Abstract 1228: Identification of a novel p53 target regulating p53-induced apoptotic pathway

In response to various cellular stresses, p53 induces its target genes and suppresses tumor development. However, the anti-tumor function of p53 has not been fully elucidated. The purpose of our study is the identification and functional analysis of novel p53 downstream targets. We conducted cDNA microarray analysis by using Hct116p53+/+ and p53-/- cells treated with adriamycin and identified p53 inducible protein (p53IP) as a novel p53 downstream target. Induction of p53IP mRNA was confirmed by qRT-PCR. We also found that p53IP protein was increased only in Hct116p53+/+ cells by adriamycin treatment. The result of reporter assay and ChIP assay revealed the direct binding of p53 to p53-binding sequence within p53IP promoter. Colony formation assay by using HCT116 cells indicated that ectopic expression of p53IP significantly inhibited tumor cell growth. Furthermore, knockdown of p53IP with siRNA inhibited apoptosis of tumor cells induced by DNA damage. Our findings indicated that p53IP as a important mediator of p53-dependent apoptotic pathway.Citation Format: Jinichi Mori, Paulysally Lo, Chizu Tanikawa, Yusuke Nakamura, Koichi Matsuda. Identification of a novel p53 target regulating p53-induced apoptotic pathway. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1228. doi:10.1158/1538-7445.AM2015-1228

Source: Cancer Research - August 2, 2015 Category: Cancer & Oncology Authors: Mori, J., Lo, P., Tanikawa, C., Nakamura, Y., Matsuda, K. Tags: Molecular and Cellular Biology Source Type: research