Introduction

DNA methylation is known to play an important role in cancer development. The long interspersed nuclear element 1 (LINE-1) is a repetitive sequence interspersed throughout the genome of some organisms. LINE-1 hypomethylation has been reported in human malignancies, it is used as an epigenetic cancer biomarker.

This study aimed to determine the diagnostic value of LINE-1 methylation in dogs with splenic masses using tissue and cell free DNA samples.

Methods

Genomic DNA was isolated from splenic masses in twelve dogs with hemangiosarcoma, nine dogs with other malignant tumor, and thirteen dogs with benign tumors. LINE-1 methylation was measured using methylation sensitive and insensitive restriction enzyme digestion, followed by real-time PCR. Additionally, blood samples were collected from some patients to isolate cell free DNA for determining LINE-1 methylation status throughout the course of disease progression.

Results

LINE-1 methylation in tumor samples was significantly lower in patients with hemangiosarcoma than in those with other malignant and benign tumors groups. Similar results were observed in cell free DNA samples. There was a measurable correlation between methylation level and clinical status during follow-up in some cases.

Conclusion

These results indicate that LINE-1 methylation may be a predictive biomarker for splenic hemangiosarcoma in dogs. Additionally, cell free DNA methylation analysis may be a potentially useful tool for monitoring the progression of splenic malignancies. Further research is required to establish the true clinical value of LINE-1 methylation status in cell free DNA as a biomarker for canine splenic hemangiosarcoma.

Funding Information

This study was supported by The Akiyama Life Science Foundation.