ABSTRACT
BACKGROUND: Metabolic reprogramming and epigenetic alterations contribute to the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). Lactate-dependent histone modification is a new type of histone mark, which links glycolysis metabolite to the epigenetic process of lactylation. However, the role of histone lactylation in PDAC remains unclear. METHODS: The level of histone lactylation in PDAC was identified by western blot and immunohistochemistry, and its relationship with the overall survival was evaluated using a Kaplan-Meier survival plot. The participation of histone lactylation in the growth and progression of PDAC was confirmed through inhibition of histone lactylation by glycolysis inhibitors or lactate dehydrogenase A (LDHA) knockdown both in vitro and in vivo. The potential writers and erasers of histone lactylation in PDAC were identified by western blot and functional experiments. The potential target genes of H3K18 lactylation (H3K18la) were screened by CUT&Tag and RNA-seq analyses. The candidate target genes TTK protein kinase (TTK) and BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) were validated through ChIP-qPCR, RT-qPCR and western blot analyses. Next, the effects of these two genes in PDAC were confirmed by knockdown or overexpression. The interaction between TTK and LDHA was identified by Co-IP assay. RESULTS: Histone lactylation, especially H3K18la level was elevated in PDAC, and the high level of H3K18la was associated with poor prognosis. The suppression of glycolytic activity by different kinds of inhibitors or LDHA knockdown contributed to the anti-tumor effects of PDAC in vitro and in vivo. E1A binding protein p300 (P300) and histone deacetylase 2 were the potential writer and eraser of histone lactylation in PDAC cells, respectively. H3K18la was enriched at the promoters and activated the transcription of mitotic checkpoint regulators TTK and BUB1B. Interestingly, TTK and BUB1B could elevate the expression of P300 which in turn increased glycolysis. Moreover, TTK phosphorylated LDHA at tyrosine 239 (Y239) and activated LDHA, and subsequently upregulated lactate and H3K18la levels. CONCLUSIONS: The glycolysis-H3K18la-TTK/BUB1B positive feedback loop exacerbates dysfunction in PDAC. These findings delivered a new exploration and significant inter-relationship between lactate metabolic reprogramming and epigenetic regulation, which might pave the way toward novel lactylation treatment strategies in PDAC therapy.
Subject(s)
Carcinoma, Pancreatic Ductal , Gene Expression Regulation, Neoplastic , Glycolysis , Histones , L-Lactate Dehydrogenase , Pancreatic Neoplasms , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/genetics , Humans , Histones/metabolism , Animals , Cell Line, Tumor , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/genetics , Mice , Feedback, Physiological , Epigenesis, Genetic , Carcinogenesis/metabolism , Carcinogenesis/genetics , Prognosis , Cell Proliferation , FemaleABSTRACT
INTRODUCTION: Prediabetes is a state of subclinical glycemic impairment, bridging normal glucose tolerance and diabetes. Globally, over 30% of individuals exhibit prediabetic conditions, with a significant proportion progressing to diabetes. Prediabetes augments risks of various diseases including cardiovascular and kidney disease. While interventions like lifestyle changes have shown promise in diabetes prevention, their long-term sustainability is challenging. Alternative pharmacological treatments, such as acarbose and metformin, have demonstrated efficacy in certain populations. Sodium-glucose co-transporter 2 inhibitors, a novel class of glucose-lowering agents, have shown potential benefits for heart and kidney health in patients with diabetes. This research aims to evaluate the effectiveness and safety of dapagliflozin in individuals with prediabetes, elucidating its potential role in diabetes prevention strategies. RESEARCH DESIGN AND METHODS: This prospective trial is being conducted at Peking University Third Hospital. A total of 240 participants with prediabetes will be enrolled and randomly divided into two groups: one receiving dapagliflozin (10 mg/day) with lifestyle education, and the other with lifestyle education alone over a 12-week duration (with male/female = 1:1 in each group). Anthropometric, clinical and laboratory tests, including body mass index, waist circumference, fasting blood glucose, oral glucose tolerance test, insulin, lipid profile, liver and kidney function, sperm quality, will be conducted at the onset and conclusion of the trial. For adherence monitoring, participants will receive phone follow-ups at week 4 and week 8. The primary outcome is the change in 2-h plasma glucose during an oral glucose tolerance test over the study duration. Secondary outcomes encompass changes in various health metrics, including body mass index, lipid profiles, and liver function. PLANNED OUTCOMES: The proposed study is set to refine diabetes prevention strategies on the basis of its potential benefits observed in patients with diabetes. CONCLUSIONS: This will be the first randomized controlled trial to evaluate the safety and effectiveness of sodium-glucose co-transporter 2 inhibitors compared with lifestyle education for individuals with prediabetes. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT05914857 (registered 24 July 2023).
