Chemopreventive agents on a mouse skin carcinogenesis model: an integrative review / Agentes quimiopreventivos em um modelo de carcinogênese de pele em camundongos: uma revisão integrativa / Agentes quimiopreventivos en un modelo de carcinogénesis cutánea en ratón: una revisión integradora

Squamous cell carcinoma (SCC) is a non-melanoma skin cancer, with chronic sun exposure as the main risk factor. Excisional surgery is the most indicated treatment; however, patients can suffer functional, aesthetic, and psychological damage depending on the lesion site. Topical administration of 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-Tetradecanoylphorbol-13- acetate (TPA) induce to the appearance of benign skin tumors in mice, some of which develop into SCC. This protocol has been used to analyze the effects of many chemopreventive agents that may block or inhibit the mechanisms of action of chemical carcinogenesis. We compared the effects of chemopreventive agents in an induced skin carcinogenesis animal model. In the Scopus, PubMed, and EMBASE databases, we searched for manuscripts published between June 16, 2011, and June 16, 2021. We excluded studies conducted in vitro or on transgenic mice; in addition, studies without drug dosage, route of administration, or tumor incidence were excluded. We selected 26 studies and analyzed their main characteristics and the outcomes of tumorigenesis analysis. Most chemopreventive agents have shown excellent potential to inhibit the development of skin tumors. This review also discusses the standardization of studies in animal models to ensure better responses and future randomized clinical trials for cancer treatment and prevention.

O carcinoma espinocelular cutâneo (CEC) é um câncer de pele não melanoma, com a exposição solar crônica como o principal fator de risco. A cirurgia excisional é o tratamento mais indicado; entretanto, os pacientes podem sofrer danos funcionais, estéticos e psicológicos dependendo do local da lesão. A administração tópica de 7,12-dimetilbenz[a]antraceno (DMBA) e 12-O- Tetradecanoilforbol-13-acetato (TPA) induz ao aparecimento de tumores cutâneos benignos em camundongos, alguns dos quais evoluíram para CEC. Este protocolo tem sido utilizado para analisar os efeitos de muitos agentes quimiopreventivos que podem bloquear ou inibir os mecanismos de ação da carcinogênese química. Comparamos os efeitos de agentes quimiopreventivos em um modelo animal que foi induzido à carcinogênese de pele. Nas bases de dados Scopus, PubMed e EMBASE, buscamos manuscritos publicados entre 16 de junho de 2011 e 16 de junho de 2021. Excluímos estudos realizados in vitro ou em camundongos transgênicos; além disso, estudos sem dosagem de drogas, via de administração ou incidência de tumores foram excluídos. Selecionamos 26 estudos e analisamos suas principais características e os resultados da análise da tumorigênese. A maioria dos agentes quimiopreventivos tem demonstrado excelente potencial para inibir o desenvolvimento de tumores cutâneos. Esta revisão também discute a padronização de estudos em modelos animais para garantir melhores respostas e futuros ensaios clínicos randomizados para tratamento e prevenção do câncer.

El carcinoma de células escamosas (CCE) es un cáncer de piel no melanoma, cuyo principal factor de riesgo es la exposición crónica al sol. La cirugía de escisión es el tratamiento más indicado; sin embargo, los pacientes pueden sufrir daños funcionales, estéticos y psicológicos dependiendo de la localización de la lesión. La administración tópica de 7,12-dimetilbenz[a]antraceno (DMBA) y 12-O-Tetradecanoilforbol-13-acetato (TPA) inducen a la aparición de tumores cutáneos benignos en ratones, algunos de los cuales se convierten en CCE. Este protocolo se ha utilizado para analizar los efectos de muchos agentes quimiopreventivos que pueden bloquear o inhibir los mecanismos de acción de la carcinogénesis química. Comparamos los efectos de los agentes quimiopreventivos en un modelo animal de carcinogénesis cutánea inducida. En las bases de datos Scopus, PubMed y EMBASE, se buscaron los manuscritos publicados entre el 16 de junio de 2011 y el 16 de junio de 2021. Se excluyeron los estudios realizados in vitro o en ratones transgénicos; además, se excluyeron los estudios sin dosis de fármacos, vía de administración o incidencia tumoral. Se seleccionaron 26 estudios y se analizaron sus características principales y los resultados del análisis de la tumorigénesis. La mayoría de los agentes quimiopreventivos han mostrado un excelente potencial para inhibir el desarrollo de tumores cutáneos. Esta revisión también analiza la estandarización de los estudios en modelos animales para garantizar mejores respuestas y futuros ensayos clínicos aleatorios para el tratamiento y la prevención del cáncer.

Burdock (Arctium lappa L.) root attenuates preneoplastic lesion development in a diet and thioacetamide-induced model of steatohepatitis-associated hepatocarcinogenesis.

Nonalcoholic steatohepatitis (NASH) is considered growing risk factor for hepatocellular carcinoma development in high-income countries. Diet- and chemically induced rodent models have been applied for the translational study of NASH-associated hepatocarcinogenesis due to their morphological and molecular similarities to the corresponding human disease. Arctium lappa L. (burdock) root tea has been extensively consumed in Traditional Chinese Medicine due to its potential therapeutic properties. Indeed, the bioactive compounds of A. lappa root, as the polyphenols, have already showed antioxidant and anti-inflammatory properties in different in vivo and in vitro bioassays. In this study, we investigated whether burdock root ethanolic extract (BRE) administration attenuates NASH-associated hepatocarcinogenesis. Eight-week-old male Wistar rats received choline-deficient high-fat diet for 8 weeks and multiple thioacetamide doses for 4 weeks in order to induce NASH and preneoplastic glutathione-S-transferase pi (GST-P)+ preneoplastic foci. Subsequently, rats were treated with BRE (100 or 200 mg/kg body weight) or vehicle by oral gavage for 2 weeks. BRE displayed high levels of chlorogenic and caffeic acids and BRE administration reduced total fatty acid and lipid hydroperoxide levels, while increasing the activities of antioxidant superoxide dismutase and catalase enzymes in the liver. Furthermore, burdock intervention diminished the size of GST-P+ remodeling preneoplastic lesions (PNLs) and displayed a trend on reducing hepatocyte proliferation (Ki-67) inside them. These findings suggest that short-term exposure to BRE alleviated remodeling PNL development in NASH-associated hepatocarcinogenesis.

Effects of methylene blue-mediated photodynamic therapy on a mouse model of squamous cell carcinoma and normal skin.

BACKGROUND: Photodynamic therapy is used to treat a variety of cancers and skin diseases by inducing apoptosis, necrosis, immune system activation, and/or vascular damage. Here, we describe the effects of a single photodynamic therapy session using methylene blue on a mouse model of squamous cell carcinoma and normal skin. METHODS: The photodynamic therapy protocol comprised application of a 1% methylene blue solution, followed by irradiation with a diode laser for 15 min at 74 mW/cm2, for a total dose of 100 J/cm2. Morphological changes, cell proliferation, apoptosis, collagen quantity, immune system activity, and blood vessel number were analyzed 24 h and 15 days after photodynamic therapy. RESULTS: In the squamous cell carcinoma group, photodynamic therapy reduced tumor size and cell proliferation and raised cytokine levels. In normal skin, it decreased cell proliferation and collagen quantity and increased apoptosis and blood vessel numbers. CONCLUSIONS: The effects of photodynamic therapy were greater on normal skin than squamous cell carcinoma tissues. The reduced epithelial thickness and keratinization of the former are factors that contribute to the efficacy of this treatment. Adjustments to the treatment protocol are necessary to potentiate the effects for squamous cell carcinoma therapy.

Morphophysiopathology of synovial plica from knee joint: a literature review

Synovial plicae around the knees are a relatively common occurrence. They have been the object of many clinical and anatomical researches, not only because of their intra-articular existence, but also for their painful symptomatology caused on knee joint. These plicae are excessive folds of synovial membrane and are remnants from embryonic septum, which were not properly absorbed during fetal development. These synovial plicae are divided anatomically, as location and existence, and are classified into suprapatellar, infrapatellar, medial patellar and lateral patellar plicae; being still each of these subdivided according to their appearance and juxtaposition. Material and methods: A retrospective literature review selected articles in PubMed and MEDLINE databases; papers were searched using the keywords: synovial plicae, knee, embryology, anatomy, histology and treatment. Results: In this literature review was verified the incidence about the types, shape, location, symptoms, pathophysiology, and the main methods of study for the verification of synovial plica and treatments. Conclusion: In summary, asymptomatic plica can become symptomatic due to a bucket‑handle tear following a twisting injury and lateral traction to the knee, when carefully diagnosed; a synovial plica represents a potential cause of pain in patients. After careful examination, arthroscopic resection of the bucket‑handle portion of the plica is sufficient for the improvement of the symptoms if conservative treatment of pathological plica fail.