Objective:To screen for microRNAs(miRNAs)highly expressed in the serum exosomes(Exo)of esophageal squamous cell carcinoma(ESCC)patients and analyze their relationship with the clinicopathological characteristics of the patients,and to explore the potential of Exo-derived miRNAs as clinical auxiliary diagnostic markers for ESCC.Methods:Serum and relevant clinical data of 50 healthy subjects and 45 newly diagnosed ESCC patients admitted to the Fourth Hospital of Hebei Medical University between December 2021 and June 2023 were collected,serving as the control group and the ESCC group respectively.The Gene Expression Omnibus(GEO)database and qPCR were used to screen and identify the candidate miRNA for increased expression in the serum of ESCC patients-miR-1246.The diagnostic efficacy of serum miR-1246 for ESCC was analyzed by the receiver operating characteristic curve.The relationship between miR-1246 and the clinical feature progression of ESCC patients was analyzed by Logistic regression,and the relationship between miR-1246 and the clinicopathological characteristics of ESCC patients was analyzed by the χ2 test.Exosomes in the serum of the subjects were isolated,purified and characterized for verification.The expression of miR-1246 in Exo was detected by qPCR.ESCC KYSE150 and KYSE30 cells were routinely cultured.mimics-NC and miR-1246 mimics were transfected respectively into KYSE150 cells using Lipofectamine 2000.Inhibitor-NC and miR-1246 inhibitor were transfected into KYSE30 cells,which were respectively denoted as the minics-NC,miR-1246 mimics,inhibitor-NC and miR-1246-inhibitor groups.KYSE150 and KYSE30 cells were treated with Exo derived from KYSE150 cells in the mimics-NC and miR-1246 mimics groups.The proliferation,migration and invasion abilities of cells in each group were detected by the CCK-8 assay,scratch wound healing assay and Transwell chamber assay respectively.The expressions of Exo markers,epithelial-mesenchymal transition-related proteins,TET family methylcytosine dioxygenase 2(TET2)and cell adhesion molecule 1(CADM1)proteins in each group of cells were detected by WB assay.The targeting binding relationship between miR-1246 and TET2 and CADM1 was verified by the dual-luciferase reporter gene assay.Results:Bioinformatics screening showed that the miRNA with the most significant differential expression in the serum of ESCC patients was miR-1246.The serum Exo extracted from the patients conformed to the typical Exo characteristics.The expression level of serum Exo-miR-1246 in ESCC patients at stages Ⅰ-Ⅱ was significantly higher than that in healthy subjects(P<0.01);the level of serum Exo-miR-1246 in ESCC patients at stages Ⅲ-Ⅳ was significantly higher than that in patients at stages Ⅰ-Ⅱ(P<0.01).ROC curve analysis showed that Exo-miR-1246 in serum had a high value for auxiliary differential diagnosis of ESCC(P<0.05),and the auxiliary diagnostic efficacy of Exo-miR-1246 for the clinical progression of ESCC patients was higher than that of CEA and SCC-Ag(P<0.05).The combined detection of the three could further improve the efficacy of auxiliary diagnosis of patient staging(P<0.01).Exo-miR-1246 might be an independent risk factor for the clinical progression of ESCC patients(P<0.05).The expression level of serum Exo-miR-1246 was associated with the T-stage,N-stage and clinical stage of ESCC(P<0.01).Overexpression of miR-1246 could promote the proliferation,migration,invasion,epithelial-mesenchymal transition and inhibit apoptosis of ESCC cells,while inhibition of miR-1246 had the opposite effect.Database data analysis found that TET2 and CADM1 were the target genes of miR-1246.The dual-luciferase reporter gene assay confirmed that miR-1246 could directly bind to TET2 and CADM1 mRNA and inhibit their expressions(P<0.01).Treatment of KYSE150 and KYSE30 cells with Exo derived from cells overexpressing miR-1246 had the same effect as overexpressing miR-1246 in these cells.Conclusion:Exo-derived miR-1246 has the potential to be a clinical auxiliary diagnostic marker for ESCC.It may affect the occurrence and development of ESCC by regulating the expression levels of TET2 and CADM1.

Objective:To screen for microRNAs(miRNAs)highly expressed in the serum exosomes(Exo)of esophageal squamous cell carcinoma(ESCC)patients and analyze their relationship with the clinicopathological characteristics of the patients,and to explore the potential of Exo-derived miRNAs as clinical auxiliary diagnostic markers for ESCC.Methods:Serum and relevant clinical data of 50 healthy subjects and 45 newly diagnosed ESCC patients admitted to the Fourth Hospital of Hebei Medical University between December 2021 and June 2023 were collected,serving as the control group and the ESCC group respectively.The Gene Expression Omnibus(GEO)database and qPCR were used to screen and identify the candidate miRNA for increased expression in the serum of ESCC patients-miR-1246.The diagnostic efficacy of serum miR-1246 for ESCC was analyzed by the receiver operating characteristic curve.The relationship between miR-1246 and the clinical feature progression of ESCC patients was analyzed by Logistic regression,and the relationship between miR-1246 and the clinicopathological characteristics of ESCC patients was analyzed by the χ2 test.Exosomes in the serum of the subjects were isolated,purified and characterized for verification.The expression of miR-1246 in Exo was detected by qPCR.ESCC KYSE150 and KYSE30 cells were routinely cultured.mimics-NC and miR-1246 mimics were transfected respectively into KYSE150 cells using Lipofectamine 2000.Inhibitor-NC and miR-1246 inhibitor were transfected into KYSE30 cells,which were respectively denoted as the minics-NC,miR-1246 mimics,inhibitor-NC and miR-1246-inhibitor groups.KYSE150 and KYSE30 cells were treated with Exo derived from KYSE150 cells in the mimics-NC and miR-1246 mimics groups.The proliferation,migration and invasion abilities of cells in each group were detected by the CCK-8 assay,scratch wound healing assay and Transwell chamber assay respectively.The expressions of Exo markers,epithelial-mesenchymal transition-related proteins,TET family methylcytosine dioxygenase 2(TET2)and cell adhesion molecule 1(CADM1)proteins in each group of cells were detected by WB assay.The targeting binding relationship between miR-1246 and TET2 and CADM1 was verified by the dual-luciferase reporter gene assay.Results:Bioinformatics screening showed that the miRNA with the most significant differential expression in the serum of ESCC patients was miR-1246.The serum Exo extracted from the patients conformed to the typical Exo characteristics.The expression level of serum Exo-miR-1246 in ESCC patients at stages Ⅰ-Ⅱ was significantly higher than that in healthy subjects(P<0.01);the level of serum Exo-miR-1246 in ESCC patients at stages Ⅲ-Ⅳ was significantly higher than that in patients at stages Ⅰ-Ⅱ(P<0.01).ROC curve analysis showed that Exo-miR-1246 in serum had a high value for auxiliary differential diagnosis of ESCC(P<0.05),and the auxiliary diagnostic efficacy of Exo-miR-1246 for the clinical progression of ESCC patients was higher than that of CEA and SCC-Ag(P<0.05).The combined detection of the three could further improve the efficacy of auxiliary diagnosis of patient staging(P<0.01).Exo-miR-1246 might be an independent risk factor for the clinical progression of ESCC patients(P<0.05).The expression level of serum Exo-miR-1246 was associated with the T-stage,N-stage and clinical stage of ESCC(P<0.01).Overexpression of miR-1246 could promote the proliferation,migration,invasion,epithelial-mesenchymal transition and inhibit apoptosis of ESCC cells,while inhibition of miR-1246 had the opposite effect.Database data analysis found that TET2 and CADM1 were the target genes of miR-1246.The dual-luciferase reporter gene assay confirmed that miR-1246 could directly bind to TET2 and CADM1 mRNA and inhibit their expressions(P<0.01).Treatment of KYSE150 and KYSE30 cells with Exo derived from cells overexpressing miR-1246 had the same effect as overexpressing miR-1246 in these cells.Conclusion:Exo-derived miR-1246 has the potential to be a clinical auxiliary diagnostic marker for ESCC.It may affect the occurrence and development of ESCC by regulating the expression levels of TET2 and CADM1.