Clinical Significance Of Expression Of RARB And Its Promoter Methylation In Gastric Carcinoma

Objective: 1.The associations between RARB m RNA expression and clinicopathological characteristics of patients with GC were subsequently investigated.2.The associations between promoter methylation of the RARB genes and clinicopathological characteristics of patients with GC were subsequently analyzed.3.To analyze the relationship between the methylation status of RARB promoter and m RNA expression.Methods: 1.Fifty cases of gastric cancer specimens and matched paracancerous tissue obtained via surgical resection and pathological diagnosis in the Affiliated Hospital of Guilin Medical University from September 2019 to Decemeber 2019 were collected.2.The expression level of RARB m RNA in GC tissues and para-cancerous tissue samples were measured by q PCR and the correlation of its expression with clinicopathological features was analyzed.3.Promoter methylation of the RARB in GC tissues and paracancerous tissue samples were measured by BSP and the correlation of its methylation with clinicopathological features was analyzed.4.The relationship between the degree of methylation of RARB promoter and m RNA expression was statistically analyzed.Results: 1.Compared with the adjacent tissues in which the relative expression of RARB was 0.26,the relative expression of RARB in GC tissues was 0.02,significantly decreased(P<0.05),and the difference between the two groups was statistically significant.2.(1)There were no significant differences in the groups by age,gender,lymph node metastasis and differentiation.(2)RARB expression was higher in the T1 and T2 stage of gastric cancer than that in the T3 and T4 stage,with a significant difference(P<0.05).(3)The m RNA expression levels of RARB were significantly different in different TNM stages,with a significant difference(P<0.05).Furthermore,there was a significant difference in RARB m RNA expression between the two groups of TNM staging of I and III(P<0.05)and no statistically significant difference both in the I vs II,and II vs III groups(P >0.05).3.The methylation status of the promoter regions of RARB gene in cancer tissues and adjacent tissues were 44%and 24% respectively,with a significant difference(P<0.05).RARB methylation was higher in the gastric cancer accompanied with lymph node metastasis than that without lymph node metastasis,with a significant difference(P<0.05),and was lower in the moderately/highly differentiated group than in the poorly differentiated group(P<0.05).4.The expression of RARB m RNA in the methylation-positive group was significantly lower than that of the methylation-negative group,with a significant difference(P<0.05).Conclusion: 1.The frequency of RARB promoter methylation in GC tissues was significantly higher than that in the adjacent tissues,This suggest that RARB methylation may be involved in the process of occurrence and development of GC.2.Patients with lymph node metastasis and poorly differentiated have more hypermethylation in the promoter region of RARB gene,suggesting that the severity of patients with gastric cancer can be assisted by detecting the methylation status of the promoter region of RARB gene.3.The expression of RARB in the methylation-positive group was significantly lower than that of the methylation-negative group,suggesting that the methylation of the RARB promoter region may be accounting for its low expression in gastric cancer and increasing the depth of invasion and tumor stage.