Fig 2: Expression of p-STAT3 expression in tissues derived from patients with NSCLC. (A) Western blot analysis of p-STAT3 and T-STAT3 expression in two subtypes of NSCLC. (B) Quantitative analysis of the p-STAT3/T-STAT3 expression ratio in tumor, adjacent and normal tissues of adenocarcinoma and squamous cell carcinoma subtypes. (C) IHC staining of p-STAT3 in tumor, adjacent and normal tissues of adenocarcinoma and squamous cell carcinoma subtypes (scale bar, 200 and 50 µm); (D) Quantitative analysis of IHC staining scores of p-STAT3 in tumor, adjacent and normal tissues. (E) Quantitative analysis of IHC staining scores of p-STAT3 in adenocarcinoma and squamous cell carcinoma subtypes. (F) Correlation analysis for IHC scores of p-STAT3 and LIF expression in tumor, adjacent and normal tissues. *P<0.05, **P<0.01. STAT3, signal transducer and activator of transcription 3; p-, phosphorylated; T-, total; NSCLC, non-small cell lung cancer; IHC, immunohistochemistry.

Fig 3: LIF expression in tissues derived from patients with NSCLC. (A) Relative mRNA expression of LIF/ß-actin in NSCLC tumor, adjacent and normal tissues. (B) Relative mRNA expression of LIF/ß-actin in adenocarcinoma and squamous cell carcinoma subtypes. (C) Western blot analysis of LIF expression in NSCLC tumor, adjacent and normal tissues. (D) Quantitative analysis of the western blot results for relative protein expression of LIF/ß-actin in tumor, adjacent and normal tissues in adenocarcinoma and squamous cell carcinoma subtypes. (E) IHC staining of LIF in tumor, adjacent and normal tissues of adenocarcinoma and squamous cell carcinoma subtypes (scale bar, 200 and 50 µm). (F) Quantitative analysis of IHC staining scores of LIF in tumor, adjacent and normal tissues. (G) Quantitative analysis of IHC staining scores of LIF in adenocarcinoma and squamous cell carcinoma subtypes. *P<0.05, **P<0.01. NSCLC, non-small cell lung cancer; LIF, leukemia inhibitory factor; IHC, immunohistochemistry.

Fig 4: LIF promotes non-small cell lung cancer progression. (A) Cell proliferation was assessed by Cell Counting Kit-8 assay in A549 cells subjected to different levels of LIF stimulation. (B) Wound healing assays were used to evaluate the migration of A549 cells treated with different concentrations of LIF (magnification, ×100). (C) Quantitative analysis of wound healing rate. (D) Transwell assays were used to measure the effects of LIF on the invasion of A549 cells (magnification, ×400). (E) Quantitative analysis of number of invasive cells. (F) Western blot analysis of p-STAT3 and T-STAT3 expression in A549 cells subjected to different levels of LIF stimulation. (G) Quantitative analysis of p-STAT3 and T-STAT3 expression. *P<0.05, **P<0.01. STAT3, signal transducer and activator of transcription 3; p-, phosphorylated; T-, total; LIF, leukemia inhibitory factor; OD, optical density; CON, control.

Fig 5: Representative image of LIF expression in patients with non-small cell lung cancer. Scale bar, 200 µm. LIF, leukemia inhibitory factor.