Simple Enzyme-Free Biosensor for Highly Sensitive and Selective Detection of miR-21 Based on Multiple Signal Amplification Strategy

Two-Dimensional Analysis Method for Highly Sensitive Detection of Dual MicroRNAs in Breast Cancer Cells

“…Therefore, multiple biomarker detection is often highly desirable. As an important class of biomarkers, microRNA is closely related to the diagnosis and treatment of cancers . During the growth and metastasis of cancers, multiple microRNAs are often expressed at an abnormal level. , Thus, in order to achieve the accurate diagnosis, two or more microRNA expression levels are usually used to determine the type of tumor and the pathological stage. − MicroRNA-21 and Let-7a are two accepted breast cancer biomarkers, and the simultaneous detection of them will help improve the accuracy and reliability of early breast cancer diagnosis .…”

“…As an important class of biomarkers, microRNA is closely related to the diagnosis and treatment of cancers. 1 During the growth and metastasis of cancers, multiple microRNAs are often expressed at an abnormal level. 2,3 Thus, in order to achieve the accurate diagnosis, two or more microRNA expression levels are usually used to determine the type of tumor and the pathological stage.…”

Intermolecular and Intramolecular Priming Co-directed Synergistic Multi-strand Displacement Amplification Empowers Ultrasensitive Determination of microRNAs

“…In particular, it becomes increasingly clear that the expression level of miRNAs shows close relationship to the initiation and metastasis of different types of tumors . For instance, increasing evidence shows that miRNA-21 mainly targets and regulates the tumor suppressor genes to affect the occurrence and development of tumors. , The overexpression of miRNA-21 has been identified in a variety of cancer cells, including prostate, breast, and lung cancers. , Owing to this characteristic, miRNA-21 has been considered as a very important biomarker for cancer diagnosis and prognosis and has received much attention for its less-invasive monitoring in saliva, blood, and sweat since miRNAs exist in all body fluids. − …”

“…9,10 The overexpression of miRNA-21 has been identified in a variety of cancer cells, including prostate, breast, and lung cancers. 11,12 Owing to this characteristic, miRNA-21 has been considered as a very important biomarker for cancer diagnosis and prognosis and has received much attention for its less-invasive monitoring in saliva, blood, and sweat since miRNAs exist in all body fluids. 13−17 At present, the most commonly used assay technique for miRNA analysis is still quantitative real-time polymerase chain reaction (qRT-PCR), which is carried out by using a miRNAspecific stem-loop primer for reverse transcription, followed by PCR amplification using miRNA-specific primers.…”

Single Nanoparticle Counting-Based Liquid Biopsy for Cancer Diagnosis

“…By detecting and analyzing circulating targets in body fluids (blood, urine, and saliva), it can provide comprehensive physiopathological information in real time in a noninvasive manner. − Compared to traditional tissue biopsy, liquid biopsy breaks through the constraints of time and space to screen for cancer in asymptomatic patients and allows for repeat blood collection, providing insight into the evolutionary dynamics of cancer . MicroRNAs (miRNAs), as a class of short noncoding RNAs with a length of approximately 18 to 25 nucleotides, are very promising biomarkers in liquid biopsy strategies. , MiRNAs have been demonstrated that their expression has a critical role in biological processes such as cancer initiation and tumor progression; moreover, they can remain stable in the blood. − However, many studies have revealed that a series of miRNAs can better distinguish cancer types and status than a single miRNA. − Moreover, it is very necessary to detect miRNAs along with the endogenous control to alleviate the biases in miRNA expression levels caused by individual physiological diversity and technical discrepancies, which results from sample collection and RNA extraction. , Currently, techniques including Northern blotting, real-time quantitative PCR (RT-qPCR), and microarray have been successfully applied for miRNA detection. Nevertheless, these techniques require elaborate designs to improve sensitivity, as well as their multiplexing ability that is impeded by complicated operation processes combined with inferior specificity. , Hence, it is greatly desired for further development of highly sensitive and multicomponent analytical methods for amplification-free sample analysis for rapid diagnosis.…”