Fig. 1: NUSAP1 promotes 5-FU resistance in gastric cancer.

A IC50 assays were performed to evaluate the sensitivity of BGC-823 and SGC-7901 parental and 5-FU-resistant (5-FU-R) cell lines to 5-FU. B Volcano plot analysis showing differentially expressed genes (−log10 P-value < 15, log2 −10 < FC < -1 or 1 < FC < 10) between 5-FU-resistant and parental gastric cancer cells. Upregulated and downregulated genes are highlighted. Venn diagrams showing the overlap of significantly downregulated (C) and upregulated (D) genes in BGC-823-5-FU-R and SGC-7901-5-FU-R cell lines compared to their parental counterparts. E Western blot analysis of NUSAP1 protein expression in BGC-823, SGC-7901, and their 5-FU-resistant derivatives. Tubulin served as a loading control. F Western blot analysis confirming overexpression of NUSAP1 in BGC-823 and SGC-7901 cells transfected with a NUSAP1 overexpression plasmid (NUSAP1-OE). MYC-tag was used to validate NUSAP1 expression.G IC50 assays were performed to determine the effect of NUSAP1 overexpression on 5-FU sensitivity in BGC-823 and SGC-7901 cells. H Western blot analysis of NUSAP1 protein levels in BGC-823-5-FU-R and SGC-7901-5-FU-R cells transfected with shNUSAP1-1#, shNUSAP1-2#, or shGFP control (negative control). I IC50 assays were performed to evaluate the effect of NUSAP1 knockdown on 5-FU sensitivity in BGC-823-5-FU-R and SGC-7901-5-FU-R cells.