New Frontiers for the Early Diagnosis of Cancer: Screening miRNAs Through the Lateral Flow Assay Method

Abstract

MicroRNAs (miRNAs), which circulate in the serum and plasma, play a role in several biological processes, and their levels in body fluids are associated with the pathogenesis of various diseases, including different types of cancer. For this reason, miRNAs are considered promising candidates as biomarkers for diagnostic purposes, enabling the early detection of pathological onset and monitoring drug responses during therapy. However, current methods for miRNA quantification, such as northern blotting, isothermal amplification, RT-PCR, microarrays, and next-generation sequencing, are limited by their reliance on centralized laboratories, high costs, and the need for specialized personnel. Consequently, the development of sensitive, simple, and one-step analytical techniques for miRNA detection is highly desirable, particularly given the importance of early diagnosis and prompt treatment in cases of cancer. Lateral flow assays (LFAs) are among the most attractive point-of-care (POC) devices for healthcare applications. These systems allow for the rapid and straightforward detection of analytes using low-cost setups that are accessible to a wide audience. This review focuses on LFA-based methods for detecting and quantifying miRNAs associated with the diagnosis of various cancers, with particular emphasis on sensitivity enhancements achieved through the application of different labels and detection systems. Early, non-invasive detection of these diseases through the quantification of tailored biomarkers can significantly reduce mortality, improve survival rates, and lower treatment costs.

Keywords: biosensor; cancer; lateral flow assay; microRNA; point-of-care.

Figure 2

(A) Scheme of the LFA-based assay. (B) Readout based on DSN-mediated and AND logic gate. Reprinted with permission from Ref. [49]. Copyright 2023 American Chemical Society. (B) Scheme of the isothermal amplification-based LFA. (a) RCA-based isothermal amplification reaction for miRNA detection in blood samples (B: biotin; F: FAM fluorescent dye). (b) The amplified RCA product binds to antibody-modified GNPs, and the target miRNA can be visually identified. Reprinted with permission from Ref. [52]. (C) Scheme of the assay principle for MB-BSH LFA. Conjugated DNA complementary to the 3′ stem and ancillary sequence in the loop of MB compete with the 5′ stem for binding to the 3′ stem. The MBs switch their structures in the presence of the target. Reprinted with permission from Ref. [54].

Figure 3

(A) Scheme of AuPt NF-based LFA: (a) the configuration of the assay; (b) enhancement of colorimetric signal through addition of the chromogenic substrate. Reprinted with permission from Ref. [75]. (B) Scheme of the reaction for the detection of miRNA based on HRCA reaction. Reprinted with permission from Ref. [85].

Figure 4

(A) The schematic diagram and synthetic route of the multimode lateral flow assay (LFA) biosensor for microRNA detection are shown. Upon adding the analyte to the strip, Au-DTNB@Ag NPs quench the fluorescence through the FRET process, leading to detectable changes in the fluorescence signal. Simultaneously, the colorimetric and SERS signals are enhanced as the Au-DTNB@Ag NPs accumulate on the T-line. The flowcharts on both sides detail the synthetic pathways of the nanoparticles. Reprinted with permission from Ref. [104]. (B) Schematic representation of (a) the preparation and functionalization of Pd-Au nanoplates and chain hybridization for miRNA detection; (b) the components; and (c) the construction of a P-LFLNAB, illustrating the relationship between colorimetric and thermal signals and the concentration of Pd-Au nanoplates. Reprinted with permission from Ref. [108].

Figure 1

Schematic representation of advantages and open issues in coupling LFA-based methods with miRNA quantification applied to cancer diagnosis.