Breast cancer is the most common malignancy in women worldwide, and environmental factors, especially diet, have a role in the etiology of this disease. This work aimed to investigate the influence of high fat diets (rich in corn oil or extra virgin olive oil -EVOO-) and the timing of dietary intervention (from weaning or after induction) on tumor metabolism in a seven,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer model in rat. The effects of lipids (oils and fatty acids) have also been investigated in MCF-7 cells. The results have confirmed different effects on tumor progression depending on the type of lipid. Molecular analysis at mRNA, protein and activity level of enzymes of the main metabolic pathways have also shown differences among groups. Thus, the animals fed with the EVOO-enriched diet developed tumors with less degree of clinical and morphological malignancy and showed modified glucose and mitochondrial metabolism when compared to the animals fed with the corn oil-enriched diet. Paradoxically, no clear influence on lipid metabolism by the high fat diets was observed. Considering previous studies on proliferation and apoptosis in the same samples, the results suggest that metabolic changes have a role in the molecular context that results in the modulation of different signaling pathways. Moreover, metabolic characteristics, without the context of other pathways, may not reflect tumor malignancy. The time of dietary intervention plays also a role, suggesting the importance of metabolic plasticity and the relation with mammary gland status when the tumor is induced.

乳腺癌是全世界女性最常见的恶性肿瘤，环境因素，尤其是饮食，在该疾病的病因学中起作用。这项工作旨在研究高脂肪饮食（富含玉米油或特级初榨橄榄油 -EVOO-）和饮食干预时机（从断奶或诱导后）对 7,12-二甲基苯的肿瘤代谢的影响 [a ]蒽（DMBA）诱导的大鼠乳腺癌模型。还研究了 MCF-7 细胞中脂质（油和脂肪酸）的影响。结果证实了取决于脂质类型对肿瘤进展的不同影响。对主要代谢途径的 mRNA、蛋白质和酶活性水平的分子分析也显示出组间差异。因此，与饲喂富含玉米油的饮食的动物相比，饲喂富含 EVOO 饮食的动物患上临床和形态学恶性肿瘤程度较低的肿瘤，并显示出葡萄糖和线粒体代谢改变。矛盾的是，没有观察到高脂肪饮食对脂质代谢的明显影响。考虑到先前对同一样本中增殖和凋亡的研究，结果表明代谢变化在分子环境中起作用，导致不同信号通路的调节。此外，在没有其他途径背景的情况下，代谢特征可能无法反映肿瘤的恶性程度。饮食干预的时间也很重要，这表明代谢可塑性的重要性以及诱导肿瘤时与乳腺状态的关系。