The Expression Of ATAD2 In Esophageal Squamous Cell Carcinoma And Its Role In The Progression Of Esophageal Carcinoma

Esophageal cancer(EC)is considered one of the most malignant tumors,and could be ranking the sixth cause of death in the world and third in China.Esophageal carcinoma mainly includes esophageal squamous cell carcinoma(ESCC)and esophageal adenocarcinoma(EAC).Esophageal squamous cell carcinoma is the predominant subtype of esophagus cancer in developing countries,especially common in China.Despite rapid advances in surgical treatment and therapeutic techniques including chemotherapy and radiotherapy,the rapid progression and extensive metastasis still led to low 5-year survival rate of 15%-25%.ATPase family AAA domain containing 2(ATAD2),also known as AAA+nuclear co-regulatory cancer-related protein(ANCCA)or PRO2000,is a member of the AAA+protein family.The ATAD2 protein contains both a bromine domain and an ATPase domain.ATAD2 maps to chromosome 8q24.13,a region that is often amplified in cancer.Consistent with this,ATAD2 was found to be significantly overexpressed in a variety of cancer types,such as breast,lung,prostate,and liver cancer.Related studies have shown that ATAD2,as a co-regulator,participates in transcriptional regulation mediated by multiple genes including c-MYC,RB-E2F and EZH2,thus regulating a variety of cellular activities and playing an important role in tumorigenesis.ObjectiveTo investigate the expression of ATAD2 in esophageal squamous cell carcinoma,and to detect the correlation between the expression level of ATAD2 and the clinicopathological characteristics by analyzing the clinical data of the patients.We preliminarily explored the effect of ATAD2 on the biological function of ESCC cells,thus providing new ideas for the early diagnosis and treatment of esophageal squamous cell carcinoma,and providing experimental basis for further exploration of the mechanism of ATAD2 in esophageal squamous cell carcinoma.Methods1.The location and expression of ATAD2 in the tissues of esophageal squamous cell carcinoma patients were detected by immunohistochemistry.To investigate the expression of ATAD2 in ESCC tissues,we analyzed the ATAD2 protein level in 120 samples including 60 ESCC tissues,30 adjacent esophageal tissues and 30 atypical hyperplasia of esophageal tissue by immunohistochemistry.2.Analyze the correlation between the expression of ATAD2 in ESCC tissues and the pathological features of patients.By analyzing the clinical data of the patients,the correlation between the ATAD2 expression level in the samples and the clinicopathological characteristics of the patients was analyzed to provide a basis for exploring the relationship between the expression of ATAD2 and the occurrence and development of esophageal squamous cell carcinoma.3.Explore the effect of ATAD2 on the biological function of ESCC cells.(1)Small interfering RNA(siRNA)constructed targeting ATAD2 was used to inhibit the expression of ATAD2.To prevent the occurrence of off-target effect,two sirnas were constructed and transfected into ESCC cells.The knockdown efficiency was determined by Western Blot.(2)To investigate the effect of ATAD2 on the proliferation of ESCC cells,we performed the CCK8 cell proliferation analysis on EC 109 and EC1 cell lines.(3)We examined the migration and invasion ability of ESCC cells through Transwell assay and statistically analyzed the changes of migration and invasion ability of ESCC cells after the expression of ATAD2 was inhibited,and evaluated the effect of ATAD2 knockout on migration and invasion ability of esophageal cancer cells.(4)Cell Apoptosis was detected by flow cytometry analysis,and we evaluated the effect of ATAD2 knockdown on the apoptosis of esophageal carcinoma cells.Results1.The expression of ATAD2 was upregulated in ESCC and ATAD2 level was correlated with the differentiation grade(P<0.05)and lymph node metastasis(P<0.05).2.The knockdown of ATAD2 in ESCC cell lines EC109 and KYSE30 significantly inhibited the proliferation of ESCC cells(P<0.05),and its migration and invasion abilities were also significantly decreased(P<0.05).In addition,the inhibition of ATAD2 expression promoted the apoptosis of ESCC cells(P<0.05).Conclusions1.The expression of ATAD2 was increased in esophageal squamous cell carcinoma tissues,and it was significantly correlated with the differentiation degree and lymph node metastasis of esophageal squamous cell carcinoma.2.After knockdown of ATAD2,the proliferation,migration and invasion ability of ESCC cells was decreased,and the apoptosis of ESCC cells was promoted,providing new ideas for the treatment of esophageal squamous cell carcinoma.