Fig. 1.

Increased expression of xCT in CRC and 5-FU resistance. (A) IHC analysis of xCT expression in tissue microarray composed of 90 CRC and paired adjacent normal tissues. (B) Representative images and results of IHC analysis of xCT expression in 19 paired primary and LM sites. (C) Immunoblot and mRNA results showing increased expression of xCT in 5-FU resistant cells. (D) H₂S fluorescent probe indicating increased H₂S levels in 5-FU resistant cells. (E) GEPIA online analysis showing significantly higher expression of xCT was observed in tumor patients (N = 275) compared with healthy controls (N = 349) in TCGA database. (F) High expression of xCT together with SLC3A2 is associated with a decrease in overall survival in CRC patients. (G) Leading upregulated genes after xCT knockdown in HCT-116 cells. (H) and (I) Quantitative real-time PCR and immunoblot images showing increased CBS and CTH levels in HCT-116 cells with xCT knockdown. J, H₂S fluorescent probe indicating decreased H₂S levels in HCT-116 cells with xCT knockdown. (*P < 0.05, ** P < 0.01)