Figure 1. IL-6 knockdown in NSCLC cells increased in vitro and in vivo sensitivity to cisplatin.
A. Cisplatin cytotoxicity tests of A549IL-6si/sc cells upon various concentrations of cisplatin for 2 days. B. Cisplatin cytotoxicity tests of H157IL-6si/sc cells upon various concentrations of cisplatin for 2 days. C. Tumor regression analyses of A549IL-6si and A549sc cells-derived xenografts in nude mice on cisplatin treatments. Xenografts were developed by subcutaneously injecting 1 × 106 A549IL-6si or A549sc cells into flanks of 8 week old female nude mice. When tumor volumes reached 400 mm3, cisplatin (3 mg/kg, i.p. two times per week) treatment started. Tumor growth was monitored twice per week and at the end of three weeks of treatment, mice were sacrificed. D. H&E and IHC staining of tumor tissues. Tumor tissues of A549IL-6si/sc xenografts were processed and subjected to H&E and IHC staining. Upper panels show H&E staining, middle panels present IHC staining with IL-6 antibody, and lower panels are the IHC staining results using antibody against Ki67 (magnification, 100x). Quantitation of IL-6 and Ki67 IHC staining is shown on right. *p < 0.05, **p < 0.01, ***p < 0.001.