microRNAs in gastric cancer invasion and metastasis.

microRNAs (miRNAs) are fundamental gene regulators that can control cell proliferation, differentiation, and apoptosis during tumor development. These molecules can function as oncogenes or tumor suppressors in human cancers. In gastric cancer (GC), miRNAs play a dual role of either promoting or inhibiting cancer invasion and metastasis. In addition, some miRNAs are involved in only the invasion or metastasis, while other miRNAs have multiple functions and participate in invasion, migration and metastasis. In this review, we will discuss the role of miRNAs in the invasion and metastasis of GC.