Molecular mechanism of initial stage of extracellular matrix invasion of oral squamous cell carcinoma

Abstract

Invadopodia are membrane protrusions into the extracellular matrix by aggressive tumor cells. Through reorganization of the actin cytoskeleton, these structures are associated with sites of matrix degradation and invasiveness of malignant tumor cells in an in vitro fibronectin degradation/invasion assay. In this study, we examined cell morphology and invasive activity for three cell lines derived from human oral squamous cell carcinomas with different invasive modes. According to Yamamoto-Kohama's classification, OSC-20 was classified as grade 3, OSC-19 as grade 4C, and HOC313 as grade 4D. OSC-20 and OSC-19 showed pavement stone patterns, and HOC313 showed a fibroblast-like cell pattern. OSC-19 and HOC313 showed dot-like degradation in the in vitro fibronectin degradation/invasion assay, whereas OSC-20 showed diffuse-type degradation. Our results suggest that reorganization of the actin cytoskeleton and cell shape are related to the invasiveness of oral squamous carcinoma cells.