Expression Of SAMD4A In Gastric Adenocarcinoma And Its Clinical Significance

Purpose:Gastric cancer is one of the most prevalent malignant tumours in the world.SAMD4A is a posttranscriptional regulator that has been shown to be involved in the development of breast cancer,oral cancer,colon cancer,as well as osteosarcoma,however,it has not been reported in gastric cancer.Therefore,SAMD4A was chosen as the research object of this paper in order to explore the expression level and clinical significance of SAMD4A in gastric adenocarcinoma.Methods:The gene SAMD4A,which is expressed most differently in gastric adenocarcinoma,gastric signet ring cell carcinoma and adjacent tissues,was screened using microarray technology.The tissue of 60 patients with gastric cancer admitted to Yantai Yu Huang Ding Hospital from February 2020 to June 2020 was collected.Those 60 patients then underwent surgery and were pathologically diagnosed with gastric adenocarcinoma.By utilising q RT-PCR and Western blot,SAMD4A mRNA and protein expression levels were detected in carcinoma and adjacent tissue.The relationship between its expression level and clinicopathological characteristics was analysed.Sixty pathological sections of carcinoma and adjacent carcinoma from March 2016 to August 2016 in the gastric adenocarcinoma specimen library of Yantai Yu Huang Ding Hospital were chosen and their clinicopathological data has been gathered.IHC was used to identify the expression level of SAMD4A in all pathological sections,which is followed by examining the correlation between its expression level and clinicopathological characteristics.GEPIA database was used to analyse the relationship between SAMD4A expression level as well as overall survival.SAMD4A knockdown cell lines were constructed to determine whether SAMD4A affected the proliferation,invasion,and migration ability of AGS and MKN45 cells.Results:1.The findings of human microarray indicated that the expression of SAMD4A was up-regulated in gastric adenocarcinoma and GSRCC.The expression of SAMD4A in gastric adenocarcinoma was 4.16 times higher in comparison to that in para-cancerous tissue.2.The results of q RT-PCR revealed that in comparison to corresponding normal gastric tissues(1.202±0.683),the expression level of SAMD4A mRNA in gastric adenocarcinoma tissue(2.076±1.124)was higher.Following the statistical analysis,the difference between the two was significant(P<0.0001).The expression level of SAMD4A was associated with depth of invasion(χ2=5.192,P=0.023).3.Western blot results pointed out that compared with para-cancerous tissue(0.724±0.479),the expression level of SAMD4A protein in gastric adenocarcinoma tissue(0.912±0.723)was substantially higher(P<0.05).After statistical analysis,the difference was obvious.The expression level of SAMD4A was correlated with the depth of invasion(χ2=4.239,P=0.040).4.The immunohistochemical analysis presented that the positive expression of SAMD4A was 43.3%(26/60)in para-cancerous tissue while it is 65.0%(39/60)in gastric adenocarcinoma tissues.The difference was statistically significant(χ~2=5.673,P<0.05).5.As shown by Univariate analysis,SAMD4A was associated with depth of invasion(χ~2=11.774,P=0.001),p TNM stage(χ~2=12.702,P=0.002)and lymph node metastasis(χ~2=10.231,P=0.017).There were no statistically significant correlations between SAMD4A expression in gastric cancer tissues and age,gender,tumour maximum diameter,tumour location,degree of differentiation,Lauren classification,and vascular tumour thrombus.The depth of invasion,according to Binary logistic regression,was an independent factor for SAMD4A expression level,and it is positively correlated with the depth of invasion in gastric adenocarcinoma(P<0.05).6.Survival analysis of the GEPIA database exhibited that the overall survival time of patients with positive SAMD4A expression in gastric adenocarcinoma was shorter in contrast to that of patients with negative expression,and the difference was statistically significant(P<0.05).7.SAMD4A knockdown cell lines were established and validated.The results of CCK8 and cloning experiments indicated that the proliferation of the SAMD4A knockdown cell group was considerably slowed compared with the control group,with statistically significant differences(P<0.05).Transwell assays showed that the invasion and migration ability of the SAMD4A knockdown group was lower than that of the control group.The difference was statistically significant(P<0.05).Conclusion:This study is the first to determine that the expression level of SAMD4A in gastric adenocarcinoma is higher than that in para-cancerous tissue.The degree of lymph node metastasis,the depth of tumour invasion,and the p TNM stage were all associated with the expression level of SAMD4A.GEPIA database analysis showed that patients with positive SAMD4A expression had a shorter survival time when compared with negative SAMD4A expression in gastric adenocarcinoma.In vitro,SAMD4A promotes the proliferation,invasion,and migration ability of gastric adenocarcinoma cells.These findings suggest that SAMD4A may not only play a crucial role in tumorigenesis but it is also expected to be an effective indicator for the diagnosis as well as prognosis of gastric adenocarcinoma.