroscopy and HiSS MRI demonstrated water and fat composition changes in mammary glands due to a Western diet, which was low in potassium, high in sodium, animal fat, and simple carbohydrates. Measurements of PUFA with MRI could be used to evaluate cancer risk, improve cancer detection and diagnosis, and guide preventative therapy.
利用磁共振波谱和波谱成像技术，研究了不同饮食对SV40 T抗原（Tag）转基因小鼠乳腺脂肪酸组成的影响，该小鼠是一种成熟的人类三阴性乳腺癌模型。雌性C3(1) SV40 Tag转基因小鼠（n = 12）在4周龄时被分为三组：低脂饮食（LFD）组、高动物脂肪饮食（HAFD）组和高果糖饮食（HFruD）组。在饮食8周后，用9.4 T扫描仪对乳腺进行MRI扫描。使用点分辨波谱法（PRESS）从腹股沟乳腺两侧无癌症、淋巴结或淋巴管的两个1 mm3区域采集1H谱。还从九个1 mm厚的切片采集了高光谱和空间分辨率（HiSS）图像。使用高斯函数和洛伦兹函数的组合对波谱进行拟合。根据每个拟合波谱计算多不饱和脂肪酸（PUFA）、单不饱和脂肪酸（MUFA）和饱和脂肪酸（SFA）的百分比。从HiSS数据生成水和脂肪峰高图像（图谱）。结果显示，HAFD小鼠的PUFA显著低于LFD组（p < 0.001）和HFruD组（p < 0.01）小鼠。根据1H谱计算，HAFD小鼠的乳腺脂质含量比LFD组高得多（p = 0.03），但与HFruD组小鼠相似（p = 0.10）。根据HiSS脂肪图谱计算，HAFD小鼠乳腺的平均脂肪信号强度比LFD组高约60%（p = 0.04）。HFruD组小鼠计算参数的均值或中位数介于LFD组和HAFD组小鼠之间。因此，PRESS波谱和HiSS MRI显示，西式饮食（低钾、高钠、动物脂肪和简单碳水化合物）会导致乳腺水和脂肪成分发生变化。用MRI测量PUFA可用于评估癌症风险、改善癌症检测和诊断，并指导预防性治疗。
