A, IL-17 stimulated IL-6 secretion in SKPs and KPCs as determined by ELISA analysis (mean±SEM). ** P<0.01; ns, no significance. B, IL-17 stimulated the expression of hTERT and Oct-4 in SKPs and KPCs as determined by Western blot analysis. C, Blocking IL-6, but not IL-17 attenuated the basal expression of hTERT and Oct-4 in SKPs and KPCs. Cells were treated with 5 µg/mL of neutralizing antibody for either IL-6 (IL-6 Ab), or IL-17 (IL-17Ab), or both for 24 hours and expression of hTERT and Oct-4 was determined by Western blot analysis. D, IL-17-induced upregulation of hTERT and Oct-4 expression in SKPs and KPCs was significantly attenuated by treatment with neutralizing antibodies for either IL-17, or IL-6, or both. After serum-starved for 24 hours, cells were pretreated with neutralizing antibodies, followed by incubation with 20 ng/mL of IL-17. The expression of hTERT and Oct-4 was determined by Western blot analysis. E, IL-6-induced upregulation of hTERT and Oct-4 expression in SKPs and KPCs was attenuated only by IL-6Ab, not by IL-17Ab. Following serum-starvation for 24 hours, cells were pretreated with neutralizing antibodies and incubated with 20 ng/mL of IL-6. Expression of hTERT and Oct-4 was determined by Western blot analysis. An isotype-matched normal mouse IgG (mIgG) was used as negative controls. The results are representative of at least five independent experiments using KPCs and the matched SKPs from different patient donors (n = 5).