Expression Correlation And Regulatory Mechanism Of Autophagy-related Factor ATG7 And Tumor Suppressor PTEN In Tumor Tissues

Objective: As a tumor suppressor with dual specific phosphatase activities,tensin homologous phosphatase and tensin homology deleted on chromosomes(PTEN)gene regulate cell apoptosis,cell cycle arrest,cell migration and proliferation by controlling the balance of signal pathways of phosphatidylinositol 3-kinase(Pl3K)/protein kinase B(AKT)and mitogen-activated protein kinases(MAPKs).The abnormal expression of PTEN plays a vital role in the pathogenesis of diseases such as cancer,neurodevelopmental disorders,and cardiovascular dysfunction.Cell autophagy is a self-digesting process commonly found in eukaryotes.It can not only inhibit the mechanism of tumorigenesis,but also provide energy for tumor cells during tumor growth.Therefore,autophagy has both positive and negative effects on tumor survival.Autophagy-related factor ATG7,as an important autophagy protein,participates in a variety of physiological and pathological regulation processes.However,the relationship between ATG7 and PTEN as important factors affecting tumorigenesis and development has not been reported.This study explores the correlation between ATG7 and PTEN expression,and provides new ideas for clinical treatment of related diseases caused by abnormal PTEN expression.Methods: 1.The expression levels of ATG7 and PTEN were detected in 5 normal tissues and 45 cancer tissues using immunohistochemical techniques.2.Observe the binding of ATG7 and PTEN by co-immunoprecipitation.3.CRISPR / Cas9 technology was used to construct targeted gene editing plasmids,and construct ATG7 or PTEN stable knockout KLE,HCT116,HEK293,HepG2 by cell transfection and antibiotic screening,respectively.4.The expression levels of ATG7 and PTEN proteins were detected by Western Blot,and the relationship between PTEN expression and ATG7 expression was analyzed.Results: 1.The results of immunohistochemistry showed that ATG7 was highly expressed in cancer tissues compared with normal tissues,and PTEN expression was weakly positive or negative.2.The results of co-immunoprecipitation show that ATG7 regulates PTEN expression by binding to PTEN.3.In tumor cells cultured in vitro,ATG7 negatively regulates the expression of PTEN.Conclusion: ATG7 negatively regulates the expression of PTEN.