Abstract 4317: Application of gene methylation analysis for distinguishing primary tumor cells from normal epithelial cells from lung cancer patients in conditionally reprogrammed cell cultures

In vitro drug sensitivity assays utilizing “conditionally reprogrammed cells” (CRCs) from different primary tumor types to guide personalized therapy has been emerging. However, this approach has been hindered by the growth of normal epithelial cells in CRC cultures and the lack of effective biomarkers/assays to distinguish them from primary tumor cells. In this study, we developed a DNA methylation-based, real-time PCR assay to investigate the methylation status of SHOX2,PTGER4 and Septin9 gene promotor regions in human lung cancer formalin fixed paraffin-embedded (FFPE) samples. Our results showed increased DNA methylation for at least one of the three genes in 90% (28/31) of tumor samples as compared with the corresponding adjacent normal samples. Then we tested gene methylation in fresh surgical tumors versus normal adjacent tissues from lung cancer patients, and their respective in vitro CRC cultures. Increased methylation for at least one of the three genes was detected in 91.6% of tumor samples (11/12) as compared with the adjacent tissues, and these positive methylation statuses were maintained in 75% (9/12) of CRC cultures. Further results from in vitro assays showed a correlation between higher cell methylation status and increased growth property in 3D culture, as well as differential response to chemotherapy. Together, our results demonstrated that methylation of SHOX2, PTGER4 and Septin9 genes can be used as reliable biomarkers to monitor tumor cells in in vitro CRC cultures. Citation Format: Guodong Wu, Yangui Xiao, Fuyuan Fang, Da Yao, Ji Liu, Yanhua Cao, Yu Mao, Benjamin Yu, Youhui Qian, Derek Yu. Application of gene methylation analysis for distinguishing primary tumor cells from normal epithelial cells from lung cancer patients in conditionally reprogrammed cell cultures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4317.