Analysis of In Situ Fluorescent Probes for Rapid Screening of Epidermal Growth Factor Receptor and KRAS Mutations in Exfoliated Cells from Pleural Fluid in Patients with Lung Cancer

To improve the detection rate of non-small-cell lung cancer (NSCLC) exfoliated cells in pleural effusion, we designed nano-MSN-DNA fluorescent probes that could efficiently bind to mutated oncogenes in tumor cells. Mutated NSCLC cells could be detected directly by fluorescence intensity through confocal microscopy without using conventional polymerase chain reaction (PCR). In addition, the DNA probe was highly permeable in NSCLC cells and was stable in methanol at low temperatures. Using the nano-MSN-DNA fluorescent probes, we detected a significantly higher incidence of epidermal growth factor receptor (EGFR) and KRAS mutations in NSCLC pleural effusions and cells compared to those in normal patients, especially in lung adenocarcinoma cells. EGFR and KRAS mutations were more likely to occur in poorly differentiated and clinically advanced NSCLC, and the mutations enhanced tumor aggressiveness, leading to poor prognosis. The nano-MSN-DNA fluorescent probe was significantly more sensitive than Wright staining for screening pleural fluid exfoliated lung squamous carcinoma and adenocarcinoma cells. Thus, the nano-MSN-DNA fluorescent probe shows great potential for screening exfoliated cells from pleural fluid of patients with lung cancer and guiding targeted therapies.