1.Department of Gastrointestinal Surgery, the Second AffiliatedHospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China; 2.Departmentof Pathology, the Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University,Wenzhou 325027, China; 3.Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, Wenzhou Medical University, Wenzhou 325035, China
CHEN Chenbin,HUANG Qunjia,XIE Wangkai, et al. The expression and localization of DAXX in gastric cancer and the effect of its SUMO on the malignant phenotype of gastric cancer[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2020, 50(10): 775-781.
Abstract：Objective: To explore the expression and localization of DAXX in gastric cancer and the effect of its SUMO-induced DAXX on the malignant phenotype of gastric cancer cells. Methods: The expression and prognosis of DAXX in gastric cancer from TCGA database were analyzed. Real-time quantitative PCR (RT-qPCR) was used to detect the mRNA level of DAXX in gastric cancer cell lines. Samples of gastric cancer and the adjacent tissue were collected from 20 patients after surgery between January and June 2017 in the Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University. The expression and localization of DAXX were detected by immunohistochemistry. CCK-8 and wound healing assays were used to examine the effect of DAXX on cell proliferation and migration, respectively. Western blot was used to detect the distribution of DAXX and its correlation with SUMO-2/3.Results: Bioinformatics analysis showed that the expression level of
DAXX in gastric cancer was higher than that in adjacent normal tissues, but had no effect on the survival prognosis of patients (P=0.52). The immunohistochemical results showed that the positive rate of DAXX expression in gastric cancer tissues (65.0%) was higher than that in cancer tissues (50%). And DAXX was mainly expressed in the nuclear. RT-qPCR confirmed that the mRNA expression level of DAXX in gastric cancer cell lines was significantly increased. The results of CCK-8 assay indicated that DAXX significantly inhibited cell proliferation(P<0.05), while the wound healing assay indicated that DAXX significantly promoted cell migration (P<0.01).Western blot showed differences in the distribution of DAXX and there was a significant SUMO-2/3 modification in DAXX. Conclusion: DAXX is highly expressed in gastric cancer and is mainly localized in the nucleus. DAXX may affect nuclear-plasma transport by inhibiting gastric cancer cell proliferation and promoting metastasis via interaction with SUMO2/3.
