Treatment of renal cell carcinoma cell line A-498 with zebularine

Cultures of A-498 cells were treated for 120hours with 1000µM zebularine (SIGMA) in three independent biological experiments. Zebularine acts as a DNA methyltransferase (DNMT) inhibitor thereby upregulating genes that are inactivated by e.g. promotor hypermethylation. The experiment aimed to search for upregulated transcripts to provide new targets for biomarker development and therapeutic use. 308 candidates were upregulated more than 1.5-fold. Members of the metallothionein group (MT1G, MT1H, and MT2A) were validated in 49 clinical samples of renal cell carcinomas. Total RNA of treated (1000µM zebularine) and untreated A-498 cells (experiment A05-A07) was subjected to Affymetrix array analysis to detail the overall expression changes after treatment with a DNMT inhibitor. Treated cells showed no obvious signs of zebularine-induced cytotoxicity as revealed by XTT assays. Cell were split twice during the 120hour treatment period.