TGFBI expression reduces in vitro and in vivo metastatic potential of lung and breast tumor cells.

Controversy has arisen as to the role of transforming growth factor-β-induced protein (TGFBI) in the regulation of tumor metastasis. Using lung and breast cancer cell lines (H522 and MCF-7, respectively), we established that TGFBI induced cell adhesion to extracellular matrix proteins by activating adhesion-associated signaling and subsequent structure reformation, ultimately leading to cells less motile; whereas TGFBI reduced abilities of colony formation in soft agar, penetration through matrix gel, and activation of matrix metalloproteinases 2 and 9. Furthermore, injection of TGFBI-expressing cells into immuno-deficient mice resulted in a significant reduction in tumor metastasis in vivo. Taken together, these data suggest that TGFBI moderates the metastatic potential of cancer cells.