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Traditionally, biosensors are designed to detect one specific analyte. Nevertheless, disease progression is regulated in a highly interactive way by different classes of biomolecules like proteins and nucleic acids. Therefore, a more comprehensive analysis of biomarkers from a single sample is of utmost importance to further improve both, the accuracy of diagnosis as well as the therapeutic success. This review summarizes fundamentals like biorecognition and sensing strategies for the simultaneous detection of proteins and nucleic acids and discusses challenges related to multianalyte biosensor development. We present an overview of the current state of biosensors for the combined detection of protein and nucleic acid biomarkers associated with widespread diseases, among them cancer and infectious diseases. Furthermore, we outline the multianalyte analysis in the rapidly evolving field of single-cell multiomics, to stress its significance for the future discovery and validation of biomarkers. Finally, we provide a critical perspective on the performance and translation potential of multianalyte biosensors for medical diagnostics.
The mode of the antitumoral activity of multimutated oncolytic herpes simplex virus type 1 G207 has not been fully elucidated yet. Because the antitumoral activity of many drugs involves the inhibition of tumor blood vessel formation, we determined if G207 had an influence on angiogenesis. Monolayers of human umbilical vein endothelial cells and human dermal microvascular endothelial cells, but not human dermal fibroblasts, bronchial epithelial cells, and retinal glial cells, were highly sensitive to the replicative and cytotoxic effects of G207. Moreover, G207 infection caused the destruction of endothelial cell tubes in vitro. In the in vivo Matrigel plug assay in mice, G207 suppressed the formation of perfused vessels. Intratumoral treatment of established human rhabdomyosarcoma xenografts with G207 led to the destruction of tumor vessels and tumor regression. Ultrastructural investigations revealed the presence of viral particles in both tumor and endothelial cells of G207-treated xenografts, but not in adjacent normal tissues. These findings show that G207 may suppress tumor growth, in part, due to inhibition of angiogenesis.
The mode of the antitumoral activity of multimutated oncolytic herpes simplex virus type 1 G207 has not been fully elucidated yet. Because the antitumoral activity of many drugs involves the inhibition of tumor blood vessel formation, we determined if G207 had an influence on angiogenesis. Monolayers of human umbilical vein endothelial cells and human dermal microvascular endothelial cells, but not human dermal fibroblasts, bronchial epithelial cells, and retinal glial cells, were highly sensitive to the replicative and cytotoxic effects of G207. Moreover, G207 infection caused the destruction of endothelial cell tubes in vitro. In the in vivo Matrigel plug assay in mice, G207 suppressed the formation of perfused vessels. Intratumoral treatment of established human rhabdomyosarcoma xenografts with G207 led to the destruction of tumor vessels and tumor regression. Ultrastructural investigations revealed the presence of viral particles in both tumor and endothelial cells of G207-treated xenografts, but not in adjacent normal tissues. These findings show that G207 may suppress tumor growth, in part, due to inhibition of angiogenesis.
The antineoplastic alkaloid ellipticine is a prodrug, the pharmacological efficiency of which is dependent on its cytochrome P450 (CYP)- and/or peroxidase-mediated activation to species forming DNA adducts in target tissues. Here, we found that this compound is cytotoxic to human BHT-101, B-CPAP and 8505-C thyroid cancer cells and blocks one or more phases of cell cycle in these cancer cells. Ellipticine toxicity to the thyroid cancer cells corresponded to levels of DNA adducts generated by the CYP- and/or peroxidase-mediated ellipticine metabolites, 12-hydroxy- and 13-hydroxyellipticine, in these cells. Cultivation of all tested cells under hypoxic conditions (1 % oxygen) led to a decrease in ellipticine toxicity. Such a lower sensitivity of cells to ellipticine correlates with a decrease in the formation of ellipticine-derived DNA adducts in these cells. Using Western blotting, the expression of CYP1A1, 1B1, 3A4, thyroid peroxidase (TPO), cyclooxygenase-1 (COX-1) and cytochrome b5, the enzymes that catalyze, and/or influence ellipticine metabolism, was investigated in the cancer cells. Furthermore, the effects of ellipticine treatment on the expression levels of these proteins in thyroid cancer cells were also examined. The results indicate that the highest expression levels of cytochrome b5 together with CYP1A1 and 3A4 determine the highest DNA adduct formation and cytotoxicity of ellipticine in B-CPAP cells. They also demonstrate that formation of covalent DNA adducts by ellipticine is the predominant mechanism responsible for its cytotoxicity in studied cells.
Osteocalcin, Azan and Toluidine blue staining in fibrous dysplasia and ossifying fibroma of the jaws
(2018)
Background: Fibrous dysplasia (FD) and ossifying fibroma (OF) are fibro-osseous lesions (FOLs) having several overlaps that may make final diagnosis difficult by hematoxylin and eosin (H/E) alone.
Aim: This study seeks to detect any association between Azan and Toluidine blue staining as compared with osteocalcin in FD and OF diagnosis.
Methods:Forty formalin fixed paraffin embedded (FFPE) blocks of FD and OF were prepared for Azan, Toluidine blue and osteocalcin staining. Brown staining of calcified structures was considered as positive for osteocalcin. Scoring for Azan and Toluidine blue was evaluated based on intensity and localization. Level of agreement of original and revised diagnosis was determined.
Results: Six (40%) of 15 FD were corroborated by osteocalcin. Eight cases initially diagnosed as OF were revised to FD. There were 25 OF according to H/E, and 17 (68%) were validated by osteocalcin. Measure of agreement between histology and immunohistochemistry was 0.081; p = .608. Eleven (42.3%) OF expressed strong toluidine blue staining of the intervening fibrous connective tissue stroma while only 2 (14.2%) FD showed similar staining, this difference was statistically significant [p = .001].
Conclusions: Histomorphometric analysis with Toluidine blue may reduce diagnostic errors of OF and FD.
Endocannabinoids (ECs) are potent lipid mediators with high physiological relevance. They are involved in a wide variety of diseases like depression or multiple sclerosis and are closely connected to metabolic parameters in humans. Therefore, their suitability as a biomarker in different (patho-)physiological conditions is discussed intensively and predominantly investigated by analyzing systemic concentrations in easily accessible matrices like blood. Carefully designed pre-analytical sample handling is of major importance for high-quality data, but harmonization is not achieved yet. Whole blood is either processed to serum or plasma before the onset of analytical workflows and while knowledge about pre-analytical challenges in plasma handling is thorough they were not systematically investigated for serum.
Therefore, the ECs AEA and 2-AG, and closely related EC-like substances 1-AG, DHEA, and PEA were examined by LC-MS/MS in serum samples of nine healthy volunteers employing different pre-analytical sample handling protocols, including prolonged coagulation, and storage after centrifugation at room temperature (RT) or on ice. Furthermore, all analytes were also assessed in plasma samples obtained from the same individuals at the same time points to investigate the comparability between those two blood-based matrices regarding obtained concentrations and their 2-AG/1-AG ratio.
This study shows that ECs and EC-like substances in serum samples were significantly higher than in plasma and are especially prone to ex vivo changes during initial and prolonged storage for coagulation at RT. Storage on ice after centrifugation is less critical. However, storage at RT further increases 1-AG and 2-AG concentrations, while also lowering the already reduced 2-AG/1-AG ratio due to isomerization. Thus, avoidance of prolonged processing at RT can increase data quality if serum as the matrix of choice is unavoidable. However, serum preparation in itself is expected to initiate changes of physiological concentrations as standard precautionary measures like fast and cooled processing can only be utilized by using plasma, which should be the preferred matrix for analyses of ECs and EC-like substances.
The emerging disciplines of lipidomics and metabolomics show great potential for the discovery of diagnostic biomarkers, but appropriate pre-analytical sample-handling procedures are critical because several analytes are prone to ex vivo distortions during sample collection. To test how the intermediate storage temperature and storage period of plasma samples from K3EDTA whole-blood collection tubes affect analyte concentrations, we assessed samples from non-fasting healthy volunteers (n = 9) for a broad spectrum of metabolites, including lipids and lipid mediators, using a well-established LC-MS-based platform. We used a fold change-based approach as a relative measure of analyte stability to evaluate 489 analytes, employing a combination of targeted LC-MS/MS and LC-HRMS screening. The concentrations of many analytes were found to be reliable, often justifying less strict sample handling; however, certain analytes were unstable, supporting the need for meticulous processing. We make four data-driven recommendations for sample-handling protocols with varying degrees of stringency, based on the maximum number of analytes and the feasibility of routine clinical implementation. These protocols also enable the simple evaluation of biomarker candidates based on their analyte-specific vulnerability to ex vivo distortions. In summary, pre-analytical sample handling has a major effect on the suitability of certain metabolites as biomarkers, including several lipids and lipid mediators. Our sample-handling recommendations will increase the reliability and quality of samples when such metabolites are necessary for routine clinical diagnosis.
Small molecule biomarker discovery: Proposed workflow for LC-MS-based clinical research projects
(2023)
Mass spectrometry focusing on small endogenous molecules has become an integral part of biomarker discovery in the pursuit of an in-depth understanding of the pathophysiology of various diseases, ultimately enabling the application of personalized medicine. While LC-MS methods allow researchers to gather vast amounts of data from hundreds or thousands of samples, the successful execution of a study as part of clinical research also requires knowledge transfer with clinicians, involvement of data scientists, and interactions with various stakeholders.
The initial planning phase of a clinical research project involves specifying the scope and design, and engaging relevant experts from different fields. Enrolling subjects and designing trials rely largely on the overall objective of the study and epidemiological considerations, while proper pre-analytical sample handling has immediate implications on the quality of analytical data. Subsequent LC-MS measurements may be conducted in a targeted, semi-targeted, or non-targeted manner, resulting in datasets of varying size and accuracy. Data processing further enhances the quality of data and is a prerequisite for in-silico analysis. Nowadays, the evaluation of such complex datasets relies on a mix of classical statistics and machine learning applications, in combination with other tools, such as pathway analysis and gene set enrichment. Finally, results must be validated before biomarkers can be used as prognostic or diagnostic decision-making tools. Throughout the study, quality control measures should be employed to enhance the reliability of data and increase confidence in the results.
The aim of this graphical review is to provide an overview of the steps to be taken when conducting an LC-MS-based clinical research project to search for small molecule biomarkers.
Studies have demonstrated an increased risk of accidents and injuries in children, adolescents and adults with attention-deficit/hyperactivity disorder (ADHD). However, little is known about how accident risk may alter over the lifespan. Additionally, it would be important to know if the most common types of accidents and injuries differ in ADHD patients over different age groups. Furthermore, there is increasing evidence of an ameliorating effect of ADHD medication on accident risk. Lastly, the underlying risk factors and causal mechanisms behind increased accident risk remain unclear. We therefore conducted a systematic review focusing on the above described research questions. Our results suggested that accident/injury type and overall risk changes in ADHD patients over the lifespan. ADHD medication appeared to be similarly effective at reducing accident risk in all age groups. However, studies with direct comparisons of accident/injuries and effects of medication at different age groups or in old age are still missing. Finally, comorbidities associated with ADHD such as substance abuse appear to further increase the accident/injury risk.