Liquid Biopsy Markers Research Articles

Circulating Long Non-Coding RNAs LINC00324 and LOC100507053 as Potential Liquid Biopsy Markers for Esophageal Squamous Cell Carcinoma: A Pilot Study.

BackgroundDespite the availability of advanced technology to detect and treat esophageal squamous cell carcinoma (ESCC), the 5-year survival rate of ESCC patients is still meager. Recently, long non-coding RNAs (lncRNAs) have emerged as essential players in the diagnosis and prognosis of various cancers.ObjectiveThis pilot study focused on identifying circulating lncRNAs as liquid biopsy markers for the ESCC.MethodologyWe performed next-generation sequencing (NGS) to profile circulating lncRNAs in ESCC and healthy individuals’ blood samples. The expression of the top five upregulated and top five downregulated lncRNAs were validated through quantitative real-time PCR (qRT-PCR), including samples used for the NGS. Later, we explored the diagnostic/prognostic potential of lncRNAs and their impact on the clinicopathological parameters of patients. To unravel the molecular target and pathways of identified lncRNAs, we utilized various bioinformatics tools such as lncRnome, RAID v2.0, Starbase, miRDB, TargetScan, Gene Ontology, and KEGG pathways.ResultsThrough NGS profiling, we obtained 159 upregulated, 137 downregulated, and 188 neutral lncRNAs in ESCC blood samples compared to healthy individuals. Among dysregulated lncRNAs, we observed LINC00324 significantly upregulated (2.11-fold; p-value = 0.0032) and LOC100507053 significantly downregulated (2.22-fold; p-value = 0.0001) in ESCC patients. Furthermore, we found LINC00324 and LOC100507053 could discriminate ESCC cancer patients’ from non-cancer individuals with higher accuracy of Area Under the ROC Curve (AUC) = 0.627 and 0.668, respectively. The Kaplan-Meier and log-rank analysis revealed higher expression levels of LINC00324 and lower expression levels of LOC100507053 well correlated with the poor prognosis of ESCC patients with a Hazard ratio of LINC00324 = 2.48 (95% CI: 1.055 to 5.835) and Hazard ratio of LOC100507053 = 4.75 (95% CI: 2.098 to 10.76)]. Moreover, we also observed lncRNAs expression well correlated with the age (>50 years), gender (Female), alcohol, tobacco, and hot beverages consumers. Using bioinformatics tools, we saw miR-493-5p as the direct molecular target of LINC00324 and interacted with the MAPK signaling pathway in ESCC pathogenesis.ConclusionThis pilot study suggests that circulating LINC00324 and LOC100507053 can be used as a liquid biopsy marker of ESCC; however, multicentric studies are still warranted.

Clinical Validity of Circulating Tumor DNA as Prognostic and Predictive Marker for Personalized Colorectal Cancer Patient Management.

Simple SummaryCtDNA analysis is a promising tool in liquid biopsy for the detection of tumor recurrence and progression, and is increasingly adopted into clinical practice. Still, guidelines for the accurate clinical interpretation of ctDNA analysis results are largely lacking, especially for tumor mutant variants detected at very low frequencies. Here, we show that cutoff determination for the detection and quantification of low-frequency mutant variants enables the accurate prediction of residual disease, tumor recurrence and progression, even before clinical evidence. CtDNA analysis using these cutoffs outperformed cfDNA and CEA level measurements. With these findings, we highlight the need to thoroughly validate each liquid biopsy assay and define the assay-specific limit of blanks (LOB) and limit of quantifications (LOQ) of BRAF p.V600E and KRAS p.G12/p.G13 assays for clinical interpretation. Our approach enables accurate clinical interpretation to support clinical decision making.Circulating tumor DNA (ctDNA) is a promising liquid biopsy (LB) marker to support clinical decisions in precision medicine. For implementation into routine clinical practice, clinicians need precise ctDNA level cutoffs for reporting residual disease and monitoring tumor burden changes during therapy. We clinically validated the limit of blank (LOB) and the limit of quantification (LOQ) of assays for the clinically most relevant somatic variants BRAF p.V600E and KRAS p.G12/p.G13 in colorectal cancer (CRC) in a study cohort encompassing a total of 212 plasma samples. We prove that residual disease detection using the LOB as a clinically verified cutoff for ctDNA positivity is in concordance with clinical evidence of metastasis or recurrence. We further show that tumor burden changes during chemotherapy and the course of disease are correctly predicted using the LOQ as a cutoff for quantitative ctDNA changes. The high potential of LB using ctDNA for accurately predicting the course of disease was proven by direct comparison to the routinely used carcinoembryonic antigen (CEA) as well as the circulating free DNA (cfDNA) concentration. Our results show that LB using validated ctDNA assays outperforms CEA and cfDNA for residual disease detection and the prediction of tumor burden changes.

Current and future opportunities for liquid biopsy of circulating biomarkers to aid in early cancer detection

Early diagnosis of cancer can significantly improve treatment and survival outcomes. Imaging and tissue biopsy are the gold standard diagnostic approaches but are costly, invasive, and often unable to detect early-stage tumors. The past decade has marked an acceleration in the discovery and development of liquid biopsy tests for aiding in the detection of various types of tumor markers in non-tissue samples, such as blood. Liquid biopsy markers include circulating tumor cells, as well as tumor cell fragments, nucleic acids, and proteins. Liquid biopsy may be useful in screening patients considered to be at high risk of developing cancer, for refining diagnosis when combined with other test results, and for early detection of recurrence. Advances in big data analytics, informatics, and artificial intelligence will make it possible to combine patient history, clinical data, and liquid biopsy marker profiles to achieve more accurate and earlier diagnosis. In this review, we summarize the current use of liquid biopsy in cancer care, including the development of multi-analyte panels to improve diagnostic accuracy and detect several cancer types in a single assay. We highlight recent advances for potential future applications of liquid biopsy to aid in the diagnosis of early-stage lung cancer. We also discuss the opportunities and challenges of integrating liquid biopsy into current algorithms for cancer screening and diagnosis.

Early detection of lung cancer via biointerference-free, target microRNA-triggered core-satellite nanocomposites.

MicroRNAs (miRNAs) are emerging as essential liquid biopsy markers for early cancer detection. Currently, the clinical applications of miRNAs are lagging behind due to their high sequence similarity and rarity. Herein, we propose biointerference-free, target-triggered core-satellite nanocomposites for ultrasensitive surface-enhanced Raman spectroscopy (SERS) detection of lung cancer-related miRNA-21. Through the hybridization-based recognition effect, we observe an enormous SERS signal enhancement caused by miRNA-21-triggered assembly of core-satellite nanocomposites. This enables the sensitive detection of miRNA-21 down to the 0.1 fM level in a linear range of 10 fM to 1 nM. The use of a biointerference-free reporter further allows quantitative and direct detection of miRNA-21 from complex plasma samples, without RNA pre-extraction. As a proof of principle, we measure the level of plasma miRNA-21 in 20 lung cancer patients and 10 healthy participants. Significantly higher levels of miRNA-21 are determined in lung cancer patients than in healthy participants, with clear lower expression in stage I (n = 10) than in stage III-IV (n = 10) lung cancer patients. We, therefore, believe that this proposed strategy will have high clinical potential for sensitive quantification of miRNA markers in liquid biopsy samples and act as a complementary method for the early detection of lung cancer.

Plasma extracellular vesicle long RNA profiles in the diagnosis and prediction of treatment response for breast cancer

A large number RNAs are enriched and stable in extracellular vesicles (EVs), and they can reflect their tissue origins and are suitable as liquid biopsy markers for cancer diagnosis and treatment efficacy prediction. In this study, we used extracellular vesicle long RNA (exLR) sequencing to characterize the plasma-derived exLRs from 112 breast cancer patients, 19 benign patients and 41 healthy participants. The different exLRs profiling was found between the breast cancer and non-cancer groups. Thus, we constructed a breast cancer diagnostic signature which showed high accuracy with an area under the curve (AUC) of 0.960 in the training cohort and 0.900 in the validation cohort. The signature was able to identify early stage BC (I/II) with an AUC of 0.940. Integrating the signature with breast imaging could increase the diagnosis accuracy for breast cancer patients. Moreover, we enrolled 58 patients who received neoadjuvant treatment and identified an exLR (exMSMO1), which could distinguish pathological complete response (pCR) patients from non-pCR with an AUC of 0.790. Silencing MSMO1 could significantly enhance the sensitivity of MDA-MB-231 cells to paclitaxel and doxorubicin through modulating mTORC1 signaling pathway. This study demonstrated the value of exLR profiling to provide potential biomarkers for early detection and treatment efficacy prediction of breast cancer.

Capture, Detection, and Simultaneous Identification of Rare Circulating Tumor Cells Based on a Rhodamine 6G-Loaded Metal-Organic Framework.

Circulating tumor cells (CTCs) play a key role in the development of tumor metastasis. It will be a big step forward for CTC application as a reliable clinical liquid biopsy marker to be able to identify the captured CTCs while achieving a high capture efficiency within one analytical system. Herein, in this work, a stimuli-responsive and rhodamine 6G (Rho 6G)-entrapped fluorescent metal-organic framework (MOF) probe, named MOF-Rho 6G-DNA, was designed to capture, detect, and subsequently identify CTCs from blood samples of cancer patients. The probe was fabricated by modifying the epithelial cell adhesion molecule (EpCAM) hairpin DNA aptamer with Rho 6G enclosed and an Arm-DNA-attached UiO-66-NH2 MOF by sequence complementation. CTCs could be captured by the EpCAM hairpin DNA on the probe; as a result, Rho 6G loaded in the probe was released, and the number of CTCs was positively related to the concentration of released Rho 6G. An excellent correlation of fluorescence intensities with CTC numbers was obtained from 2 to 500 cells/mL. More importantly, the MOF-Rho 6G-DNA probe simultaneously realized rapid identification of the captured cells within 30 min by only relying on the residue Rho 6G in the MOF cavity. The captured target cells can be conveniently released from the probe using the complementary DNA sequence. These performance features of the probe were further verified by blood samples from patients of various types of tumor.

Detection of Atherosclerosis by Small RNA-Sequencing Analysis of Extracellular Vesicle Enriched Serum Samples.

Atherosclerosis can occur throughout the arterial vascular system and lead to various diseases. Early diagnosis of atherosclerotic processes and of individual disease patterns would be more likely to be successful if targeted therapies were available. For this, it is important to find reliable biomarkers that are easily accessible and with little inconvenience for patients. There are many cell culture, animal model or tissue studies that found biomarkers at the microRNA (miRNA) and mRNA level describing atherosclerotic processes. However, little is known about their potential as circulating and liquid biopsy markers in patients. In this study, we examined serum-derived miRNA – profiles from 129 patients and 28 volunteers to identify potential biomarkers. The patients had four different atherosclerotic manifestations: abdominal aneurysm (n = 35), coronary heart disease (n = 34), carotid artery stenosis (n = 24) and peripheral arterial disease (n = 36). The samples were processed with an extracellular vesicle enrichment protocol, total-RNA extraction and small RNA-sequencing were performed. A differential expression analysis was performed bioinformatically to find potentially regulated miRNA biomarkers. Resulting miRNA candidates served as a starting point for an overrepresentation analysis in which relevant target mRNAs were identified. The Gene Ontology database revealed relevant biological functions in relation to atherosclerotic processes. In patients, expression of specific miRNAs changed significantly compared to healthy volunteers; 27 differentially expressed miRNAs were identified. We were able to detect a group-specific miRNA fingerprint: miR-122-5p, miR-2110 and miR-483-5p for abdominal aortic aneurysm, miR-370-3p and miR-409-3p for coronary heart disease, miR-335-3p, miR-381-3p, miR493-5p and miR654-3p for carotid artery stenosis, miR-199a-5p, miR-215-5p, miR-3168, miR-582-3p and miR-769-5p for peripheral arterial disease. The results of the study show that some of the identified miRNAs have already been associated with atherosclerosis in previous studies. Overrepresentation analysis on this data detected biological processes that are clearly relevant for atherosclerosis, its development and progression showing the potential of these miRNAs as biomarker candidates. In a next step, the relevance of these findings on the mRNA level is to be investigated and substantiated.

Protein biomarkers in breast cancer-derived extracellular vesicles for use in liquid biopsies.

Breast cancer is the most common malignant disease in women worldwide. Early diagnosis and treatment can greatly improve the management of breast cancer. Liquid biopsies are becoming convenient detection methods for diagnosing and monitoring breast cancer due to their noninvasiveness and ability to provide real-time feedback. A range of liquid biopsy markers, including circulating tumor proteins, circulating tumor cells, and circulating tumor nucleic acids, have been implemented for breast cancer diagnosis and prognosis, with each having its own advantages and limitations. Circulating extracellular vesicles are messengers of intercellular communication that are packed with information from mother cells and are found in a wide variety of bodily fluids; thus, they are emerging as ideal candidates for liquid biopsy biomarkers. In this review, we summarize extracellular vesicle protein markers that can be potentially used for the early diagnosis and prognosis of breast cancer or determining its specific subtypes.

Clinical Applications of Circulating Tumor Cells and Circulating Tumor DNA as a Liquid Biopsy Marker in Colorectal Cancer.

Simple SummaryColorectal cancer is one of the most frequent malignant tumors worldwide and the spread of tumor cells through the blood circulation followed by the colonization of distant organs (“metastases”) is the main cause of cancer-related death. The blood is, therefore, an important fluid that can be explored for diagnostic purposes. Liquid biopsy is a new diagnostic concept defined as the analysis of circulating tumor cells or cellular products such as cell-free DNA in the blood or other body fluids of cancer patients. In this review, we summarize and discuss the latest findings using circulating tumor cells and cell-free DNA derived from tumor lesions in the blood of patients with colorectal cancer. Clinical applications include early detection of cancer, identification of patients with a high risk for disease progression after curative surgery, monitoring for disease progression in the context of cancer therapies, and discovery of mechanisms of resistance to therapy.Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. It is a heterogeneous tumor with a wide genomic instability, leading to tumor recurrence, distant metastasis, and therapy resistance. Therefore, adjunct non-invasive tools are urgently needed to help the current classical staging systems for more accurate prognostication and guiding personalized therapy. In recent decades, there has been an increasing interest in the diagnostic, prognostic, and predictive value of circulating cancer-derived material in CRC. Liquid biopsies provide direct non-invasive access to tumor material, which is shed into the circulation; this enables the analysis of circulating tumor cells (CTC) and genomic components such as circulating free DNA (cfDNA), which could provide the key for personalized therapy. Liquid biopsy (LB) allows for the identification of patients with a high risk for disease progression after curative surgery, as well as longitudinal monitoring for disease progression and therapy response. Here, we will review the most recent studies on CRC, demonstrating the clinical potential and utility of CTCs and ctDNA. We will discuss some of the advantages and limitations of LBs and the future perspectives in the field of CRC management.

Circulating Cellular Communication Network Factor 1 Protein as a Sensitive Liquid Biopsy Marker for Early Detection of Breast Cancer.

Despite recent progress in liquid biopsy technologies, early blood-based detection of breast cancer is still a challenge. We analyzed secretion of the protein cellular communication network factor 1 (CCN1, formerly cysteine-rich angiogenic inducer 61) in breast cancer cell lines by an enzyme-linked immunosorbent assay (ELISA). Soluble CCN1 in the plasma (2.5 µL) of 544 patients with breast cancer and 427 healthy controls was analyzed by ELISA. The breast cancer samples were acquired at the time of primary diagnosis prior to neoadjuvant therapy or surgery. A classifier was established on a training cohort of patients with breast cancer and age-adapted healthy controls and further validated on an independent cohort comprising breast cancer patients and healthy controls. Samples from patients with benign breast diseases were investigated as additional controls. Samples from patients with acute heart diseases (n = 127) were investigated as noncancer controls. The diagnostic accuracy was determined by receiver operating characteristic using the parameters area under the curve, sensitivity, and specificity. CCN1 was frequently secreted by breast cancer cell lines into the extracellular space. Subsequent analysis of clinical blood samples from patients with breast cancer and age-adjusted healthy controls revealed an overall specificity of 99.0% and sensitivity of 80.0% for cancer detection. Remarkably, 81.5% of small T1 cancers were already CCN1-positive, while CCN1 concentrations in patients with benign breast lesions were below the threshold for breast cancer detection. Circulating CCN1 is a potentially novel blood biomarker for the detection of breast cancer at the earliest invasive stage.

Clinical significance of golgi protein-73 as a diagnostic marker for Egyptian patients with colorectal cancer: Preliminary study.

BackgroundColorectal cancer is one of the most common cancers and the leading cause of cancer‐related death worldwide. Early diagnostic methods help in therapeutic success and higher survival rate. Golgi protein 73 (gp73) could help in diagnosis of colorectal cancer at an earlier stage.AimA case‐control study aimed to assess serum level of golgi protein 73 (gp73) as a liquid biopsy marker in Egyptian colorectal cancer patients.Methods and resultsIn the current study, ninty (90) patients were included and classified into three groups; thirty (30) patients with Colorectal cancer (CRC) as study group; 30 patients (20 patients with irritable bowel disease and 10 patients with rectal polyps) as pathological control and 30 healthy adult individuals as normal control. The diagnosis was based on the history, clinical, laboratory, endoscopic, and histological data. Golgiprotein 73 (GP73) was measured by ELISA immunoassay Kit. Serum GP73 level was higher in CRC patients than pathological control group and normal control group with high sensitivity and specificity p < .005.ConclusionGP73 alone or combined with Carcinoembryonic antigen (CEA) may be good diagnositic marker in CRC. However large studies are warranted on different stages of the disease to assess its diagnostic and prognositic value.

Analytical Technologies for Liquid Biopsy of Subcellular Materials.

Liquid biopsy markers, which can be secured from a simple blood draw or other biological samples, are used to manage a variety of diseases and even monitor for bacterial or viral infections. Although there are several different types of liquid biopsy markers, the subcellular ones, including cell-free DNA, microRNA, extracellular vesicles, and viral particles, are evolving in terms of their utility. A challenge with liquid biopsy markers is that they must be enriched from the biological sample prior to analysis because they are a vast minority in a mixed population, and potential interferences may be present in the sample matrix that can inhibit profiling the molecular cargo from the subcellular marker. In this article, we discuss existing and developing analytical enrichment platforms used to isolate subcellular liquid biopsy markers, and discuss their figures of merit such as recovery, throughput, and purity.

Structure and function of DEAH-box helicase 32 and its role in cancer.

DEAH-box helicase 32 (DHX32) is an RNA helicase with unique structural characteristics that is involved in numerous biological processes associated with RNA, including ribosome biosynthesis, transcription, mRNA splicing and translation. Increasing evidence suggests that abnormal DHX32 expression contributes to cancer initiation and development, due to dysregulated cell proliferation, differentiation, apoptosis and other processes. In the current review, the discovery, structure and function of DHX32, as well as the association between abnormal DHX32 expression and tumors are discussed. DHX32 expression is downregulated in acute lymphoblastic leukemia, but upregulated in solid tumors, including colorectal and breast cancer. Furthermore, DHX32 expression levels are associated with the pathological and clinical features of the cancer. Therefore, DHX32 may serve as a novel liquid biopsy marker for auxiliary diagnosis and prognosis screening, as well as a possible target for cancer therapy. The molecular mechanism underlying the contribution of DHX32 towards the initiation and development of cancer requires further investigation for the development of anticancer treatments based on manipulating DHX32 expression and function.

Liquid Biopsies in the Clinical Management of Germ Cell Tumor Patients: State-of-the-Art and Future Directions.

Liquid biopsies constitute a minimally invasive means of managing cancer patients, entailing early diagnosis, follow-up and prediction of response to therapy. Their use in the germ cell tumor field is invaluable since diagnostic tissue biopsies (which are invasive) are often not performed, and therefore only a presumptive diagnosis can be made, confirmed upon examination of the surgical specimen. Herein, we provide an overall review of the current liquid biopsy-based biomarkers of this disease, including the classical, routinely used serum tumor markers—the promising microRNAs rapidly approaching the introduction into clinical practice—but also cell-free DNA markers (including DNA methylation) and circulating tumor cells. Finally, and importantly, we also explore novel strategies and challenges for liquid biopsy markers and methodologies, providing a critical view of the future directions for liquid biopsy tests in this field, highlighting gaps and unanswered questions.

Detecting Resistance to Therapeutic ALK Inhibitors in Tumor Tissue and Liquid Biopsy Markers: An Update to a Clinical Routine Practice.

The survival of most patients with advanced stage non-small cell lung cancer is prolonged by several months when they are treated with first- and next-generation inhibitors targeting ALK rearrangements, but resistance inevitably emerges. Some of the mechanisms of resistance are sensitive to novel ALK inhibitors but after an initial tumor response, more or less long-term resistance sets in. Therefore, to adapt treatment it is necessary to repeat biological sampling over time to look for different mechanisms of resistance. To this aim it is essential to obtain liquid and/or tissue biopsies to detect therapeutic targets, in particular for the analysis of different genomic alterations. This review discusses the mechanisms of resistance to therapeutics targeting genomic alterations in ALK as well as the advantages and the limitations of liquid biopsies for their identification.

Liquid Biopsies in Ewing Sarcoma.

Liquid biopsies enable noninvasive therapy monitoring in patients with solid tumors. Specific serum markers such as proteins, hormones, or enzymes released from tumor cells or in response to tumor growth can be used for quantification of the tumor burden. However, only a fraction of pediatric tumors has none of these serum markers, but tumor-specific genetic alterations represent reliable alternatives. Here we describe a method for using genomic fusion sequences as liquid biopsy markers in Ewing sarcoma patients.

An exploratory proteomic study delineating the local and systemic immune-oncologic profile of urinary bladder cancer patients

Cancer of the urinary bladder (UBC) primarily derives from the urothelium, encompassing the inner surface of the bladder. Tumors infiltrating the detrusor muscle are categorized as muscle-invasive bladder cancer (MIBC) and constitutes 20-25% of all newly diagnosed UBC. These tumors are more likely to spread to peripheral organs and lymph nodes, compared to the more prevalent (75-80%) non-muscle invasive bladder cancer subtype (NMIBC). To this end, cystoscopy and urine cytology are the current standards for diagnosing and surveying UBC, which provides limited information regarding their immunological profile. We performed a targeted human protein biomarker analysis from collected plasma and urine from a well-categorized UBC patient cohort. In short, 92 immuno-oncology related proteins were investigated by a novel Proximity Extension Assay multiplex technology (Olink). The assayed proteins depicted a heterogenic immune profile. Neither PCA or unsupervised hierarchical clustering identified distinct groups associated with clinical features. However, a direct comparison between non-invasive and invasive cases resulted in 4 differentially expressed proteins (p<0.05). MIBC patients had lower urine levels of the TNF-receptor superfamily members CD27 and CD40, and a systemic increase of matrix metallopeptidase 7 (MMP7) and C-C motif chemokine ligand 23 (CCL23). We further developed and trained a random forest machine learning classifier on our plasma samples. It consistently ranked CCL23 and MMP7 as the most important markers for invasiveness. When extended to survival analysis, we moreover found MMP levels to best predict a dismal survival status with MMP12 being the highest ranked variable. A finding supported by MMP12 being the most significant protein in individual cox-regression survival analyses. This study highlights the heterogenic nature of the immunogenic landscape in UBC and its potential role in immunotherapy treatment responses. Our findings indicate that systemic MMP levels should be further explored as a potential liquid biopsy marker for patient stratification purposes. The role of MMPs in UBC may be linked to an invasive tumor characteristic, as shown by previous UBC studies where high levels of MMPs correlated to reduced overall survival.

Liquid Biomarkers for Pediatric Brain Tumors: Biological Features, Advantages and Perspectives.

Tumors of the central nervous system are the most frequent solid tumor type and the major cause for cancer-related mortality in children and adolescents. These tumors are biologically highly heterogeneous and comprise various different entities. Molecular diagnostics are already well-established for pediatric brain tumors and have facilitated a more accurate patient stratification. The availability of targeted, biomarker-driven therapies has increased the necessity of longitudinal monitoring of molecular alterations within tumors for precision medicine-guided therapy. Nevertheless, diagnosis is still primarily based on analyses of the primary tumor and follow-up is usually performed by imaging techniques which lack important information on tumor biology possibly changing the course of the disease. To overcome this shortage of longitudinal information, liquid biopsy has emerged as a promising diagnostic tool representing a less-invasive source of biomarkers for tumor monitoring and therapeutic decision making. Novel ultrasensitive methods for detection of allele variants, genetic alterations with low abundance, have been developed and are promising tools for establishing and integrating liquid biopsy techniques into clinical routine. Pediatric brain tumors harbor multiple molecular alterations with the potential to be used as liquid biomarkers. Consequently, studies have already investigated different types of biomarker in diverse entities of pediatric brain tumors. However, there are still certain pitfalls until liquid biomarkers can be unleashed and implemented into routine clinical care. Within this review, we summarize current knowledge on liquid biopsy markers and technologies in pediatric brain tumors, their advantages and drawbacks, as well as future potential biomarkers and perspectives with respect to clinical implementation in patient care.

Clinical utility of Epstein-Barr virus DNA and other liquid biopsy markers in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor ubiquitously associated with the Epstein‐Barr virus (EBV), which is highly prevalent in South China, Southeast Asia, and North Africa. Despite being a highly radio‐sensitive and treatable cancer, a majority of NPC patients are diagnosed in their advanced stage, and locoregional and distant relapses following definitive treatment contribute largely to cancer‐specific mortality among these patients. Given that EBV‐driven NPC is the predominant variant seen in endemic regions, various EBV detection methods have been developed and are utilized in screening, prognostication, and post‐treatment surveillance of NPC patients. While the Immunoglobulin A (IgA) serology assay is the most extensively studied EBV detection method, the detection of plasma EBV DNA released during replication or cellular apoptosis has shown superior outcomes in endemic population screening, prognostication, and detection of distant relapse. Furthermore, there is emerging evidence on the use of circulating tumor cells, microRNAs, DNA hypermethylation, and combination assays in various clinical scenarios. Herein, this paper provides a comprehensive overview of the relevant studies using various EBV detection techniques in the management of NPC. Specifically, the recent advances, clinical evidence, and challenges associated with the clinical application of EBV liquid biopsies in population screening, prognostication, and surveillance of NPC are presented.

Emerging role of miRNAs as liquid biopsy markers for prediction of glioblastoma multiforme prognosis.

Serum miRNAs (miRs) have gained consideration as encouraging molecular markers for cancer diagnosis and prediction of prognosis. The authors aimed to identify the exact role of miR-17-5p, miR-125b, and miR-221 among glioblastoma multiforme (GBM) patients before and after standard treatment, and correlate their expression with survival pattern. The study included 25 GBM patients and 20 healthy controls. Serum miR-17-5p, miR-125b, and miR-221 expression were analyzed before and after treatment using quantitative real-time polymerase chain reaction (qPCR). The diagnostic efficacy for the tested miRs was evaluated using the receiver operating characteristic (ROC) curve, and the relation of miRs expression versus clinical criteria for GBM was assessed. Patients' survival patterns were examined versus miRs expression levels. A significant difference was reported between miRs expression among the enrolled individuals. Both miR-17-5p and miR-221 reported significant elevations in GBM patients who: are above 60years old, underwent biopsy resection, have a non-frontal lesion, with tumor size above 5cm, and with performance status equals 2 according to the Eastern Cooperative Oncology Group (ECOG) Performance Status. With regard to miR-125b, a significant difference was detected according to surgery strategy, primary lesion of the tumor, and ECOG status. MiRs levels were significantly decreased for GBM patients after treatment. Survival patterns demonstrated an increase in miR-17-5p, miR-125b, and miR-221 in GBM patients with worse progression-free survival and among those with worse overall survival. Detection of serum miR-17-5p, miR-125b, and miR-221 aids in the prediction of prognosis and response to treatment strategy for GBM patients.