Involvement of GASL1 in postoperative distant recurrence of gastric adenocarcinoma after gastrectomy distal resection and the possible mechanism: WANG et al.

: As a cancer-related long noncoding RNA, functionality of GASL1 has only been characterized in liver cancer. Our study aimed to investigate the possible involvement of GASL1 in postoperative recurrence of gastric adenocarcinoma. A total of 112 gastric adenocarcinoma patients with a tumor located in the distal third who received gastrectomy distal resection in The Second Hospital of Dalian Medical University from January 2012 to January 2015 were included in this study. Patients were followed up for 3 years. Another 56 healthy people were also included to serve as a control group. Blood was extracted from each subject on the day of discharge, on the day of diagnosis of recurrence or at the end of follow-up. The GASL1 expression vector was transfected into gastric adenocarcinoma cell lines. It was observed that plasma levels of GASL1 were significantly lower, while plasma levels of transforming growth factor-β1 (TGF-β1) were significantly higher in patients than in healthy controls on the day of discharge. Patients with distant recurrence showed significantly lower plasma levels of GASL1 and significantly higher plasma levels of TGF-β1 compared with patients with local recurrence and patients without recurrence. During follow-up, plasma levels of GASL1 and TGF-β1 were negatively correlated in patients with distant recurrence but not in other groups of patients. GASL1 overexpression inhibited, while TGF-β1 treatment promoted cell migration and invasion. Overexpression of GASL1 led to downregulated and GASL1 knockdown led to upregulated TGF-β1. However, TGF-β1 showed no significant effects on GASL1 expression. We conclude that GASL1 may participate in the distant recurrence of gastric adenocarcinoma through the interactions with TGF-β1.