Direct Bisulfite-Free Detection of 5-Methylcytosine by Using Electrochemical Measurements Aided by a Monoclonal Antibody

Electrochemical biosensing to move forward in cancer epigenetics and metastasis: A review

Early detection and effective treatment are crucial to reduce the physical, emotional, and financial pressure exerted by growing cancer burden on individuals, families, communities, and health systems. Currently, it is clear that the accurate analysis of emerging cancer epigenetic and metastatic-related biomarkers at different molecular levels is envisaged as an exceptional solution for early and reliable diagnosis and the improvement of therapy efficiency through personalized treatments. Within this field, electrochemical biosensing has demonstrated to be competitive over other emerging and currently used methodologies for the determination of these biomarkers accomplishing the premises of user-friendly, multiplexing ability, simplicity, reduced costs and decentralized analysis, demanded by clinical oncology, thus priming electrochemical biosensors to spark a diagnostic revolution for cancer prediction and eradication. This review article critically discusses the main characteristics, opportunities and versatility exhibited by electrochemical biosensing, through highlighting representative examples published during the last two years, for the reliable determination of these emerging biomarkers, with great diagnostic, predictive and prognostic potential. Special attention is paid on electrochemical affinity biosensors developed for the single or multiplexed determination of methylation events, non-coding RNAs, ctDNA features and metastasis-related protein biomarkers both in liquid and solid biopsies of cancer patients. The main challenges to which further work must be addressed and the impact of these advances should have in the clinical acceptance of these emerging biomarkers are also discussed which decisively will contribute to understand the molecular basis involved in the epigenetics and metastasis of cancer and to apply more efficient personalized therapies.

DNA methylation detection: recent developments in bisulfite free electrochemical and optical approaches

DNA methylation is one of the significant epigenetic modifications involved in mammalian development as well as in the initiation and progression of various diseases like cancer. Over the past few decades, an enormous amount of research has been carried out for the quantification of DNA methylation in the mammalian genome. Earlier, most of these methodologies used bisulfite treatment. However, the low conversion, false reading, longer assay time and complex chemical reaction are the common limitations of this method that hinder their application in routine clinical screening. Thus, as an alternative to bisulfite conversion-based DNA methylation detection, numerous bisulfite-free methods have been proposed. In this regard, electrochemical biosensors have gained much attention in recent years for being highly sensitive yet cost-effective, portable, and simple to operate. On the other hand, biosensors with optical readouts enable direct real time detection of biological molecules and are easily adaptable to multiplexing. Incorporation of electrochemical and optical readouts into bisulfite free DNA methylation analysis is paving the way for the translation of this important biomarker into standard patient care. In this review, we provide a critical overview of recent advances in the development of electrochemical and optical readout based bisulfite free DNA methylation assays.