Lactate And P53 Regulate The Survival Mechanism Of Colorectal Cancer Cells Under Glucose Starvation

Background ＆ Objective Cancer cells preferentially obtain energy through glycolysis,even when oxygen is available.Aerobic glycolysis metabolic characteristics of what is known as the Warburg effect,is characterized by high glucose,inefficient production,and produce a large number of lactate.Lactate was originally considered a metabolic waste,and the latest studies indicate lactate plays an important biological role in tumorigenesis,and targeting lactate related metabolic pathways can be a valuable target in tumor therapy.The tumor suppressor p53 has long been known to function as a tumor suppressor gene,but some studies have shown that p53 can participate in tumor metabolic reprogramming and protect tumor cells in the absence of some nutrients.Therefore,it is of great significance to further explore the molecular mechanism of glucose metabolism in tumor cells in order to find effective therapeutic targets and metabolic pathways.Our study found that Akt mediates the accumulation of P53 and transcriptionally regulates NUPR1 to play a protective role under glucose starvation,while lactate can activate the Akt signaling pathway to promote cell proliferation and alleviate colorectal cancer cell death under glucose starvation,and inhibit the levels of P53 and NUPR1.This further enriched our understanding of the stable mechanism and molecular network of P53 function under the condition of glucose deficiency,and preliminarily explored the function of lactate.Methods1.CCK8 assay was used to measure absorbance to reflect cell proliferation,and flow cytometry assay was used to detect cell cycle and apoptosis.2.The expression levels of P53 and phosphorylation of Akt under different treatment conditions were detected by Western Blot assay.3.Transcriptome sequencing revealed that NUPR1 was upregulated under glucose starvation,and the sequencing results were verified by fluorescence quantitative PCR.4.The P53 binding site on the promoter sequence of NUPR1 was analyzed on the website.The binding relationship was verified by CHIP assay,and the double luciferase reporter gene plasmid mutated at different binding sites was constructed.Whether NUPR1 was regulated by P53 was detected by double luciferase assay.Results1.High expression of P53 in colorectal cancer cells under glucose starvation promotes cell survival.2.The expression of P53 depends on the phosphorylation of Akt in glucose starvation.3.Lactate activates Akt to promote cell survival under glucose starvation.4.Lactate and P53 reduce apoptosis induced by glucose starvation.5.P53 can transcriptionally regulate NUPR1.6.NUPR1 has a protective effect on cells under glucose starvation.ConclusionUnder glucose starvation,the Ak T-p53-NUPR1 axis is beneficial to cell survival,and lactate activates Akt to play a protective role in a different pathway from that of Akt-p53-NUPR1.