The Warburg effect, originally discovered by Otto Warburg, refers to the metabolic reprogramming of tumor cells from aerobic oxidation to glycolysis, enabling rapid energy production to support their growth and metastasis. This process is accompanied by the massive production and accumulation of lactate both intracellularly and extracellularly. The resulting acidic microenvironment impairs the normal physiological functions of immune cells and promotes tumor progression. An increasing number of studies indicate that lactate, a key metabolite in the tumor microenvironment (TME), acts as a pivotal immunosuppressive signaling molecule that modulates immune cell function. This review aims to comprehensively examine lactate's role as an immunosuppressive molecule in TME. It focuses on mechanisms such as membrane receptor binding, functional reshaping of immune cells via lactate shuttle transport, epigenetic regulation of gene expression through histone lactylation, and modulation of protein structure and function through nonhistone lactylation, emphasizing lactate's importance in immune regulation within the TME. Ultimately, this review offers novel insights into immunosuppressive therapies aimed at targeting lactate function.
Humans ; Neoplasms/metabolism* ; Tumor Microenvironment/immunology* ; Lactic Acid/immunology* ; Warburg Effect, Oncologic ; Animals ; Glycolysis ; Epigenesis, Genetic

Metabolic reprogramming is a common phenomenon in cancer, with aerobic glycolysis being one of its important characteristics. Hypoxia-inducible factor-1α (HIF1Α) is thought to play an important role in aerobic glycolysis. Meanwhile, naringin is a natural flavanone glycoside derived from grapefruits and many other citrus fruits. In this work, we identified glycolytic genes related to HIF1Α by analyzing the colon cancer database. The analysis of extracellular acidification rate and cell function verified the regulatory effects of HIF1Α overexpression on glycolysis, and the proliferation and migration of colon cancer cells. Moreover, naringin was used as an inhibitor of colon cancer cells to illustrate its effect on HIF1Α function. The results showed that the HIF1Α and enolase 2 (ENO2) levels in colon cancer tissues were highly correlated, and their high expression indicated a poor prognosis for colon cancer patients. Mechanistically, HIF1Α directly binds to the DNA promoter region and upregulates the transcription of ENO2; ectopic expression of ENO2 increased aerobic glycolysis in colon cancer cells. Most importantly, we found that the appropriate concentration of naringin inhibited the transcriptional activity of HIF1Α, which in turn decreased aerobic glycolysis in colon cancer cells. Generally, naringin reduces glycolysis in colon cancer cells by reducing the transcriptional activity of HIF1Α and the proliferation and invasion of colon cancer cells. This study helps to elucidate the relationship between colon cancer progression and glucose metabolism, and demonstrates the efficacy of naringin in the treatment of colon cancer.
Glycolysis ; Colonic Neoplasms/metabolism* ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Phosphopyruvate Hydratase/metabolism* ; Flavanones/pharmacology* ; Cell Line, Tumor ; Databases, Genetic ; Cell Proliferation/drug effects* ; Transfection ; Warburg Effect, Oncologic