Biology subjects

van Gastel, N.

Publications and source records attributed to van Gastel, N..

3 recordsLinked to original sources

bioRxiv2025

The EAAT1 aspartate/glutamate transporter is dispensable for acute myeloid leukemia cell growth and response to therapy

Acute myeloid leukemia (AML) is an aggressive malignancy of hematopoietic stem and progenitor cells characterized by profound metabolic dysregulation. Pyrimidine biosynthesis has emerged as a critical metabolic dependency in AML, but clinical translation has been hampered by unacceptable toxicity of current pyrimidine synthesis inhibitors. Since aspartate is an essential nutrient for pyrimidine biosynthesis, we investigated the role of aspartate import via the excitatory amino acid transporter 1 (EAAT1) in AML. We found that EAAT1 is broadly expressed across AML cell lines and patient samples, with enrichment in M4 and M5 subtypes and increasing levels following chemotherapy treatment. Pharmacological inhibition of EAAT1 impaired AML cell viability in vitro, but metabolomic profiling and nutrient rescue experiments showed that these effects were independent of intracellular aspartate levels. Moreover, AML cells cultured in aspartate-free medium maintained proliferation and did not become more sensitive to chemotherapy. EAAT1 inhibition in mice increased bone marrow plasma aspartate levels, confirming inhibition of cellular aspartate uptake, but did not affect growth or chemosensitivity of MLL-AF9-expressing AML cells in vivo. These findings suggest that AML cells possess several complementary mechanisms to support their aspartate requirements and that EAAT1 inhibition does not impair AML growth or response to chemotherapy.

cancer biology↗

bioRxiv2025

Lactate dehydrogenase A-coupled NAD+ regeneration is critical for acute myeloid leukemia cell survival

BackgroundEnhanced glycolysis plays a pivotal role in fueling the aberrant proliferation, survival and therapy resistance of acute myeloid leukemia (AML) cells. Here, we aimed to elucidate the extent of glycolysis dependence in AML by focusing on the role of lactate dehydrogenase A (LDHA), a key glycolytic enzyme converting pyruvate to lactate coupled with the recycling of NAD+. MethodsWe compared the glycolytic activity of primary AML patient samples to protein levels of metabolic enzymes involved in central carbon metabolism including glycolysis, glutaminolysis and the tricarboxylic acid cycle. To evaluate the therapeutic potential of targeting glycolysis in AML, we treated AML primary patient samples and cell lines with pharmacological inhibitors of LDHA and monitored cell viability. Glycolytic activity and mitochondrial oxygen consumption were analyzed in AML patient samples and cell lines post-LDHA inhibition. Perturbations in global metabolite levels and redox balance upon LDHA inhibition in AML cells were determined by mass spectrometry, and ROS levels were measured by flow cytometry. ResultsAmong metabolic enzymes, we found that LDHA protein levels had the strongest positive correlation with glycolysis in AML patient cells. Blocking LDHA activity resulted in a strong growth inhibition and cell death induction in AML cell lines and primary patient samples, while healthy hematopoietic stem and progenitor cells remained unaffected. Investigation of the underlying mechanisms showed that LDHA inhibition reduces glycolytic activity, lowers levels of glycolytic intermediates, decreases the cellular NAD+ pool, boosts OXPHOS activity and increases ROS levels. This increase in ROS levels was however not linked to the observed AML cell death. Instead, we found that LDHA is essential to maintain a correct NAD+/NADH ratio in AML cells. Continuous intracellular NAD+ supplementation via overexpression of water-forming NADH oxidase from Lactobacillus brevis in AML cells effectively increased viable cell counts and prevented cell death upon LDHA inhibition. ConclusionsCollectively, our results demonstrate that AML cells critically depend on LDHA to maintain an adequate NAD+/NADH balance in support of their abnormal glycolytic activity and biosynthetic demands, which cannot be compensated for by other cellular NAD+ recycling systems. These findings also highlight LDHA inhibition as a promising metabolic strategy to eradicate leukemic cells.

cancer biology↗

bioRxiv2024

Intensive Chemotherapy Induces Cardiotoxicity via Reverse Electron Transport

Chemotherapy-induced cardiotoxicity has emerged as an important focus in oncology, driven by the growing number of cancer survivors. Intensive chemotherapies (iCT) used in the treatment of acute myeloid leukemia (AML) often lead to significant adverse cardiac events, which can reduce therapeutic benefits, limit treatment options, or even necessitate discontinuation--particularly for patients with pre-existing cardiac conditions, resulting in a loss of therapeutic opportunity. This study shows that the iCT triggers severe mitochondrial dysfunction in cardiac tissue, mirroring effects seen in ischemia-reperfusion models. Specifically, iCT results in succinate accumulation and elevated reactive oxygen species production, consistent with reverse electron transport phenomenon. Importantly, these effects were entirely prevented with RET inhibitors such as malonate or S1QEL1.1. In vivo, we demonstrate that malonate administration successfully prevents iCT-induced cardiotoxicity, maintaining left ventricular ejection fraction and fibrosis levels comparable to controls. Additionally, in an MLL-AF9-driven AML model, malonate sensitized leukemic cells to iCT. These findings support the dual potential of malonate: as an OXPHOS metabolism inhibitor to overcome chemoresistance in AML, while also reducing cardiotoxic risk for already vulnerable patients. One Sentence Summary: This study demonstrates that malonate prevents chemotherapy-induced cardiotoxicity by inhibiting mitochondrial reverse electron transport (RET), preserving cardiac function, and simultaneously sensitizing AML cells to intensive chemotherapy.

pathology↗