Role Of Lactate-HIF-1 Pathway In The Formation Of Tumor-associated Macrophages In Bladder Cancer

Objective: Bladder cancer is the most common malignancy in urology.As its incidence continues to increase every year,it poses a great threat to the life and health of patients.An important reason for the rapid progression of bladder cancer and its ability to develop drug resistance is that it can recode immune cells in the tumor microenvironment to form a microenvironment that is conducive to tumor growth.The occurrence of this phenomenon is related to the immune relationship between tumor cells and the tumor microenvironment.The mechanism of the direct or indirect interaction of cells is not clear.Bladder tumors are usually dominated by warburg metabolism,that is: under aerobic conditions,bladder cancer is also mainly glycolysis,metabolizing glucose to lactic acid and releasing a small amount of ATP.Previous studies have considered that the main role of warburg metabolism is to rapidly provide ATP for tumor cell growth and produce lactic acid as a substrate for synthesizing ribonucleic acid.However,recent studies have shown that bladder cancer warburg metabolism plays an important role in tumor immune escape.The main cause of acid-p H and p H-dependent TAM cell function inhibitory effects in the tumor microenvironment has been identified as lactic acid.Our group’s previous experiments showed that bladder cancer microenvironment has bladder cancer → microenvironment → tumor-associated macrophage lactic acid flow.So we speculated that bladder cancer cells produce a large amount of lactic acid through aerobic glycolysis.The intracellular lactic acid is transported to the microenvironment of bladder cancer and then transported into macrophages and converted to pyruvate by lactate dehydrogenase.By reducing the degradation of HIF-1 and increasing the expression level of HIF-1,TAM can be converted into M2 type TAM.M2 type TAM further promotes the proliferation,invasion and metastasis of bladder cancer cells,promotes the formation of tumor blood vessels,and enhances the chemotactic effects of bladder cancer cells on TAM.Therefore,we preliminary studied the expression of HIF-1,PFKFB3,CD163,and CD68 in bladder cancer tissues and adjacent tissues,and explored the role of bladder cancer-derived lactic acid flow in the induction of M2 TAM,and explored its possible mechanisms and mechanisms.The role of bladder cancer immune escape,invasion,and metastasis in order to provide a new target for the immune activation therapy of bladder cancer.Methods: Patients who underwent bladder radical resection at the Affiliated Hospital of Qingdao University from January 2010 to December 2015 were collected.Finally,114 bladder cancer tissues and 20 adjacent normal tissues were collected from surgical patients.Immunohistochemistry was used to detect the expression of HIF-1,CD68,CD163,and PFKFB3 proteins in bladder cancer tissues and adjacent normal tissues.Further observe the differences in the expression of bladder cancer and adjacent normal tissues.SPSS.24 statistical software was used for statistical analysis.Fisher’s exact probability method was used to compare the difference of positive expression rates of HIF-1 and PFKFB3 between the two groups.The ratio of CD163+ to CD68+ was calculated and defined as the percentage of M2 macrophages.The t-test was used for statistical analysis.Pearson correlation analysis was used to analyze the relationship between HIF-1 and PFKFB3;the t test was used to analyze the relationship between HIF-1/PFKFB3 and the percentage of M2 macrophages.Results:1.Immunohistochemistry results showed that the positive rate of HIF-1 expression in normal bladder cancer tissues was significantly different from that in adjacent normal tissues(69.3% and 45%,respectively)(P<0.05)..2.The expression of PFKFB3 in bladder cancer tissues(64.9%)was significantly higher than that in adjacent normal tissues(35%),and the difference between them was statistically significant(P<0.05).The percentage of M2 macrophages in bladder cancer and normal bladder tissue were 0.400 ± 0.2478 and 0.185 ± 0.1899,respectively,and the difference was statistically significant(P<0.05).Conclusions: 1.The proportion of HIF-1,PFKFB3,and M2 macrophages in total macrophages was significantly higher in bladder cancer tissues than in adjacent normal tissues,and the expression levels of the three in bladder cancer tissues at T2 b stage.Above the lower stage of bladder cancer,it is suggested that all three are involved in the occurrence and development of bladder cancer.2.The proportion of macrophage in M2 line was increased in bladder cancer tissues with high expression of PFKFB3 and high expression of HIF1.It was proved that the intensity of Warburg metabolism in bladder cancer microenvironment was significantly correlated with the proportion of M2 macrophages,which confirmedOur experimental hypothesis is that bladder cancer can recode macrophages through the lactic acid flow produced by Warburg’s metabolism.3The study also found that the expression of M2 macrophages was an independent risk factor for the survival analysis of bladder cancer.The survival of the patients was not related to the tumor’s number,HIF-1,PFKFB3 which may be related to the small sample size and sampling error.