Methylation is a primary epigenetic mechanism regulating gene expression. 5-aza-2'-deoxycytidine is an FDA-approved drug prescribed for treatment of cancer by inhibiting DNA-Methyl-Transferase 1 (DNMT1). Results of this study suggest that prolonged treatment with 5-aza-2'-deoxycytidine could induce centrosome abnormalities in cancer cells and that CEP131, a centrosome protein, is regulated by DNMT1. Interestingly, cancer cell growth was attenuated in vitro and in vivo by inhibiting the expression of Cep131. Finally, Cep131-deficient cells were more sensitive to treatment with DNMT1 inhibitors. These findings suggest that Cep131 is a potential novel anti-cancer target. Agents that can inhibit this protein may be useful alone or in combination with DNMT1 inhibitors to treat cancer.