Overexpression of ADAM9 in non-small cell lung cancer correlates with brain metastasis

The 'a disintegrin and metalloprotease' (ADAM) family contributes to regulation of the cell-cell and cell-matrix interactions that are critical determinants of malignancy. To determine the relationship between metastasis and ADAM proteins, we compared the mRNA levels of ADAM9,-10,-12,-15, and-17 in sublines of an EBC-1 lung cancer cell line that were highly metastatic to either brain or bone. ADAM9 mRNA levels were significantly higher in highly brain-metastatic sublines than in the parent or highly bonemetastalic sublines. To elucidate the role ofADAM9 in brain metastasis, we stably transfected A549 and EBC-1 cells with a fulllength ADAM9 expression vector. Compared with mock-transfectants, ADAM9 overexpression resulted in increased invasive capacity