Posters
Academic Level (Author 1)
Medical Student
Discipline Track
Biomedical Science
Abstract
Background: SF3B1 gene mutations are the most common spliceosome mutations seen in myelodysplastic syndrome (MDS) patients. Though it is well known SF3B1 mutations cause downstream changes in erythroid differentiation and the cell cycle, which leads to malignancy, metabolic changes arising from this mutation are unknown. Our preliminary data shows that patient samples harboring an SF3B1 mutation exhibit alternative splicing of the gene LUC7L2. Interestingly, this gene encodes for another protein of the spliceosome complex: U1 snRNP. The gene LUC7L2 has been shown to regulate metabolic processes by promoting glycolysis while repressing oxidative phosphorylation (OXPHOS) via various downstream mechanisms. We therefore hypothesize that SF3B1-mutant MDS could result in alternative splicing of the gene LUC7L2, thereby altering the metabolic dependencies of these cells towards OXPHOS.
Methods: RNA sequencing was performed to compare four SF3B1-mutant MDS patient samples with non-mutant ones. LUC7L2 was found to be alternatively spliced and downregulated in SF3B1 mutant cells. Genetic inhibition of LUC7L2 was then performed in the non-mutant MOLM-13 myeloid malignant cell line using siRNA technology, and a Western blot was performed to ensure siRNA inhibition was successful. Seahorse assays were then performed to assess oxidative phosphorylation upon knockdown of LUC7L2.
Results: OXPHOS is increased in MOLM-13 myeloid malignant cells when LUC7L2 is inhibited. The results suggested that this gene, which is alternatively spliced and shows lower expression in SF3B1-mutant MDS, increases myeloid malignant dependence on OXPHOS. To test whether SF3B1-mutant cells are dependent on OXPHOS for survival, they were treated with oligomycin, an ATP synthase inhibitor. Mutated cells show less viability than the wild type suggesting an increased dependence on OXPHOS.
Conclusion: With lower expression of LUC7L2 in SF3B1-mutant MDS cells, OXPHOS becomes the main source of energy production in these cells, and it is therefore a potential therapeutic target.
Presentation Type
Poster
Recommended Citation
Cisneros, Carlos; Inguva, Anagha; Tolison, Hunter; Amaya, Maria; and Jordan, Craig, "OXPHOS Inhibition via LUC7L2 as a Target for SF3B1-Mutant Myelodysplastic Syndrome" (2024). Research Colloquium. 3.
https://scholarworks.utrgv.edu/colloquium/2023/posters/3
Included in
OXPHOS Inhibition via LUC7L2 as a Target for SF3B1-Mutant Myelodysplastic Syndrome
Background: SF3B1 gene mutations are the most common spliceosome mutations seen in myelodysplastic syndrome (MDS) patients. Though it is well known SF3B1 mutations cause downstream changes in erythroid differentiation and the cell cycle, which leads to malignancy, metabolic changes arising from this mutation are unknown. Our preliminary data shows that patient samples harboring an SF3B1 mutation exhibit alternative splicing of the gene LUC7L2. Interestingly, this gene encodes for another protein of the spliceosome complex: U1 snRNP. The gene LUC7L2 has been shown to regulate metabolic processes by promoting glycolysis while repressing oxidative phosphorylation (OXPHOS) via various downstream mechanisms. We therefore hypothesize that SF3B1-mutant MDS could result in alternative splicing of the gene LUC7L2, thereby altering the metabolic dependencies of these cells towards OXPHOS.
Methods: RNA sequencing was performed to compare four SF3B1-mutant MDS patient samples with non-mutant ones. LUC7L2 was found to be alternatively spliced and downregulated in SF3B1 mutant cells. Genetic inhibition of LUC7L2 was then performed in the non-mutant MOLM-13 myeloid malignant cell line using siRNA technology, and a Western blot was performed to ensure siRNA inhibition was successful. Seahorse assays were then performed to assess oxidative phosphorylation upon knockdown of LUC7L2.
Results: OXPHOS is increased in MOLM-13 myeloid malignant cells when LUC7L2 is inhibited. The results suggested that this gene, which is alternatively spliced and shows lower expression in SF3B1-mutant MDS, increases myeloid malignant dependence on OXPHOS. To test whether SF3B1-mutant cells are dependent on OXPHOS for survival, they were treated with oligomycin, an ATP synthase inhibitor. Mutated cells show less viability than the wild type suggesting an increased dependence on OXPHOS.
Conclusion: With lower expression of LUC7L2 in SF3B1-mutant MDS cells, OXPHOS becomes the main source of energy production in these cells, and it is therefore a potential therapeutic target.