TRIM29 facilitates gemcitabine resistance via MEK/ERK pathway and is modulated by circRPS29/miR-770–5p axis in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease. Chemotherapy based on gemcitabine (GEM) remains the first-line drug for patients with advanced PDAC. However, GEM resistance impairs its therapeutic effectiveness. Therefore, identifying effective therapeutic targets are urgently needed to overcome GEM resistance. The clinical significance of Tripartite Motif Containing 29 (TRIM29) was identified by exploring GEO datasets and TCGA database and its potential biological functions were predicted by GSEA analysis. The regulatory axis was established by bioinformatics analysis and validated by mechanical experiments. Then, in vitro and in vivo assays were performed to validate the roles of TRIM29 in PDAC GEM resistance. High TRIM29 expression was associated with poor prognosis of PDAC and functional experiments demonstrated that TRIM29 promoted GEM resistance in PDAC GEM-resistant (GR) cells. Furthermore, we revealed that circRPS29 promoted TRIM29 expression via competitive interaction with miR-770–5p and then activated MEK/ERK signaling pathway. Additionally, both in vitro and in vivo functional experiments demonstrated that circRPS29/miR-770–5p/TRIM29 axis promoted PDAC GEM resistance via activating MEK/ERK signaling pathway. Our results identify the significance of the signaling axis, circRPS29/miR-770–5p/TRIM29-MEK/ERK, in PDAC GEM resistance, which will provide novel therapeutic targets for PDAC treatment.