Characterization of a novel AICARFT inhibitor which potently elevates ZMP and has anti-tumor activity in murine models

Abstract

AICARFT is a folate dependent catalytic site within the ATIC gene, part of the purine biosynthetic pathway, a pathway frequently upregulated in cancers. LSN3213128 is a potent (16 nM) anti-folate inhibitor of AICARFT and selective relative to TS, SHMT1, MTHFD1, MTHFD2 and MTHFD2L. Increases in ZMP, accompanied by activation of AMPK and cell growth inhibition, were observed with treatment of LY3213128. These effects on ZMP and proliferation were dependent on folate levels. In human breast MDA-MB-231met2 and lung NCI-H460 cell lines, growth inhibition was rescued by hypoxanthine, but not in the A9 murine cell line which is deficient in purine salvage. In athymic nude mice, LSN3213128 robustly elevates ZMP in MDA-MB-231met2, NCI-H460 and A9 tumors in a time and dose dependent manner. Significant tumor growth inhibition in human breast MDA-MB231met2 and lung NCI-H460 xenografts and in the syngeneic A9 tumor model were observed with oral administration of LSN3213128. Strikingly, AMPK appeared activated within the tumors and did not change even at high levels of intratumoral ZMP after weeks of dosing. These results support the evaluation of LSN3213128 as an antineoplastic agent.

Current Status of the Use of Multifunctional Enzymes as Anti-Cancer Drug Targets

“…It is a folate competitive non-classical anti-folate inhibitor selective for AICAR TFase relative to other folate dependent enzymes [66]. In vivo studies have shown that LSN3213128 is orally bioavailable and that it demonstrates anti-tumor activity in murine models [66,67]. To data there are no records of any specific ATIC inhibitors in active clinical development.…”

“…The current status of the development of inhibitors targeting the four enzymes described in this review is summarized in Table 1. 3PO [46] yes [46] yes [46] no PFK15 [48] yes [48] yes [48] no PFK158 [48] yes [49] yes [49] NCT02044861 [50] PFK-2 activity of PFKFB4 5MPN [51] yes [51] yes [51] no ATIC AICAR TFase BW1540 [57] no no no AICAR TFase BW2315 [57] no no no AICAR TFase LSN3213128 [66] yes [66,67] yes [66,67] no LTA 4 H epoxide hydrolase and aminopeptidase activities Acebilustat no available data no available data no (1) epoxide hydrolase and aminopeptidase LYS006 [105] yes [105] yes [105] no (1) epoxide hydrolase RH00633 [112] yes [112] no no…”

Folic Acid Antagonists: Antimicrobial and Immunomodulating Mechanisms and Applications

“…Thus, the use of certain antifolates as inhibitors of these two enzymes have been demonstrated to be another way to disrupt the normal DNA synthesis in highly multiplying cells. Some non-classical antifolates have been synthesized and successfully inhibit tumor growth both in vitro and in vivo [25,26]. However, this approach cannot be applied for P. falciparum infections because it lacks of the necessary enzymes for the de novo purine synthesis [27].…”

Survival-Associated Metabolic Genes and Risk Scoring System in HER2-Positive Breast Cancer

“…LSN3213128 is a potent antifolate inhibitor of AICARFT. Treatment with this inhibitor in a mouse-based triple-negative breast cancer xenograft model showed inhibition of tumor growth ( 17 ). Considering that the experiments were performed using triple-negative breast cancer, but based on the correlations we observed between the expression of ATIC and the survival outcome of HER2-positive breast cancer, the targeted ATIC products may be more toxic to HER2-positive breast cancer.…”