MiRNA29a-3p negatively regulates ISL1–Integrin β1 axis to suppress gastric cancer progression

Insulin gene enhancer protein 1 (ISL1) belongs to the LIM homeodomain transcription factor family, which is closely related to the development of several cancers. We previously found that abnormally high ISL1 expression is involved in gastric cancer (GC) metastasis. However, the specific role of ISL1 and its regulatory mechanisms in GC metastasis warrant elucidation. In this study, we found that ISL1 is highly expressed in GC tissues and positively correlated with GC development, promoting cell migration and invasion in vivo and in vitro. Moreover, miRNA29a-3p can target ISL1 and thus inhibit GC cell migration. Furthermore, ISL1 upregulates ITGB1 by binding to its enhancer; nevertheless, ISL1–ITGB1 axis expression can be regulated using miRNA29a-3p. In GC cell nuclei, ISL1 and annexin A2 (ANXA2) form a transcriptional activator complex at the ITGB1 enhancer, thus promoting ITGB1 expression. In GC cell cytoplasm, the ISL1–ANXA2 complex synergistically activates matrix metalloproteinases, thus promoting cell migration. In conclusion, ISL1 is a potential therapeutic target for GC.