Self-Referencing Nanopipette Sensor for the Single-Cell Determination of Carcinoembryonic Antigen (CEA) Using Electrochemical Ligands

Antibody-Modified 2D MXene Nanosheet Probes for Selective, picolevel Detection of Cancer Biomarkers

Despite the widespread availability of immunohistochemical and other methodologies for screening and early detection of lung and breast cancer biomarkers, diagnosis of the early stage of cancers can be difficult and prone to error. The identification and validation of early biomarkers specific to lung and breast cancers, which would permit the development of more sensitive methods for detection of early disease onset, is urgently needed. In this paper, ultra-small and bright nanoprobes based on quantum dots (QDs) conjugated to single domain anti-HER2 (human epidermal growth factor receptor 2) antibodies (sdAbs) were applied for immunolabeling of breast and lung cancer cell lines, and their performance was compared to that of anti-HER2 monoclonal antibodies conjugated to conventional organic dyes Alexa Fluor 488 and Alexa Fluor 568. The sdAbs-QD conjugates achieved superior staining in a panel of lung cancer cell lines with differential HER2 expression. This shows their outstanding potential for the development of more sensitive assays for early detection of cancer biomarkers.

Blood-based early detection of breast cancer has recently gained novel momentum, as liquid biopsy diagnostics is a fast emerging field. In this study, we aimed to identify secreted proteins which are up-regulated both in tumour tissue and serum samples of breast cancer patients compared to normal tissue and sera. Based on two independent tissue cohorts (n = 75 and n = 229) and one serum cohort (n = 80) of human breast cancer and healthy serum samples, we characterised AGR3 as a novel potential biomarker both for breast cancer prognosis and early breast cancer detection from blood. AGR3 expression in breast tumours is significantly associated with oestrogen receptor α (P<0.001) and lower tumour grade (P<0.01). Interestingly, AGR3 protein expression correlates with unfavourable outcome in low (G1) and intermediate (G2) grade breast tumours (multivariate hazard ratio: 2.186, 95% CI: 1.008-4.740, P<0.05) indicating an independent prognostic impact. In sera analysed by ELISA technique, AGR3 protein concentration was significantly (P<0.001) elevated in samples from breast cancer patients (n = 40, mainly low stage tumours) compared to healthy controls (n = 40). To develop a suitable biomarker panel for early breast cancer detection, we measured AGR2 protein in human serum samples in parallel. The combined AGR3/AGR2 biomarker panel achieved a sensitivity of 64.5% and a specificity of 89.5% as shown by receiver operating characteristic (ROC) curve statistics. Thus our data clearly show the potential usability of AGR3 and AGR2 as biomarkers for blood-based early detection of human breast cancer.

Highly sensitive label-free electrochemical aptasensors based on photoresist derived carbon for cancer biomarker detection

Early cancer detection is crucial for improving patient outcomes. Molecular imaging biomarkers offer the potential for non-invasive, early-stage cancer diagnosis. To evaluate the effectiveness and accuracy of molecular imaging biomarkers for early cancer detection across various imaging modalities and cancer types. A comprehensive search of PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, and Scopus was performed, covering the period from January 2010 to December 2023. Eligibility criteria included original research articles published in English on molecular imaging biomarkers for early cancer detection in humans. The risk of bias for included studies was evaluated using the QUADAS-2 tool. The findings were synthesized through narrative synthesis, with quantitative analysis conducted where applicable. In total, 50 studies were included. Positron emission tomography (PET)-based biomarkers showed the highest sensitivity (mean: 89.5%, range: 82-96%) and specificity (mean: 91.2%, range: 85-100%). Novel tracers such as [68Ga]-PSMA for prostate cancer and [18F]-FES for breast cancer demonstrated promising outcomes. Optical imaging techniques showed high specificity in intraoperative settings. Molecular imaging biomarkers show significant potential for improving early cancer detection. Integration into clinical practice could lead to earlier interventions and improved outcomes. Further research is needed to address standardization and cost-effectiveness.

Early detection of cancer biomarkers provides clinically valuable information. While the conventional enzyme-linked immunosorbent assay (ELISA) has been routinely used for individual cancer markers, methods for simultaneous determination of multiple markers within a single sample are still in demand. Here, we present a novel oligonucleotide-linked immunosorbent assay (OLISA) with a multiplexing capability on the same microwell plate-based system as in ELISA. Employing a DNA oligonucleotide that is covalently conjugated to the detection antibody and a complementary RNA oligonucleotide which is appended with a fluorophore and a quencher, degradation of the RNA in the DNA-RNA duplex by RNase H is exploited for fluorescent signal generation. Iterative cycles of DNA-RNA duplexation and subsequent degradation of the RNA in the duplex by RNase H further lead to amplification of the detection signal in OLISA. Moreover, the use of antibody-oligonucleotide conjugates enables multiplexing of OLISA, which is successfully demonstrated by tethering DNA molecules to detection antibodies and by performing assays for three common cancer markers including α-fetoprotein, prostate-specific antigen, and carcinoembryonic antigen. With the simple procedure and reliable detection performance, the developed multiplex OLISA has a wide potential for use in analysis of a panel of biomarkers in clinical diagnostics.

Plasma Protein Profiling by Mass Spectrometry for Cancer Diagnosis: Opportunities and Limitations

Globally, cancer is one of the leading causes of death, with a significant proportion of cancer deaths due to delayed diagnosis. It is necessary to develop non-invasive, low-cost diagnostic techniques to ensure early and prompt cancer detection. Immunosensors have emerged as promising tools in the identification of cancer biomarkers for early cancer detection, as well as in the monitoring of cancer treatment. In this chapter, we describe immunosensors that have been fabricated for the detection of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), cancer antigen 125 (CA 125), cancer antigen 15-3 (CA 15-3), and prostate-specific antigen (PSA). We discuss current trends in cancer immunosensors for these specific cancer biomarkers, as well as their promises, challenges, and future directions.

10632 Background: Identification of cancer-specific oncoproteins is an effective approach to develop novel diagnostics and therapeutics. Methods: We have established a strategy as follows to identify new oncoproteins; i) To identify up-regulated genes in lung cancers using the cDNA microarray representing 27,648 genes and 120 lung cancers, ii) To verify the candidate genes for their low expression in 23 normal tissues by northern-blot analysis, iii) To validate the clinicopathological significance of their protein expression by tissue microarray covering 422 non-small cell lung cancers (NSCLCs), iv) To verify whether they are essential for the growth of cancer cells by siRNA assays, and v) To measure their serum protein levels by ELISA using three independent sets of samples. Results: We identified 25 oncoproteins and selected a cell surface protein, Nectin- 4. Nectin-4 protein positivity in tumors was associated with poor prognosis for NSCLCs (p < 0.0001; n = 422), and multivariate analysis confirmed its independent prognostic value (p < 0.0001). We established an ELISA for serum Nectin-4 and found that serum Nectin-4-positive cases was 88 (53.7%) of 164 NSCLCs, while 3 (2.3%) of 131 healthy volunteers were falsely diagnosed, which was superior to carcinoembryonic antigen (CEA) and cytokeratin 19- fragment (CYFRA21-1). The prognostic value of serum Nectin-4 was examined in two additional sets of serum samples. The median survival time of serum Nectin-4 positive patients with stage I NSCLC after curative surgery (n = 95) or stage IIIB-IV NSCLC treated with an identical protocol of the 1st-line chemotherapy (carboplatin and paclitaxel; n = 62) was shorter than those of patients with serum Nectin-4 negative (p = 0.0219 and p = 0.0269, respectively). In addition, suppression of Nectin-4 expression by siRNAs inhibited lung cancer cell growth, while expression of Nectin-4 increased the lamellipodia formation and the invasive ability of mammalian cells through activation of small GTPase Rac1. Conclusions: Nectin-4 is a biomarker for early cancer detection and for predicting the disease progression and a target for developing new drugs such as nucleic acid drugs, monoclonal antibodies, and cancer vaccines. No significant financial relationships to disclose.

The clinical management of patients with persistent or recurrent medullary thyroid carcinoma (MTC) is still under debate, because these patients either have a long-term survival, due to an indolent course of the disease, or develop rapidly progressing disease leading to death from distant metastases. At this moment, it cannot be predicted what will happen within most individual cases. Biomarkers, indicators which can be measured objectively, can be helpful in MTC diagnosis, molecular imaging and treatment, and/or identification of MTC progression. Several MTC biomarkers are already implemented in the daily management of MTC patients. More research is being aimed at the improvement of molecular imaging techniques and the development of molecular systemic therapies. Recent discoveries, like the prognostic value of plasma calcitonin and carcino-embryonic antigen doubling-time and the presence of somatic RET mutations in MTC tissue, may be useful tools in clinical decision making in the future. In this review, we provide an overview of different MTC biomarkers and their applications in the clinical management of MTC patients.

Signal amplification strategies in photoelectrochemical sensing of carcinoembryonic antigen

Cancer is the disease found to be the reason for the largest portion of deaths in the world annually and these mortality values are expected to increase in the future. Early detection of cancer biomarkers may help save millions of lives, particularly by implementing non-invasive and economical detection methods. In this review, we tabulated and quantitatively compared the data collected in 173 rows from 124 publications, which describe the clinical application of various methods in detection of cancer biomarkers. Those methods include mass spectrometry (MS), immunoassays (IAs), enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), surface-enhanced Raman spectroscopy (SERS), and Fourier-transform infrared spectroscopy (FTIR). We found that direct methods may have an advantage over indirect methods. Direct SERS reported in clinical applications can also achieve a higher area under the curve, higher sensitivity, and specificity than those parameters for ELISA, PCR, MS, and FTIR applications. Based on the average area under the curve (AUC) values reported in the last 6-7 years for each method, the performance of the analytical methods for the clinical cancer detection increases from IAs (0.76), ELISA (0.83), MS (0.87), and PCR (0.89) to FTIR (0.95) and SERS (0.97).

生物膜作为细胞内外环境之间的选择性屏障和沟通桥梁，在信号转导、能量传递和物质交换中发挥着重要作用。生物膜由脂质、蛋白质、糖类和其他成分组成，是细胞识别和通讯的枢纽。生物膜介导的特异性识别和结合，在疾病的早期诊断、药物靶向递送、环境监测等诸多方面具有潜在的应用价值。分子印迹聚合物（molecularly imprinted polymer，MIP）作为一种人工抗体，具有成本低、稳定性高和可重复使用等优点，已经成为特异性识别和结合生物膜上生物分子的有力工具。本文概述了针对生物膜上脂质、蛋白和糖分子印迹聚合物的最新进展，并深入探讨了MIP在生物医学领域中的应用。MIP作为高效的分子识别工具，能够实现对疾病生物标志物的高灵敏度和选择性检测；作为药物载体，MIP通过识别特定的疾病标志物，实现了精准的药物靶向递送；在细胞成像方面，MIP用于标记细胞表面的各类生物分子，丰富了成像的分子类型；此外，MIP还可构建传感器，用于检测生物样品中的目标分子。同时，文章也总结了当前MIP面临的主要挑战，包括合成步骤的复杂性、模板去除的不完全性、规模化生产的困难、性能的不足以及糖类模板制备的难题。为应对这些挑战，文中展望了使用虚拟模板或替代模板、整合新兴技术等可行性方案，并深入探讨了MIP应用的生物相容性问题以及应用转化的制约因素，旨在为实现MIP的实际转化应用提供合理的策略。

Extracellular K+ and adenosine triphosphate (ATP) levels are significantly elevated in the tumor microenvironment (TME) and can be used as biomarkers for early cancer detection and tumor localization. Most reported TME sensors only respond to single abnormal factors, resulting in a lack of accuracy and specificity for the detection of complex environments. Thus, precisely locating the TME remains challenging. In this work, we aimed to develop an intelligent DNA nanoassembly controlled by a "YES-AND" logic circuit using a bimolecular G-quadruplex (G4) and ATP aptamer as logical control units. As a proof of concept, in the presence of K+ (input 1) and ATP (input 2), the YES-AND Boolean operator returned a true value and the output was the fluorescence resonance energy transfer (FRET) signal, indicating high sensitivity and selectivity. After being anchored to living cell surfaces, this logic nanosensor imaged extracellular K+ and ATP present at abnormal levels in situ. Owing to diverse disease markers in the TME, this novel logic sensor might hold great promise for the targeted delivery of intelligent anticancer drugs and Boolean logic-controlled treatment.

Surface-enhanced Raman spectroscopy as effective tool for detection of sialic acid as cancer biomarker.