Figure 5. Effect of EXT1 expression on ER stress with or without 5-FU and IFN-α/5-FU.

(A, B) Real-time reverse transcription-polymerase chain reaction analysis of BiP/GRP78 (A) and CHOP (B) mRNA expression. mRNA expression levels were normalized to β-actin. Data are expresses as mean ± standard deviation (n = 3). Statistical significance was determined using Student’s t-test. *P<0.05, compared to control. (C) Western blot analysis for ATF4, CHOP, BiP/GRP78, and LC3B. Actin was used as an internal control. (D) LC3B expression in HepG2 cells treated with 5-FU in the presence and absence of IFN-α. Cells infected with adenoviruses were treated with 5 µg/mL of 5-FU alone and in combination with 200 U/mL of IFN-α for 48 h. LC3B (green) and nuclei (DAPI, blue) signals were examined by immunofluorescence analysis using confocal microscopy. Treatment with 20 mg/mL of tunicamycin was used as a positive control. (E) Viability of HepG2 cells infected with adenovirus-carrying EXT1 in the presence or absence of TUDCA. Cells were treated with 5 µg/mL of 5-FU alone and in combination with 200 U/mL of IFN-α for 72 h. During this treatment, cells were exposed to TUDCA. Data are expressed as mean ± standard deviation (SD) (n = 3). Statistical significance was determined using Student’s t-test. *P<0.05 between two groups. N.S., not significant.