Circulating nucleic acids: An analysis of their occurrence in malignancies

Diagnosing and staging epithelial ovarian cancer by serum glycoproteomic profiling

BACKGROUND

There is a need for diagnostic tests for screening, triaging and staging of epithelial ovarian cancer (EOC). Glycoproteomics of blood samples has shown promise for biomarker discovery.

METHODS

We applied glycoproteomics to serum of people with EOC or benign pelvic masses and healthy controls. A total of 653 analytes were quantified and assessed in multivariable models, which were tested in an independent cohort. Additionally, we analyzed glycosylation patterns in serum markers and in tissues.

RESULTS

We identified a biomarker panel that distinguished benign lesions from EOC with sensitivity and specificity of 83.5% and 90.1% in the training set, and of 86.7 and 86.7% in the test set, respectively. ROC analysis demonstrated strong performance across a range of cutoffs. Fucosylated multi-antennary glycopeptide markers were higher in late-stage than in early-stage EOC. A comparable pattern was found in late-stage EOC tissues.

CONCLUSIONS

Blood glycopeptide biomarkers have the potential to distinguish benign from malignant pelvic masses, and early- from late-stage EOC. Glycosylation of circulating and tumor tissue proteins may be related. This study supports the hypothesis that blood glycoproteomic profiling can be used for EOC diagnosis and staging and it warrants further clinical evaluation.

Seminal cell-free DNA as a potential marker for in vitro fertility of Nellore bulls

PURPOSE

This study aimed to identify a marker for freezability and in vitro fertility of sperm samples before freezing.

METHODS

Semen was collected from nine Nelore bulls; half of the ejaculate was used for seminal plasma cell-free DNA (cfDNA) quantification, and the other half was cryopreserved. Evaluation of sperm movement using computer-assisted semen analysis and plasma membrane integrity and stability, acrosomal integrity, apoptosis, and mitochondrial potential using flow cytometry were performed on fresh and frozen/thawed semen at 0, 3, 6, and 12 h after thawing. Frozen/thawed sperm was also used for in vitro embryo production. cfDNA was extracted from each bull, and the total DNA and number of cell-free mitochondrial DNA (cfmtDNA) copies were quantified. Semen from each animal was used for IVF, and cleavage, blastocyst formation, and cell counts were evaluated.

RESULTS

Two groups were formed and compared based on the concentrations of cfDNA and cfmDNA present: low-cfDNA and high-cfDNA and low-cfmtDNA and high-cfmtDNA. Up to 12 h post-thawing, there were no differences between the groups in the majority of the sperm parameters evaluated. Cleavage, day 6 and 7 blastocyst rates, and the number of cells were higher in the high cfDNA group than in the low cfDNA group. Similar results were observed for cfmtDNA, except for the number of cells, which was similar between the groups.

CONCLUSION

The concentration of cfDNA and the relative number of copies of cfmtDNA in seminal plasma cannot predict the freezability of semen but can be used to predict in vitro embryo production.

Circulating Nucleic Acids in Colorectal Cancer: Diagnostic and Prognostic Value

Colorectal cancer (CRC) is the third most prevalent cancer in the world and the fourth leading cause of cancer-related mortality. DNA (cfDNA/ctDNA) and RNA (cfRNA/ctRNA) in the blood are promising noninvasive biomarkers for molecular profiling, screening, diagnosis, treatment management, and prognosis of CRC. Technological advancements that enable precise detection of both genetic and epigenetic abnormalities, even in minute quantities in circulation, can overcome some of these challenges. This review focuses on testing for circulating nucleic acids in the circulation as a noninvasive method for CRC detection, monitoring, detection of minimal residual disease, and patient management. In addition, the benefits and drawbacks of various diagnostic techniques and associated bioinformatics tools have been detailed.

Molecular tumour boards - current and future considerations for precision oncology

Over the past 15 years, rapid progress has been made in developmental therapeutics, especially regarding the use of matched targeted therapies against specific oncogenic molecular alterations across cancer types. Molecular tumour boards (MTBs) are panels of expert physicians, scientists, health-care providers and patient advocates who review and interpret molecular-profiling results for individual patients with cancer and match each patient to available therapies, which can include investigational drugs. Interpretation of the molecular alterations found in each patient is a complicated task that requires an understanding of their contextual functional effects and their correlations with sensitivity or resistance to specific treatments. The criteria for determining the actionability of molecular alterations and selecting matched treatments are constantly evolving. Therefore, MTBs have an increasingly necessary role in optimizing the allocation of biomarker-directed therapies and the implementation of precision oncology. Ultimately, increased MTB availability, accessibility and performance are likely to improve patient care. The challenges faced by MTBs are increasing, owing to the plethora of identifiable molecular alterations and immune markers in tumours of individual patients and their evolving clinical significance as more and more data on patient outcomes and results from clinical trials become available. Beyond next-generation sequencing, broader biomarker analyses can provide useful information. However, greater funding, resources and expertise are needed to ensure the sustainability of MTBs and expand their outreach to underserved populations. Harmonization between practice and policy will be required to optimally implement precision oncology. Herein, we discuss the evolving role of MTBs and current and future considerations for their use in precision oncology.

Liquid Biopsy in Head and Neck Cancer: Its Present State and Future Role in Africa

The rising mortality and morbidity rate of head and neck cancer (HNC) in Africa has been attributed to factors such as the poor state of health infrastructures, genetics, and late presentation resulting in the delayed diagnosis of these tumors. If well harnessed, emerging molecular and omics diagnostic technologies such as liquid biopsy can potentially play a major role in optimizing the management of HNC in Africa. However, to successfully apply liquid biopsy technology in the management of HNC in Africa, factors such as genetic, socioeconomic, environmental, and cultural acceptability of the technology must be given due consideration. This review outlines the role of circulating molecules such as tumor cells, tumor DNA, tumor RNA, proteins, and exosomes, in liquid biopsy technology for the management of HNC with a focus on studies conducted in Africa. The present state and the potential opportunities for the future use of liquid biopsy technology in the effective management of HNC in resource-limited settings such as Africa is further discussed.

MALAT1 in Liquid Biopsy: The Diagnostic and Prognostic Promise for Colorectal Cancer and Adenomas?

Introduction

The development of colorectal cancer (CRC) is a multistep process accompanied by the accumulation of mutations that start from specific precancerous lesion - colorectal adenomas (CA). CRC incidence and mortality can be reduced by the early identification of these neoplasm. Colonoscopy is the most widely used screening method for CRC identification. Nowadays, clinical research interest is shifting to the use of liquid biopsy that may help with the early diagnosis of CA and CRC. In our previous study, we identified long non-coding RNA MALAT1 gene amplification associated with the development of CA.

Methods

This study aimed to describe the potential of MALAT1 expression levels in the adenoma tissue of patients used in the previous study by real-time qPCR. Furthermore, we analysed the plasma samples of an independent group of patients with CA (n=97), CRC (n=101), and cancer-free individuals (CFI, n=48).

Results

There was no difference in the MALAT1 expression level between CA patients with or without MALAT1 amplification. However, the plasma MALAT1 expression levels were significantly upregulated in patients with CRC and CA compared to CFI (for both p<0.001). Moreover, a correlation between MALAT1 expression and histological types of adenomas was identified- high-CRC-risk adenomas also displayed the highest MALAT1 expression levels. Furthermore, in CRC patients, MALAT1 levels were associated with a response to therapy.

Conclusion

MALAT1 expression levels could serve as a promising circulating biomarker for early CA and CRC diagnosis, and even as a predictor of therapy response in CRC patients.

Circulating tumor nucleic acids: biology, release mechanisms, and clinical relevance

BACKGROUND

Despite advances in early detection and therapies, cancer is still one of the most common causes of death worldwide. Since each tumor is unique, there is a need to implement personalized care and develop robust tools for monitoring treatment response to assess drug efficacy and prevent disease relapse.

MAIN BODY

Recent developments in liquid biopsies have enabled real-time noninvasive monitoring of tumor burden through the detection of molecules shed by tumors in the blood. These molecules include circulating tumor nucleic acids (ctNAs), comprising cell-free DNA or RNA molecules passively and/or actively released from tumor cells. Often highlighted for their diagnostic, predictive, and prognostic potential, these biomarkers possess valuable information about tumor characteristics and evolution. While circulating tumor DNA (ctDNA) has been in the spotlight for the last decade, less is known about circulating tumor RNA (ctRNA). There are unanswered questions about why some tumors shed high amounts of ctNAs while others have undetectable levels. Also, there are gaps in our understanding of associations between tumor evolution and ctNA characteristics and shedding kinetics. In this review, we summarize current knowledge about ctNA biology and release mechanisms and put this information into the context of tumor evolution and clinical utility.

CONCLUSIONS

A deeper understanding of the biology of ctDNA and ctRNA may inform the use of liquid biopsies in personalized medicine to improve cancer patient outcomes.

Whole transcriptome profiling of liquid biopsies from tumour xenografted mouse models enables specific monitoring of tumour-derived extracellular RNA

While cell-free DNA (cfDNA) is widely being investigated, free circulating RNA (extracellular RNA, exRNA) has the potential to improve cancer therapy response monitoring and detection due to its dynamic nature. However, it remains unclear in which blood subcompartment tumour-derived exRNAs primarily reside. We developed a host-xenograft deconvolution framework, exRNAxeno, with mapping strategies to either a combined human-mouse reference genome or both species genomes in parallel, applicable to exRNA sequencing data from liquid biopsies of human xenograft mouse models. The tool enables to distinguish (human) tumoural RNA from (murine) host RNA, to specifically analyse tumour-derived exRNA. We applied the combined pipeline to total exRNA sequencing data from 95 blood-derived liquid biopsy samples from 30 mice, xenografted with 11 different tumours. Tumoural exRNA concentrations are not determined by plasma platelet levels, while host exRNA concentrations increase with platelet content. Furthermore, a large variability in exRNA abundance and transcript content across individual mice is observed. The tumoural gene detectability in plasma is largely correlated with the RNA expression levels in the tumour tissue or cell line. These findings unravel new aspects of tumour-derived exRNA biology in xenograft models and open new avenues to further investigate the role of exRNA in cancer.

Whole genome sequencing of low input circulating cell-free DNA obtained from normal human subjects

Cell-free DNA circulates in plasma at low levels as a normal by-product of cellular apoptosis. Multiple clinical pathologies, as well as environmental stressors can lead to increased circulating cell-free DNA (ccfDNA) levels. Plasma DNA studies frequently employ targeted amplicon deep sequencing platforms due to limited concentrations (ng/ml) of ccfDNA in the blood. Here, we report whole genome sequencing (WGS) and read distribution across chromosomes of ccfDNA extracted from two human plasma samples from normal, healthy subjects, representative of limited clinical samples at <1 ml. Amplification was sufficiently robust with ~90% of the reference genome (GRCh38.p2) exhibiting 10X coverage. Chromosome read coverage was uniform and directly proportional to the number of reads for each chromosome across both samples. Almost 99% of the identified genomic sequence variants were known annotated dbSNP variants in the hg38 reference genome. A high prevalence of C>T and T>C mutations was present along with a strong concordance of variants shared between the germline genome databases; gnomAD (81.1%) and the 1000 Genome Project (93.6%). This study demonstrates isolation and amplification procedures from low input ccfDNA samples that can detect sequence variants across the whole genome from amplified human plasma ccfDNA that can translate to multiple clinical research disciplines.

Utilizing Publicly Available Cancer Clinicogenomic Data on CBioPortal to Compare Epidermal Growth Factor Receptor Mutant and Wildtype Non-Small Cell Lung Cancer

Publicly available clinicogenomic data on platforms such as the cancer BioPortal (cBioPortal.org) allow for efficient analyses by researchers with little or no experience working with Big Data. cBioPortal.org also allows for appropriate statistical testing and downloadable images for easy dissemination of findings. In this study, the cBioPortal.org platform was tested and its utility demonstrated by comparing cases of non-small cell lung cancer (NSCLC) with and without epidermal growth factor receptor gene (EGFR) mutations. Patients with EGFR mutations were more likely to be female, of Asian ethnicity, never-smokers, and be diagnosed with lung adenocarcinoma. Metastasis to the pleura, pleural fluid, and liver was common in patients with EGFR mutant NSCLC. On the other hand, lymph node, brain, and adrenal gland metastases were more common in patients with other mutations. While the median overall survival was about the same in the two groups, progression-free survival was significantly shorter in the EGFR mutant group. The mutational landscape was significantly different in the two groups with EGFR mutant NSCLCs having a lower mutational burden. Differences in copy number alterations between the two groups were also noted. The descriptive data generated from this study such as age, gender, smoking history, and histological subtype recapitulate findings of other studies on EGFR mutant NSCLCs. Further prospective and/or preclinical studies are needed to confirm differences noted in this study. cBioPortal.com queries may be used to supplement clinical/pre-clinical studies or to generate novel hypotheses.

Rapid and ultrasensitive detection of circulating human papillomavirus E7 cell-free DNA as a cervical cancer biomarker

Circulating cell-free DNA (cfDNA) has attracted attention as a non-invasive biomarker for diagnosing and monitoring various cancers. Given that human papillomavirus (HPV) DNA integration and overexpression of E6/E7 oncogenes are pivotal events for carcinogenesis, we sought to determine if HPV E7 cfDNA could serve as a specific biomarker for cervical cancer detection. We applied droplet digital PCR (ddPCR) to quantify HPV16/18 E7 cfDNA from the serum of patients with cervical cancer, cervical intraepithelial neoplasia, and controls. HPV16/18 E7 cfDNA was highly specific for cervical cancer, displaying 30.77% sensitivity, 100% specificity, and an area under the curve of 0.65. Furthermore, we developed a sensitive isothermal detection of HPV16/18 E7 and the PIK3CA WT reference gene based on recombinase polymerase amplification combined with a lateral flow strip (RPA-LF). The assay took less than 30 min and the detection limit was 5-10 copies. RPA-LF exhibited 100% sensitivity and 88.24% specificity towards HPV16/18 E7 cfDNA in clinical samples. The agreement between RPA-LF and ddPCR was 83.33% (κ = 0.67) for HPV16 E7 and 100% (κ = 1.0) for HPV18 E7, indicating a good correlation between both tests. Therefore, we conclude that HPV E7 cfDNA represents a potential tumor marker with excellent specificity and moderate sensitivity for minimally invasive cervical cancer monitoring. Moreover, the RPA-LF assay provides an affordable, rapid, and ultrasensitive tool for detecting HPV cfDNA in resource-limited settings.

Putative Origins of Cell-Free DNA in Humans: A Review of Active and Passive Nucleic Acid Release Mechanisms

Through various pathways of cell death, degradation, and regulated extrusion, partial or complete genomes of various origins (e.g., host cells, fetal cells, and infiltrating viruses and microbes) are continuously shed into human body fluids in the form of segmented cell-free DNA (cfDNA) molecules. While the genetic complexity of total cfDNA is vast, the development of progressively efficient extraction, high-throughput sequencing, characterization via bioinformatics procedures, and detection have resulted in increasingly accurate partitioning and profiling of cfDNA subtypes. Not surprisingly, cfDNA analysis is emerging as a powerful clinical tool in many branches of medicine. In addition, the low invasiveness of longitudinal cfDNA sampling provides unprecedented access to study temporal genomic changes in a variety of contexts. However, the genetic diversity of cfDNA is also a great source of ambiguity and poses significant experimental and analytical challenges. For example, the cfDNA population in the bloodstream is heterogeneous and also fluctuates dynamically, differs between individuals, and exhibits numerous overlapping features despite often originating from different sources and processes. Therefore, a deeper understanding of the determining variables that impact the properties of cfDNA is crucial, however, thus far, is largely lacking. In this work we review recent and historical research on active vs. passive release mechanisms and estimate the significance and extent of their contribution to the composition of cfDNA.

High frequency of exon 20 S768I EGFR mutation detected in malignant pleural effusions: A poor prognosticator of NSCLC

BACKGROUND

Lung cancer is the cause of a fourth of all cancer-related deaths. About a third of all lung adenocarcinoma tumours harbour mutations on exons 18 to 21 of the epidermal growth factor receptor (EGFR) gene. Detection of these mutations allows for targeted therapies in the form of EGFR Tyrosine kinase inhibitors. Recently, "liquid biopsies" have emerged as an alternative to conventional tissue mutation detection.

AIM

In this pilot study, we attempted to optimize EGFR mutation detection from malignant pleural effusions (MPEs) as "liquid biopsies" when tissue biopsies were unavailable. Resulting mutations were then to be mapped on the EGFR gene and explored using cBioPortal, a public cancer genomic database.

METHODS AND RESULTS

We first attempted a direct sequencing approach and showed that single nucleotide variants (SNVs) were likely to be missed in MPEs. We then switched to and optimized an EGFR mutant-specific quantitative polymerase chain reaction-based assay. This assay was piloted on n = 10 pleural effusion samples (one non-malignant pleural effusion as a negative control). 5/9 (55.55%) samples harboured EGFR mutations with 2/9 (22.22%) being exon 19 deletions and 3/9 (33.33%) the S768I mutation. The frequency of the S768I SNV in our study was significantly higher than that observed in other studies (~0.2%). Utilizing cBioPortal data, we report that patients with S768I have a shorter median survival time (6 months vs 38 months), progression-free survival time (8 months vs 44 months) and lower tumor mutation count compared to patients with other EGFR mutations.

CONCLUSIONS

The shorter survival of patients with the S768I SNV predicts aggressive disease and poor prognosis as a result of this mutation. Studies in larger cohorts and/or animal models are necessary to confirm these findings.

Serum expression and diagnostic potential of long non-coding RNAs NEAT1 and TUG1 in viral hepatitis C and viral hepatitis C-associated hepatocellular carcinoma

BACKGROUND

The present study investigated the serum detectability and the diagnostic implications of long non-coding RNAs; nuclear enriched abundant transcript 1 (NEAT1) and taurine upregulated gene 1 (TUG1) in viral hepatitis C (HCV) and HCV-associated hepatocellular carcinoma (HCC).

METHODS

The study included twenty healthy controls, forty non-malignant HCV patients and forty HCV-associated HCC patients. The study assessed liver function tests, the antioxidant status, serum alpha fetoprotein, p53, NEAT1 and TUG1.

RESULTS

Diminished serum expression of NEAT1 and TUG1 was observed in HCV and HCV-associated HCC and was closely associated with deregulated liver function and elevated AFP levels. A model of NEAT1, TUG1 and AFP accurately differentiated between HCC patients and healthy controls with sensitivity greater than that of AFP alone. Additionally, the diagnostic performance of a model of TUG1, p53 and AFP was superior to that of each marker alone for predicting HCC in HCV patients.

CONCLUSION

Significant alterations in the serum expression of NEAT1 and TUG1 in HCV and HCV-associated HCC patients were recorded. We propose NEAT1 and TUG1 as non-invasive, cost-effective and complementary biomarkers that improve the diagnostic characteristics of AFP.

When Less Is More: Specific Capture and Analysis of Tumor Exosomes in Plasma Increases the Sensitivity of Liquid Biopsy for Comprehensive Detection of Multiple Androgen Receptor Phenotypes in Advanced Prostate Cancer Patients

We evaluated the advantages and the reliability of novel protocols for the enrichment of tumor extracellular vesicles (EVs), enabling a blood-based test for the noninvasive parallel profiling of multiple androgen receptor (AR) gene alterations. Three clinically relevant AR variants related to response/resistance to standard-of-care treatments (AR-V7 transcript, AR T878A point mutation and AR gene amplification) were evaluated by digital PCR in 15 samples from patients affected by Castration-Resistant Prostate Cancer (CRPC). Plasma was processed to obtain circulating RNA and DNA using protocols based on tumor EVs enrichment through immuno-affinity and peptide-affinity compared to generic extraction kits. Our results showed that immuno-affinity enrichment prior to RNA extraction clearly outperforms the generic isolation method in the detection of AR-V7, also allowing for a distinction between responder (R) and non-responder (NR) patients. The T878A mutation was detected, overall, in nine out of 15 samples and no approach alone was able to reveal mutations in all harboring samples, showing that the employed methods complement each other. AR amplification was detected in the majority of CRPC samples analysed using either cell-free DNA (cfDNA) or exosome isolation kits (80%). We demonstrated that selective isolation of a subset of circulating exosomes enriched for tumor origin, rather than analysis of total plasma exosomes, or total plasma nucleic acids, increases sensitivity and specificity for the detection of specific alterations.

2D Materials in Development of Electrochemical Point-of-Care Cancer Screening Devices

Effective cancer treatment requires early detection and monitoring the development progress in a simple and affordable manner. Point-of care (POC) screening can provide a portable and inexpensive tool for the end-users to conveniently operate test and screen their health conditions without the necessity of special skills. Electrochemical methods hold great potential for clinical analysis of variety of chemicals and substances as well as cancer biomarkers due to their low cost, high sensitivity, multiplex detection ability, and miniaturization aptitude. Advances in two-dimensional (2D) material-based electrochemical biosensors/sensors are accelerating the performance of conventional devices toward more practical approaches. Here, recent trends in the development of 2D material-based electrochemical biosensors/sensors, as the next generation of POC cancer screening tools, are summarized. Three cancer biomarker categories, including proteins, nucleic acids, and some small molecules, will be considered. Various 2D materials will be introduced and their biomedical applications and electrochemical properties will be given. The role of 2D materials in improving the performance of electrochemical sensing mechanisms as well as the pros and cons of current sensors as the prospective devices for POC screening will be emphasized. Finally, the future scopes of implementing 2D materials in electrochemical POC cancer diagnostics for the clinical translation will be discussed.

Identification of Actionable Genomic Alterations Using Circulating Cell-Free DNA

PURPOSE

Cell-free DNA (cfDNA) next-generation sequencing is a noninvasive approach for genomic testing. We report the frequency of identifying alterations and their clinical actionability in patients with advanced/metastatic cancer.

PATIENTS AND METHODS

Prospectively consented patients had cfDNA testing performed. Alterations were assessed for therapeutic implications.

RESULTS

We enrolled 575 patients with 37 tumor types. Of these patients, 438 (76.2%) had at least one alteration detected, and 205 (35.7%) had one or more alterations of high potential for clinical action. In diseases with 10 or more patients enrolled, 50% or more had at least one alteration deemed of high potential for clinical action. Trials were identified in 80% of patients (286 of 357) with any alteration and in 92% of patients (188 of 205) with one or more alterations of high potential for clinical action of whom 57.6% (118 of 205) had 6 or more months of follow-up available. Of these patients, 10% (12 of 118) had received genomically matched therapy through enrollment in clinical trials (n = 8), off-label drug use (n = 3), or standard of care (n = 1). Although 88.6% of all patients had a performance status of 0 or 1 upon enrollment, the primary reason for not acting on alterations was poor performance status at next treatment change (28.1%; 27 of 96).

CONCLUSION

cfDNA testing represents a readily accessible method for genomic testing and allows for detection of genomic alterations in most patients with advanced disease. Utility may be higher in patients interested in investigational therapeutics with adequate performance status. Additional study is needed to determine whether utility is enhanced by testing earlier in the treatment course.

The Prospect and Challenges to the Flow of Liquid Biopsy in Africa

Liquid biopsy technologies have the potential to transform cancer patient management as it offers non-invasive diagnosis and real-time monitoring of disease progression and treatment responses. The use of liquid biopsy for non-invasive cancer diagnosis can have pivotal importance for the African continent where access to medical infrastructures is limited, as it eliminates the need for surgical biopsies. To apply liquid biopsy technologies in the African setting, the influence of environmental and population genetic factors must be known. In this review, we discuss the use of circulating tumor cells, cell-free nucleic acids, extracellular vesicles, protein, and other biomolecules in liquid biopsy technology for cancer management with special focus on African studies. We discussed the prospect, barriers, and other aspects that pose challenges to the use of liquid biopsy in the African continent.

Survival analysis and functional annotation of long non-coding RNAs in lung adenocarcinoma

Long non-coding RNAs (lncRNAs) are a subclass of non-protein coding transcripts that are involved in several regulatory processes and are considered as potential biomarkers for almost all cancer types. This study aims to investigate the prognostic value of lncRNAs for lung adenocarcinoma (LUAD), the most prevalent subtype of lung cancer. To this end, the processed data of The Cancer Genome Atlas LUAD were retrieved from GEPIA and circlncRNAnet databases, matched with each other and integrated with the analysis results of a non-small cell lung cancer plasma RNA-Seq study. Then, the data were filtered in order to separate the differentially expressed lncRNAs that have a prognostic value for LUAD. Finally, the selected lncRNAs were functionally annotated using a bioinformatic and systems biology approach. Accordingly, we identified 19 lncRNAs as the novel LUAD prognostic lncRNAs. Also, based on our results, all 19 lncRNAs might be involved in lung cancer-related biological processes. Overall, we suggested several novel biomarkers and drug targets which could help early diagnosis, prognosis and treatment of LUAD patients.

Continuous biomarker monitoring by particle mobility sensing with single molecule resolution

Healthcare is in demand of technologies for real-time sensing in order to continuously guard the state of patients. Here we present biomarker-monitoring based on the sensing of particle mobility, a concept wherein particles are coupled to a substrate via a flexible molecular tether, with both the particles and substrate provided with affinity molecules for effectuating specific and reversible interactions. Single-molecular binding and unbinding events modulate the Brownian particle motion and the state changes are recorded using optical scattering microscopy. The technology is demonstrated with DNA and protein as model biomarkers, in buffer and in blood plasma, showing sensitivity to picomolar and nanomolar concentrations. The sensing principle is direct and self-contained, without consuming or producing any reactants. With its basis in reversible interactions and single-molecule resolution, we envisage that the presented technology will enable biosensors for continuous biomarker monitoring with high sensitivity, specificity, and accuracy.

Circulating cell-free high mobility group AT-hook 2 mRNA as a detection marker in the serum of colorectal cancer patients

BACKGROUND

Detection of circulating cell-free mRNA serves as noninvasive tools for cancer diagnosis. As an oncofetal protein, HMGA2 (high mobility group AT-hook 2) is upregulated in colorectal cancer (CRC) tissues. However, it is not clear whether the increased levels of circulating cell-free HMGA2 mRNA functions as potential biomarkers for improved diagnosis of CRC.

METHODS

To assess its clinical significance in diagnosis and prediction, we evaluated serum levels of circulating HMGA2 mRNA in CRC patients and in healthy controls. In this study, 83 CRC patients and 11 normal controls were enrolled in this study. We used real-time quantitative reverse transcription-PCR to evaluate the plasma mRNA levels of HMGA2 and analyze the correlation between their expression and clinicopathologic characteristics.

RESULTS

We found that the levels of HMGA2 mRNA were significantly higher in CRC patients compared with healthy volunteers. The patients with right-sided CRC, colon cancer, positive nerve infiltration, positive vascular invasion, negative microsatellite instability (MSI), and increasing in serum carbohydrate antigen (CA) 199 had higher levels of plasma HMGA2 mRNA. A strong positive correlation between circulating cell-free HMGA2 mRNA and CA199 level in serum was found in our study. Furthermore, statistical analysis revealed that levels of HMGA2 mRNA in plasma and in tumors were strictly correlated.

CONCLUSIONS

Collectively, our data suggested that cell-free HMGA2 mRNA in plasma might function as a novel diagnostic marker for CRC.

Autoantibodies: Opportunities for Early Cancer Detection

Cancer cells can induce an immunological response resulting in the production of tumor-associated (TA) autoantibodies. These serum immunobiomarkers have been detected for a range of cancers at an early stage before the development of clinical symptoms. Their measurement is minimally invasive and cost effective using established technologies. TA autoantibodies are present in a clinically significant number of individuals and could supplement current screening modalities to aid early diagnosis of high-risk populations and assist the clinical management of patients. Here we review their production, discovery, and validation as biomarkers for cancer and their current and future potential as clinical tools.