Influences of tumor stroma on the malignant phenotype

The microenvironment makes a significant contribution to the progression of oral carcinomas. Many different stromal events, such as vascularization, fibroblast activation, myofibroblast differentiation, and the presence of specific stromal proteins, such as proteolytic enzymes, fibronectin and laminin 5 are all characteristics of the tumor stroma. Less is, however, known of the significance of the biophysical properties of the tumor stroma. The purpose of the present study was to investigate how cellular and mechanical properties of the three-dimensional collagen matrix may influence cell proliferation and invasion of oral carcinoma cell lines.

Oral cancer cells were cultured in an organotypic culture system on different collagen concentrations, and invasion was measured. Furthermore, the presence of cancer associated proteins such as glycosylated oncofetal fibronectin and laminin 5 was investigated.

We found that expression of glycosylated oncofetal fibronectin was increased in the invasive phenotype of oral carcinoma cell lines. Furthermore we demonstrated that certain concentrations of collagen in the connective tissue equivalent, appears to stimulate invasiveness of oral carcinoma cells.