Abstract LB-89: A combined epigenetic and genetic biomarker panel for detection of lung cancer.

Abstract Introduction: Lung cancer is the leading cause of cancer-related deaths in human. However, there is no valid screening procedure or test available at the present time. Although National Lung Screening Trial (NLST) demonstrated, for the first time, that low-dose helical CT screening in high-risk population reduced lung cancer mortality by 20%, the procedure is associated with over 95% false positive results (Aberle DR et al. N Engl J Med. 2011, 365:395). A confirmatory test is urgently needed. We have been developing a combined epigenetic and genetic molecular biomarker panel to verify the presence of lung cancer on the blood samples. Methods: Lung cancer cell lines NCI-H69 (small cell carcinoma), NCI-H1299 and NCI-H460 (large cell lung cancer), NCI-H1781 and A549 (adenocarcinoma), NCI- H358 (bronchioalveolar carcinoma) and NCI-H520 (squamous cell carcinoma) were obtained from ATCC (Manassas, VA). Blood samples of patients with lung cancer (n=105) and non-cancer patients were collected at MU Health Care System with an IRB approval. Genomic DNA was extracted from cell lines, mononuclear cell fraction and plasma using QIAamp DNA mini kit and circulating nucleic acid kit (QIAGEN, Valencia, CA), respectively. Isolated DNAs were digested with 4 methylation sensitive restriction enzymes followed by PCR for DNA methylation assay. Genomic DNAs were also subject to allele-specific PCR for PT53, EGFR and BRAF gene mutation assay. All PCR reactions were carried out in an iQ5 Real-time PCR system (Bio-Rad, Hercules, CA). Results: Specific CGI DNA methylation of HOXA7, HOXA6 and PCDHGA12A was detected in all lung cancer cell lines except NCI-H1299 in HOXA7. Only NCI-H460 was positive for EGFR L858R mutation. Among patient blood samples, HOXA7 methylation was detectable in 9 out of 105 patient mononuclear cell DNAs, but neither in patient plasma nor in non-cancer patients or normal blood control DNAs. EGFR L858R mutation was detected in only 4 lung cancer patient DNA samples. The sensitivity of HOXA7 DNA methylation assay, determined by serial dilutions of cancer cell DNA into normal DNA, was 0.1%. Conclusion: A combined epigenetic DNA methylation and genetic mutation panel could be utilized for lung cancer detection or verification in patient blood sample. Citation Format: Michael X. Wang, Dan Guo, Mary Andersen, Vamsi Guntur. A combined epigenetic and genetic biomarker panel for detection of lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-89. doi:10.1158/1538-7445.AM2013-LB-89