m6A eraser FTO impairs gemcitabine resistance in pancreatic cancer through influencing NEDD4 mRNA stability by regulating the PTEN/PI3K/AKT pathway

作者：Kai Lin, Endi Zhou, Ting Shi, Siqing Zhang, Jinfan Zhang, Ziruo Zheng, Yuetian Pan, Wentao Gao, Yabin Yu · 发表于：Journal of Experimental & Clinical Cancer Research · 年份：2023 · DOI：10.1186/s13046-023-02792-0 · 被引用次数：93 · 研究领域：RNA modifications and cancer、Ubiquitin and proteasome pathways、Ferroptosis and cancer prognosis

BACKGROUND: Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant regulatory role in chemosensitivity; however, it is not apparent whether gemcitabine resistance can be regulated by fat mass and obesity-associated protein (FTO). METHODS: Cells with established gemcitabine resistance and tissues from pancreatic cancer patients were used to evaluate FTO expression. The biological mechanisms of the effects of FTO on gemcitabine resistant cells were investigated using CCK-8, colony formation assay, flow cytometry, and inhibitory concentration 50. Immunoprecipitation/mass spectrometry, MeRIP-seq, RNA sequencing and RIP assays, RNA stability, luciferase reporter, and RNA pull down assays were employed to examine the mechanism of FTO affecting gemcitabine resistant pancreatic cancer cells. RESULTS: The results revealed that FTO was substantially expressed in cells and tissues that were resistant to gemcitabine. Functionally, the gemcitabine resistance of pancreatic cancer could be enhanced by FTO, while its depletion inhibited the growth of gemcitabine resistant tumor cells in vivo. Immunoprecipitation/mass spectrometry showed that the FTO protein can be bound to USP7 and deubiquitinated by USP7, leading to the upregulation of FTO. At the same time, FTO knockdown significantly decreased the expression level of NEDD4 in an m6A-dependent manner. RNA pull down and RNA immunop...