透過調節代謝緩解MV4-11細胞對Cytarabine的抗性

Abstract

急性骨髓性白血病（AML）是一種以血球前驅細胞異常增生為特徵的惡性疾病，會導致貧血、疲勞和感染等症狀。由於AML主要影響65歲以上的族群，年長患者對高強度化療的耐受性較低，治療上面臨如抗藥性等諸多挑戰。近期研究顯示AML細胞可透過調控細胞代謝，特別是增強糖解作用與氧化磷酸化，產生對臨床用藥的抗藥性。我們在實驗室中建立了對阿糖胞苷具抗藥性的AML細胞株MV4-11R，並觀察到相較於母株細胞MV4-11P，MV4-11R展現出更強的代謝能力。我們期望透過抑制MV4-11R的代謝以減緩其對阿糖胞苷的抗藥性。 首先，我們確認MV4-11R對阿糖胞苷具有抗藥性，並伴隨糖解作用與氧化磷酸化能力的增強。在代謝抑制藥物的初步篩選中，我們發現使用糖解抑制劑(2-脫氧-D-葡萄糖)或氧化磷酸化抑制劑(貝達喹啉)處理MV4-11R後，其細胞活性顯著下降。接著，在雙藥合併組合測試中，2-脫氧-D-葡萄糖合併貝達喹啉使MV4-11R細胞型態顯著改變。當分別與阿糖胞苷合併使用時，2-脫氧-D-葡萄糖、貝達喹啉皆可以顯著降低MV4-11R細胞活性，誘導細胞週期停滯於G0/G1、並降低細胞代謝，如ATP產量、乳酸產量、活性氧水平及粒線體膜電位。進一步進行三藥合併測試，亦即2-脫氧-D-葡萄糖、貝達喹啉與阿糖胞苷合併處理MV4-11R，相較於雙藥合併的作用，細胞凋亡與死亡更多，細胞停滯於G0/G1期更多，細胞代謝作用更進一步地下降。雖然這些調控效果可能僅限於分子層面，但這些結果突顯了代謝調控在減緩AML對cytarabine抗藥性中的潛力。

Acute myeloid leukemia (AML) is a malignant hematological disease characterized by the abnormal proliferation of hematopoietic precursor cells, leading to symptoms such as anemia, fatigue, and increased susceptibility to infections. AML primarily affects individuals over the age of 65, and these elderly patients often have poor tolerance to intensive chemotherapy, presenting many therapeutic challenges, including the development of drug resistance. Recent studies have revealed that AML cells may acquire resistance to chemotherapeutic drugs by reprogramming cellular metabolism, particularly through upregulation of glycolysis and oxidative phosphorylation (OXPHOS). In our laboratory, we previously established a cytarabine-resistant AML cell line, MV4-11R, which exhibits enhanced metabolism compared to its parental counterpart, MV4-11P. To resolve this cytarabine resistance, we aim to target the metabolic plasticity of MV4-11R cells to mitigate their chemoresistance. First, we confirmed that MV4-11R cells exhibited resistance to cytarabine, which was associated with an increased reliance on glycolysis and oxidative phosphorylation (OXPHOS). Next, a preliminary screening of metabolic inhibitors revealed that treatment with either the glycolytic inhibitor, 2-deoxy-D-glucose (2-DG), or the OXPHOS inhibitor, bedaquiline, significantly reduced the viability of MV4-11R cells. In subsequent combination treatment assays, combination of 2-DG and bedaquiline induced significant change in cellular morphology of MV4-11R. When administered separately with cytarabine, 2-DG and bedaquiline significantly reduced MV4-11R viability, induced G0/G1 cell cycle arrest, and suppressed ATP production, lactate production, reactive oxygen species (ROS) levels, and mitochondrial membrane potential (ΔΨm). Further investigation using triple drug combination therapy with 2-DG, bedaquiline, and cytarabine demonstrated that compared to dual-drug treatments, it was more effective in inducting apoptosis and cell death with pronounced G0/G1 arrest, and further inhibition of metabolic activities. Although these regulatory effects may be confined to the molecular level, our findings underscore the therapeutic potential of metabolic modulation in overcoming cytarabine resistance in AML.