The Role And Molecular Mechanism Of Amine Oxidase Copper-containing 1(AOC1)in The Progression Of Gastric Cancer

Purpose:Gastric cancer is the fifth most common malignant tumor in the world,with approximately 1 million newly diagnosed cases every year;it is also the third leading cause of cancer-related deaths,with more than 720,000 deaths per year.Currently,gastric cancer is still a serious global health burden.Amine oxidase copper-containing1(AOC1)is a copper-containing enzyme responsible for catalyzing the oxidative deamination of short-chain fatty diamines.The main substrates are putrescine and histamine.At present,there is no research report on the role of AOC1 in cancer progression.This study aims to reveal the expression pattern,specific biological functions and molecular regulation mechanisms of AOC1 in gastric cancer tissues and cells.Methods:1.GEPIA online database analysis,q RT-PCR and western blot methods were used to analyze and detect the m RNA and protein expression patterns of AOC1 in human gastric cancer tissues.2.Gastric cancer cell lines AGS and MKN45 were selected as cell models for in vitro research.Specific si RNA was designed,synthesized,and transfected into cells to knock down the expression of AOC1 in cells.The pc DNA3.1 recombinant plasmid was designed and transfected into cells to overexpress the expression of AOC1 in the cells.3.CCK8,clone formation,flow cytometry,Transwell,western blot and other methods were used to detect the effects of changes in AOC1 expression on AGS and MKN45 cell proliferation,growth,apoptosis,migration and invasion and other cell biological functions.4.The AKT pathway agonist IGF-1 and the inhibitor Ipatasertib(GDC-0068)were used in rescue experiments.5.The high-throughput transcriptome sequencing on AGS cells transfected with empty pc DNA3.1 plasmid or pc DNA3.1-AOC1 overexpression plasmid was performed using the Illumina Hiseq platform to find the transcriptome changes caused by AOC1 overexpression in gastric cancer cells.Results:1.AOC1 was significantly highly expressed in the 408 human stomach adenocarcinoma(STAD)tissues,compared with the 211 normal gastric epithelial tissues stored in the GEPIA.Similarly,AOC1 was significantly highly expressed in clinically collected human gastric cancer tissues compared with adjacent normal tissues.2.Knockdown of AOC1 significantly inhibited the proliferation,growth,migration,invasion,and epithelial-mesenchymal transition(EMT)of AGS and MKN45 cells,and induced apoptosis;overexpression of AOC1 significantly promoted the proliferation,growth,migration,invasion and EMT process of AGS cells,and inhibited cell apoptosis.3.Knockdown of AOC1 reduced the phosphorylation level of AKT and the expression of its downstream effectors p70S6 K and Cyclin D1 in AGS and MKN45cells;in contrast,overexpression of AOC1 enhanced the phosphorylation level of AKT and its downstream effectors p70S6 K and Cyclin D1 expression.The treatment of IGF-1 rescued the effects of AOC1 knockdown on cell proliferation,migration and invasion.At the same time,the treatment of Ipatasertib hindered the effect of AOC1 overexpression on cell proliferation,migration and invasion.4.The results of high-throughput transcriptome sequencing showed that each sample produced 6.29 Gb of data on average,and an average of 14,705 genes were detected per sample.After AOC1 overexpression in AGS cell,182 differentially expressed genes were identified.Among them,152 genes were significantly up-regulated and 30 genes were significantly down-regulated in AGS cells.Conclusion:In summary,this study found that the expression of AOC1 in gastric cancer tissue was significantly up-regulated,and played a key cancer-promoting factor function by activating the AKT signaling pathway,significantly promoting the progression of gastric cancer cells.Specific antibodies or small molecule inhibitors targeting AOC1 will benefit for the future treatment of gastric cancer.