Identification of genes regulated during passaging of human osteosarcoma cell lines

To identify the genes that are regulated during passaging of the parental osteosarcoma cells SAOS-2 and HOS with low metastatic potential, and SAOS-2-derived LM5 cells and Ki-ras transformed HOS cells (143B) with increased metastatic potential, we performed global gene expression profiling in early and late passage cells. Total RNA was extracted from early and late passage cells cultured in three independent replicates for each condition. Cy3-labeled cRNA was synthesized and hybridized to Agilent human 8 x 60K microarrays. Raw data, obtained after array image analysis were normalized and used to retrieve differentially expressed genes in early and late passage cells.