Fig. 4
Activated CAF were abundant in KL tumors and fibroblastic FAK was hyperactivated. A The correlation between CAF infiltration and COL1A1 or COL3A1 via TIMER2.0. B The correlation between markers of activated CAF (FAP or α-SMA) and COL1A1 or COL3A1 via TIMER2.0. C Computed method calculating infiltrating levels of CAF in KP and KL subcutaneous tumors (n = 3 per each group) [48]. D Expression levels of FAP in L929 cells, after co-cultured with KL or KP tumors cells for 72 h by RT-qPCR. The gene expression data of 72 h treated L929 cells were normalized to the DMEM control group. Additional TGF-β was used as positive control for activating CAF. Data represents mean ± SEM from three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001, and ns represents p-values with no statistical difference. E Representative immunofluorescent staining of sections from KL or KP tumors. Red, FAP staining; green, α-SMA staining; blue, DAPI staining. Scale bars, 200 μm. magnified scale bars,100 μm. F KEGG analysis for significantly upregulated genes in KL tumors compared to KP tumors. Representative and related KEGG signal pathways among top 30 upregulated pathways were listed here. G Immunofluorescence staining and IHC staining co-localizing CAF and activated FAK. Scale bars, 100 μm. magnified scale bars, 20 μm. KL, KRASG12DLKB1−/−; KP, KRASG12DTP53−/−; CAF, cancer-associated fibroblast; FAK, focal adhesion kinase; FAP, fibroblast activation protein; SMA, smooth muscle actin; IHC, immunohistochemistry; TGF-β, transforming growth factor-beta; DMEM, dulbecco's modified eagle's medium; SEM, standard error of mean