Circulating Virus–Host Chimera DNAs in the Clinical Monitoring of Virus-Related Cancers
Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
Center for Genomic Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
Division of Gastroenterology, Department of Internal Medicine, National Taiwan University Hospital, Taipei 100, Taiwan
Authors to whom correspondence should be addressed.
Academic Editor: Elin S. Gray
Received: 18 March 2022
Revised: 18 May 2022
Accepted: 18 May 2022
Published: 20 May 2022
Cell-free tumor DNA (ctDNA), the DNA released into circulation from tumors, is a promising tumor marker with versatile applications. The associations of the amount, somatic mutation frequency, and epigenetic modifications of ctDNA with the tumor burden, tumor behavior, and prognosis have been widely investigated in different types of tumors. However, there are still some challenging issues to be resolved before ctDNA can complement or even replace current serum tumor markers. We propose employing exogenous viral DNA integration that produces unique virus–host chimera DNA (vh-DNA) at junction sites. Cell-free vh-DNA may become a new biomarker because it overcomes background interference detection problems, takes advantage of virus tropism to localize the tumor, and acts as a universal marker for monitoring clonal expansion or tumor loads in tumors related to oncogenic viruses.