Electrochemical and spectral behaviour of miR-34a-5p

Abstract

MicroRNAs are a family of small noncoding RNAs, regulating gene expression at the post-transcriptional level and playing a crucial role as potential biomarkers and targets for many types of cancer. Our attention was given to electrochemical and spectral studies of miR-34a-5p, related to head and neck and also prostate cancer. Voltammetric experiments on a hanging mercury drop electrode and circular dichroic spectroscopic experiments in buffer solutions were performed in the range of pH from 3 to 6 and from 3 to 8, respectively. The miRNA and its DNA sequential analogues (miDNA) provided interesting and significantly different results. A comparison of miRNA and both miDNA (U) and (T) showed the effect of substitution of ribose to deoxyribose, and structural diversity of nucleic acids was confirmed by both electrochemical and spectral methods. It emerged that a single substitution of ribose to deoxyribose (equivalent to miRNA -> miDNA (U)) leads on to the formation of a second guanine oxidation peak, and an RNA molecule in contrast to DNA analogues offers circular dichroic spectra of higher variability (indicating more terminal structures) and a more observable dependence on pH in the range of 3-6. [GRAPHICS] .