A Study On Changes Of G₀S₂ Expression In Esophageal Carcinoma And Its Effect On Proliferation And Apoptosis Of Esophageal Cancer Cells

Background:Esophageal cancer is one of the most common malignancies in humans.China is a high-risk area for esophageal cancer,with the incidence and mortality ranking the first in the world,and it has a rising trend.The occurrence of esophageal cancer involves changes in the activation of proto-oncogenes,inactivation of tumor suppressor genes,etc.,which are accompanied by changes in epigenetics.Abnormal changes in epigenetics can lead to the inactivation of tumor suppressor genes,including DNA Methylation is one of the most common epigenetic changes.The G0S2 gene is a gene that has recently been found to inhibit the occurrence and development of cancer.It is commonly expressed in normal tissues and cells,and the expression level is significantly reduced in cancer tissues and cancer cells.The role of G0S2 gene in esophageal cancer needs further verification and exploration.Objective:To observe the difference of G₀S₂ expression between esophageal cancer tissues and adjacent tissues of esophageal cancer and to explore its effects on the proliferation and apoptosis of esophageal cancer cells.Methods:（1）Collected from March 2016 to April 2017 in Shiyan People’s Hospital surgical resection of 45 cases of esophageal cancer tissue and the corresponding para-cancer tissue（More than 5 cm from the edge of the cancer tissue）,and the collected tissue samples were subjected to RNA extraction and assayed for the concentration and purity of the extracted sample RNA,Real-time quantitative PCR（qRT-PCR）was used to detect the ct values of G₀S₂ gene in 45 esophageal cancer tissues and adjacent esophageal cancer tissues,and the relative expression of G0S2 in each sample was calculated by the measured ct valuesto compare the expression of G₀S₂ in esophageal cancer tissues and adjacent tissues.（2）Esophageal cancer KYSE-70 cells were culturedin vitro,the cultured esophageal cancer KYSE-70 cells were randomly divided into blank group,Ad-Null group,Ad-G₀S₂ group,and5-aza-2-deoxycytidine treatment group at 0,25,50 and 100μmol/L,Ad-Null group and Ad-G₀S₂ group were transfected with adenovirus-mediated G₀S₂（Ad-G₀S₂）,Ad-Null,0,25,50,100μmol/L 5-aza-2-deoxycytidine group were given 0,25,50,100μmol/Lmethylationinhibitor 5-aza-2-deoxycytidine treatment,and then continue to culture in vitro for 24 h.The cell RNA was extracted and its concentration and purity were determined.The expression of G₀S₂ mRNA in each group was detected by qRT-PCR as the same as method1.（3）The cell viability was detected by CCK-8 assay,and cell proliferation was measured by the absorbance;Cell apoptosis was detected by Annexin V-FITC/PI double staining and flow cytometry.Results:（1）.Through the detection of 45 esophageal specimens,the expression level of G₀S₂ gene in esophageal cancer tissues was significantly lower than that in adjacent tissues of esophageal cancer,and the difference was significant（P<0.001）.（2）There was no significant difference between the blank group and Ad-Null group（P>0.05）,and at a lower level,andthe expression of Ad-G₀S₂ cells was significantly higher than the other two groups（P<0.01）.Under the different concentrations of 5-aza-2-deoxycytidine,the expression of G₀S₂ mRNA in cancer cells was significantly different and increasedwith increasing 5-aza-2-deoxycytidine concentration,;The absorbance of Ad-G₀S₂ group was lower than that of blank group and Ad-Null group（P<0.05）,and there was no significant difference in absorbance between blank group and Ad-Null group（P>0.05）.As the concentration of5-aza-2-deoxycytidine increased,the absorbance gradually decreased（P<0.05）.（3）The apoptotic rate of Ad-G₀S₂ group was significantly higher than that of Ad-Null group（P<0.001）,and there was no significant difference in apoptotic rate between Ad-G₀S₂ group and Ad-Null group（P>0.05）.As the concentration of 5-aza-2-deoxycytidine increased,the apoptosis rate increased（P<0.05）.Conclusion:By q RT-PCR technology and cell proliferation and apoptosis detection methods,we can show that the occurrence of esophageal cancer is closely related to the low expression or silencing of G₀S₂ gene,and G₀S₂ gene can inhibit esophageal cancer cell proliferation,promote esophageal cancer cell apoptosis,so it will provide a reference for the early diagnosis of esophageal cancer for the clinical treatment of esophageal cancer and new targets and programs.