Role Of ESCO2 Gene In Cell Proliferation Of Gastric Cancer

Objective: ESCO2 is an important regulatory protein for the establishment and maintenance of chromosome cohesion,that directly determines the accuracy of chromosome segregation and the chromosomal stability.It is well known that chromosomal instability can promote the development of gastric cancer.However,the contribution of ESCO2 gene to gastric cancer remains unclear.The present study was therefore aimed to investigate the role and mechanism of ESCO2 gene in the development of gastric cancer,in an attempt to provide a new potential molecular target for the diagnosis and treatment of gastric cancer.Methods: We used bioinformatics techniques to analyze gastric adenocarcinoma sample data in TCGA database.The protein expression in gastric adenocarcinoma tissue chip was detected by immunohistochemistry.shRNA lentivirus,sgRNA lentivirus and over-expressing adenovirus were used to infect AGS,BGC-823,SGC-7901 and MKN-74 gastric cancer lines.CCK-8 assay was used to detect the activity of gastric cancer cells,and EdU cell proliferation assay was used to detect DNA replication activity.Cell clone formation assay was used to detect cell proliferation ability.Cell scratching and Transwell migration assay were used to detect cell migration ability;Annexin V-APC single staining-FACS was used to detect cell apoptosis.The cell cycle was detected by PI-FACS.The tumor growth was detected in nude mice.Protein expression microarray,relative quantitative proteomics,quantitative PCR and Western blotting were used to detect the expression of proliferation and cell cycle-related signaling molecules.Co-IP assay was used to analyze protein interaction.Results: 1.ESCO2 mRNA expression was significantly increased in gastric carcinoma tissues compared with normal gastric mucosa tissue in TCGA database,and the expression level in gastric adenocarcinoma among the Asian yellow race was negatively correlated with tumor staging and positively correlated with patient prognosis.ESCO2 protein expression was significantly increased in carcinoma tissues compared with tissue adjacent to carcinoma in gastric adenocarcinoma tissue chip.2.ESCO2 gene knockdown inhibited gastric cancer cell proliferation,whereas gene overexpression increased proliferation.ESCO2 gene knockdown inhibited DNA replication activity and cell clone formation in gastric cancer cells,and promoted early apoptosis of gastric cancer cells.ESCO2 gene knockdown caused gastric cancer cells to arrest in the G2/M phase,whereas the cells in G2/M phase are reduced.ESCO2 gene knockout significantly inhibited gastric cancer cell proliferation and promoted cell apoptosis.3.ESCO2 gene knockdown significantly decreased the phosphorylation level of mTOR and its downstream S6K1 and RPS6 proteins.In contrast,the phosphorylation of AMPKα in the upstream of mTOR was significantly up-regulated.There were 14 differentially expressed proteins directly related to cell cycle regulation after ESCO2 gene knockdown,and these proteins were significantly enriched in the "crosstalk" of the p53 signaling pathway,ubiquitination protein hydrolysis and the cell cycle pathway.ESCO2 gene knockdown promoted p53 and p21 expression and inhibited Skp2 and CyclinB1 expression.The interaction between ESCO2 protein and p53 protein existed in gastric cancer cells.ESCO2 gene knockdown inhibited the size and tumor weight of subcutaneous tumors in nude mice.Conclusions: The expression of ESCO2 gene was high in gastric adenocarcinoma tissues.ESCO2 gene promoted cell proliferation and regulated cell cycle in gastric cancer.These regulatory effects may be closely related to mTOR sinaling molecule and p53/p21/CyclinB1 signaling pathway.ESCO2 gene knockdown inhibited subcutaneous tumor generation in nude mice.This gene could be a potential molecular target for individualized treatment of gastric cancer.