Breast cancer is one of the most common cancers worldwide, which makes it a very impactful malignancy in the society. Breast cancers can be classified through different systems based on the main tumor features and gene, protein, and cell receptors expression, which will determine the most advisable therapeutic course and expected outcomes. Multiple therapeutic options have already been proposed and implemented for breast cancer treatment. Nonetheless, their use and efficacy still greatly depend on the tumor classification, and treatments are commonly associated with invasiveness, pain, discomfort, severe side effects, and poor specificity. This has demanded an investment in the research of the mechanisms behind the disease progression, evolution, and associated risk factors, and on novel diagnostic and therapeutic techniques. However, advances in the understanding and assessment of breast cancer are dependent on the ability to mimic the properties and microenvironment of tumors in vivo, which can be achieved through experimentation on animal models. This review covers an overview of the main animal models used in breast cancer research, namely in vitro models, in vivo models, in silico models, and other models. For each model, the main characteristics, advantages, and challenges associated to their use are highlighted.

Breast cancer is one of the most frequently diagnosed malignancies and common causes of cancer death in women. Recent studies suggest that environmental exposures to certain chemicals, such as 7,12-Dimethylbenzanthracene (DMBA), a chemical present in tobacco, may increase the risk of developing breast cancer later in life. The first-line treatments for breast cancer (surgery, chemotherapy or a combination of both) are generally invasive and frequently associated with severe side effects and high comorbidity. Consequently, novel approaches are strongly required to find more natural-like experimental models that better reflect the tumors’ etiology, physiopathology and response to treatments, as well as to find more targeted, efficient and minimally invasive treatments. This study proposes the development and an in deep biological characterization of an experimental model using DMBA-tumor-induction in Sprague-Dawley female rats. Moreover, a photothermal therapy approach using a near-infrared laser coupled with gold nanoparticles was preliminarily assessed. The gold nanoparticles were functionalized with Epidermal Growth Factor, and their physicochemical properties and in vitro effects were characterized. DMBA proved to be a very good and selective inductor of breast cancer, with 100% incidence and inducing an average of 4.7 tumors per animal. Epigenetic analysis showed that tumors classified with worst prognosis were hypomethylated. The tumor-induced rats were then subjected to a preliminary treatment using functionalized gold nanoparticles and its activation by laser (650–900 nm). The treatment outcomes presented very promising alterations in terms of tumor histology, confirming the presence of necrosis in most of the cases. Although this study revealed encouraging results as a breast cancer therapy, it is important to define tumor eligibility and specific efficiency criteria to further assess its application in breast cancer treatment on other species.

The foods used for feeding, as well as the way they’re cooked and mixed in the meals, are elements of great importance to the health of populations.舲 The aim of this study is to evaluate the existence of morphological changes in the periodontal ligament after administration of red wine and an extract of Genipa americana. In this study were used 30 Wistar male rats with eight weeks at baseline, kept under physiological conditions of maintenance and handling, in accordance with the legislation in force. The Wistar male rats were distributed into three groups of 10. Group I was the control group continued for 8 weeks with no manipulation. The Group II was submitted to the administration of mature red wine, five times per week, for 8 weeks at a dose of 3.57 ml / kg each takes, and Group III was subjected to 8 weeks administration of an extract of G. americana. The extract was prepared by carrying out the juice of the fruit, the husk and seeds. All animals were sacrificed and necropsy was made at the end of the administration.舲 In group I the ratio between the hyalinization areas and the total ligament area (R1) was 0.017 ± 0.015 and the ratio of the Tooth‐hard tissue area and periodontal ligament area (R2) was 0.896 ± 0.497. In group II the value of R1 was 0.03 ± 0.01 and the R2 of 0.87 ± 0.49. In group III the value of R1 was 0.03 ± 0.03 varying from 0 to 0,129 and R 2 0.83 ± 0.3, ranging from 0.39 and 1.63. According to these results the administration of wine interferes with the tooth structure reflecting in the periodontal ligament and administration of genipapo doesn’t have a significant action on the dental structures studied.