Attachment to and Degradation of Collagen Substrata by Adenovirus-transformed Cells of Varying Tumorigenicity

The interaction of adenovirus-transformed cells of different tumorigenicity with different collagen substrata has been investigated. The adenovirus type 2 (Ad2)-transformed cells are nontumorigenic in syngeneic rats while, the adenovirus type 12 (Ad12)-transformed cells induce tumors with high efficiency. Cells transformed with Ad2 preferentially attach to collagen type I and this attachment is enhanced by fibronectin. Highly tumorigenic Ad12-transformed cells attach less efficiently to collagen type I and their attachment ability is unaffected by fibronectin. These cells, however, strongly attach to type IV collagen and this attachment is considerably enhanced by laminin. Ad2-transformed cells attach less efficiently to collagen type IV and laminin has no effect on this process. The ability of adenovirus-transformed cells to degrade collagen also has been examined. The nontumorigenic cells secrete significant amounts of collagenolytic activity directed against type I collagen into the medium, but very little type IV collagenolytic activity is secreted. The highly tumorigenic cells secrete collagenolytic activity directed against both collagen types I and IV. In addition, their secreted type IV collagenolytic activity is significantly higher than that of the nontumorigenic cells. These results suggest that laminin mediated attachment to and degradation of type IV collagen may play a significant role in determining the tumorigenic and invasive potential of adenovirus-transformed cells.