Dual detection system for cancer-associated point mutations assisted by a multiplexed LNA-based amperometric bioplatform coupled with rolling circle amplification

Abstract

DNA point mutation in a BRAF proto-oncogene, V600E, is considered an important prognostic and predictive biomarker in various types of cancer, such as melanoma or colorectal cancer. We report here a novel electrochemical (EC) bioplatform for the analysis of BRAF V600E mutation coupled with rolling circle amplification (RCA) and locked nucleic acid (LNA) capture probes. A dual detection system was implemented, whereby two padlock probes complementary to either wild-type (wt) BRAF gene or DNA with V600E mutation (mut) led to amplification of wt or mut variant, respectively. Hybridization with specific LNA capture probes then increased the assay specificity, while EC detection provided rapid measurement times. The bioplatform was applied to analyze BRAF V600E mutation of cancer cells and tumor tissues from patients with melanoma or colorectal cancer. This is the first RCA-based EC bioplatform for BRAF analysis in a dual format without using PCR or sophisticated instrumentation.