Beta-6 Integrin, tenascin-C, and MMP-1 expression in salivary gland neoplasms.

Beta-6 Integrin, tenascin-C, and MMP-1 (matrix metalloproteinase-1) are invasion-related proteins that are frequently overexpressed in many human malignancies. The objective of this study was to determine whether there is overexpression of these molecules in three types of salivary neoplasms showing markedly different behavior. A total of 55 formalin-fixed, paraffin-embedded archived specimens comprising 19 adenoid cystic carcinomas (ACC), 18 polymorphous low-grade adenocarcinomas (PLGA) and 18 pleomorphic adenomas (PA) were utilized in this study.

Assessment of p63 expression in oral squamous cell carcinomas and dysplasias.

Objectives: p63, a p53 homologue, may be associated with tumorigenesis in epithelial tissues through its inhibition of p53 transactivation functions. We sought to determine the pattern and levels of p63 expression in oral dysplasias and carcinomas using standard immunohistochemical staining. We also assessed and compared expression of p53 and a cell proliferation marker in these lesions.

Overexpression of c-met in oral SCC promotes hepatocyte growth factor-induced disruption of cadherin junctions and invasion.

Hepatocyte growth factor (HGF), the ligand for the c-met proto-oncogene product, is a multifunctional protein that enhances tumor cell motility, extracellular matrix invasion, and mitogenic or morphogenic activities of various cell types. In this study we examined the expression of the c-Met receptor in human oral squamous cell carcinoma (SCC) in vivo and in vitro to explore its relationship to tumor progression and invasiveness. Biopsy specimens of human oral SCC were immunohistochemically stained for c-Met.

Matrix metalloproteinases and TGFbeta1 modulate oral tumor cell matrix.

The integrin beta6 has been shown to promote invasion and experimental metastasis by oral squamous cell carcinoma (SCC). In this study, we demonstrate that the expression of beta6 by oral SCC9 cells increased activation of the UPA --> MMP3 --> MMP9 pathway. We also demonstrate that the deposition of fibronectin and tenascin-C matrices by SCC9beta6 cells and peritumor fibroblast cocultures is counter-regulated by the UPA --> MMP3 --> MMP9 pathway.