Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Biotechnology

The concept of using liquid biopsies in identification of genetic tumor profiling has been researched as a new potential noninvasive technique in cancer detection. Elevated levels of circulating cell free DNA (cf DNA) in plasma has been reported as promising biomarker in diagnosis of cancer. The aim of this study was to investigate if cf DNA marker can distinguish lung cancer patients and healthy control and to study if cf DNA have a role in tumor response to chemotherapy with EGFR-TKI treatment in lung cancer. Additionally, it was suggested that smoking affect the integrity of DNA and by using three markers ALU 115, ALU 247 and DNA integrity index, the degree of effect on apoptosis and necrosis could be examined. Finally, we compared HRM (High Resolution Melting) analysis and sequencing for testing mutation in exon 19 EGFR that have a predictive role for various therapies in NSCLC. Methods: Plasma samples were obtained from 50 lung cancer patients, 25 from them receiving chemotherapy and 50 healthy controls, 25 from them are heavy smoker were chosen for this study. Cf DNA was extracted using Triton/heat/ phenol (THP) method and quantification was measured by q-PCR using ALU 115 and ALU 247, their diagnostic and prognostic potential was estimated using receiver operating characteristics (ROC). Lung cancer patients and heavy smoker were tested for EGFR exon 19 mutation by HRM and Sanger sequencing

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