FIGURE 4.

RET/PTC3-induced activation of canonical NF-κB pathway is involved in STAT1 and IDO1 gene expression. PTC3–5 cells were incubated with Dox (1 μg/ml) for the indicated times in the presence or absence of the NF-κB inhibitors Bay11-7085 (2 and 5 μm) or JSH-23 (10 μm) and harvested for cell lysate preparation or total RNA extraction and cDNA synthesis. A, immunoblottings for RET, STAT1, and tubulin were performed and B, the bands of three independent experiments were analyzed by densitometry and normalized with tubulin. Inhibition of canonical NF-κB pathway or inhibition of p65 nuclear translocation down-regulated STAT1 expression in a statistically significant manner. C, STAT1 mRNA expression levels were assayed by quantitative PCR. D, IDO1 mRNA expression levels were assayed by quantitative PCR. The data are presented as means of arbitrary units. Inhibition of the canonical NF-κB pathway or inhibition of p65 nuclear translocation down-regulated STAT1 and IDO1 mRNA expression. All experiments were repeated three times and the more representative results are depicted. p values were calculated applying the two-tailed unpaired Student's t test. *, p < 0.05.