Abnormal expression of miR-301a in gastric cancer associated with progression and poor prognosis

Background and objectives: miR-301a is significantly overexpressed in many cancers. However, its expression and biological role in gastric cancer remain poorly understood. We investigated microRNA-301a (miR-301a) expression in gastric cancer and determined its effects on cancer cell behavior and its clinical significance in the development and progression of gastric cancer.

Methods: We determined miR-301a expression in gastric tumors and gastric cancer cell lines by reverse transcription-polymerase chain reaction. The effects of miR-301a on cell clone formation, migration, and invasion of HGC-27 and SGC-7901 cells were detected following transfection of an miR-301a inhibitor. miR-301a expression in a 304-tissue gastric cancer microarray was determined by in situ hybridization and its role in progression and prognosis was analyzed.

Results: miR-301a was upregulated in gastric tumor tissues and cell lines. Down-regulation of miR-301a significantly inhibited cell clone formation, migration, and invasion of HGC-27and SGC-7901 cells. Overexpression of miR-301a in primary gastric cancer tissues was associated with tumor size, invasion depth, lymph node metastasis, and TNM stage.

Conclusions: miR-301a overexpression correlated with TNM stage and prognosis, suggesting that miR-301a is involved in cellular clone formation, migration, and invasion in vitro and may play an important role in the clinical progression and prognosis of gastric cancer.