Detecting cancer biomarkers in blood: challenges for new molecular diagnostic and point-of-care tests using cell-free nucleic acids

Abstract

As we move into the era of individualized cancer treatment, the need for more sophisticated cancer diagnostics has emerged. Cell-free (cf) nucleic acids (cf-DNA, cf-RNA) and other cellular nanoparticulates are now considered important and selective biomarkers. There is great hope that blood-borne cf-nucleic acids can be used for 'liquid biopsies', replacing more invasive tissue biopsies to analyze cancer mutations and monitor therapy. Conventional techniques for cf-nucleic acid biomarker isolation from blood are generally time-consuming, complicated and expensive. They require relatively large blood samples, which must be processed to serum or plasma before isolation of biomarkers can proceed. Such cumbersome sample preparation also limits the widespread use of powerful, downstream genomic analyses, including PCR and DNA sequencing. These limitations also preclude rapid, point-of-care diagnostic applications. Thus, new technologies that allow rapid isolation of biomarkers directly from blood will permit seamless sample-to-answer solutions that enable next-generation point-of-care molecular diagnostics.

Epigenetic Biomarkers in the Management of Ovarian Cancer: Current Prospectives

“…The analysis of blood borne cell-free DNA has tremendous potential to enable rapid, non-invasive molecular diagnosis of cancer. They are of great clinical relevance as they provide specific targets for initial diagnosis, permit monitoring of treatment efficacy as well as information about tumor profile and its dynamics which are critical for treatment decisions (De Mattos-Arruda et al, 2014;Lewis et al, 2015).…”

“…The limitation of bisulfite conversion of cfDNA is the missing DNA. Because of the technical difficulties of DNA methylation analysis, only few DNA methylation based markers has been identified to date, which apply only to a fraction of gynecological cancers including breast, ovarian and endometrial cancers (Wittenberger et al, 2014;Lewis et al, 2015).…”

Biological Functions and Current Advances in Isolation and Detection Strategies for Exosome Nanovesicles

“…This is because the cargo is protected from many harsh conditions inside the encapsulated protective environment of the exosomes (e.g., exosomal miRNA is protected from ribonuclease (RNase) mediated RNA degradation). However, this major advantage of exosomal miRNA may pose a significant challenge, i.e., for the analysis of miRNA, because it needs to be released from the isolated exosomes, which incurs multiple additional complicated steps in the analysis . There are also many fundamental questions still unanswered concerning the functionality of exosomes and their contents .…”

Dielectrophoresis for Biomedical Sciences Applications: A Review

“…Furthermore, unlike optical tweezers, DEP provides a low applied voltage and an alternating current for gene transfection from DNA that can prevent cell membrane damage [165]. DEP techniques use a smaller sample volume and can isolate to the extent of a nanoscale-sized bio-particle, making it an excellent candidate for further development as a point-of-care (POC) diagnostic tool, especially in molecular research [176,177,178]. …”