Genome-wide CRISPR/Cas9 library screening identified OGDH as a regulator of disease progress and resistance to decitabine in myelodysplastic neoplasm by reprogramming glutamine metabolism

Myelodysplastic neoplasms (MDS) are clonal disorders of hematopoietic stem cells, characterized by ineffective hematopoiesis, cytopenia, and dysplasia, which often progress to acute myeloid leukemia (AML) [1]. Decitabine (DAC), a hypomethylating agents (HMAs), plays a crucial role in the treatment of MDS [2]. However, the complete remission rate with HMAs remains low at 15–20%, and nearly half of the patients ultimately develop resistance during therapy [3, 4]. The molecular mechanisms underlying resistance to decitabine in MDS are still not fully understood [5]. With an increasing understanding of tumor pathogenesis, metabolic reprogramming, especially enhanced reductive carboxylation of glutamine or disrupted oxidative phosphorylation, is also reported to be closely associated with drug resistance in hematological malignancies [6, 7].

Herein, a combination of genome-wide CRISPR/Cas9 library screening and whole exome sequencing (WES) was employed to identify candidate genes involved in decitabine sensitivity. OGDH, which encodes a key enzyme in the tricarboxylic acid (TCA) cycle, was identified as a regulator of resistance to decitabine in MDS. The biological functions of OGDH in regulating glutamine metabolism were explored both in vitro and in vivo. Overall, we first reported that low expression of OGDH enhances reductive glutamine metabolism in MDS. The results highlight the important role of OGDH in resistance to decitabine and provide insights into potential therapeutic strategies for MDS, including targeting glutaminase (GLS).