Human Papilloma Virus in salivary exosomes may help in the early detection of mouth & throat cancer
DURHAM, N.C., U.S./BIRMINGHAM, U.K.: Cancers that occur in the back of the mouth or in the upper throat are often diagnosed only when they are advanced as they are difficult to spot in their early stages. Acoustofluidics is a novel, noninvasive method that analyzes saliva for the presence of human papillomavirus (HPV)-16, which happens to be the pathogenic strain linked with oropharyngeal cancers (OPC). This new technique has demonstrated a high success rate in detecting OPC in whole saliva in almost half of the patients tested and in the majority of confirmed OPC patients.
Earlier studies that had attempted to evaluate the detection of human papilloma viral (HPV) DNA in the whole saliva as a diagnostic measure for HPV-associated oropharyngeal cancer (HPV-OPC) were not really successful. Researchers in the current study hypothesized that salivary exosomes, the membrane-bound extracellular vesicles that are believed to play a role in various types of cancers, are packaged with HPV-associated biomarkers. They hypothesized that efficient enrichment of salivary exosomes through isolation can enhance diagnostic and prognostic performance for HPV-OPC.
“OPC has an approximate incidence of 115,000 cases per year worldwide and is one of the fastest rising cancers in Western countries due to increasing HPV-related incidence, especially in younger patients,” explained co-author Dr Tony Jun Huang, William Bevan distinguished professor of mechanical engineering and mechanical science at Duke University in North Carolina.
“Considering these factors, the successful detection of HPV from salivary exosomes isolated by our acoustofluidic platform offers distinct advantages, including early detection, risk assessment, and screening,” Huang added. The technique may also be instrumental in helping physicians predict which patients will respond well to radiation therapy and in improving progression-free survival.
Exosomes, the membrane-bound extracellular vesicles, are believed to play a role in intercellular communication and are associated with several types of cancers. In the study, the researchers analyzed saliva samples from ten HPV-positive OPC patients using a tiny acoustofluidic chip developed to isolate salivary exosomes. They removed the unwanted particles based on their size, leaving exosome-rich concentrated samples that helped detect tumour-specific biomarkers. The technique identified the tumour biomarker HPV-16 DNA in 80% of the cases when coupled with droplet digital polymerase chain reaction.
“The acoustofluidic separation technique provides a fast, biocompatible, high-yield, high-purity, label-free method for exosome isolation from saliva,” said co-author Prof. David T.W. Wong, associate dean for research and director of the Center for Oral/Head and Neck Oncology Research at the University of California, Los Angeles (UCLA). The researchers believe that the technology can also be used to analyze other biofluids, including blood, urine, and plasma.
“With these features, the acoustofluidic technology has the potential to significantly exceed current industry standards, address unmet needs in the field, help expedite exosome-related biomedical research, and aid in the discovery of new exosomal biomarkers,” Huang commented.
The study is an international collaboration between Duke University, UCLA and the University of Birmingham. “The results are a testament to the power of interdisciplinary research and international collaboration,” said Prof. Hisham Mehanna, director of the Institute of Head and Neck Studies and Education at the University of Birmingham.
The study, titled “Acoustofluidic salivary exosome isolation: A liquid biopsy compatible approach for human papillomavirus-associated oropharyngeal cancer detection,” was published online on Dec. 13, 2019, in the Journal of Molecular Diagnostics, ahead of inclusion in an issue.