Evaluation of Circulating Tumor Cells-DNA Methylated Separation Nano-Polylactic-co-Glycolic Acid Magnetic Beads with Epithelial Cell Adhesion Molecul/Epidermal Growth Factor Receptor Double Antibody Modification and Its Application in Lung Cancer Diagnosis

Through the dynamic detection of peripheral blood circulating tumor cells (CTCs) and the correlation analysis of DNA methylation, the application of relevant indicators of peripheral blood circulating tumor cells (CTCs) in patients with early lung cancer (LC). Double antibody (EpCAM and EGFR antibodies) modified nano-PLGA magnetic beads have been used for CTC sorting. Functional characterization and analysis were performed to confirm that the prepared nano-PLGA MB had good stability and specificity. Furthermore, the separation and identification of CTCs from lung cancer patients were realized by double-antibody nano-PLGA MB (Ep+ER nano-PLGA MB), suggesting that the system had high separation efficiency, with a positive rate of separation of >80%. Meanwhile, methylation-specific PCR was conducted following the extraction DNA from peripheral blood to analyze the methylation level of p16, MGMT and RASSF1A. Corresponding results revealed that the level of p16 methylation could be used as an important index for lung cancer screening. In addition, the association between CTC-DNA methylation and early screening of tumor was analyzed by integrating the clinical information and related indexes of patients. To sum up, in the screening and identification of lung cancer patients, auxiliary effect can be provided through dynamic monitoring of CTC count in peripheral blood and analysis of CTC-DNA methylation level. It is expected to provide scientific basis for screening, therapeutic strategy formulation, gene correlation analysis and prognosis monitoring of LC.