DNA methylation profiling of malignant pleural mesothelioma

Diagnosis of malignant pleural mesothelioma (MPM) is a challenging task because of its overlap with other neoplasms or even reactive conditions. Recently, DNA methylation analysis proved to be an effective tool for tumor diagnosis. We thus set out to test this approach for MPM diagnosis. A discovery (n=33) and an independent validation cohort (n=46) of MPM samples were subjected to array-based DNA methylation analyses and their DNA methylation patterns were compared to a representative set of both malignant and benign diagnostic mimics. By both unsupervised hierarchical clustering and t-distributed stochastic neighbor embedding analysis, MPM samples of the discovery cohort exhibited a distinct DNA methylation profile, different from that of other neoplastic and reactive mimics. Bisulphite converted DNA from 79 samples was hybridized to Illumina Infinium Human MethylationEPIC Methylation BeadChip array