Abstract We recently reported that P01 is a potent p53 pathway-restoring small molecule that acts through increasing levels of TAp73. Further, it also interferes with the p73-mutant p53 protein-protein interaction and by downregulation of ΔNp73 (Tian, Zhang and El-Deiry, abstract# 3830, AACR 2016). P01 is a member of the natural products that have been shown to have potent anti-cancer activity against tumors with mutated p53. Based on the structure of the pharmacophore of compound P01, we designed and synthesized new analogs based on published structure-activity relationship and organic synthesis papers. The newly synthesized analogs were potent in reducing both short-term and long-term proliferation in a broad panel of mutant p53 cell lines such as HT29, SW480, DLD-1, MDA-MB-231and H1975 with EC50s in the range of 0.16 μM to 0.26 μM. We are currently evaluating the anti-cancer effects of three analogs P301, P304 and P306, of which only two of these analogs induce TAp73 as assayed by western blot. We are currently characterizing the analog P306, which is the most potent compound among them. P306 engages the apoptosis pathway by upregulation of pro-apoptotic proteins like PUMA, DR5, and BIM and downregulation of anti-apoptotic markers such as Mcl-1 in a time-and dose-dependent manner in colorectal cancer cell lines. P306 treatment also downregulates both mRNA and protein level of MET and EGFR in HT29 cells that overexpress MET and EGFR receptors. We are currently investigating the mechanisms of induction of both PUMA and DR5 in mutant p53 cells and determining whether either gene is necessary for the apoptotic effects of P306 in colorectal cancer cells. Our preliminary data indicates that upregulation of DR5 is through the ATF4/CHOP pathway post-P306 treatment. It has been reported that Puma is a target gene of ATF4, CHOP and p73, however, we found that none of them is responsible for P306-induced upregulation of PUMA in p53 mutated DLD1, SW480 or HCT116 p53-null cell lines. Thus, our ongoing in vitro studies are focused on further understanding the mechanism of action of P306 in mutant p53 cells and potentially exploring combinations with FDA-approved therapies. We are also in the process of conducting, first-in animal studies of P306 as single agent or in combination with chemotherapy or targeted therapy. Citation Format: Xiaobing Tian, Shengliang Zhang, Amriti Lulla, wafik S. El-Deiry. P53 pathway restoring compound P306 inhibits colorectal cancer growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2154. doi:10.1158/1538-7445.AM2017-2154