NAT10 Knockdown Improves Cisplatin Sensitivity in Non-Small Cell Lung Cancer by Inhibiting the TRIM44/PI3K/AKT Pathway.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide, and cisplatin (DDP) resistance remains a significant challenge in NSCLC treatment. METHODS: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze NAT10 and tripartite motif containing 44 (TRIM44) mRNA levels. Western blotting assay was used to detect protein expression. Cell viability was analyzed by a cell counting kit-8 assay. Cell proliferation, apoptosis, invasion, and stem-like traits were assessed using a 5-Ethynyl-2'-deoxyuridineassay, flow cytometry, Transwell invasion assay, and sphere formation assay, respectively. The association between NAT10 and TRIM44 was identified by an RNA immunoprecipitation assay. A xenograft mouse model was established to evaluate the effect of NAT10 silencing on DDP sensitivity in vivo. RESULTS: NAT10 expression was upregulated in DDP-resistant NSCLC tissues and cells. NAT10 knockdown enhanced DDP sensitivity in DDP-resistant NSCLC cells, accompanied by decreased protein expression of multidrug resistance 1 (MDR1). The silencing of NAT10 also inhibited the proliferation, invasion, and stem-like traits of DDP-resistant NSCLC cells, while inducing cell apoptosis. However, NAT10 overexpression displayed the opposite effects. Moreover, NAT10 maintained TRIM44 mRNA stability in an ac4C-dependent manner. TRIM44 overexpression reversed the NAT10 knockdown-induced effects on DDP sensitivity and the malignant progression of NSCLC cells. In addition, NAT10 silencing inactivated the PI3K/AKT pathway by regulating TRIM44 in DDP-resistant NSCLC cells. The treatment of the PI3K/AKT pathway inhibitor, LY294002, mitigated the effects of TRIM44 overexpression on DDP sensitivity and NSCLC cell progression. Further, NAT10 knockdown improved the sensitivity of tumors to DDP in vivo. CONCLUSION: NAT10 knockdown improved DDP sensitivity in NSCLC by inhibiting the TRIM44/PI3K/AKT pathway, which may have significant clinical implications for overcoming DDP resistance in NSCLC treatment.