Photodynamic therapy provides the formation of reactive oxygen species that are capable of inducing cell death. Human laryngeal carcinoma (HEp-2) cells have been evaluated in this study under PDT treatment. Cells were treated with photosensitizer aluminum phthalocyanine tetrasulfonate (AlPcS4) and irradiated with a Biopdi/Irrad-Led5 660 LED with 660 nm wavelength, intensity of delivered light of 25 mW/cm2, power of 70 mW, fluence of 5 J/cm2 for 24 h and 48 h, and then evaluated. Cell population was not increased by PDT treatment after the tested period. The apoptosis assay demonstrated that control groups exhibit approximately 60% of living cells in the 24 h and 48 h periods, however. A significant increase in apoptotic cells was observed after the photodynamic therapy treatments, for both 24 and 48 h groups. Over 50% of cells were under apoptosis after photodynamic therapy, evidencing a death process generated from the oxidative damage of the treatment. Comet assay and micronucleus assessments, both of which evaluate genotoxicity, demonstrated favorable results to damages caused by the photodynamic therapy treatment. Thus, photodynamic therapy is proposed to damage nuclear cells and the subcellular structure of carcinogenic cells. Impact statement Recently, the use of photodynamic therapy grows as an alternative treatment for cancer, since it has a noninvasive characteristic and affinity to the tumor tissue. Accordingly, understanding the therapy’s foci of action is important for the technique improvement. This work aims to understand the genotoxic effect triggered by the therapy action, thus evidencing the permanent changes caused to the genetic material of the tumor cell after the treatment. Therefore, to increase the knowledge in this study field, the methodology of the comet assay and count of micronucleus formed after the therapy was adopted in order to understand if the damage caused to the DNA of tumor cell makes its replication process unfeasible in future generations. The study allows a better therapeutic approach to the cancer treatment, making the process of association between therapies a more effective option during the disease treatment.

Introduction: Cancer is one of the diseases with the highest incidence globally and that associated with the patient's emotional state, can act positively or negatively in the treatment. Cortisol is a principal primary stress hormone in the human body. The corticoids can increase cell proliferation and reactive oxygen species that contribute to DNA damage. Prolonged exposure to stress can contribute to tissues becoming insensitive to cortisol, the primary human stress hormone. Objective: This study explores cortisol's influence on tumor cell development, particularly in human cells of carcinoma of the human laryngeal (HEp-2). Methodology: HEp-2 cells were exposed to increasing cortisol (hydrocortisone) concentrations for 24 or 48 hours, and cytotoxicity (MTT assay) proliferation assay (crystal violet assay), and immunolabeled 3D culture for fibronectin and FAK were analyzed. Results: The group treated with hydrocortisone showed a significant increase in mitochondrial activity, as for the evaluation by the violet crystal, the treated group showed similar behavior to the control. The 3D culture showed dispersed cells within 24 hours with reduced FAK labeling; however, no changes were observed within 48 hours. Conclusion: Although some cases favored corticosteroid use in cancer patients, a more detailed analysis is necessary before prescribing them.

Proteínas de choque térmico (HSP) são moléculas intracelulares multifuncionais que, eventualmente, podem estar envolvidas na malignização celular. Terapia fotodinâmica (TFD) pode levar à redução do tumor e vasos sanguíneos ao redor. Objetivo foi avaliar ação da TFD sobre as HSPs em células neoplásicas de carcinoma de laringe humana (HEp-2). As células foram irradiadas com LED a 660 nm, 5 J/cm2, 70 mW, por 3 minutos e 20 segundos; incubadas por períodos de 24, 48 e 72 horas; após os períodos de incubação foi realizada a extração de proteínas e corrido gel de poliacrilamida para avaliação das proteínas por Western-Blotting. As células foram imunomarcadas com anticorpos anti-HSP27, anti-HSP70 e anti-HSP90 e analisadas no microscópio confocal. A viabilidade celular foi avaliada pelo teste de cristal violeta. No gel de poliacrilamida foram identificadas bandas próximas a 27 kDa, 70 kDa e 90 kDa. Nas fotomicrografias observou-se redução do número de células após TFD, comprovado por teste de viabilidade (cristal violeta); e intensa marcação de HSPs após TFD, principalmente próximas ao núcleo. Concluiu-se que HSP27, HSP70 e HSP90 são muito produzidas em células HEp-2. TFD foi eficaz devido à redução do número de células e considerada opção viável para o tratamento dessa doença. Embora seja relatada a participação das HSPs 27, 70 e 90 como protetoras das células tumorais, nossos resultados indicam que a TFD ativa tais proteínas para a redução das células tumorais.

Titanium-Niobium (TiNb) alloys have been considered a good alternative for several biomedical applications. Titanium-35niobium (Ti-35Nb) alloy has an excellent biological profi le and shows a great potential for biomedical application in both the orthopedic and dentistry fi elds. In this study, the comet assay and micronucleus assays, sensitive assays for DNA damage, were used to evaluate potential genotoxicity in model cell type exposed to Ti-35Nb alloy and pure titanium (Ti pure). Human osteosarcoma cells (MG63) were exposed to Ti-35Nb and Ti pure extracts and DNA damage assessed at 24 h, 48 h, and 72 h. The assays, comet and micronucleus, showed that Ti-35Nb alloy did not cause damage to the cells DNA. Our results demonstrated that Ti-35Nb alloy does not present genotoxicity, reinforcing that this alloy is a promising material and constitutes an alternative in the substitution to the materials currently used in orthopedics and in dentistry. Impact Statement The applications of titanium based alloys are widely used as orthopedic implants due to their excellent combination of mechanical properties, corrosion resistance and outstanding biocompatibility. Recently studies have been demonstrated titanium-niobium alloys do not present cytotoxicity, exhibit corrosion resistance similar or superior to titanium and have elastic modulus signifi cantly lower than other titanium alloys. These characteristics make these materials an alternative for several biomedical applications, mainly implants. Previous studies demonstrated that Ti-35Nb alloy exhibits the closest elastic modulus of bone, and have good performance in key parameters of osteogenesis, which means that this alloy has an excellent biological profi le and shows a great potential for biomedical application. In the present study it was demonstrated that Ti-35Nb alloy did not present DNA damage. Thus, these results consolidate this alloy has a promising material to substitution to the materials currently used in orthopedics and in dentistry, with absence of cytotoxity and genotoxity.

Photodynamic Therapy (PDT) is a cancer treatment that used the interaction of a photosensitizing drug and a light source. PDT can lead to changes in the expression of various cellular elements, compromising cell adhesion, and cytoskeleton integrity in cells undergoing treatment. However, the pathways of cellular alterations caused by this treatment are little known. Alterations in expression in surface glycoproteins and glycolipids are significant features in malignant tumor transformation and are strongly associated with tumor cell adhesion, invasion, and metastasis. This study evaluated photodynamic therapy effects on indirect distribution surface glycoproteins in human laryngeal carcinoma HEp-2 cell line surface, using Click-iT™ Metabolic Glycoprotein Labeling Reagent. Aluminum Phthalocyanine Tetrasulfonate (AlPcS4) was administrated at 5 μM/mL, followed by one hour of the incubation period for its accumulation in the tumor cells. After this time, cultures were irradiated with LED (light-emitting diode) dispositive (BioPdi/IRRAD-LED) λ = 660 nm. Evaluation of glycoproteins was performed by flow cytometry. Knowledge of the cellular alterations caused by the treatment will allow obtaining tools for the potentiation or optimization and personalization of the anticancer treatment. This therapy has a low cost and better efficacy, when applied early, about radiotherapy chemotherapy.