Fig. 1

Establishment of genome-wide DNA methylation profiles of patient-derived xenograft (PDX) models of NSCLC tumors. a Establishment and chemosensitivity testing was performed as described before [21]. Patient’s NSCLC tumors were resected and transplanted into immunodeficient NOD/SCID mice for tumor growth. Each patient-derived xenograft (PDX) tumor was passaged into 12 NMRI-nu/nu mice for chemosensitivity testing, with 6 mice as untreated control group and 6 mice as treatment group. Tumor size was measured, and the relative tumor volume was determined to distinguish between sensitive and resistant NSCLC tumors. The open square with arrow indicates sample resection for targeted next-generation sequencing, DNA methylation profiling, and gene expression analyses. b Chemotherapeutic responsiveness of PDX to carboplatin is given as average relative tumor volume of treated to control in %. c Dendogram reflecting hierarchical clustering of methylation differences between PDX versus normal tissue of MeDIP- and Methyl-Seq (BS)-derived data. d Scatterplot of average methylation differences of six PDX normalized to its corresponding normal samples analyzed by MeDIP- and Methyl-Seq. e Principal component analysis of MeDIP-Seq derived data of 22 PDXs (orange), their corresponding normal lung tissues (green), and 6 primary NSCLC tumors (violet). PCAs have been computed in QSEA, based on the % methylation (beta) values of all windows overlapping promoter regions. From these, QSEA selects the 1000 most variable regions over all samples. Plotted are the first and the second components. n number