Fig 2: (A) Images taken 10 min after addition of QA-2OMeSiR to cell lines at 2 days after siRNA transfection. A549, H441, and H226 cells transfected with DPP4 siRNA or PSA siRNA show a suppressed increase of fluorescence compared to the Control siRNA-transfected cell lines. The scale bar represents 50 µm. (B) Increase in fluorescence intensity at 10 min after addition of QA-2OMeSiR, averaged over 15 cells. (C) Mean values of 15 measurements for each cell line and results of statistical comparison (t-test) of the effects of the siRNAs used.

Fig 3: Pathological confirmation of the presence of DPP4 and PSA by HE staining and immunohistochemical staining of adenocarcinoma, squamous cell carcinoma and normal lung tissue. Both adenocarcinoma and squamous cell carcinoma are positive for DPP4 and PSA staining. In normal lung tissue, some macrophages and alveolar epithelium were positive for DPP4, but others were negative. PSA was negative in all normal tissues.

Fig 4: Quantitative PCR analysis of DPP4 and PSA expression in lung cancer. In adenocarcinoma, both DPP4 and PSA were more highly expressed in the tumor than in normal lung tissue (n = 3, #11, #14, #17). In squamous cell carcinoma, DPP4 was rarely observed in either normal or tumor tissues, but PSA was frequently observed in tumor tissues (n = 3, #22, #23, #24).