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. Author manuscript; available in PMC: 2020 Jan 1.
Published in final edited form as: Mol Cancer Ther. 2018 Oct 23;18(1):3–16. doi: 10.1158/1535-7163.MCT-18-0863

Figure 5. PTC299 demonstrates broad activity and potent inhibition of leukemia cell proliferation in vitro and in animal models.

Figure 5.

(A) Box-plot of log2 expression level (microarray) for CDA and UPP1, two pyrimidine salvage enzymes for converting cytidine and uracil, respectively, to uridine. The box represents the lower and upper quartile of the data. The white line in the box represents the median value. The whiskers represent the extension of data up to 1.5x of interquartile range (IQR) below the lower quartile or above the upper quartile. P-values are calculated with Software R (https://www.r-project.org/, version 3.3.1) based on t-test comparing hematopoietic tumors (n = 54) and solid tumors (n = 178); (B) PTC299 sensitive cells in general have less salvage UMP production. Four sensitive (HeLa, HT1080, A549 and K562) and four insensitive lines (U87MG, MCF7, PC3 and Huh7) were cultured in the presence of 15N-Glutamine for 8 hours, then the unlabeled and 15N-labeled UMP in the cell lysates were measured by LC-MS/MS analysis. Data are mean ± SEM, n = 4, p value from t-test. (C) PTC299 inhibits the proliferation of MOLM13 AML cells more potently than do other known DHODH inhibitors. Cells were treated with indicated compounds for 72 hours and cell proliferation was measured Celltiter Glo (Promega). % inhibition was calculated against the vehicle (0.5% DMSO) treatment. Data are mean ± SD, n = 2. (D) PTC299 is active in all five AML patient-derived cells in vitro. Patient-derived AML cells were treated with PTC299 for 72 hours and then cell proliferation was assessed using Celltiter Glo (Promega); Assays were done in duplicate (AML-002,004 and 005) or triplicate (AML-001 and 003). (E) PTC299 prolongs survival of mice bearing human acute lymphoid leukemia (ALL) after IV inoculation of NOD/SCID mice with MOLT-4 cells (10 mice/group), Treatment with PTC299 (10 mg/kg, qd), or with doxorubicin (0.5 mg/kg or 1 mg/kg IP once per week), was initiated 7 days after tumor inoculation; (F) PTC299 inhibits MOLM-13 acute myeloid leukemia xenograft tumor growth in nude mice. Values shown represent the mean of 8 mice per group and error bars show the standard error of the mean.