Abstract

Therapies targeting somatic bystander genetic events represent a new avenue for cancer treatment. We recently identified a subset of colorectal cancer (CRC) patients who are heterozygous for a wild-type and a low activity allele (NAT2*6) but lack the wild-type allele in their tumors due to loss of heterozygosity (LOH) at 8p22. These tumors were sensitive to treatment with a cytotoxic substrate of NAT2 (6-(4-aminophenyl)-N-(3,4,5-trimethoxyphenyl)pyrazin-2-amine, APA), and pointed to NAT2 loss being a therapeutically exploitable vulnerability of CRC tumors. To better estimate the total number of treatable CRC patients, we here determined whether tumor cells retaining also other NAT2 low activity variants after LOH respond to APA treatment. The prevalent low activity alleles NAT2*5 and NAT2*14, but not NAT2*7, were found to be low metabolizers with high sensitivity to APA. By analysis of two different CRC patient cohorts, we detected heterozygosity for NAT2 alleles targetable by APA, along with allelic imbalances pointing to LOH, in ~ 24% of tumors. Finally, to haplotype the NAT2 locus in tumor and patient-matched normal samples in a clinical setting, we develop and demonstrate a long-read sequencing based assay. In total, > 79.000 CRC patients per year fulfil genetic criteria for high sensitivity to a NAT2 LOH therapy and their eligibility can be assessed by clinical sequencing.

Details

Title
Defining eligible patients for allele-selective chemotherapies targeting NAT2 in colorectal cancer
Author
Rendo Veronica 1 ; Kundu Snehangshu 2 ; Rameika Natallia 2 ; Ljungström Viktor 2 ; Svensson, Richard 3 ; Palin Kimmo 4 ; Aaltonen Lauri 4 ; Stoimenov Ivaylo 2 ; Sjöblom, Tobias 2 

 Uppsala University, Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala, Sweden (GRID:grid.8993.b) (ISNI:0000 0004 1936 9457); Dana-Farber Cancer Institute, Boston, USA (GRID:grid.65499.37) (ISNI:0000 0001 2106 9910) 
 Uppsala University, Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala, Sweden (GRID:grid.8993.b) (ISNI:0000 0004 1936 9457) 
 Uppsala University, Uppsala Drug Optimization and Pharmaceutical Profiling Facility (UDOPP), SciLifeLab Chemical Biology Consortium Sweden (CBCS), Department of Pharmacy, Uppsala, Sweden (GRID:grid.8993.b) (ISNI:0000 0004 1936 9457); Uppsala University, SciLifeLab Drug Discovery and Development Platform, ADME of Therapeutics facility (UDOPP), Department of Pharmacy, Uppsala, Sweden (GRID:grid.8993.b) (ISNI:0000 0004 1936 9457) 
 University of Helsinki, Biomedicum Helsinki, Applied Tumor Genomics Research Program, Faculty of Medicine, Helsinki, Finland (GRID:grid.8993.b); University of Helsinki, Biomedicum Helsinki, Department of Medical and Clinical Genetics, Helsinki, Finland (GRID:grid.8993.b) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2474384768
Copyright
© The Author(s) 2020. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.