Open AccessRelationship of microsatellite instability to mismatch repair deficiency in malignant tumors of dogs
Author(s) -
Inanaga Sakuya,
Igase Masaya,
Sakai Yusuke,
Hagimori Kenji,
Sunahara Hiroshi,
Horikirizono Hiro,
Itamoto Kazuhito,
Baba Kenji,
Ohsato Yoshiharu,
Mizuno Takuya
Publication year - 2022
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.16454
Subject(s) - microsatellite instability , dna mismatch repair , medicine , genome instability , immunohistochemistry , cancer research , microsatellite , cancer , melanoma , pathology , biology , gene , dna , colorectal cancer , dna damage , genetics , allele
Background Microsatellite instability (MSI) is a type of genomic instability caused by mismatch repair deficiency (dMMR) in tumors. Studies on dMMR/MSI are limited, and the relationship between dMMR and MSI is unknown in tumors of dogs. Objectives We aimed to identify the frequency of dMMR/MSI by tumor type and evaluate the relationship between dMMR and MSI in tumors of dogs. Animals In total, 101 dogs with 11 types of malignant tumors were included. Methods We extracted DNA from fresh normal and tumor tissues. Twelve microsatellite loci from both normal and tumor DNA were amplified by PCR and detected by capillary electrophoresis. Each microsatellite (MS) was defined as MSI if a difference in product size between the tumor and normal DNA was detected. The dMMR was evaluated by immunohistochemistry with formalin‐fixed paraffin‐embedded tumor tissues. Next, we confirmed whether dMMR induces MSI by serial passaging of MMR gene knockout cell lines for 3 months. Results Microsatellite instability was detected frequently in oral malignant melanoma. The number of MSI‐positive markers was higher in cases with dMMR than in those with proficient MMR ( P < .0001). Statistical analysis indicated that the occurrence of MSI in FH2305 might have relevance to dMMR. Furthermore, MSI occurred in dMMR cell lines 3 months after passaging. Conclusions and Clinical Importance Microsatellite instability and dMMR more frequently were found in oral malignant melanoma than in other tumors, and dMMR has relevance to MSI in both clinical cases and cell lines.