Tumor Liquid Biopsy Research Articles

New insights into red blood cells in tumor precision diagnosis and treatment.

Red blood cells (RBCs), which function as material transporters in organisms, are rich in materials that are exchanged with metabolically active tumor cells. Recent studies have demonstrated that tumor cells can regulate biological changes in RBCs, including influencing differentiation, maturation, and morphology. RBCs play an important role in tumor development and immune regulation. Notably, the novel scientific finding that RBCs absorb fragments of tumor-carrying DNA overturns the conventional wisdom that RBCs do not contain nucleic acids. RBC membranes are excellent biomimetic materials with significant advantages in terms of their biocompatibility, non-immunogenicity, non-specific adsorption resistance, and biodegradability. Therefore, RBCs provide a new research perspective for the development of tumor liquid biopsies, molecular imaging, drug delivery, and other tumor precision diagnosis and treatment technologies.

Research progress of CTC, ctDNA, and EVs in cancer liquid biopsy

Circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vehicles (EVs) have received significant attention in recent times as emerging biomarkers and subjects of transformational studies. The three main branches of liquid biopsy have evolved from the three primary tumor liquid biopsy detection targets—CTC, ctDNA, and EVs—each with distinct benefits. CTCs are derived from circulating cancer cells from the original tumor or metastases and may display global features of the tumor. ctDNA has been extensively analyzed and has been used to aid in the diagnosis, treatment, and prognosis of neoplastic diseases. EVs contain tumor-derived material such as DNA, RNA, proteins, lipids, sugar structures, and metabolites. The three provide different detection contents but have strong complementarity to a certain extent. Even though they have already been employed in several clinical trials, the clinical utility of three biomarkers is still being studied, with promising initial findings. This review thoroughly overviews established and emerging technologies for the isolation, characterization, and content detection of CTC, ctDNA, and EVs. Also discussed were the most recent developments in the study of potential liquid biopsy biomarkers for cancer diagnosis, therapeutic monitoring, and prognosis prediction. These included CTC, ctDNA, and EVs. Finally, the potential and challenges of employing liquid biopsy based on CTC, ctDNA, and EVs for precision medicine were evaluated.

DNA nanotechnology in tumor liquid biopsy: enrichment and determination of circulating biomarkers (1/2024)

DNA nanotechnology in tumor liquid biopsy: enrichment and determination of circulating biomarkers (1/2024)

DNA nanotechnology in tumor liquid biopsy: Enrichment and determination of circulating biomarkers

AbstractMonitoring tumor biomarkers in a non‐invasive manner for tumor diagnosis has attracted increasing attention. Liquid biopsy mainly includes three types of biomarkers: circulating tumor cells, extracellular vesicles, and circulating nucleic acids. These biomarkers released by tumor cells can travel to other parts of the circulation system. The analysis of circulating tumor markers in the circulation enables early tumor diagnosis, progression evolution, and treatment monitoring, which are important for individualized clinical decisions. In this study, we summarize different DNA nanotechnology strategies that can be used to capture, amplify, and measure circulating biomarkers and discuss the current challenges and outlook.

CRISPR/dCas9-Mediated Specific Molecular Assembly Facilitates Genotyping of Mutant Circulating Tumor DNA.

Breakthroughs in circulating tumor DNA (ctDNA) analysis are critical in tumor liquid biopsies but remain a technical challenge due to the double-stranded structure, extremely low abundance, and short half-life of ctDNA. Here, we report an electrochemical CRISPR/dCas9 sensor (E-dCas9) for sensitive and specific detection of ctDNA at a single-nucleotide resolution. The E-dCas9 design harnesses the specific capture and unzipping of target ctDNA by dCas9 to introduce a complementary reporter probe for specific molecular assembly and signal amplification. By efficient homogeneous assembly and interfacial click reaction, the assay demonstrates superior sensitivity (up to 2.86 fM) in detecting single-base mutant ctDNA and a broad dynamic range spanning 6 orders of magnitude. The sensor is also capable of measuring 10 fg/μL of a mutated target in excess of wild-type ones (1 ng/μL), equivalent to probing 0.001% of the mutation relative to the wild type. In addition, our sensor can monitor the dynamic expression of cellular genomic DNA and allows accurate analysis of blood samples from patients with nonsmall cell lung cancer, suggesting the potential of E-dCas9 as a promising tool in ctDNA-based cancer diagnosis.

Hybrid chain reaction and selective recognition-based homogeneous dual-fluorescence analysis of circulating tumor cells in clinical ovarian cancer samples

BackgroundOncological analysis is important in tumor diagnosis. We constructed a dual-fluorescence and binary visual analysis system for circulating tumor cells (CTCs) using the folate receptor as a biomarker, combined with hybridization chain reaction and nanomaterial amplification. This strategy integrates terminal protection, selective recognition properties of N-methyl mesoporphyrin IX and CdTe quantum dots for Cu2+ and double-stranded templated copper nanoparticles, and inkjet printing technology. ResultsIn fluorescence mode, folate receptor and A2780 ovarian cancer cells were specifically detected with a limit of detection of 0.1 fg mL−1, and 10 cells mL−1 were observed. The detection limits of both the color and distance reading modes were comparable to those obtained in fluorescence mode. The applicability of the method for quantifying CTCs was validated using 27 (6 negative and 21 positive) clinical ovarian cancer samples; the results agreed with those of both the clinical folate receptor-polymerase chain reaction kit and radiological and pathological results. SignificanceThis dual-fluorescence and binary visual CTCs detection method provides multiple options for clinical tumor liquid biopsy.

Success of Liquid Tumor Biopsy in Men with Metastatic Prostate Cancer According to Self-Identified Race.

Liquid biopsy using cell-free DNA (cfDNA) is increasingly used to identify somatic prostate cancer (PrCa) alterations when tissue biopsy of a metastatic lesion is infeasible or impractical. High-risk somatic alterations identified by cfDNA have been recently shown to predict the benefit of metastasis-directed therapy with stereotactic body radiation therapy in PrCa. However, given the older age of PrCa patients, liquid biopsy is often contaminated with alterations related to clonal hematopoiesis of indeterminate potential (CHIP), generating uncertainty in the clinical utility of the results. Given the higher incidence and aggressiveness of metastatic PrCa in Black men, we sought to determine if the success of cfDNA testing varied by race in a large and diverse cohort of United States Veterans with metastatic PrCa, hypothesizing that race would not influence the success of cfDNA testing. Veterans with metastatic PrCa underwent next-generation sequencing of cfDNA biopsy specimens through the VA National Precision Oncology Program from February 2019 to November 2022. Successful identification of PrCa with cfDNA testing was defined as the identification of an alteration in one or more PrCa-related related genes in the gene panel tested (AR, CDK12, SPOP, MED12, CCND1, BRAF, AKT1, TMPRSS2, ERG, ETV1, and ETV4). Univariate logistic regression was employed to explore the association between patient self-identified race, as well as other patient and disease-specific factors at the time of cfDNA biopsy, with the likelihood of yielding a successful cfDNA biopsy result. A total of 2066 cfDNA tests from 1985 Veterans were related to a diagnosis of PrCa, passed quality control measures, and were linkable to patient-level demographics. Median age at testing was 74, median PSA at testing was 22.7, median PSA doubling time (PSADT) was 3.6 months, and median Gleason score was 8. 57% of Veterans self-identified as White, 33% as Black, and 10% as Other. Eight hundred fourteen (39%) tests were deemed successful by finding a PrCa related gene alteration. Among successful tests, the most frequently encountered alterations were AR alterations in 60.4% White men and 33.9% Black men (p = 0.72), followed by TMPRSS2 alterations in 70.3% White men and 22.0% Black men (p<0.001). Despite a lower rate of PrCa-specific alterations in Black men, on univariate analysis, Veteran self-identified race was not associated with successful cfDNA testing (OR 0.95, 95% CI 0.78-1.14, p = 0.6), whereas PSA in quintiles 2-4, PSADT <12 months, and unit increase in Gleason score were associated with successful cfDNA testing (p<0.01 for all). Successful cfDNA biopsy in metastatic PrCa is associated with PSA and PSADT, but not related to patient self-identified race. In appropriate clinical scenarios, patients who self-identify as Black or White are equally likely to have PrCa-specific alterations detected on cfDNA testing when evaluating metastatic PrCa patients for local and systemic therapies.

Identification of combinatorial miRNA panels derived from extracellular vesicles as biomarkers for esophageal squamous cell carcinoma.

MicroRNAs (miRNAs) are relatively stable in blood, emerging as one of the most promising biomarkers in tumor liquid biopsy. Both total and extracellular vesicles (EVs) encapsulated miRNA have been studied for prognostic potential in a variety of cancers. Here, we systematically compared and verified the total and vesicle-derived miRNA expression profiles from plasma samples in healthy controls and patients with esophageal squamous cell carcinoma (ESCC). In the present study, four miRNA species miR-636, miR-7641, miR-28-3p, and miR-1246 that were differentially expressed in ESCC patients were chosen for further study. We first elucidated their essential function in ESCC progression and further explored their preliminary mechanism by identifying target proteins and involving signal pathways. Subsequently, the prognostic miRNA panels including miR-636, miR-7641, miR-1246, and miR-28-3p for ESCC diagnosis were constructed and validated using different cohort. Our results showed that the panel including the above four miRNAs derived from plasma EVs was most effective in distinguishing tumor patients from normal subjects, while integrated plasma EVs-derived miR-1246, miR-28-3p and total plasma miRNAs miR-636, miR-7641 showed the best capability in predicting lymph node metastasis. In summary, our studies revealed that plasma EVs-derived miRNAs could be emerged as promising biomarkers for ESCC diagnosis.

Abstract PO-095: TGF-β carrying exosomes in plasma of HNSCC as potential biomarkers of disease progression in patients with HNSCC

Abstract Background: The contribution of TGFβ+ exosomes, now referred to as small extracellular vesicles (sEV), in plasma of cancer patients to disease progression has been unclear. Levels of TGFβ in plasma often do not correlate with clinicopathological data, and TGFβ can exert dual (yin-yang) effects as a tumor promoter and a tumor inhibitor. We evaluated the potential of tumor-derived sEV dubbed TEX to serve as liquid tumor biopsy in patients with HNSCC. Methods: Plasma was obtained from 3 different cohorts of patients with HNSCC (n=97) and HDs (n=22). Clinicopathology/demographic data were available for all patients. sEV were isolated by ultrafiltration/size exclusion chromatography (SEC) from plasma or cell supernatants. TGF-β levels in plasma were assessed by ELISA; TGF-β expression in tissues was studied by IHC and immunoblots; immunoblots, flow cytometry and LC-MS/MS were used to measure TGF-β in isolated sEV. TGFB1 gene expression was analyzed using the TCGA Head and Neck Cancer database (n=520 cases and 44 NC). TGF-β signaling and activity of EVs were quantified in the reporter cell (MFB-F11) proliferation assays. Changes of TGF-β expression levels in plasma, tissues and sEV during carcinogenesis were studied in an orthotopic 4NQO mouse model. Results: Using the TCGA we found high expression levels of the vesiculation genes regulating EV production/release and of the TGFB1 gene expression in HNSCC. In the 4NQO orthotopic model of OSCC, cancer progression correlated with TGF-β accumulations in tumor tissues and a significant increase in circulating TGF-β+ sEV. In HNSCC patients, TGF-β levels and activity in plasma and TGF-β expression levels in tumor tissues were significantly elevated relative to controls but did not correlate with clinicopathologic data, tumor burden or disease outcome. TEX produced by HNSCC cell lines carried TGF-β and initiated Smad3 signaling in reporter cells. TGF-β inhibitors blocked this signaling. High TGFβ abundance in sEV was confirmed by proteomics and by RNAseq using the TCGA data base. Levels of TGF-β expression in sEV, sEV numbers and TGF-β activity of sEV were significantly elevated in HNSCC patients vs HDs’ sEV and correlated with tumor stage and LN involvement. Conclusions: TEX and sEV from HNSCC patients’ plasma carry TGF-β which reflects disease progression in HNSCC patients and in a mouse model of oral carcinogenesis. Neither plasma levels of TGF-β (ELISA) nor levels of TGF-β expression in the tumor (IHC) correlated with disease progression. Only sEV-associated TGF-β correlates with tumor burden and shows promise as a non-invasive biomarker of HNSCC progression and response to therapy. Citation Format: Nils Ludwig, Saigopalakrishna S. Yerneni, Theresa L. Whiteside. TGF-β carrying exosomes in plasma of HNSCC as potential biomarkers of disease progression in patients with HNSCC [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-095.

Simplified Rapid Enrichment of CTCs and Selective Recognition Prereduction Enable a Homogeneous ICP-MS Liquid Biopsy Strategy of Lung Cancer.

The effective enrichment and hypersensitivity analysis of circulating tumor cells (CTCs) in clinical whole blood samples are highly significant for clinical tumor liquid biopsy. In this study, we established an easy operation and affordable CTCs extraction technique while simultaneously performing the homogeneous inductively coupled plasma mass spectrometry (ICP-MS) determination of CTCs in lung cancer clinical samples based on selective recognition reactions and prereduction phenomena. Our strategy allowed for the pretreatment of whole blood samples in less than 45 min after step-by-step centrifugation, which only required lymphocyte separation solution and erythrocyte lysate. Furthermore, a three-stage signal amplification system consisting of catalytic hairpin assembly (CHA), selective recognition for C-Ag+-C structures and Ag+ of copper sulfide nanoparticles (CuS NPs), and prereduction of Hg2+ through ascorbic acid (AA) was constructed by using mucin 1 as the CTCs marker and the aptamer for identification probes. In optimal conditions, the detection limits of ICP-MS were as low as 0.3 ag/mL for mucin 1 and 0.25 cells/mL for A549 cells. This method analyzed CTCs in 58 clinical samples quantitatively, and the results were consistent with clinical CT images and pathological findings. The area under the curve (AUC) value of the receiver operating characteristic (ROC) curve was 0.957, which provided a specificity of 100% and a sensitivity of 91.5% for the assay. Therefore, the simplicity of the extraction method, the accessibility, and the high sensitivity of the assay method make the strategies attractive for clinical CTCs testing applications.

Superresolution Fluorescence Microscopy of Platelet Subcellular Structures as a Potential Tumor Liquid Biopsy.

Blood-based tumor liquid biopsies are promising as an alternative or complement to tissue biopsies due to their noninvasiveness, convenience, and safety, and there is still a great demand for the discovery of new biomarkers for these biopsies. Here, nanoscale distribution patterns of subcellular structures in platelets, as imaged by structured illumination superresolution fluorescence microscopy, as a new type of potential biomarker for tumor liquid biopsies are presented. A standardized protocol for platelet sample preparation and developed an automated high-throughput image analysis workflow is established. The diagnostic capability based on the statistical analysis of 280000 superresolution images of individual platelets from a variety of tumor patients, benign mass patients, and healthy volunteers (n = 206) is explored. These results suggest that the nanoscale distribution patterns of α-granules in platelets have the potential to be biomarkers for several cancers, including glioma and cervical, endometrial, and ovarian cancers, facilitating not only diagnosis but also therapeutic monitoring. This study provides a promising novel type of platelet parameter for tumor liquid biopsies at the subcellular level rather than the existing cellular or molecular level and opens up a new avenue for clinical applications of superresolution imaging techniques.

Clinical factors associated with successful liquid tumor biopsy in men with prostate cancer.

e13567 Background: Liquid biopsies using cell-free DNA (cfDNA) can be used in prostate cancer (PrCa) patients when tissue is unavailable and repeat biopsy is not feasible. Given the older age of PrCa patients, liquid biopsy may detect alterations related to clonal hematopoiesis of indeterminate potential (CHIP), generating uncertainty in the clinical utility of the results. We sought to identify clinical predictors of successful cfDNA biopsy, where the reported alterations are more likely to reflect the individual’s prostate cancer cfDNA instead of CHIP in a large cohort of United States Veterans with PrCa. Methods: Next-generation sequencing of cfDNA biopsy specimens was performed through the VA National Precision Oncology Program (NPOP) from February 2019 to November 2022. Successful identification of PrCa cfDNA testing was defined as the identification of an alteration in one or more PrCa-related genes included on the panel ( AR, CDK12, SPOP, MED12, CCND1, BRAF, AKT1, TMPRSS2, ERG, ETV1, and ETV4). Student’s t-tests, univariate, and multivariate logistic regression estimated significant patient and disease-specific factors at the time of cfDNA biopsy and the likelihood of obtaining a successful cfDNA biopsy result. Results: Among 5611 total cfDNA tests performed, 2066 cfDNA tests from 1985 Veterans listed PrCa as the clinical indication, passed quality control measures, and could be linked to patient-level demographics. 814 (39%) tests were deemed successful based upon identification of at least one PrCa related gene alteration. The most frequently encountered PrCa alterations were in AR (76.5%) and TMPRSS2 (22.4%). PSA was significantly higher (IQR 209.1 ng/ml) and PSA doubling time (PSADT) was significantly shorter (IQR 2.4 months) in the cohort of Veterans with successful cfDNA testing (p&lt;0.001). Among 1581 tests that reported tumor fraction, an elevated tumor fraction &gt;10 was also significantly associated with success (46.3% vs 8.1%, p&lt;0.001). On multivariate analysis, PSA elevation above 4.8 ng/ml (p&lt;0.001) and PSADT &lt;6 months (p&lt;0.001) were significantly associated with successful cfDNA testing. Actionable DDR mutations, including ATM (15.2% vs 11.7%, p=0.02), BRCA1 (1.7% vs 0.6%, p=0.03), and BRCA2 (7.4% vs 4.4%, p=0.01) were significantly more likely to be detected in a successful test compared to an unsuccessful test. Conclusions: High PSA and short PSADT are significant predictors of a cfDNA test identifying PrCa-related gene alterations in Veterans with metastatic disease instead of alterations due solely to CHIP. Liquid biopsy in PrCa should be reserved for patients with relatively higher disease burden or more aggressive growth rate, reflected by PSA values &gt; 4.8 and PSADT &lt; 6 months, to increase the likelihood of identifying actionable alterations and improve interpretation of testing.

A dual aptamer recognition-based fluorescent biosensor for extracellular vesicles assays with high sensitivity and specificity

Cancer-derived extracellular vesicles (EVs) play a crucial role in intercellular information transmission, tumor metastasis and invasion, which has become one of the most promising biomarkers for tumor liquid biopsy. Herein, we propose a novel dual aptamer recognition-based fluorescent biosensor assisted by functionalized metal−organic frameworks (MOFs) and rolling circle amplification (RCA) method for ultrasensitive cancer-derived EVs assay. This approach exhibits excellent specificity and sensitivity toward EVs. The linear range of EVs detection was 5 × 104 particles/μL to 1 × 107 particles/μL and the limit of detection (LOD) was 2.2 × 104 particles/μL, which is superior to those of most reported methods. Moreover, double aptamer recognition improved the accuracy of this strategy in practical application. This method has been successfully used for the diagnosis of leukemia by detecting EVs from the normal and leukemia patient’s serum, which is expected to be applied as an effective tool for EVs research and has considerable potential for early clinical diagnosis of disease.

Evaluating tumor cell- and T cell-derived extracellular vesicles as potential biomarkers of cancer and immune cell competence

ABSTRACT Introduction Extracellular vesicles (EVs) produced by tumors, also called tumor-derived exosomes (TEX), have been implicated in inducing immune cell suppression in vitro and in vivo. The development of a novel category of noninvasive biomarkers for precision oncology remains an unmet need, and TEX emerge as a promising liquid tumor biopsy component. Areas covered TEX play a critical role in monitoring cancer presence/progression and in reprograming of anti-tumor effector T cells to producers of EVs with pro-tumor activity. TEX are a subset of circulating EVs. Their separation by immune capture from EVs derived from nonmalignant cells allows for TEX phenotypic/functional assessments. TEX cross-talking with CD3(+) T cells induce the release of CD3(+) small EV (sEV), whose cargo of suppressor proteins resembles that of TEX and further contributes to cancer-induced immune suppression. While TEX recapitulate the genetic/molecular phenotype of tumor cells, CD3(+) sEV might serve as ‘T cell liquid biopsy.’ Expert opinion Preclinical explorations of the role in cancer body fluids of TEX and CD3(+) sEV as cancer biomarkers suggest that these EV subsets may qualify as liquid tumor biopsy noninvasive components in the near future. Their potential to simultaneously serve as noninvasive liquid tumor biopsy and T cell biopsy remains to be validated in future clinical trials.

Small extracellular vesicles in metabolic remodeling of tumor cells: Cargos and translational application.

Warburg effect is characterized by excessive consumption of glucose by the tumor cells under both aerobic and hypoxic conditions. This metabolic reprogramming allows the tumor cells to adapt to the unique microenvironment and proliferate rapidly, and also promotes tumor metastasis and therapy resistance. Metabolic reprogramming of tumor cells is driven by the aberrant expression and activity of metabolic enzymes, which results in the accumulation of oncometabolites, and the hyperactivation of intracellular growth signals. Recent studies suggest that tumor-associated metabolic remodeling also depends on intercellular communication within the tumor microenvironment (TME). Small extracellular vesicles (sEVs), also known as exosomes, are smaller than 200nm in diameter and are formed by the fusion of multivesicular bodies with the plasma membrane. The sEVs are instrumental in transporting cargoes such as proteins, nucleic acids or metabolites between the tumor, stromal and immune cells of the TME, and are thus involved in reprogramming the glucose metabolism of recipient cells. In this review, we have summarized the biogenesis and functions of sEVs and metabolic cargos, and the mechanisms through they drive the Warburg effect. Furthermore, the potential applications of targeting sEV-mediated metabolic pathways in tumor liquid biopsy, imaging diagnosis and drug development have also been discussed.

BIOM-08. IL13RA2 AS A LIQUID BIOPSY BIOMARKER FOR NERVOUS SYSTEM TUMORS

Abstract While tumors of the nervous system (NS) are rare, they contribute to significant morbidity and mortality. Despite advances in imaging technology, initial diagnosis and characterization of treatment response remains problematic for devastating tumors such as glioblastoma (GBM). A liquid biopsy can provide a minimally-invasive and serial source of biomarkers to supplement current diagnostic methods. Here, we utilize a unique characteristic of NS tumors including GBM and schwannoma/neurofibroma – the overexpression of the a2 variant of the IL-13 receptor which is not detectable in normal tissue. Previously, we have shown that IL13Ra2 is elevated in the plasma of some GBM patients above baseline levels. We hypothesize that the presence of circulating IL13Ra2 not only predicts the level of this receptor in the tumor tissue, but also has clinical prognostic value. Here, we used ELISA to measure the plasma levels of IL13Ra2 in the GBM (n=77) and schwannoma/neurofibroma (n=15) patients and correlated these levels to tumor levels, diagnosis, and clinical characteristics. We have demonstrated that elevated levels of plasma IL13Ra2 correlated with tumor presence compared to non-tumor controls for both GBM and schwannoma/neurofibroma patients, indicating this biomarker’s diagnostic utility. Further, for both GBM and schwannoma/neurofibroma patients the plasma concentration of IL13Ra2 is correlated to its tumor concentration, indicating that sampling patient plasma could provide insight into the tumor’s composition. Finally, elevated levels of IL13Ra2 protein in the tumor and plasma of GBM patients predicted longer patient survival. These exciting findings lay the groundwork for a plasma-based NS tumor liquid biopsy.

The future of brain tumor liquid biopsies in the clinic

The future of brain tumor liquid biopsies in the clinic

Gold island‐enhanced multiplex quantum dots fluorescent system for biomedical analysis of circulating tumor nucleic acids

AbstractCirculating tumor nucleic acids (CTNAs) have been employed as the potential markers for tumor diagnosis and management, which are highly correlated with the tumorigenesis, progression, and metastasis processes. Therefore, it is important to develop a highly‐sensitive and reliable method for the detection of CTNAs, especially the multiplex point mutation detection of blood‐derived CTNAs. Herein, a versatile gold island‐enhanced multiplex quantum dots (GIEM‐QDs) fluorescent platform was constructed for the highly‐sensitive detection of CTNAs in serum. The GIEM fluorescent strategy was designed as the highly‐efficient signal giving‐out mode which could amplify the fluorescence intensity of QDs, thus realizing a homogeneous platform for the enrichment, multiplex detection, and point mutations monitoring of CTNAs with the principle of base‐stacking. A high sensitivity of 10 amol and desirable specificity was achieved, and the performance index for analysis of clinical tumor patients’ samples indicated that the GIEM‐QDs fluorescent strategy could realize multiplex point mutation detection of CTNAs in complex blood samples. Hence, this platform could achieve a high detection rate in clinical samples that suitably met the clinical requirements for multiplex detection and point mutations monitoring of CTNAs, and thus has the potential to serve as the tumor liquid biopsy strategy based on CTNAs.

Designer tetrahedral DNA framework-based microfluidic technology for multivalent capture and release of circulating tumor cells.

Circulating tumor cells (CTCs) have been recognized as a general biomarker for the early detection, diagnosis and therapy monitoring of cancer. Due to their extreme rarity in peripheral blood, the isolation and analysis of CTCs with high efficiency, high purity and high viability remains a tremendous technological challenge. Herein, we combined tetrahedral DNA framework (TDFs), herringbone channel (HB) chip, together with aptamer-triggered hybridization chain reaction (apt-HCR) to develop an efficient microfluidic system (T-μFS) for capture and release of simulated CTCs. The capture efficiency of MCF-7 ​cells was from 83.3% to 94.2% when the cell numbers ranged from 10 to 103 using our T-μFS in the whole blood. The release efficiency of the MCF-7 ​cells was 96.2% and the MCF-7 ​cell viability after release was 94.6% using our T-μFS in PBS buffer. Reculture and RT-qPCR studies showed that there was almost no damage by the capture and release treatment for the MCF-7 ​cells viability. These results revealed that our T-μFS could be developed as an integrated and automatic technical platform with great performance for multivalent capture and release of CTCs and have a wide application prospect for tumor liquid biopsy.

Tim4‐Functionalized HBEV‐Chip by Isolating Plasma‐Derived Phosphatidylserine‐Positive Small Extracellular Vesicles for Pan‐Cancer Screening (Adv. Mater. Technol. 7/2022)

Pan-Cancer Screening In the background of the inside cover, highlighting article number 2101115 by Kun Deng and co-workers, the body is primarily made up of lung, colorectum, pancreas and blood vessels, which represents the concept of pan-cancer screening in tumor liquid biopsy. The drop of blood entrances into HBEV-Chip are indicating the isolation of tumor-derived small extracellular vesicles from microlitre volume plasma for pan-cancer screening in clinic and the high quality materials for mass spectrometry detection in lab.