NAT2: A Novel Target in Intrahepatic Cholangiocarcinoma and its Role in Modulating Tumor Behavior.

Background: Intrahepatic cholangiocarcinoma (ICC) is a primary liver cancer typically diagnosed at advanced stages, limiting treatment options and reducing survival rates. Targeted therapy presents a promising strategy to improve outcomes. This study aims to identify novel molecular biomarkers influencing ICC development and explore their roles in tumor progression.

Methods: Data from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were analyzed using weighted gene co-expression network analysis (WGCNA) to identify genes related to tumor metastasis and recurrence. Survival analysis and gene set enrichment analysis (GSEA) assessed the relationship between gene expression and survival, as well as associated signaling pathways. Cellular experiments, including small interfering RNA (siRNA) knockdown, cell viability assays, Transwell migration assays, and flow cytometry, were performed.

Results: The Kaplan-Meier analysis showed that ICC patients with high N-acetyltransferase 2 (NAT2) expression had significantly shorter survival times than those with low expression (P < .001). Gene set enrichment analysis revealed enrichment of MYC and MTORC1 pathways, linked to tumor proliferation, and E2F and G2M pathways, which regulate the cell cycle, in high NAT2 expression samples (P < .01). The NAT2 knockdown reduced RBE cell proliferation (P < .001) and increased late apoptosis (P < .001). Immunofluorescence analysis showed increased Bax and Caspase-3 expression and decreased BCL-2 expression (P < .05), supporting NAT2's role in regulating ICC cell apoptosis.

Conclusion: NAT2, a novel therapeutic target, holds significant potential to improve the prognosis of ICC patients.