ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of microRNA-100 (miR-100) in human gastric cancer cells and its role of miR-100 in migration, invasion and proliferation in gastric cancer cell line SGC7901.</p><p><b>METHODS</b>Total RNAs were extracted from formalin-fixed and paraffin-embedded tissue samples of SGC7901 cells, gastric cancer (50 cases), non-tumor (18 cases) and lymph nodes with metastases (18 cases). The expression of miR-100 was examined by reverse transcription (RT)-qPCR. Additionally, SGC7901 cells were transfected with Pre-miR-100 and negative control constructs, and then their ability of migration, invasion and proliferation in vitro was documented after 48 hours.</p><p><b>RESULTS</b>RT-qPCR showed that although miR-100 expressed in all samples, compared to non-tumour tissues, the expression was lower both in SGC7901 cells and gastric cancer tissues (P = 0.0077, P < 0.01). SGC7901 cells and primary gastric cancer tissues with lymph nodes metastasis had lower miR-100 expression than those of without lymph node metastasis (P = 0.0361, P = 0.0356). The migration ability and invasion of SGC7901 cells transfeced with pre-miR-100 decreased as compared with control cells (P = 0.0025, P = 0.0028 respectively). However, miR-100 expression had no significant effects on the cell proliferation.</p><p><b>CONCLUSIONS</b>Expression of miR-100 inhibits the migration and invasion of gastric cancer cells without significant alteration of proliferation. Therefore, miR-100 may play an inhibitory role in the progression of gastric carcinoma.</p>