Research Paper Volume 12, Issue 2 pp 1685—1703

The Interleukin-33/ST2 axis promotes glioma mesenchymal transition, stemness and TMZ resistance via JNK activation

Figure 6. IL-33 prevents TMZ-induced apoptosis and blocked IL-33/ST2 increases tumor apoptosis. (A and B) Effects of IL-33 on proliferation of glioma. Glioma cell lines were cultured with or without IL-33 (20 ng/mL) for 6 days. The cell viability was determined by CCK-8 assay. (C and D) Effects of si-IL-33 on glioma cells proliferation. Si-IL-33 and control si-RNA expressing glioma cells were cultured with or without IL-33 (20 ng/mL) for 5 days. The cell viability was determined by CCK-8. (E and F) Effects of anti-ST2 on glioma cells proliferation. Glioma cell lines Ln229 and U251 were treated with anti-ST2 antibody (1 ug/mL) or IgG control for 6 days. The cell viability was determined by CCK-8. (G and H) Effects of IL-33 on glioma chemotherapy. Glioma cell lines Ln229 and U251 were cultured with or without IL-33 (20 ng/mL) for 24 hours and were subsequently exposed to TMZ for 48 hours. The cell viability was determined by CCK-8 assay. (IK) IL33 was knocked down by si-IL-33 and si-control, the si and control groups were treated with IL-33 (20 ng/mL) or/and TMZ (200uM). The expression of Bax, Bcl-2 were detected by western blot (I) and the cell viability was determined by CCK-8 (J and K). (LM) We performed the Annexin V/PI staining to measure apoptosis. Glioma cells were treated with PBS, anti-ST2, TMZ and anti-ST2+TMZ. Percent of 7-AAD-PE+ cells were counted for analysis. All results are expressed as the mean ± SD from at least three independent experiments; n=4; *, P < 0.05; **, P<0.01; ***, P<0.001; ****, P<0.0001.