J Thorac Oncol. 2021 May 31. pii: S1556-0864(21)02186-9. [Epub ahead of print]
BACKGROUND: Malignant mesothelioma is an aggressive cancer type linked to asbestos exposure. Due to several intrinsic challenges, mesothelioma is often diagnosed in an advanced disease stage. Therefore, there is need for diagnostic biomarkers that may contribute to early detection. Recently, the epigenome of tumours is extensively being investigated to identify biomarkers. This manuscript is a systematic review summarizing the state-of-the-art research investigating DNA methylation in mesothelioma.METHODS: Four literature databases (Pubmed, Scopus, Web of Science, Medline) were systematically searched for studies investigating DNA methylation in mesothelioma up to October 16, 2020. A meta-analysis was performed per gene investigated in at least two independent studies.
RESULTS: Fifty-three studies investigated DNA methylation of 97 genes in mesothelioma and are described in a qualitative overview. Ten studies investigating 13 genes (APC, CDH1, CDKN2A, DAPK, ESR1, MGMT, miR-34b/c, PGR, RARβ, RASSF1, SFRP1, SFRP4, WIF1) were included in the quantitative meta-analysis. In this meta-analysis, the APC gene is significantly hypomethylated in mesothelioma, while CDH1, ESR1, miR-34b/c, PGR, RARβ, SFRP1 and WIF1 are significantly hypermethylated in mesothelioma. The three genes that are the most appropriate candidate biomarkers from this meta-analysis are APC, miR-34b/c and WIF1. However, both study number and study objects comprised in this meta-analysis are too low to draw final conclusions about their clinical applications.
CONCLUSION: The elucidation of the genome-wide DNA methylation profile of mesothelioma is desirable in the future, using a standardized genome-wide methylation analysis approach. The most informative CpG sites from this signature could then form the basis of a panel of highly sensitive and specific biomarkers that can be used for the diagnosis of mesothelioma and even for the screening of an at high-risk population of asbestos-exposed individuals.
Keywords: DNA methylation; Mesothelioma; biomarker; epigenetics