LncRNA MIR17HG drives cisplatin resistance partially via miR-138-5p/AKAP9 axis in cholangiocarcinoma.

Objectives: This study aims to discover the role of lncRNA MIR17HG, referred to as MIR17HG, in cisplatin resistance for cholangiocarcinoma (CCA).

Methods: QRT-PCR was conducted to measure the expression of MIR17HG in cisplatin-resistant/sensitive CCA cells and clinical CCA specimens. Log-rank test was used to analyze the survival curve. Cck8-assay and flow cytometry were employed to detect the sensitivity of CCA cells to cisplatin and the apoptosis rate following different treatments, respectively. The next-generation sequencing was carried out to get gene transcripts after silencing MIR17HG in HCCC-9810 cells. The LncBase database was used to predict the target miRNA of MIR17HG, and MS2 RIP assay and dual luciferase assay were conducted to confirm their binding. MiRwalk database and the RNA sequencing data were utilized to screen the key genes regulated by MIR17HG/miR-138-5p axis and a dual luciferase assay was performed to confirm the binding site of miR-138-5p with AKAP9. Immunoblotting was further employed to give assistant evidence. Rescue experiments were performed to observe the function of miR-138-5p and AKAP9 in MIR17HG-induced cisplatin resistance.

Results: MIR17HG overexpression predicts cisplatin resistance and poor prognosis in CCA. MIR17HG could bind with miR-138-5p to release AKAP9, thereby inhibiting cisplatin-induced apoptosis and promoting cisplatin resistance in CCA. MIR17HG silencing in CCA cells leads to expression alteration of genes, which are enriched in platinum resistance-related pathways.

Conclusions: LncRNA MIR17HG regulates platinum resistance-associated genes and promotes cisplatin resistance partially via the miR-138-5p/AKAP9 axis by inhibiting cisplatin-induced apoptosis in CCA.