FX11 inhibits aerobic glycolysis and growth of neuroblastoma cells

Background. The MYC family of proteins promotes neuroblastoma tumorigenesis at least in part through the induction of aerobic glycolysis by promoting the transcription of key glycolytic enzymes, such as LDHA. FX11 is a selective inhibitor of LDHA that has demonstrated preclinical efficacy in adult cancers. Herein, we hypothesized that FX11 would inhibit aerobic glycolysis and block growth of neuroblastoma cells. Methods. We surveyed 3 MYCN-single copy and 5 MYCN-amplified neuroblastoma cell lines to correlate C-MYC/N-MYC protein levels with LDHA expression. Cell viability was measured with FX11 using a tetrazolium-based assay. Cell cycle analysis using propidium iodide with flow cytometry was performed to evaluate for growth arrest. Immunoblotting demonstrated PARP and Caspase 3 cleavage as evidence of apoptosis. Results. LDHA is frequently expressed in both MYCN amplified and MYCN-single copy cell lines. NMYC and C-MYC protein levels did not correlate with LDHA protein expression. FX11 inhibits aerobic glycolysis and growth in three MYCN-amplified and one MYCN single copy neuroblastoma cell lines. FX11 induces modest G1 cell cycle arrest with selective induction of apoptosis. Conclusion. Small molecule LDHA inhibition is capable of blocking aerobic glycolysis and growth of neuroblastoma cell lines in vitro and merits further in vivo evaluation of its preclinical efficacy in neuroblastomas.