Prognostic Significance of Stromal Periostin Expression in Non-Small Cell Lung Cancer

Figure 1. Representative immunohistochemical images with stromal periostin (POSTN) expression in non-small cell lung carcinoma (NSCLC), scored as (A) 0—no reaction, (B) 1—weak expression, (C) 2—moderate expression, and (D) 3—strong expression. Magnification 200×. Bar = 100 µm.

Figure 2. Expression levels of periostin (POSTN) in the tissue of two non-small cell lung carcinoma (NSCLC) subtypes: squamous cell cancer (SCC) and adenocarcinoma (AC) (*** p < 0.001); Mann–Whitney U test.

Figure 3. Serial sections of non-small cell lung carcinoma (NSCLC) immunostained for (A) periostin (POSTN), (B) α-smooth muscle actin (α-SMA), (C) podoplanin (D2-40), and (D) vimentin in cancer-associated fibroblasts (CAFs). Magnification 50×. Bar = 200 µm.

Figure 4. Expression of periostin (POSTN) in (A) non-malignant lung tissue (NMLT), (B) squamous cell cancer (SCC), and (C) adenocarcinoma (AC). Immunohistochemical evaluation of periostin (POSTN) expression level in (D) non-small cell lung carcinoma (NSCLC), (E) squamous cell cancer (SCC), and (F) adenocarcinoma (AC) compared to non-malignant lung tissue (NMLT), (**** p < 0.0001); Mann–Whitney U test. Magnification 200×. Bar = 100 µm.

Figure 5. Expression level of periostin (POSTN) with regard to the clinicopathological factors of patients. Comparison of immunohistochemical periostin (POSTN) expression in the stromal cells (CAFs) of the non-small cell lung carcinoma (NSCLC), squamous cell cancer (SCC), and adenocarcinoma (AC) subtypes, (A,D,G, respectively) according to the tumour size (* p < 0.05, ** p < 0.005, *** p < 0.001), (B,E,H) clinical cancer stage (* p < 0.05, ** p < 0.005, *** p < 0.001, **** p < 0.0001), and (C,F,I) lymph node status (* p < 0.05, ** p < 0.005); Mann–Whitney U test.

Figure 6. Comparison of periostin (POSTN) expression levels in different grades of malignancy (G) of the tumour in (A) non-small cell lung carcinoma (NSCLC) (**** p < 0.0001), (B) squamous cell cancer (SCC) (** p < 0.005), and (C) adenocarcinoma (AC) (**** p < 0.0001); Mann–Whitney U test. Immunohistochemical expression of periostin (POSTN) in stromal cells increased with a higher malignancy grade (G) in squamous cell cancer (SCC): G1 (D), G2 (E), G3 (F), and in adenocarcinoma (AC): G1 (G), G2 (H), and G3 (I). Magnification 200×. Bar = 100 µm.

Figure 7. Correlations of periostin (POSTN) expression levels in stromal cells (CAFs) with podoplanin (D2-40) in (A) non-small cell lung carcinoma (NSCLC) (r = 0.27, *** p < 0.001), (B) squamous cell cancer (SCC) (r = 0.25, *** p < 0.001), and (C) adenocarcinoma (AC), (r = 0.20, *** p < 0.001).

Figure 8. Kaplan–Meier survival curves reflecting the prognostic impact of periostin (POSTN) expression by cancer-associated fibroblasts (CAFs) on overall survival (OS) of patients with non-small cell lung cancer (NSCLC). The prognostic impact of periostin (POSTN) expression levels (immunohistochemistry, IHC) was studied in (A) the whole patient cohort (**** p < 0.0001) and in individual histological types, i.e., (B) squamous cell cancer (SCC) (**** p < 0.0001) and (C) adenocarcinoma (AC) (**** p < 0.0001); Mann–Whitney U test. Cut-off points for the analysis were estimated based on the median.

Figure 9. Confocal images showing colocalisation of (A) periostin (POSTN)/α-smooth muscle actin (α-SMA) (r = 0.37) and (B) periostin (POSTN)/podoplanin (D2-40) (r = 0.28) in non-small cell lung carcinoma (NSCLC).. Objective 60×/1.40 Oil; pinhole airy 1.25. Bar = 20 µm.

Figure 10. Significantly higher mRNA expression of periostin (POSTN) in the microdissected (LCM) stromal cells (CAFs) as compared to their expression in (A) cancer cells (**** p < 0.0001) and (B) non-malignant lung cells (NMLC) (*** p < 0.001). (C) Comparison of mRNA periostin (POSTN) expression in squamous cell cancer (SCC) and its expression in adenocarcinoma (AC); Mann–Whitney U test.