miR-199a regulates the tumor suppressor mitogen-activated protein kinase kinase kinase 11 in gastric cancer.

Small noncoding microRNAs (miRNAs) have been shown to play an important role in tumor proliferation and metastasis. However, their function and mechanism in the proliferation and metastasis of gastric cancer has not yet been elucidated. Here, we investigated the relationship between miRNA-199a and gastric cancer proliferation and metastasis. Using real-time reverse-transcriptase (RT)-polymerase chain reaction, we found that miR-199a is highly expressed in gastric cancer compared to normal gastric tissues and in metastatic, compared to non-metastatic gastric cancer tissues. MiR-199a positively regulated gastric cancer cell proliferation, migration and invasion. Further studies showed that mitogen-activated protein kinase kinase kinase 11 was significantly down-regulated by miR-199a at the post-transcriptional level and, the level of miR-199a expression in gastric cancer significantly correlated with clinical progression. These findings suggested miR-199a promoted proliferation and metastasis of gastric cancer cells through a regulatory pathway in gastric cancer that has yet to be described. miR-199a may be useful as a new potential therapeutic target for gastric cancer.