Open AccessQuantitative analysis of the BRAF V595E mutation in plasma cell-free DNA from dogs with urothelial carcinoma
Author(s) -
Michihito Tagawa,
Naomi Tambo,
Masaki Maezawa,
Mizuki Tomihari,
Kenichi Watanabe,
Hisashi Inokuma,
Koshiro Miyahara
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0232365
Subject(s) - mutation , cancer research , carcinoma , biomarker , polymerase chain reaction , cell free fetal dna , allele , real time polymerase chain reaction , liquid biopsy , biology , microbiology and biotechnology , medicine , gene , cancer , pathology , genetics , pregnancy , fetus , prenatal diagnosis
Circulating tumor DNA (ctDNA), which carries tumor-specific mutations, is an emerging candidate biomarker for malignancies and for monitoring disease status in various human tumors. Recently, BRAF V595E mutation has been reported in 80% of dogs with urothelial carcinoma. This study investigates the BRAF V595E allele concentration in circulating cell-free DNA (cfDNA) and assesses the clinical significance of BRAF -mutated ctDNA levels in canines with urothelial carcinoma. A total of 15 dogs with urothelial carcinoma were included. cfDNA concentration was measured using a real-time polymerase chain reaction (PCR) of the LINE-1 gene. To measure the concentration of the mutated BRAF gene in cfDNA, allele-specific real-time PCR with a locked nucleic acid probe was performed. BRAF mutations were detected in 11 (73%) of the 15 tested tumor samples. BRAF -mutated ctDNA concentrations were significantly higher in dogs with the BRAF mutation (14.05 ± 13.51 ng/ml) than in wild-type dogs (0.21 ± 0.41 ng/ml) ( p = 0.031). The amount of BRAF -mutated ctDNA in plasma increased with disease progression and responded to treatment. Our results show that BRAF -mutated ctDNA can be detected using allele-specific real-time PCR in plasma samples of canines with urothelial carcinoma with the BRAF V595E mutation. This ctDNA analysis may be a potentially useful tool for monitoring the progression of urothelial carcinoma and its response to treatment.