Histone Butyrylation/ Acetylation Remains Unchanged in Triple Negative Breast Cancer Cells after a Long Term Metabolic Reprogramming

BACKGROUND: Altered metabolism is one of the hallmarks of the cancer cells which reciprocally interrelate with epigenetic processes, such as post-translational histone modifications to maintain their desired gene expression profiles. The role of beta-hydroxybutyrate as a ketone body in cancer cell biology and histone modifications are reported. The present study aimed to evaluate the impacts of long-term metabolic reprogramming via glucose restriction and beta-hydroxybutyrate treatment on histone acetylation and butyrylation in MDA-MB231 cells as a model of triple negative stem-like breast cancer. METHODS: For long-term treatment, cells were set up in three groups receiving DMEM with restricted glucose (250 mg/L), DMEM with restricted glucose but enriched with five millimolar beta-hydroxybutyrate and DMEM with standard glucose (1g\L) and investigated for a month. Histone modifications, including H3 acetylation and butyrylation, were investigated by immunoblotting after an acid extraction of the histone proteins. RESULTS AND CONCLUSION: Neither beta-hydroxybutyrate enrichment nor glucose restriction elicited a significant effect on the butyrylation or acetylation level of histone H3 upon a long-term treatment. Metabolic plasticity of cancer cells, mainly stem-like triple negative breast cancer cells alleviate or neutralize the impact of long-term metabolic reprogramming via restriction of glucose and histone modifications enrichment. These results shed new light upon the mechanism of controversial efficacy of ketogenic diets in clinical trials.