Identification of the possible molecules by which acquired platinum resistance induces EMT-like changes in urothelial carcinoma

To identify the possible targets in EMT-acquisition after developing acquired platinum resistance in urothelial carcinoma (UC), we examined the changes in global gene expression before and after development of acquired platinum resistance. Comparing two types of acquired platinum resistant UC cells and their corresponding parent cells, in the end we identified 49 genes (25 up-regulated and 24 down-regulated genes) which were commonly changed in two acquired platinum resistant UC cells. Four invasive UC cell lines, T24, 5637, and those acquired platinum-resistant sublines T24PR and 5637PR, were used for microarrays. T24PR and 5637PR cells were newly established in our laboratory, which were grown and passaged upon reaching confluence in medium containing CDDP over a 6-month period. In preliminary studies, we found that these cell lines had an altered phenotype with morphologic and molecular changes consistent with EMT, and exhibited a marked difference in migratory potential before and after developing platinum resistance.