Figure 1.

Establishment of 5-Fluourouracil-resistant (5-FUR) human pancreatic cancer cells (CPFAC-1 and BxPC-3). (a) Viability of human pancreatic ductal adenocarcinoma (PDAC) cells and their 5-FUR counterparts following treatment with increasing doses of 5-Fluourouracil (5-FU) for 48 h, as measured by the MTT assay; (b) Western blotting showed the expression of nuclear factor (erythroid-derived 2)-related factor 2 (NRF2), NAD(P)H quinone dehydrogenase 1 (NQO1), heme oxygenase-1 (HO-1), and superoxide dismutase 2 (SOD2) was not changed in control cell lines with 5-FU treatment (1 µg/mL) for 24 h. (c) Intracellular reactive oxygen species (ROS) levels were higher in 5-FUR PDAC cells than in control PDAC cells, based on 2′,7′-dichlorofluorescein diacetate (H₂DCFDA) staining; (d) RT-qPCR showed that the mRNA expression levels of NRF2 (n > 5), HO-1 (n = 3), NQO1 (n = 3), and SOD2 (n = 3) were higher in 5-FUR PDAC cells than in parental cells; (e) Western blotting confirmed that expression of NRF2, HO-1, NQO1, and SOD2 was upregulated in 5-FUR PDAC cells compared with parental cells. * p < 0.05.