PT  - JOURNAL ARTICLE
AU  - Arnoud Boot
AU  - Mi Ni Huang
AU  - Alvin W.T. Ng
AU  - Szu-Chi Ho
AU  - Jing Quan Lim
AU  - Yoshiiku Kawakami
AU  - Kazuaki Chayama
AU  - Bin Tean Teh
AU  - Hidewaki Nakagawa
AU  - Steven G. Rozen
TI  - In-depth characterization of the cisplatin mutational signature in human cell lines and in esophageal and liver tumors
AID  - 10.1101/189233
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 189233
4099  - http://biorxiv.org/content/early/2017/12/17/189233.short
4100  - http://biorxiv.org/content/early/2017/12/17/189233.full
AB  - Background and aims Cisplatin reacts with DNA, and thereby likely generates a characteristic pattern of somatic mutations, called a mutational signature. Despite widespread use of cisplatin in cancer treatment and its role in contributing to secondary malignancies, its mutational signature has not been delineated. We hypothesize that cisplatin’s mutational signature can serve as a biomarker to identify cisplatin mutagenesis in suspected secondary malignancies. Knowledge of which tissues are at risk of developing cisplatin-induced secondary malignancies could lead to guidelines for non-invasive monitoring for secondary malignancies after cisplatin chemotherapy.Methods We performed whole genome sequencing of 10 independent clones of cisplatin-exposed MCF-10A and HepG2 cells, and delineated the patterns of single- and dinucleotide mutations in terms of flanking sequence, transcription strand bias, and other characteristics. We used the mSigAct signature presence test and non-negative matrix factorization to search for cisplatin mutagenesis in hepatocellular carcinomas and esophageal adenocarcinomas.Results All clones showed highly consistent patterns of single- and dinucleotide substitutions. The proportion of dinucleotide substitutions was high: 8.1% of single nucleotide substitutions were part of dinucleotide substitutions, presumably due to cisplatin’s propensity to form intra-and inter-strand crosslinks between purine bases in DNA. We identified likely cisplatin exposure in 9 hepatocellular carcinomas and 3 esophageal adenocarcinomas. All hepatocellular carcinomas for which clinical data were available and all esophageal cancers indeed had histories of cisplatin treatment.Conclusions We experimentally delineated the single- and dinucleotide mutational signature of cisplatin. This signature enabled us to detect previous cisplatin exposure in human hepatocellular carcinomas and esophageal adenocarcinomas with high confidence.