A Step Forward in Breast Cancer Research: From a Natural-Like Experimental Model to a Preliminary Photothermal Approach

Abstract

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.

Proof-of-Concept Study of Multifunctional Hybrid Nanoparticle System Combined with NIR Laser Irradiation for the Treatment of Melanoma

“…Nevertheless, the exposure limit corresponds to the maximum level of exposure for which no adverse skin effects are expected, but it can be exceeded for diagnostic and therapeutic purposes when the intended benefits of the procedure overcome the potential side effects [54]. Additionally, previous in vitro results from the group [50] were taken into account in this decision. None of the laser irradiation times compromised the skin integrity or promoted signs of injury, either macroscopically or based on histological analysis.…”

“…Primarily, the cell lines were incubated with increasing concentrations of uncoated and HAOA-coated GNPs (25,50,75, and 100 µM). These concentrations were based on the content of gold.…”

“…Slices were examined under an Olympus BX51 microscope (Olympus Corporation, Tokyo, Japan), im- The NIR laser (JDSU L4-2495-003 coupled to a source Laserpak ARO-485-08-05) used in these experiments had a wavelength of 811 nm and 2.5 W/cm 2 irradiance at the target. The time of exposure was chosen based on our previous in vitro results [50] and considered exposure times and irradiation doses found in the literature [51,52] as well as the exposure limits in guidelines for the use of NIR radiation [53,54].…”

An update of advanced nanoplatforms for glioblastoma multiforme management

“…The main disadvantage of a synthetic approach is that some chemicals used can be an environmental and/or health hazard. For this reason, various green methods using microorganisms like bacteria, fungi, plants and algae have been devised (Molnár et al, 2018[ 84 ]; Amina and Guo, 2020[ 7 ]) but also other methods with hazardous chemicals-free AuNPs for the treatment of melanoma (Silva et al, 2016[ 108 ]; Lopes et al, 2020[ 72 ], 2021[ 73 ]), breast cancer (Costa et al, 2020[ 28 ]) and thyroid cancer (Amaral et al, 2020[ 5 ], 2021[ 6 ]).…”

Effect of Sphagneticola Trilobata Extract on Histological Wistar Rat Kidney Induced by DMBA

“…Free radicals can be induced from several carcinogenic compounds such as benzo pyrene and dimethylbenz (α) anthracene (DMBA). Benzo (α) pyrene and DMBA can easily insert into deoxyribonucleic acid (DNA), causing genetic mutations that trigger the growth of cancer cells [1] [2]. The discovery of new anticancer agent by exploring natural ingredients has the potential to be developed, particularly in the use of herbal medicines.…”