The expression and clinical significance of the tRNA aspartic acid methyltransferase 1 protein in gastric cancer.

Objectives: This study aimed to investigate the role of the tRNA aspartic acid methyltransferase 1 (TRDMT1) protein in the development and progression of gastric cancer (GC).

Methods: The 90 GC tissues and 35 paracancerous tissues (gastric mucosa) were collected from patients (31 males and 59 females; average age 66), who were pathologically diagnosed as GC. The expression of TRDMT1 in three GC cell lines (MKN28, BGC823, and MGC803) and tissues from GC patients were detected by western blotting and immunological staining, respectively. The relationship between TRDMT1 expression and clinicopathological parameters in GC patients was explored. TRDMT1 was knocked down by RNAi lentivirus in GC cells. GC cell migration and invasion were analyzed using scratch and transwell assays.

Results: TRDMT1 expression in the GC cell lines was higher than that in the normal gastric mucosal epithelial cell line (P < 0.05). Positive TRDMT1 protein expression in the GC tissue was higher than that in the adjacent tissue. The expression of TRDMT1 was positively associated with tumor size, histological grade, invasion depth, lymph node metastasis, and tumor node metastasis (TNM) stage (P < 0.05). High TRDMT1 expression predicted poor OS of GC patients. Tumor size, differentiation degree, invasion depth, lymph node metastasis, TNM stage, and TRDMT1 expression were independent predictors of the OS of GC patients. Knockdown of TRDMT1 inhibited the migration and invasion of MKN28 cells.

Conclusion: TRDMT1 was highly expressed in GC cell lines and tissues. TRDMT1 expression was independent predictor of the OS of GC patients. TRDMT1 knockdown reduced GC cell migration and invasion. All these results suggested that TRDMT1 has the potential to be used as a target for the diagnosis and treatment of GC.