Application of aptamer-based biosensors in early diagnosis of gastric cancer

The advent of precision medicine has significantly enhanced our understanding of individual patient responses to medical treatments. This approach considers unique genetic, physiological, and molecular characteristics, leading to more tailored and effective healthcare strategies. Traditionally, tissue biopsy has been the cornerstone for disease diagnosis and understanding pathology. However, the development of less invasive methods, such as liquid biopsy, has marked a significant advancement in personalized medicine. Liquid biopsies detect disease biomarkers like circulating tumor cells (CTCs), microRNAs (miRNAs), proteins, and extracellular vesicles in bodily fluids, offering a promising alternative to conventional tissue biopsies.

Aptamers are synthetic single-stranded DNA or RNA sequences that form specific three-dimensional shapes, allowing them to bind selectively to various targets, including proteins, miRNAs, metal ions, and cells​(ERHM.2022.8(3).229.0012…)​. Compared to antibodies, aptamers offer several advantages: they are less expensive, more stable across different environmental conditions, and can be synthesized without the need for animal models. These features make aptamers a promising tool for detecting disease markers, particularly in cancer diagnostics.

The systematic evolution of ligands by exponential enrichment (SELEX) is a key technique developed in the early 1990s for selecting aptamers with high affinity for specific targets. The SELEX process involves several steps: preparing a large library of oligonucleotides, incubating them with a target, and repeatedly selecting and amplifying those with the highest binding affinity. This method has proven efficient in generating aptamers that can specifically bind to target molecules under various conditions.

Gastric cancer (GC) remains one of the deadliest cancers worldwide, particularly in Asia, where it is highly prevalent. Current screening methods, such as endoscopy, are invasive and not always effective in early detection. Aptamer-based biosensors offer a promising alternative for early GC diagnosis due to their high sensitivity and specificity. These biosensors can detect various biomarkers associated with GC, such as carcinoembryonic antigen (CEA) and CA125, which are crucial for early diagnosis and prognosis assessment.

Recent research underscores the versatility and effectiveness of aptamers in the context of GC. For example, studies have highlighted the potential of aptamers in identifying specific exosomes and other biomarkers in bodily fluids, which can serve as early indicators of GC. This capability is particularly beneficial given the often asymptomatic nature of early-stage GC, which makes timely diagnosis challenging.

Aptamer-coupled gold-decorated polymorphic carbon has been used to identify early GC exosomes in urine samples, achieving over 90% accuracy. This highlights the potential of aptamers in non-invasive GC screening. Various types of aptamers, such as those targeting human epidermal growth factor receptor 2 (HER2) and growth hormone-releasing hormone (GHRH), have shown promise in GC diagnostics and treatment.

Beyond detection, aptamers can be designed to deliver therapeutic agents directly to cancer cells, enhancing treatment efficacy while minimizing side effects. This dual functionality of aptamers—as both diagnostic and therapeutic tools—represents a significant leap forward in cancer treatment strategies.

The integration of aptamer-based biosensors in clinical practice could revolutionize GC screening and diagnosis. These biosensors are not only cost-effective but also offer high specificity and stability. Replacing antibody-based methods with aptamers could significantly reduce healthcare costs and improve early detection rates, ultimately enhancing patient outcomes. Future research should focus on optimizing the stability and binding efficiency of aptamers, developing multiplexed detection systems, and conducting large-scale clinical trials to validate the efficacy of aptamer-based diagnostics in real-world settings.

Aptamer-based biosensors represent a significant advancement in the early diagnosis of gastric cancer. Their unique properties make them an optimal alternative to traditional antibody-based detection systems. Continued research and development are essential to fully realize the potential of aptamers in clinical applications, potentially transforming the landscape of cancer diagnostics and personalized medicine.

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https://www.xiahepublishing.com/2472-0712/ERHM-2022-00125

The study was recently published in the Exploratory Research and Hypothesis in Medicine.

Exploratory Research and Hypothesis in Medicine (ERHM) publishes original exploratory research articles and state-of-the-art reviews that focus on novel findings and the most recent scientific advances that support new hypotheses in medicine. The journal accepts a wide range of topics, including innovative diagnostic and therapeutic modalities as well as insightful theories related to the practice of medicine. The exploratory research published in ERHM does not necessarily need to be comprehensive and conclusive, but the study design must be solid, the methodologies must be reliable, the results must be true, and the hypothesis must be rational and justifiable with evidence.

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