Methylation of breast cancer predisposition genes in early-onset breast cancer: Australian breast cancer family registry

Cameron M. Scott, Ji Hoon Eric Joo, Neil O'Callaghan, Daniel D Buchanan, Mark Clendenning, Graham G. Giles, John L. Hopper, Ee Ming Wong, Melissa C. Southey

Research output: Contribution to journalArticleResearchpeer-review

10 Citations (Scopus)

Abstract

DNA methylation can mimic the effects of both germline and somatic mutations for cancer predisposition genes such as BRCA1 and p16INK4a . Constitutional DNA methylation of the BRCA1 promoter has been well described and is associated with an increased risk of early-onset breast cancers that have BRCA1-mutation associated histological features. The role of methylation in the context of other breast cancer predisposition genes has been less well studied and often with conflicting or ambiguous outcomes. We examined the role of methylation in known breast cancer susceptibility genes in breast cancer predisposition and tumor development. We applied the Infinium HumanMethylation450 Beadchip (HM450K) array to blood and tumor-derived DNA from 43 women diagnosed with breast cancer before the age of 40 years and measured the methylation profiles across promoter regions of BRCA1, BRCA2, ATM, PALB2, CDH1, TP53, FANCM, CHEK2, MLH1, MSH2, MSH6 and PMS2. Prior genetic testing had demonstrated that these women did not carry a germline mutation in BRCA1, ATM, CHEK2, PALB2, TP53, BRCA2, CDH1 or FANCM. In addition to the BRCA1 promoter region, this work identified regions with variable methylation at multiple breast cancer susceptibility genes including PALB2 and MLH1. Methylation at the region of MLH1 in these breast cancers was not associated with microsatellite instability. This work informs future studies of the role of methylation in breast cancer susceptibility gene silencing.

Original languageEnglish
Article numbere0165436
Number of pages13
JournalPLoS ONE
Volume11
Issue number11
DOIs
Publication statusPublished - 1 Nov 2016
Externally publishedYes

Cite this