Researchers from Duke University, UCLA, and the University of Birmingham in the U.K. report the development of a new noninvasive acoustofluidics test that analyzes saliva for the presence of human papillomavirus (HPV)-16, the pathogenic strain associated with oropharyngeal cancers (OPCs). The novel technique detected OPC in whole saliva in 40% of patients tested and 80% of confirmed OPC patients.
The team published its study (“Acoustofluidic Salivary Exosome Isolation”) in the Journal of Molecular Diagnostics.
“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. It is paramount that surveillance methods are developed to improve early detection and outcomes,” explained co-lead investigator Tony Jun Huang, PhD, department of mechanical engineering and materials science, Duke University. “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.”
This technique may also help physicians predict which patients will respond well to radiation therapy or achieve longer progression-free survival, he added.
Exosomes are tiny microvesicles originating within cells that are secreted into body fluids. They are believed to play a role in intercellular communication and their numbers are elevated in association with several types of cancers. Acoustofluidics is an advanced technology that fuses acoustics and microfluidics. Fluid samples are analyzed using a tiny acoustofluidic chip developed to isolate salivary exosomes by removing unwanted particles based on size, leaving exosome-rich concentrated samples that make it easier to detect tumor-specific biomarkers.
In this study, investigators analyzed saliva samples from 10 patients diagnosed with HPV-OPC using traditional methods. They found that the technique identified the tumor biomarker HPV-16 DNA in 80% of the cases when coupled with droplet digit PCR. Since this method is independent of sample variability that arises due to changes in saliva viscosity and collection methods used, it may prove ideal for use in clinical settings.
Huang highlighted some of the technique’s features, including automated and fast exosome isolation (less than five minutes of processing time compared to approximately eight hours of processing time using benchmark technologies). Analyses can be performed at relatively low cost and at points of care. Also, it is suitable for repeated and continuous monitoring of tumor progression and treatment, unlike traditional biopsy, according to the researchers.
“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,” noted Huang.
“The saliva exosome liquid biopsy is an effective early detection and risk assessment approach for OPC,” added co-lead investigator David T.W. Wong, DMD, DMSc, of the Center for Oral/Head and Neck Oncology Research, School of Dentistry at UCLA. “The acoustofluidic separation technique provides a fast, biocompatible, high-yield, high-purity, label-free method for exosome isolation from saliva.”
According to the researchers, this technology can also be used to analyze other biofluids such as blood, urine, and plasma.