Figure 1.

IL-6 treatment increases G6PD activity in OSCC cells.

(A) A schematic of PPP and nucleotide biosynthesis pathway.

(B) HSC-3 and CAL-27 cells were challenged by 50 ng/mL IL-6 for the indicated time. Cells were washed and then incubated with [¹⁴C]-glucose (1 μCi, 0.01 mmol/L) for 1 h. The amount of cellular [¹⁴C]-R5P was determined. The data are presented as the mean ± SD from 3 independent experiments. ∗∗P < 0.01, ∗∗∗P < 0.001.

(C-D) HSC-3 and CAL-27 cells were treated with 50 ng/mL IL-6 for 1 h. Cells were washed and then incubated with [¹⁴C]-glucose (1 μCi, 0.01 mmol/L) for 1 h. The amount of [¹⁴C]-DNA (C) or [¹⁴C]-RNA (D) was quantified. The data are presented as the mean ± SD from 3 independent experiments. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001.

(E) HSC-3 and CAL-27 cells were treated with 50 ng/mL IL-6 for 1 h. The cellular level of G6P was examined. The data are presented as the mean ± SD from 3 independent experiments. ns, not significant.

(F-G) HSC-3 and CAL-27 cells were treated with 50 ng/mL IL-6 for the indicated time. The G6P dehydrogenation activity in the cell lysates was examined (F). The expression of G6PD was determined by immunoblot (G). The data are obtained from 3 independent experiments. ∗∗P < 0.01, ∗∗∗P < 0.001.(H) HSC-3 and CAL-27 cells were transfected with Flag-G6PD. 48 h after transfection, cells were incubated with 50 ng/mL IL-6 for the indicated time. Immunoprecipitation was then performed with anti-Flag M2 antibody. The G6PD activity in the precipitates was examined. The data are presented as the mean ± SD from 3 independent experiments. ∗∗P < 0.01, ∗∗∗P < 0.001.