Pereira Saulo T, Silva Camila R, Nuñez Silvia C, Ribeiro Martha S
Center for Lasers and Applications, Energy and Nuclear Research Institute, São Paulo, Brazil.
Department of Bioengineering, University Brazil, São Paulo, Brazil.
Photochem Photobiol. 2021 Mar;97(2):435-442. doi: 10.1111/php.13338. Epub 2020 Oct 21.
Low-level light therapy has been used in health care as a therapeutic strategy for different diseases. However, its effects on cancer are controversial. This work evaluated the effects of three energies on breast cancer-bearing mice after a single red light-emitting diode (LED) irradiation. 4T1 cells were inoculated into the mammary fat pad of female BALB/c mice. When tumor volume reached 100 mm , animals were irradiated by a LED irradiator (660 ± 11 nm) with energies of 1.2, 3.6, and 6.0 J. Control without irradiation and healthy animals were also evaluated. Mice were monitored regarding tumor volume and total blood count. After euthanasia, their organs were examined. We observed that a single irradiation does not increase tumor volume. All irradiated groups exhibited better clinical conditions than control, which presented a significant decrease in platelet and red blood cell levels compared with healthy mice. The energy of 3.6 J arrested neutrophil-lymphocyte rate besides promoting longer survival and a lower number of metastatic nodules in the lungs. These findings suggest that a single red LED irradiation causes no impact on the course of the disease. Besides, the intermediary dose-effect should be further investigated since it seems to promote better outcomes on breast cancer-bearing mice.
低强度光疗法已被用于医疗保健领域，作为治疗不同疾病的一种治疗策略。然而，其对癌症的影响存在争议。这项研究评估了单次红光发光二极管（LED）照射后，三种能量对荷乳腺癌小鼠的影响。将4T1细胞接种到雌性BALB/c小鼠的乳腺脂肪垫中。当肿瘤体积达到100立方毫米时，用能量分别为1.2、3.6和6.0焦耳的LED照射器（660±11纳米）对动物进行照射。同时也评估了未照射的对照组和健康动物。对小鼠的肿瘤体积和全血细胞计数进行监测。安乐死后，检查它们的器官。我们观察到单次照射不会增加肿瘤体积。所有照射组的临床状况均优于对照组，与健康小鼠相比，对照组的血小板和红细胞水平显著降低。3.6焦耳的能量除了能延长生存期和减少肺部转移结节数量外，还能阻止中性粒细胞与淋巴细胞的比例。这些发现表明，单次红光LED照射对疾病进程没有影响。此外，由于中等剂量似乎对荷乳腺癌小鼠有更好的效果，因此应进一步研究中等剂量效应。
