An electrochemical method for sensitive and rapid detection of FAM134B protein in colon cancer samples

Current advances in detecting genetic and epigenetic biomarkers of colorectal cancer

Colorectal carcinoma (CRC) is the third most common cancer in terms of diagnosis and the second in terms of mortality. Recent studies have shown that various proteins, extracellular vesicles (i.e., exosomes), specific genetic variants, gene transcripts, cell-free DNA (cfDNA), circulating tumor DNA (ctDNA), microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and altered epigenetic patterns, can be used to detect, and assess the prognosis of CRC. Over the last decade, a plethora of conventional methodologies (e.g., polymerase chain reaction [PCR], direct sequencing, enzyme-linked immunosorbent assay [ELISA], microarray, in situ hybridization) as well as advanced analytical methodologies (e.g., microfluidics, electrochemical biosensors, surface-enhanced Raman spectroscopy [SERS]) have been developed for analyzing genetic and epigenetic biomarkers using both optical and non-optical tools. Despite these methodologies, no gold standard detection method has yet been implemented that can analyze CRC with high specificity and sensitivity in an inexpensive, simple, and time-efficient manner. Moreover, until now, no study has critically reviewed the advantages and limitations of these methodologies. Here, an overview of the most used genetic and epigenetic biomarkers for CRC and their detection methods are discussed. Furthermore, a summary of the major biological, technical, and clinical challenges and advantages/limitations of existing techniques is also presented.

Pseudevernia furfuracea inhibits migration and invasion of colorectal carcinoma cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Pseudevernia furfuracea (L.) Zopf is common lichen species, traditionally used worldwide in treating various medical conditions, among which are intestinal issues and cancer. Most studies are focused mainly on cytotoxic potential of lichens, whilst their antimigratory and antiinvasive properties are often disregarded. Migration and invasion of cancer cells are pivotal processes in cancer metastasis, wherein cancer cells are able to migrate individually or in form of a coherent mass. One of successful strategies in anticancer treatments is targeting Wnt/β-catenin signal pathway, that is aberrantly activated in colorectal carcinoma, as well as lowering level of migratory/invasive markers.

AIM OF THE STUDY

Present study aimed to show antimigratory/invasive potential of Pseudevernia furfuracea methanol extract on HCT-116 and SW-480 colorectal carcinoma cell lines and to elucidate possible mechanism of its action.

MATERIALS AND METHODS

Collective cell migration was assessed by Wound healing assay and single cell migration in real time by RTCA method. Analysis of anti- and promigratory protein expression was performed using immunofluorescent staining. Additionally, gene expression of antimigratory/promigratory and invasive (E-cadherin, β-catenin, N-cadherin, Vimentin, Snail and MMP-9) markers were investigated by qRT-PCR method. Concentration of MMP-9 was determined colorimetrically by ELISA test.

RESULTS

P. furfuracea extract was able to suppress both collective and single cancer cell migration, by inhibiting expression of promigratory/invasive markers and possibly re-establishing cell-cell adhesions. The present study indicates at P. furfuracea as effective antimigratory treatment, and HCT-116 cells were proved to be a more sensitive cell line to applied treatment.

CONCLUSIONS

This lichen species is a promising candidate for application in treatment of cancer in order to prevent metastasis.

Platismatia glauca-Lichen species with suppressive properties on migration and invasiveness of two different colorectal carcinoma cell lines

Platismatia glauca is a popular lichen traditionally used as a spice and possesses significant anti-cancer potential, whose anti-migratory/anti-invasive properties were mostly disregarded. Migration/invasion of cancer cells is processed in cancer metastasis and targeting their markers is an important strategy in anti-cancer treatment. We examined the anti-migratory/anti-invasive properties of P. glauca extract on two colorectal carcinoma cell lines (HCT-116 and SW-480) and elucidated possible mechanisms underlying these properties. Cell migration was evaluated by wound healing and RTCA methods. Immunofluorescent assay was used for the analysis of protein, while qRT-PCR for gene expression of migratory/invasive markers. ELISA assay was applied for the determination of MMP-9 concentration. P. glauca extract inhibited the motility of tested cells, by reducing pro-migratory/pro-invasive markers and potentially retaining intercellular connections. Treatment showed cell-selective effects, and HCT-116 cells were more responsive. Our study presents important scientific novelty, thus these lichen properties should be furtherly examined regarding the amelioration of anti-cancer treatment. PRACTICAL APPLICATIONS: Based on the evidence we provided in the present study, we have demonstrated that lichen species Platismatia glauca possess important biological activity, which has not been sufficiently investigated so far. It is of great importance to explore its anti-cancer potential, not only from a cytotoxic point of view but especially anti-migratory and anti-invasive. Herein, we showed that this species expresses significant suppressive effects on migration and invasiveness of colorectal carcinoma cells. This tested lichen has the potential to be used as a natural complementary anti-cancer treatment, with special reference on the dose applied and type of carcinoma. Our study represents a significant novelty in the field of scientific investigation of lichens and natural products, and further detailed studies are needed on in vitro and in vivo model systems.

Acoustofluidic multimodal diagnostic system for Alzheimer's disease

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative brain disorder that affects tens of millions of older adults worldwide and has significant economic and societal impacts. Despite its prevalence and severity, early diagnosis of AD remains a considerable challenge. Here we report an integrated acoustofluidics-based diagnostic system (ADx), which combines triple functions of acoustics, microfluidics, and orthogonal biosensors for clinically accurate, sensitive, and rapid detection of AD biomarkers from human plasma. We design and fabricate a surface acoustic wave-based acoustofluidic separation device to isolate and purify AD biomarkers to increase the signal-to-noise ratio. Multimodal biosensors within the integrated ADx are fabricated by in-situ patterning of the ZnO nanorod array and deposition of Ag nanoparticles onto the ZnO nanorods for surface-enhanced Raman scattering (SERS) and electrochemical immunosensors. We obtain the label-free detections of SERS and electrochemical immunoassay of clinical plasma samples from AD patients and healthy controls with high sensitivity and specificity. We believe that this efficient integration provides promising solutions for the early diagnosis of AD.

Predicting Diagnostic Potential of Cathepsin in Epithelial Ovarian Cancer: A Design Validated by Computational, Biophysical and Electrochemical Data

Background: Epithelial ovarian cancer remains one of the leading variants of gynecological cancer with a high mortality rate. Feasibility and technical competence for screening and detection of epithelial ovarian cancer remain a major obstacle and the development of point of care diagnostics (POCD) may offer a simple solution for monitoring its progression. Cathepsins have been implicated as biomarkers for cancer progression and metastasis; being a protease, it has an inherent tendency to interact with Cystatin C, a cysteine protease inhibitor. This interaction was assessed for designing a POCD module. Methods: A combinatorial approach encompassing computational, biophysical and electron-transfer kinetics has been used to assess this protease-inhibitor interaction. Results: Calculations predicted two cathepsin candidates, Cathepsin K and Cathepsin L based on their binding energies and structural alignment and both predictions were confirmed experimentally. Differential pulse voltammetry was used to verify the potency of Cathepsin K and Cathepsin L interaction with Cystatin C and assess the selectivity and sensitivity of their electrochemical interactions. Electrochemical measurements indicated selectivity for both the ligands, but with increasing concentrations, there was a marked difference in the sensitivity of the detection. Conclusions: This work validated the utility of dry-lab integration in the wet-lab technique to generate leads for the design of electrochemical diagnostics for epithelial ovarian cancer.

Flex Printed Circuit Board Implemented Graphene-Based DNA Sensor for Detection of SARS-CoV-2

Since the COVID-19 outbreak was declared a pandemic by the World Health Organization (WHO) in March 2020, ongoing efforts have been made to develop sensitive diagnostic platforms. Detection of viral RNA provides the highest sensitivity and specificity for detection of early and asymptomatic infections. Thus, this work aimed at developing a label-free genosensor composed of graphene as a working electrode that could be embedded into a flex printed circuit board (FPCB) for the rapid, sensitive, amplification-free and label-free detection of SARS-CoV-2. To facilitate liquid handling and ease of use, the developed biosensor was embedded with a user-friendly reservoir chamber. As a proof-of-concept, detection of a synthetic DNA strand matching the sequence of ORF1ab was performed as a two-step strategy involving the immobilization of a biotinylated complementary sequence on a streptavidin-modified surface, followed by hybridization with the target sequence recorded by the differential pulse voltammetric (DPV) technique in the presence of a ferro/ferricyanide redox couple. The effective design of the sensing platform improved its selectivity and sensitivity and allowed DNA quantification ranging from 100 fg/mL to [Formula: see text]/mL. Combining the electrochemical technique with FPCB enabled rapid detection of the target sequence using a small volume of the sample (5-[Formula: see text]). We achieved a limit-of-detection of 100 fg/mL, whereas the predicted value was ~33 fg/mL, equivalent to approximately [Formula: see text] copies/mL and comparable to sensitivities provided by isothermal nucleic acid amplification tests. We believe that the developed approach proves the ability of an FPCB-implemented DNA sensor to act as a potentially simpler and more affordable diagnostic assay for viral infections in Point-Of-Care (POC) applications.

Graphene based electrochemical immunosensor for the ultra-sensitive label free detection of Alzheimer's beta amyloid peptides Aβ(1-42)

An immunosensor capable of high sensitivity detection of beta-amyloid peptides, shown to be a reliable biomarker for Alzheimer's disease, has been developed using screen printed graphene electrodes (SPGEs) modified with ultra-thin layers of polymerised 1,5-diaminonaphthalene (pDAN). Electropolymerization of 1,5-diaminonaphthalene (DAN) was performed to coat the graphene screen printed electrodes in a continuous polymer layer with controlled thickness. The surface characteristics of pristine graphene and polymer modified graphene electrodes were examined using Raman and X-ray photoelectron spectroscopy. The effects of polymer thickness on the electron transfer rates were investigated. An immunosensor for selective detection of beta amyloid peptides Aβ(1-42) was developed via biofunctionalization of the pDAN modified SPGE with the anti-beta amyloid antibody used as the peptide bioreceptor. The immunosensor has been used for specific detection of Aβ(1-42) with a linear range of 1 pg mL^-1 to 1000 pg mL^-1 and showed 1.4 pg mL^-1 and 4.25 pg mL^-1 detection and quantification limit, respectively. The biosensor was further validated for the analysis of spiked human plasma. The immunosensor enables rapid, accurate, precise, reproducible and highly sensitive detection of Aβ(1-42) using a low-cost SPGE platform, which opens the possibilities for diagnostic ex vivo applications and research-based real time studies.

Recent Advances in Electrochemical Sensors for the Detection of Biomolecules and Whole Cells

Electrochemical sensors are considered an auspicious tool to detect biomolecules (e.g., DNA, proteins, and lipids), which are valuable sources for the early diagnosis of diseases and disorders. Advances in electrochemical sensing platforms have enabled the development of a new type of biosensor, enabling label-free, non-destructive detection of viability, function, and the genetic signature of whole cells. Numerous studies have attempted to enhance both the sensitivity and selectivity of electrochemical sensors, which are the most critical parameters for assessing sensor performance. Various nanomaterials, including metal nanoparticles, carbon nanotubes, graphene and its derivatives, and metal oxide nanoparticles, have been used to improve the electrical conductivity and electrocatalytic properties of working electrodes, increasing sensor sensitivity. Further modifications have been implemented to advance sensor platform selectivity and biocompatibility using biomaterials such as antibodies, aptamers, extracellular matrix (ECM) proteins, and peptide composites. This paper summarizes recent electrochemical sensors designed to detect target biomolecules and animal cells (cancer cells and stem cells). We hope that this review will inspire researchers to increase their efforts to accelerate biosensor progress-enabling a prosperous future in regenerative medicine and the biomedical industry.

Virus Bioresistor (VBR) for Detection of Bladder Cancer Marker DJ-1 in Urine at 10 pM in One Minute

DJ-1, a 20.7 kDa protein, is overexpressed in people who have bladder cancer (BC). Its elevated concentration in urine allows it to serve as a marker for BC. However, no biosensor for the detection of DJ-1 has been demonstrated. Here, we describe a virus bioresistor (VBR) capable of detecting DJ-1 in urine at a concentration of 10 pM in 1 min. The VBR consists of a pair of millimeter-scale gold electrodes that measure the electrical impedance of an ultrathin (≈ 150-200 nm), two-layer polymeric channel. The top layer of this channel (90-105 nm in thickness) consists of an electrodeposited virus-PEDOT (PEDOT is poly(3,4-ethylenedioxythiophene)) composite containing embedded M13 virus particles that are engineered to recognize and bind to the target protein of interest, DJ-1. The bottom layer consists of spin-coated PEDOT-PSS (poly(styrenesulfonate)). Together, these two layers constitute a current divider. We demonstrate here that reducing the thickness of the bottom PEDOT-PSS layer increases its resistance and concentrates the resistance drop of the channel in the top virus-PEDOT layer, thereby increasing the sensitivity of the VBR and enabling the detection of DJ-1. Large signal amplitudes coupled with the inherent simplicity of the VBR sensor design result in high signal-to-noise (S/N > 100) and excellent sensor-to-sensor reproducibility characterized by coefficients of variation in the range of 3-7% across the DJ-1 binding curve down to a concentration of 30 pM, near the 10 pM limit of detection (LOD), encompassing four orders of magnitude in concentration.

Electrochemical Biosensors for Determination of Colorectal Tumor Biomarkers

The accurate determination of specific tumor markers associated with cancer with non-invasive or minimally invasive procedures is the most promising approach to improve the long-term survival of cancer patients and fight against the high incidence and mortality of this disease. Quantification of biomarkers at different stages of the disease can lead to an appropriate and instantaneous therapeutic action. In this context, the determination of biomarkers by electrochemical biosensors is at the forefront of cancer diagnosis research because of their unique features such as their versatility, fast response, accurate quantification, and amenability for multiplexing and miniaturization. In this review, after briefly discussing the relevant aspects and current challenges in the determination of colorectal tumor markers, it will critically summarize the development of electrochemical biosensors to date to this aim, highlighting the enormous potential of these devices to be incorporated into the clinical practice. Finally, it will focus on the remaining challenges and opportunities to bring electrochemical biosensors to the point-of-care testing.

Regulatory effect of hsa-miR-5590-3P on TGFβ signaling through targeting of TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 transcripts

Transforming growth factor-β (TGFβ) signaling acts as suppressor and inducer of tumor progression during the early and late stages of cancer, respectively. Some miRNAs have shown a regulatory effect on TGFβ signaling and here, we have used a combination of bioinformatics and experimental tools to show that hsa-miR-5590-3p is a regulator of multiple genes expression in the TGFβ signaling pathway. Consistent with the bioinformatics predictions, hsa-miR-5590-3p had a negative correlation of expression with TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 genes, detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Then, the dual luciferase assay supported the direct interaction between hsa-miR-5590-3p and TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4-3'UTR sequences. Consistently, the TGFβ-R1 protein level was reduced following the overexpression of hsa-miR-5590-3p, detected by Western analysis. Also, hsa-miR-5590-3p overexpression brought about the downregulation of TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 expression in HCT-116 cells, detected by RT-qPCR, followed by cell cycle arrest in the sub-G1 phase, detected by flow cytometry. RT-qPCR results indicated that hsa-miR-5590-3p is significantly downregulated in breast tumor tissues (late stage) compared to their normal pairs. Altogether, data introduces hsa-miR-5590-3p as a negative regulator of the TGFβ/SMAD signaling pathway which acts through downregulation of TGFβ-R1, TGFβ-R2, SMAD3 and SMAD4 transcripts. Therefore, it can be tested as a therapy target in cancers in which the TGFβ/SMAD pathway is deregulated.

Point-of-care sensors for the management of sepsis

Point-of-care sensors that enable the fast collection of information relevant to a patient's health state can facilitate improved health access, reduce healthcare costs and improve the quality of healthcare delivery. In the diagnosis of sepsis - defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection, and the leading cause of in-patient death and of hospital readmission in the United States - predicting which infections will lead to life-threatening organ dysfunction and developing specific anti-sepsis treatments remain challenging because of the significant heterogeneity of the host response. Yet the use of point-of-care devices could reduce the time from the onset of a patient's infection to the administration of appropriate therapeutics. In this Perspective, we describe the current state of point-of-care sensors for the diagnosis and monitoring of sepsis, and outline opportunities in the use of these devices to dramatically improve patient care.

Hsa-miR-5582-3P regulatory effect on TGFβ signaling through targeting of TGFβ-R1, TGFβ-R2, SMAD3, and SMAD4 transcripts

Transforming growth factor β (TGFβ) signaling pathway which is regulated by factors such as microRNAs (miRNAs) has pivotal roles in various cellular processes. Here, we intended to verify bioinformatics predicted regulatory effect of hsa-miR-5582-3P against TGFβ/SMAD signaling pathway components. Quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis indicated a negative correlation of expression between hsa-miR-5582-3P against TGFβ-R1, TGFβ-R2, SMAD3, and SMAD4 putative target genes in all of tested cell lines. Also, hsa-miR-5582-3P was significantly downregulated in glioma, breast, and ovarian tumor tissues compared with their normal pairs, detected by RT-qPCR. Then dual luciferase assay supported direct interaction between this miRNA and TGFβ-R1, TGFβ-R2, SMAD3, and SMAD4, 3' untranslated region sequences. Western blot analysis confirmed negative effect of hsa-miR-5582-3P overexpression on at least TGFβ-R1 expression. Consistently, hsa-miR-5582-3P overexpression brought about downregulation of TGFβ-R1, TGFβ-R2, SMAD3, and SMAD4 expression in HCT-116 cell line, followed by cell cycle arrest in sub-G1 phase, detected by flow cytometry. Altogether, our data suggest that hsa-miR-5582-3P reduces the TGFβ/SMAD signaling pathway through downregulation of TGFβ-R1, TGFβ-R2, SMAD3, and SMAD4 transcripts. These data introduce hsa-miR-5582-3P as a potential tumor suppressors-miR and a therapy candidate to be tested in cancers in which TGFβ/SMAD is deregulated.

Carbon Dots-AS1411 Aptamer Nanoconjugate for Ultrasensitive Spectrofluorometric Detection of Cancer Cells

In the present study, a sensitive and selective signal-on method for aptamer based spectrofluorometric detection of cancer cells is introduced. AS1411, a nucleolin aptamer, is wrapped around water-soluble carbon dots and used as a probe for the detection of several types of cancer cells. Nucleolin, is overexpressed on the surface of cancer cells. Mouse breast 4T1, human breast MCF7, and human cervical HeLa cancer cells were selected as target cells, while human foreskin fibroblast cells HFFF-PI6 served as control cells. For the sensitive and selective spectrofluorimetric detection of target cancer cells in the presence of control cells, the cells were incubated in carbon dots-aptamer solutions, the cell suspensions were subsequently centrifuged and the fluorescence intensities were measured as an analytical signal. The specific targeting of cancer cells by AS1411 aptamers causes the release of carbon dots and enhances the fluorescence intensity. A calibration curve with a dynamic range between 10–4500 4T1 cells and detectability of roughly 7 cells was obtained. In addition, no significant change in the signal was detected by modifying the amount of human foreskin fibroblast control cells. Our results demonstrate similar responses to human MCF7 breast and cervical HeLa cancer cells.

Label-free Electrochemical Detection of ATP Based on Amino-functionalized Metal-organic Framework

A sensitive, selective and recyclable electrochemical sensor is designed for ATP detection based on amino-functionalized metal-organic framework. The functional MOF as the sensor is constructed by one-step synthesis Ce-MOF and sequentially modified on the Au electrode and conjugated with the aptamer of ATP. The presence of target ATP leads to the conformational change of aptamer strands and strong electrochemical impedance. The electrochemical sensor can detect ATP down to 5.6 nM with the linear range of 10 nm to 1000 μM. The present study is the first report on the use of MOF as an electrochemical sensor for ATP at nM level. This strategy has been successfully applied in detection of ATP in serum of cancer patients, which reveals its potential application in clinical diagnosis.