Jak2/Stat3 pathway contributed to IL-6 autocrine production in clinically isolated lung cancer cells. (A and B) Pharmacological inhibition of Jak2/Stat3, PI3-K/Akt, MEK/Erk and NF-κB pathways decreased the secretion of IL-6 in clinically isolated lung cancer cells. (A) Lung cancer cells were collected from MPE of 20 patients with lung adenocarcinomas. After resetting at 37°C for 1 hour, the cells were treated with AG490 (40 μM), LY294002 (20 μM), U0126 (5 μM), BAY11-7082 (20 μM) or medium alone for 24 hours. The culture supernatants were collected and IL-6 secretion was measured by ELISA. Each spot indicates the results of one sample. The graphs represent one experiment performed in triplicate represented as mean only. Paired t tests: **p < 0.01 and ***p < 0.001. (B) The inhibition rates of the four pharmacological inhibitors represent percent of inhibition, which was calculated by comparing IL-6 secretion in each tumor sample, with or without inhibitor treatment. It was defined as: (IL-6 level without inhibitor treatment - IL-6 level with inhibitor treatment) divided by IL-6 level without inhibitor treatment × 100%. Data represents the mean that each spot indicates the result of one sample done in triplicate.