GNA15 induces drug resistance in B cell acute lymphoblastic leukemia by promoting fatty acid oxidation via activation of the AMPK pathway.

Abstract

The prognosis of B cell acute lymphoblastic leukemia (B-ALL) is poor, primarily due to drug resistance and relapse. Ga15, encoded by GNA15, belongs to the G protein family, with G protein-coupled receptors playing a crucial role in multiple biological process. GNA15 has been reported to be involved in various malignancies; however, its potential role in B-ALL remain unknown. In this study, high expression of GNA15 in B-ALL was observed in multiple databases. We further confirmed an increased transcriptional level of GNA15 in newly diagnosed B-ALL patients which was closely correlated with relapse. We showed that GNA15 promoted cell growth, inhibited apoptosis and enhanced drug resistance in leukemia cell lines. Metabolomics analysis revealed a significant enrichment of fatty acid oxidation (FAO) according to the GNA15 expression. We further confirmed that GNA15 could enhance FAO process as evidenced by the upregulation of key molecules involved in FAO including carnitine palmitoyl transferase1 (CPT1), CPT2 and CD36. And inhibition of FAO using etomoxir partially reversed the drug resistance caused by high expression of GNA15. Mechanism study showed that GNA15 promoted FAO by up-regulation of AMPK phosphorylation thus leading to survival advantage in leukemia cells. In conclusion, we observed elevated GNA15 transcript levels in B-ALL, which were associated with relapse. GNA15 could induce drug resistance though activation of the AMPK/FAO axis in leukemia cell lines. Targeting GNA15 and FAO may represent potential therapeutic strategy for improving the prognosis of B-ALL.