Molecular Application of Aptamers in the Diagnosis and Treatment of Cancer and Communicable Diseases

Abstract

Cancer and infectious diseases such as Ebola, HIV, tuberculosis, Zika, hepatitis, measles and human schistosomiasis are serious global health hazards. The increasing annual morbidities and mortalities of these diseases have been blamed on drug resistance and the inefficacy of available diagnostic tools, particularly those which are immunologically-based. Antibody-based tools rely solely on antibody production for diagnosis and for this reason they are the major cause of diagnostic delays. Unfortunately, the control of these diseases depends on early detection and administration of effective treatment therefore any diagnostic delay is a huge challenge to curbing these diseases. Hence, there is a need for alternative diagnostic tools, discovery and development of novel therapeutic agents. Studies have demonstrated that aptamers could potentially offer one of the best solutions to these problems. Aptamers are short sequences of either DNA or RNA molecules, which are identified in vitro through a SELEX process. They are sensitive and bind specifically to target molecules. Their promising features suggest they may serve as better diagnostic agents and can be used as drug carriers for therapeutic purposes. In this article, we review the applications of aptamers in the theranostics of cancer and some infectious diseases.

Aptamers Targeting Membrane Proteins for Sensor and Diagnostic Applications

“…In terms of size, aptamers are small molecules, allowing penetration through the blood-brain barrier and versatility to bind small epitopes inaccessible to the relatively larger antibodies. Regarding the production of antibodies, the process is generally done in vivo and involves the suffering of animals, yields batch-to-batch variations, and requires expensive and time-consuming downstream processes [31,66,67]. On the other hand, the selection of aptamers is a quicker, easier, and cost-effective process, and their chemical synthesis is highly reproducible and yields aptamers with high purity [59,67,68].…”

Aptamers Enhance Oncolytic Viruses’ Antitumor Efficacy

“…Combining cyclic voltammogram characteristics made it possible to distinguish samples from lung cancer patients and healthy candidates. Several reviews focus on using aptamers to bind and visualize tumor cells and provide detailed descriptions of many successful examples [ 51 , 95 , 96 ].…”

Review—Aptamer-Based Electrochemical Sensing Strategies for Breast Cancer

“…This problem can be avoided by introducing a SELEX negative selection step with structurally similar molecules. 153 Consequently, series of aptamer sequence that is specific for breast cancer (having its 3′-and 5′-termini of nucleotides protected) have been optimized, and applied in diagnostics. See Table III below.…”