Genomic changes in low vs high metastatic A549 NSCLC cell line

Genomic changes in low and highly metastatic A549 cells were analyzed by 500K SNP arrays. A large number of genomic alterations were present in A549 cells but no significant differences were observed between the low or highly metastatic A549 cell lines. We generated a NSCLC line with highly increased propensity to form tumor nodules in murine lungs after intravenous injections. Extravasation and growth at a distant site are important parts of the metastatic process and we regarded these as a surrogate marker for in vivo aggressiveness and potential metastatic capability. A549 lung asdenocarcimona cell line with initially low metastatic potential was used for this purpose; these cells formed multiple small nodules in NOD/SCID mice after first i.v.-injection, round 1 (R1). Removal of tumor nodules from the lungs and subsequent re-injection led to a rapid increase in metastatic capacity. A highly aggressive phenotype which was stable over time was evident after three rounds (R3) of in vivo selection for the A549 cell line.