Expression and clinical significance of sHLA-G in plasma exosome in patients with colorectal cancer / 中华检验医学杂志

ABSTRACT

Objective To detect sHLA-G expression in plasma exosomes in patients with colorectal cancer and evaluate its clinical significance.Methods Retrospective study.Plasma was collected from 52 primary CRC patients,20 colorectal polyps patients,20 inflammatory bowel disease patients and 25 healthy donors in the Taizhou Hospital of Zhejiang Province from May 2017 to August 2018.The exosomes were extracted by exoEasyMaxikit and identified by nanoparticle tracking analysis (NTA) and Western blot.Exosomal sHLA-G was detected by flow cytometry (FCM) and enzyme-linked immunosorbent assay (ELISA).The diagnostic values of exosomal sHLA-G detected by FCM and ELISA were assessed,and their diagnostic performances were compared with carcinoembryonic antigen (CEA) and carbohydrate antigen CA19-9 by ROC curve and Youden index.Results The peak size of exosomes extracted from plasma in CRC patients was 101.1 nm and Western blot showed these exosomes expressed marker CD63,CDS1,and TSG101.Exosomal sHLA-G of CRC patients [28.0(21.5-35.1)U/ml] was significantly higher than that in healthy controls[19.6(16.8-21.3) U/ml,U=143.0,P＜0.001],colorectal polyps patients[19.7(16.2-22.5)U/ml,U=180.0,P＜0.001] as well as inflammatory bowel disease patients[19.9(16.7-25.2)U/ml,U=197,P＜0.001].The postoperative sHLA-G level[19.6(17.8-26.3)U / ml,U=325.5,P=0.015] was significantly lower than that in pre-operation.Exosomal sHLA-G was significantly different in different tumor status(U=64.0,P=0.006),lymph node metastasis (U=81.0,P=0.003) and TNM stage (U=105.0,P=0.015) in patients with CRC.ROC curve showed the area under the curve (AUC) of exosomal sHLA-G detected by FCM and ELISA,CEA and CA19-9 was 0.962±0.019,0.899±0.038,0.786±0.058,0.680±0.068,respectively.The difference of AUC was operated by Z test,and it showed that the exosomal sHLA-G detected by FCM was superior to CEA(Z=2.884,P=0.004)and CA19-9(Z=3.994,P＜0.001),and the exosomal sHLA-G detected by ELISA was superior to CA19-9(Z=2.811,P=0.005).Conclusion Plasma exosomal sHLA-G was associated with the progression of CRC and its diagnostic value was superior to the traditional tumor markers CEA and CA 19-9.