Down-regulation Of Acetyl-CoA Carboxylase-A Suppresses The Progression Of Prostate Cancer Through Regulating Mitochondria Function

BackgroundReprogramming of energy metabolism is one of the important features of tumors.Many cancers have a prevailing condition that some lipogenic enzymes are over-expressed.Many studies intend to explore enzyme inhibitors as potential treatments for cancer.The purpose of this study was to investigate the effects of acetyl-CoA carboxylase-A(ACACA)gene on prostate cancer cell function,mitochondrial function,metabolites,and effects of tumor formation in vivoMethodsWe detected ACACA expression in human prostate cancer tissue microarrays by immunohistochemistry and assessed it in different clinical stages.Analyzed the expression of ACACA in human prostate cancer and non-cancer from the public database GEPIA.Then we constructed prostate cancer cell lines with low expression of ACACA to detect cell function and metabolites changes.Western blot was used to detect the expression of proteins related to fatty acid and lipid metabolic pathways.Detected mitochondria function changes including mitochondria function and ATP production by Seahorse.Flow cytometry and fluorescence microscopy were used to detect mitochondrial staining.qRT-PCR detected mitochondrial DNA(mtDNA)changes Cellular reactive oxygen species(ROS)levels were detected by flow cytometry.Colorimetry was used to detect nicotinamide adenine dinucleotide(NAD+/NADH)levels.Investigated the effect of ACACA on tumor formation in nude mice in vivoResults1.The expression of ACACA in prostate cancer tissues was higher than that in normal tissues.At the same time,the clinical TNM stage showed that the ACACA expression level in patients with advanced PCa was stronger than that in low-grade patients.T3 was stronger than T2,T1,N1 was stronger than NO,and M1 was stronger than MO,all were statistically different.GEPIA statistics showed that the expression of ACACA in patients with prostate cancer was significantly higher than that in healthy patients2.Cell function experiments showed that after knocking down the ACACA gene,the migration,invasion,and proliferation abilities of DU145 cells and PC3 cells were significantly reduced.The G1 phase of the cell cycle was prolonged.All have statistical significance3.Un-targeted metabolomics test showed that after knocking down the ACACA gene,94 kinds of metabolites in DU145 cells were changed,105 kinds of substances in PC3 cells were changed,39 kinds of substances in both cells were changed at the same time,and the production of ATP was decreased in both cells.All have statistical significance.After knocking down the ACACA gene in PC3 cells,the levels of fatty acid metabolites of L-palmitcarnitine and stearylcarnitine decreased,and the levels of related metabolic pathway proteins(FAS,Lipinl,ATP-CL,P-ATP-CL,AceCS1,ACSL1)also down-regulated4.Seahorse experiments showed that after knocking down the ACACA gene,the ATP production,the basic respiration,maximum respiration,and storage respiration capacity of the two cells were significantly decreased.Real-time ATP detection found that the total ATP production rate of DU145 cells decreased(P<0.05),the mitochondrial ATP production rate decreased significantly(P<0.01)5.The mitochondrial fluorescence staining showed that after knocking down the ACACA gene,the mitochondrial staining and average fluorescence intensity of DU 145 and PC3 cells were reduced.MtDNA of DU145 and PC3 cells were significantly reduced.All have statistical significance6.NAD+/NADH detection found that after knocking down the ACACA gene,the ratio in both DU145 and PC3 cells was increased,and the intracellular ROS level was higher than that in the control group.All have statistical significance7.In the nude mouse tumorigenesis model,the tumor volume of the experimental group at each time point was significantly smaller than that of the control group,and there was a statistical difference.The tumor weight was also significantly smaller than the control groupConclusionsThe high expression of ACACA gene has a positive correlation with the TNM stage of prostate cancer.The results confirmed that down-regulation of ACACA in prostate cancer cells affected the mitochondrial potential by mitigating the balance of NAD+/NADH,mitochondria ATP production,mtDNA,and ROS levels,which decreased the proliferation capacity of tumor cells.Testing mitochondrial potential and expression of ACACA might serve as a predictive target and a therapeutic method in the future.