The relationships between expressions of miR-134 and VEGF in gastric cancer with prognosis of adjuvant chemotherapy after gastric cancer operation

Abstract

Objective To investigate the relationships between the expressions of miR-134 and vascular endothelial growth factor (VEGF) in gastric cancer with the prognosis of adjuvant chemotherapy gastric cancer after operation. Methods From May 2012 to July 2015, the tumor tissues and non-tumor tissues adjacent to cancer samples of 65 patients with gastric cancer who underwent radical surgery in the oncology department of our hospital were enrolled in this study. Quantitative polymerase chain reaction (qPCR) was used to detect the relative expression of miR-134 and VEGF in tissues, the expression of VEGF was detected by immunohistochemical staining, analyzing the relationships between the expression of miR-134 and VEGF with the clinicopathological characteristics of gastric cancer and the recurrence and metastasis of gastric cancer after adjuvant chemotherapy. Results The relative expression of miR-134 in gastric cancer tissues was lower than that in non-cancer tissues adjacent to cancer, and the relative expression and positive expression rate of VEGF was higher than that in non-cancer tissues adjacent to cancer; there was a negative correlation between the relative expression of miR-134 and VEGF mRNA (r=-0.765, P=0.003); their expression levels were correlated with the invasion of serosa, tumor node metastasis (TNM) stage, and lymph node metastasis of gastric cancer; during the follow-up period the recurrence and metastasis rate of 65 patients with gastric cancer was 41.54%(27/65); the relative expression of miR-134 in tumor tissues of patients in recurrence and metastasis group was lower than that in non-recurrence and metastasis group (P<0.05), while the VEGF positive expression rate was higher than that in non-recurrence and metastasis group (P<0.05); the median tumor-free survival (DFS) in miR-134 low expression group was lower than that in miR-134 high expression group (P<0.05), and the DFS of patients with positive expression of VEGF was lower than that of patients with negative expression (P<0.05); infiltration of serosa, lymph node metastasis, low expression of miR-134, and positive expression of VEGF were risk factors for recurrence and metastasis of gastric cancer after adjuvant chemotherapy. Conclusions The low expression of miR-134 and high expression of VEGF in gastric cancer are closely related to the recurrence and metastasis of gastric cancer after adjuvant chemotherapy and DFS. Key words: Stomach neoplasms; MicroRNAs; Vascular endothelial growth factors; Chemotherapy, adjuvant