TP53 and gastric cancer: However, p53 protein expression was reduced in GIST62 after treatment with LY294002 (50 μM) for 72 h (Figure 1B), which was in line with another early report that LY294002 (50 μM) treatment induced the maximal expression of p53 mRNA and protein in gastric cancer cell line SGC7901 at 6 hours and 24 h, respectively, but expression of p53 mRNA and protein was decreased after that time (Xing et al., 2008).