A Penicillin Derivative Exerts an Anti-Metastatic Activity in Melanoma Cells Through the Downregulation of Integrin αvß3 and Wnt/ß-Catenin Pathway.

The synthetic triazolylpeptidyl penicillin derivative, named TAP7f, has been previously characterized as an effective antitumor agent in vitro and in vivo against B16-F0 melanoma cells. In this study, we investigated the anti-metastatic potential of this compound on highly metastatic murine B16-F10 and human A375 melanoma cells. We found that TAP7f inhibited cell adhesion, migration and invasion in a dose-dependent manner. Additionally, we demonstrated that TAP7f downregulated integrin αvß3 expression and Wnt/ß-catenin pathway, a signaling cascade commonly related to tumor invasion and metastasis. Thus, TAP7f reduced both the enzymatic activity and the expression levels of matrix-metalloproteinases-2 and -9 in a time dependent manner. Moreover, TAP7f inhibited the expression of the transcription factor Snail and the mesenchymal markers vimentin, and N-cadherin, and up-regulated the expression of the epithelial marker E-cadherin, suggesting that the penicillin derivative affects epithelial-mesenchymal transition. Results obtained in vitro were supported by those obtained in a B16-F10-bearing mice metastatic model, that showed a significant TAP7f inhibition of lung metastasis. These findings suggest the potential of TAP7f as a chemotherapeutic agent for the treatment of metastatic melanoma.

Interference of doxycycline pretreatment in a model of abdominal aortic aneurysms.

BACKGROUND: Abdominal aortic aneurysm (AAA) is characterized by chronic inflammation and degradation of the extracellular matrix, mediated by matrix metalloproteinases (MMPs). Doxycycline has been reported to control the progression of AAA by regulation of MMP. We hypothesized that doxycycline pretreatment in a rat model of AAA would cause reduction in gelatinolytic activity of MMP-2 and -9 and the inflammatory response in the wall of an aneurysm, consequently decreasing the formation and development of AAAs. METHODS: Male Wistar rats were divided into the following four groups: aneurysm (A); control (C); aneurysm+doxycycline (A+D) and control+doxycycline (C+D), with 24 animals per group subdivided into n=6 animals at different time points [1, 3, 7, and 15 days postsurgery (dps)]. The (A) and (A+D) groups simultaneously received the injury and extrinsic stenosis of the aortic wall. The (C) and (C+D) groups received sham operation. The treated animals received doxycycline via gavage (30 mg/kg/day) from 48 h before surgery until the end of experiment. At 1, 3, 7, and 15 dps, the animals were euthanized, and the aortas were collected for morphological analyses, immunohistochemistry, and zymography. RESULTS: The animals from the (A) group developed AAAs. However, the animals treated with doxycycline showed a 85% decrease in AAA development, which was associated with a large reduction in gelatinolytic activity of MMP-2 and -9, and decreased inflammatory response (P<.05). CONCLUSIONS: These results suggest that pretreatment with doxycycline before surgery inhibited the activity of MMP-2 and -9, as well as the inflammatory response, and may play an important role in the prevention of the development of AAAs.

Inhibition of matrix metalloproteinases-2 and -9 prevents cognitive impairment induced by pneumococcal meningitis in Wistar rats.

Pneumococcal meningitis is a relevant clinical disease characterized by an intense inflammatory reaction into the subarachnoid and ventricular spaces, leading to blood-brain barrier breakdown, hearing loss, and cognitive impairment. Matrix metalloproteinases (MMPs) are capable of degrading components of the basal laminin, thus contributing to BBB damage and neuronal injury. In the present study, we evaluated the effects of MMP-2, MMP-9, and MMP-2/9 inhibitors on BBB integrity, learning, and memory in Wistar rats subjected to pneumococcal meningitis. The animals underwent a magna cistern tap and received either 10 µL sterile saline as a placebo or an equivalent volume of a Streptococcus pneumoniae suspension at a concentration of 5 × 10(9)cfu/mL. The rats were randomized into different groups that received adjuvant treatment with MMP-2, MMP-9 or MMP-2/9 inhibitors. The BBB integrity was evaluated, and the animals were habituated to open-field and object recognition tasks 10 days after meningitis induction. Adjuvant treatments with inhibitors of MMP-2 or MMP-2/9 prevented BBB breakdown in the hippocampus, and treatments with inhibitors of MMP-2, MMP-9 or MMP-2/9 prevented BBB breakdown in the cortex. Ten days after meningitis induction, the animals that received adjuvant treatment with the inhibitor of MMP-2/9 demonstrated that animals habituated to the open-field task faster and enhanced memory during short-term and long-term retention test sessions in the object recognition task. Further investigation is necessary to provide support for MMP inhibitors as an alternative treatment for bacterial meningitis; however, these findings suggest that the meningitis model could be a good research tool for studying the biological mechanisms involved in the behavioral alterations associated with pneumococcal meningitis.

Expressão das metaloproteinases 2 e 9 em adenocarcinoma colorretal / Metaloproteinases 2 and 9 expression in colorectal adenocarcinoma

Introdução: Os carcinomas da região colorretal representam o terceiro tipo mais comum de neoplasia maligna e a terceira causa de mortalidade relacionada ao câncer no mundo. Objetivos: Este estudo teve como objetivo verificar se existe associação entre estadiamento, invasão vascular, tamanho do tumor, classificações Duke's, Astler-Coller, grau de diferenciação tumoral e expressão das metaloproteinases 2 e 9 em células de adenocarcinoma intestinal. Métodos: Foi realizado um estudo retrospectivo de 40 blocos de parafina contendo amostras obtidas de ressecção cirúrgica de tecido intestinal anteriormente diagnosticado como adenocarcinoma de intestino humano. O material foi coletado no período entre 1998 e 2003 no Hospital Universitário de Santa Maria, RS, Brasil. Como controle, foram utilizadas amostras fígado humano para MMP-9 e células deciduais normais para MMP2. Foi realizada a técnica de imunohistoquímica e sistema de amplifica- ção por polímero não biotinilado Novolink (Novocastra, New Castle Upon Tyne, Inglaterra) para avaliar as metaloproteinases 2 e 9, por percentual de células neoplásicas coradas, semi-quantitativamente, considerando-se expressão citoplasmática. Resultados: Realizada análise estatística através do teste exato de Fisher, com nível de significância de 0,05, os testes não evidenciaram associação significativa para nenhuma das aplicações feitas. Conclusões: Os achados sugerem que não existe associação entre a expressão das metaloproteinases 2 e 9 com as variáveis deste estudo, sendo necessário estudos futuros (AU)

Introduction: Colorectal carcinomas are the third most common type of malignant neoplasia and the third leading cancer-related cause of death worldwide. Aims: This study aimed at determining if there is an association between staging, vascular invasion, tumor size, Duke and Astler-Coller classifications, tumor differentiation grade, and metalloproteinase 2 and 9 in intestinal adenocarcinoma. Methods: A retrospective study was carried out of 40 paraffin blocks containing samples from surgical resections of intestinal tissue previously diagnosed as colon adenocarcinoma. The material was collected from 1998 to 2003 in the School Hospital of Santa Maria, RS, Brazil. Human liver extracts for MMP9 and normal decidual cells for MMP2 were used as controls. Immunohistochemistry and non-tinylated polymer amplification system Novolink (Novocastra, New Castle Upon Tyne, England) were performed to evaluate metalloproteinases 2 and 9 by percentage of stained cytoplasmic neoplastic cells, semi-quantitatively, and considering the cytoplasmic expression. Results: In the statistical analysis, the Fisher's exact test was used with a level of significance of 0.05, which did not show any significant association for any of the applications done. Conclusions: The findings show that there is no association of metalloproteinases 2 and 9 expression with the variables studied here (AU)