ABSTRACT
BACKGROUND: The invasive behaviour of squamous cell carcinoma (SCC), a common malignant tumour of the mouth, is a process mediated by cell proliferation, extracellular matrix proteolysis and other factors. Studies have shown a potential relationship between growth factors, metallothionein 2A (MT2A) and matrix metalloproteinase (MMP) activation in malignant tumours. The aim of this study was to downregulate MT2A in cells (Cal27) derived from human squamous cell carcinoma. METHODS: Cal27 cells with reduced MT2A were subjected to proliferation, migration and invasion assays. Immunofluorescence and western blot confirmed MT2A depletion by siRNA. Growth curve assays assessed cell proliferation. Indirect immunofluorescence analysed the expression of MT2A, MMP-2, MMP-9, epidermal growth factor (EGF), transforming growth factor alpha (TGF-α), tumour necrosis factor alpha (TNF-α) and Ki67. Zymography evaluated the effects of MT2A silencing on MMP-2 and -9 expression. Migration and invasion activities were evaluated using migration and invasion assays. RESULTS: CAL27 cells displayed MT2A, MMP-2, MMP-9, EGF, TGF-α, TNF-α and Ki67. MT2A depletion decreased MMP-9, EGF, TGF-α and Ki67 protein levels, while increasing TNF-α. CONCLUSIONS: MT2A downregulation reduced cell proliferation, migration and invasion activities. Therefore, MT2A has an important role in cell proliferation, migration and invasion in human oral SCC cells.
Subject(s)
Carcinoma, Squamous Cell , Matrix Metalloproteinase 9 , Metallothionein , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Down-Regulation/genetics , Epidermal Growth Factor/genetics , Humans , Ki-67 Antigen/metabolism , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 9/genetics , Metallothionein/genetics , Transforming Growth Factor alpha/genetics , Tumor Necrosis Factor-alpha/geneticsABSTRACT
Buffalo production takes place in several areas worldwide. In Brazil, buffalo are raised mainly in the Northern region, specifically in the Marajó archipelago, where most of the herd is slaughtered for meat. This makes possible the extraction of numerous healthy teeth from these animals as replacements for human teeth in laboratory tests. Aim: To evaluate the morphology of enamel from species Bubalus bubalis as a replacement for human enamel in laboratory research studies, considering its wider availability in the Amazon region. Methods: After removal, the teeth were prepared for scanning electron microscopy (SEM). Teeth were sectioned in different planes - some were subjected to abrasion and others were merely polished for observation of surface enamel. All samples were submitted to a cleaning process, dried, sputter-coated with a platinum alloy and set for observation under SEM. Results: The SEM micrographs revealed an aprismatic surface enamel as well as prismatic enamel, the latter being similar to human enamel, in both arrangement and morphology. Conclusions: Buffalo enamel showed prismatic morphology, requiring further tests to corroborate its use as a substitute for human teeth.
