M~6A Demethylase ALKBH5 Inhibits Proliferation,migration And Invasion Of Esophageal Squamous Cell Carcinoma

BackgroudAccording to the World Health Organization's International Classification of Diseases 10 code C15 and GLOBOCAN 2012,esophageal cancer is a rapidly developing global problem with increasing morbidity and mortality.At present,the incidence rate ranks 9th among malignant tumors~[1],and the mortality rate ranks 6th among malignant tumors~[2].The two main pathological types are divided into squamous cell carcinoma and adenocarcinoma,of which more than 90%are esophageal squamous cell carcinoma(ESCC)~[3].At present,there are 477,000 new cases in China and 375,000 deaths~[4].Although the diagnosis and treatment and prognosis of esophageal cancer had improved with the development of technology,the five-year survival rate of esophageal cancer in many countries is still only 15%-25%~[5-7].Different from other tumors,the screening specificity of esophageal cancer is not high~[8].Therefore,we focus on the important links and key molecules in the development of esophageal cancer,in order to clarify its important role and lay the foundation for the development of new drugs and treatment.RNA modification is an extremely important post-transcriptional regulation that participates in a variety of pathophysiological processes in eukaryotes~~[9].N6-methyladenosine(m~6A)is an extremely common RNA methylation modification in eukaryotes involved in the transportion,splicing,translation and processing of eukaryotic mRNA~[9,10]m~6A affects the stability of translation and processes,therefore,plays a coordinating role during cell state maintenance and transformation~[11].As of 2017,various enzymes involved in m~6A methylation modification were identified by scientists,including demethylase,methylase and methylation recognition enzymes~[10,12].Once the enzyme involved in m~6A methylation modification is abnormal,it will cause diseases such as tumor[9,15]neuronal disorders1~[9,10],and embryonic developmental delay~~[9].ALKBH5 is a demethylase of m~6A,a member of the Alk B family,and a homolog of fat mass and obesity associated(FTO)~[12].Studies have shown that ALKBH5 is associated with proliferation and invasion and metastasis of breast cancer~[14,15],glioma~[17]and pancreaticer~[18].Recently,several reports have demonstrated that FTO is highly expressed in lung squamous cell carcinoma and cervical squamous cell carcinoma.FTO is involved in the malignant progression of lung squamous cell carcinoma,while FTO regulates CSCC chemo-radiotherapy resistance via ?-catenin through modulation of m~6A level,affecting the prognosis of patients.Therefore,we suspect that ALKBH5 may also play a role in the malignant progression of esophageal squamous cell carcinoma.Since ALKBH5 does not have any research in ESCC currently.Therefore,this study aims to study the role of ALKBH5 in the malignant progression of esophageal squamous cell carcinoma and hope to provide new ideas for the treatment and prognosis of esophageal squamous cell carcinoma.PurposesRole of m~6A demethylase ALKBH5 in the progression of esophageal squamous cell carcinoma.Methods1.Western blot analysis was used to detect the expression of ALKBH5 in 206 specimens of clinical specimens and immunohistochemistry(IHC).To explore the relationship between ALKBH5 and clinicopathological features in patients with esophageal squamous cell carcinoma.2.The construction of stable ALKBH5 knockdown or overexpression esophageal squamous cell carcinoma cell lines.3.Exploring the effect of ALKBH5 on the proliferation of esophageal squamous cell carcinoma in vitro and in vivo experiments(cell cycle,plate cloning and subcutaneous tumor formation in nude mice).4.Exploring the effect of ALKBH5 on migration and invasion in esophageal squamous cell carcinoma in vitro experiments(migration,invasion and scratch assay).Results1.ALKBH5 expression was significantly decreased in cancer tissues compared with adjacent tissues.2,ALKBH5 significantly associated with TNM stage and pathological grade.3.ESCC cell lines of knockdown or overexpression ALKBH5 were successfully established.4,ALKBH5 inhibits the proliferation of esophageal squamous cells.5.ALKBH5 inhibits the migration and invasion of esophageal squamous cellsConclusionsWe found that the expression of ALKBH5 in esophageal squamous cell carcinoma is lower than in adjacent tissue first time and is associated with elinicopathological features of esophageal squamous cell carcinoma,inhibiting the proliferation,migration and invasion of esophageal squamous cells.