CircOSBPL9 inhibits cell proliferation, migration and invasion mediated by miR-558/TPM1 axis via MEK/ERK pathway

Circular RNAs (circRNAs) are linked to the tumorigenesis and progression of various cancers. However, the roles and biological functions of circRNAs in gastric cancer (GC) progression remain unclear. Various circRNAs that are differentially expressed between GC and healthy tissues were screened, and the circRNAs that most likely inhibit GC were selected. The effects of circRNAs on malignancy-related processes, including GC cell proliferation, movement, and infiltration, in vitro and on cancer spread in vivo were studied. The molecular mechanisms underlying these processes were explored. CircOSBPL9 was identified and expressed at low levels in GC body tissues and cell lines. The circOSBPL9 expression level was linked to the clinical characteristics of patients with GC. Functionally, circOSBPL9 overexpression markedly inhibited malignancy-related processes, such as GC cell growth, movement, and infiltration in vitro and inhibited cancer spread in vivo. Mechanistically, circOSBPL9 is an adsorbent for miR-558, activating the target gene, TPM1, and inactivating the MEK/ERK pathway. CircOSBPL9 hinders GC progression through the circOSBPL9/miR-558/TPM1 pathway, suggesting its suitability as a prognostic marker and treatment target.