Looking back, to the future of circulating tumor cells

Cascaded nanozyme-based high-throughput microfluidic device integrating with glucometer and smartphone for point-of-care pheochromocytoma diagnosis

The development of point-of-care (POC) diagnostics devices for circulating tumor cells (CTCs) detection plays an important role in the early diagnosis of pheochromocytoma (PCC), especially in a low-resource setting. To further realize the rapid, portable, and high-throughput detection of CTCs, an Au@CuMOF cascade enzyme-based microfluidic device for instant point-of-care detection of CTCs was constructed by combining a smartphone application and a commercial portable glucose meter (PGM). In this microfluidic system, DOTA and norepinephrine (NE) modified Au@CuMOF signal probes and Fe3O4@SiO2 capture probes were used for the dual recognition and capture of rare PCC-CTCs. Then, the targeted binding of the Au@CuMOF cascade nanozymes to the CTCs endowed the cellular complexes with multienzyme mimetic activities (i.e., glucose oxidase-like and peroxidase-like activity) to catalyze glucose reduction as signal output for colorimetric and personal glucose meter (PGM) dual-mode detection of CTCs. The developed method has a linear range of 4 to 105 cells mL-1 and a detection limit of 3 cells mL-1. This method allows the simultaneous detection of six samples and demonstrates good applicability for CTCs detection in whole blood samples. More importantly, the combination of PGM, smartphone app and array microfluidic chips enables the rapid, portable, and high-throughput diagnoses of PCC, and providing provide a convenient and reliable alternative to traditional liquid biopsy diagnosis of various cancers.

A Novel Detection Method of Breast Cancer through a Simple Panel of Biomarkers

Circulating tumor cells (CTCs) have been identified as responsible for the spread of tumors to other organs of the body. In this sense, the development of sensitive and specific assays for their detection is important to reduce the number of deaths due to metastases. Here, we assessed whether the detection of CTCs in peripheral blood can serve in the construction of a panel of diagnosis and monitoring treatments of breast cancer (BC), focusing on the expression of markers of epithelial-mesenchymal transition. Through analyzing the blood from women without breast alterations (control), women with benign alterations, women with breast cancer without chemotherapy, and women with breast cancer with chemotherapy, we identified the best markers by transcriptional levels and determined three profiles of CTCs (mesenchymal, intermediate, and epithelial) by flow cytometry which, combined, can be used for diagnosis and therapy monitoring with sensitivity and specificity between 80% and 100%. Therefore, we have developed a method for detecting breast cancer based on the analysis of CTC profiles by epithelial-mesenchymal transition markers which, combined, can be used for the diagnosis and monitoring of therapy.

Identification of Circulating Tumor Cell Phenotype in Differentiated Thyroid Carcinoma

Objective: Circulating tumor cells (CTCs) have been considered as the origin of tumor metastasis and recurrence, which always indicate a poor prognosis. There are three phenotypes of CTCs according on different epithelial-to-mesenchymal transition (EMT) markers, including epithelial, mesenchymal, and epithelial/mesenchymal (mixed phenotypic) CTCs. We intended to explore the relationship among CTC phenotypes and the clinicopathological characteristics of patients with differentiated thyroid carcinoma (DTC). Methods: Peripheral blood samples from 58 patients with DTC were collected, and CTCs were isolated by cell sizes. To identify phenotypes of CTCs, branched DNA signal amplification technology was adopted to capture and amplify target sequences, and then multiplex RNA-in situ hybridization (RNA-ISH) assay was used to identify CTC phenotypes depended on epithelial-mesenchymal transition (EMT) markers. Results: The positive rate of CTCs was 77.59% in 58 DTC patients. Totally, 488 CTCs with detective phenotype were found. Among them, there were 121 (24.80%) epithelial CTCs, 67 (13.72%) mesenchymal CTCs, and 300 (61.48%) mixed phenotypic CTCs. An obvious increased epithelial CTCs was observed in male patients compared with female. Notably, CTCs were more prevailing in younger male patients with ETI and bilateral focus. Conclusions: The CTCs are common in DTC patients, and mixed phenotypic is the major phenotype, indicating that EMT is prevalent in DTC even though its prognosis was better than other epithelial tumors. Detection of CTC and its phenotypes might independently predict the prognosis of DTC.

New horizons in the identification of circulating tumor cells (CTCs): An emerging paradigm shift in cytosensors

Circulating tumor cells (CTCs) are cancer cells that are shed from a primary tumor into the bloodstream and function as seeds for cancer metastasis at distant locations. Enrichment and identification methods of CTCs in the blood of patients plays an important role in diagnostic assessments and personalized treatments of cancer. However, the current traditional identification methods not only impact the viability of cells, but also cannot determine the type of cancer cells when the disease is unknown. Hence, new methods to identify CTCs are urgently needed. In this context, many advanced and safe technologies have emerged to distinguish between cancer cells and blood cells, and to distinguish specific types of cancer cells. In this review, at first we have briefly discussed recent advances in technologies related to the enrichment of CTCs, which lay a good foundation for the identification of CTCs. Next, we have summarized state-of-the-art technologies to confirm whether a given cell is indeed a tumor cell and determine the type of tumor cell. Finally, the challenges for application and potential directions of the current identification methods in clinical analysis of CTCs have been discussed.

Negative-Selection Enrichment of Circulating Tumor Cells from Peripheral Blood Using the Microfluidic CTC-iChip

The ability to isolate and analyze rare circulating tumor cells (CTCs) holds the potential to increase our understanding of cancer evolution and allows monitoring of disease and therapeutic responses through a relatively non-invasive blood-based biopsy. While many methods have been described to isolate CTCs from the blood, the vast majority rely on size-based sorting or positive selection of CTCs based on surface markers, which introduces bias into the downstream product by making assumptions about these heterogenous cells. Here we describe a negative-selection protocol for enrichment of CTCs through removal of blood components including red blood cells, platelets, and white blood cells. This procedure results in a product that is amenable to downstream single-cell analytics including RNA-Seq, ATAC-Seq and DNA methylation, droplet digital PCR (ddPCR) for tumor specific transcripts, staining and extensive image analysis, and ex vivo culture of patient-derived CTCs.

Seeding metastases: The role and clinical utility of circulating tumour cells

Peripheral human blood is a readily-accessible source of patient material in which circulating tumour cells (CTCs) can be found. Their isolation and characterization holds the potential to provide prognostic value for various solid cancers. Enumeration of CTCs from blood is becoming a common practice in informing prognosis and may guide therapy decisions. It is further recognized that enumeration alone does not capture perspective on the heterogeneity of tumours and varying functional abilities of the CTCs to interact with the secondary microenvironment. Characterizing the isolated CTCs further, in particular assessing their functional abilities, can track molecular changes in the disease progress. As a step towards identifying a suite of functional features of CTCs that could aid in clinical decisions, developing a CTC isolation technique based on extracellular matrix (ECM) interactions may provide a more solid foundation for isolating the cells of interest. Techniques based on size, charge, density, and single biomarkers are not sufficient as they underutilize other characteristics of cancer cells. The ability of cancer cells to interact with ECM proteins presents an opportunity to utilize their full character in capturing, and also allows assessment of the features that reveal how cells might behave at secondary sites during metastasis. This article will review some common techniques and recent advances in CTC capture technologies. It will further explore the heterogeneity of the CTC population, challenges they experience in their metastatic journey, and the advantages of utilizing an ECM-based platform for CTC capture. Lastly, we will discuss how tailored ECM approaches may present an optimal platform to capture an influential heterogeneous population of CTCs.

Multivalent Duplexed-Aptamer Networks Regulated a CRISPR-Cas12a System for Circulating Tumor Cell Detection

Although circulating tumor cells (CTCs) have great potential to act as the mini-invasive liquid biopsy cancer biomarker, a rapid and sensitive CTC detection method remains lacking. CRISPR-Cas12a has recently emerged as a promising tool in biosensing applications with the characteristic of fast detection, easy operation, and high sensitivity. Herein, we reported a CRISPR-Cas12a-based CTC detection sensor that is regulated by the multivalent duplexed-aptamer networks (MDANs). MDANs were synthesized on a magnetic bead surface by rolling circle amplification (RCA), which contain multiple duplexed-aptamer units that allow structure switching induced by cell-binding events. The presence of target cells can trigger the release of free "activator DNA" from the MDANs structure to activate the downstream CRISPR-Cas12a for signal amplification. Furthermore, the 3D DNA network formed by RCA products also provided significantly higher sensitivity than the monovalent aptamer. As a proof-of-concept study, we chose the most widely used sgc8 aptamer that specifically recognizes CCRF-CEM cells to validate the proposed approach. The MDANs-Cas12a system could afford a simple and fast CTC detection workflow with a detection limit of 26 cells mL^-1. We also demonstrated that the MDANs-Cas12a could directly detect the CTCs in human blood samples, indicating a great potential of the MDANs-Cas12a in clinical CTC-based liquid biopsy.

Aptamer-Based Detection of Circulating Targets for Precision Medicine

The past decade has witnessed ongoing progress in precision medicine to improve human health. As an emerging diagnostic technique, liquid biopsy can provide real-time, comprehensive, dynamic physiological and pathological information in a noninvasive manner, opening a new window for precision medicine. Liquid biopsy depends on the sensitive and reliable detection of circulating targets (e.g., cells, extracellular vesicles, proteins, microRNAs) from body fluids, the performance of which is largely governed by recognition ligands. Aptamers are single-stranded functional oligonucleotides, capable of folding into unique tertiary structures to bind to their targets with superior specificity and affinity. Their mature evolution procedure, facile modification, and affinity regulation, as well as versatile structural design and engineering, make aptamers ideal recognition ligands for liquid biopsy. In this review, we present a broad overview of aptamer-based liquid biopsy techniques for precision medicine. We begin with recent advances in aptamer selection, followed by a summary of state-of-the-art strategies for multivalent aptamer assembly and aptamer interface modification. We will further describe aptamer-based micro-/nanoisolation platforms, aptamer-enabled release methods, and aptamer-assisted signal amplification and detection strategies. Finally, we present our perspectives regarding the opportunities and challenges of aptamer-based liquid biopsy for precision medicine.

Circulating tumor cell characterization of lung cancer brain metastases in the cerebrospinal fluid through single-cell transcriptome analysis

BACKGROUND

Brain metastases explain the majority of mortality associated with lung cancer, which is the leading cause of cancer death. Cytology analysis of the cerebrospinal fluid (CSF) remains the diagnostic gold standard, however, the circulating tumor cells (CTCs) in CSF (CSF-CTCs) are not well defined at the molecular and transcriptome levels.

METHODS

We established an effective CSF-CTCs collection procedure and isolated individual CSF cells from five lung adenocarcinoma leptomeningeal metastases (LUAD-LM) patients and three controls. Three thousand seven hundred ninety-two single-cell transcriptomes were sequenced, and single-cell RNA sequencing (scRNA-seq) gene expression analysis was used to perform a comprehensive characterization of CSF cells.

RESULTS

Through clustering and expression analysis, we defined CSF-CTCs at the transcriptome level based on epithelial markers, proliferation markers, and genes with lung origin. The metastatic-CTC signature genes are enriched for metabolic pathway and cell adhesion molecule categories, which are crucial for the survival and metastases of tumor cells. We discovered substantial heterogeneity in patient CSF-CTCs. We quantified the degree of heterogeneity and found significantly greater among-patient heterogeneity compared to among-cell heterogeneity within a patient. This observation could be explained by spatial heterogeneity of metastatic sites, cell-cycle gene, and cancer-testis antigen (CTA) expression profiles as well as the proportion of CTCs displaying mesenchymal and cancer stem cell properties. In addition, our CSF-CTCs transcriptome profiling allowed us to determine the biomarkers during the progression of an LM patient with cancer of unknown primary site (CUP).

CONCLUSIONS

Our results will provide candidate genes for an RNA-based digital detection of CSF-CTCs from LUAD-LM and CUP-LM cases, and shed light on the therapy and mechanism of LUAD-LM.

Coordination-driven reversible surfaces with site-specifically immobilized nanobody for dynamic cancer cell capture and release

Selective isolation of circulating tumor cells (CTCs) from blood provides a non-invasive avenue for the diagnosis, prognosis and personalized treatment for patients with cancer. The specific capture of CTCs is conventionally based on the immunoaffinity recognition between antibody and receptor on cell membranes. However, using a traditional antibody for high-efficiency isolation of CTCs remains a challenge due to the limited loading capacity of the large antibodies on material surfaces. Herein, using a small-sized nanobody (Nb), we developed a widely applicable strategy to construct reversible site-specifically immobilized Nb surfaces for the capture and release of epidermoid cancer cell line A431 cells. Coordination interaction between the histidine tag (His-tag) of the nanobody (Nb) and Ni2+ ions that chelated to the NTA-modified poly(2-hydroxyethyl methacrylate) (PHEMA) brushes was used to achieve site-specific immobilization of EGFR Nb (PHEMA-aEGFR surfaces). The high-density immobilized nanobody possessing maximized activity resulted in the high-efficiency capture of 81% rare A431 cells within just 30 min, showing a higher capture yield and shorter capture time compared with that achieved by the conventional antibody immobilized on the flat surface. Additionally, the PHEMA-aEGFR surfaces exhibited low capture limit (1 cell mL-1), cytocompatibility for captured cells, as well as negligible non-specific adhesion of PBMCs. With a one-step treatment using imidazole for competitive coordination, 86% of the captured cells were effectively released. This multifunctional and dynamic site-specifically immobilized nanobody strategy paves a new path in the development of materials and instruments for the high-efficiency capture and release of rare cells at a low cost.

Prognostic Significance of Circulating Tumor Cells with Mesenchymal Phenotypes in Patients with Gastric Cancer: A Prospective Study

BACKGROUND

Circulating tumor cells (CTCs) have been shown to be heterogeneous. Focusing on the epithelial-mesenchymal transition and perioperative kinetics, we evaluated CTCs with mesenchymal phenotypes as a potential prognostic biomarker for patients with gastric cancer.

METHODS

Peripheral blood was collected from 54 patients with gastric cancer before surgery and at 1 week and 1 month after surgery. CTCs were enriched using density-gradient centrifugation and magnetic-activated cell sorting (negative selection). Cell suspensions were characterized by multi-immunofluorescence staining against cytokeratin and N-cadherin, and by 4',6'-diamidino-2-phenyldole staining.

RESULTS

CTCs were detected in five patients (17%) with early cancer and 14 patients (56%) with advanced cancer (p < 0.05). In our system, N-cadherin, but not cytokeratin, was expressed in the CTCs of 90% (19/21) of patients. Postoperative recurrence was detected in 10 patients, all of whom had N-cadherin+/cytokeratin-/CD45- CTCs preoperatively. Regarding perioperative kinetics, we divided patients into three risk groups: a high-risk group, with one or more preoperative CTCs and increased CTCs postoperatively; an intermediate-risk group, with one or more preoperative CTCs and decreased CTCs postoperatively; and a low-risk group, with no preoperative CTCs. Recurrence rates were 57% (4/7), 33% (4/12), and 6% (2/35), respectively. The relapse-free survival rate was lower in patients at high risk versus those at intermediate or low risk, for all patients (p = 0.00024) and in patients with advanced cancer (p = 0.00103).

CONCLUSIONS

N-cadherin is a highly useful marker to detect CTCs lacking cytokeratin, and the perioperative kinetics of CTC numbers is beneficial in risk stratification for survival in patients with gastric cancer.

Global Gene Expression Characterization of Circulating Tumor Cells in Metastasic Castration-Resistant Prostate Cancer Patients

Background: Current therapeutic options in the course of metastatic castration-resistant prostate cancers (mCRPC) reinforce the need for reliable tools to characterize the tumor in a dynamic way. Circulating tumor cells (CTCs) have emerged as a viable solution to the problem, whereby patients with a variety of solid tumors, including PC, often do not have recent tumor tissue available for analysis. The biomarker characterization in CTCs could provide insights into the current state of the disease and an overall picture of the intra-tumor heterogeneity. Methods: in the present study, we applied a global gene expression characterization of the CTC population from mCRPC (n = 9), with the goal to better understand the biology of these cells and identify the relevant molecules favoring this tumor progression. Results: This analysis allowed the identification of 50 genes specifically expressed in CTCs from patients. Six of these markers (HOXB13, QKI, MAOA, MOSPD1, SDK1, and FGD4), were validated in a cohort of 28 mCRPC, showing clinical interest for the management of these patients. Of note, the activity of this CTC signature was related to the regulation of MYC, a gene strongly implicated in the biology of mCRPC. Conclusions: Overall, our results represent new evidence on the great value of CTCs as a non-invasive biopsy to characterize PC.

The Prognostic Value of Circulating Tumor Cells in Primary Breast Cancer Prior to any Systematic Therapy: A Systematic Review

BACKGROUND

Numerous studies have defined the outstanding role of circulating tumor cells (CTC) in the management of cancer, particularly the ones in association with primary tumor metastases.

OBJECTIVE

The overall aim of the present study was to investigate whether CTCs may serve as a clinical prognostic marker for survival in primary breast cancer.

METHODS

Articles Published from June 2011 to July 2017 in PubMed, EMBase, and Cochrane library databases were thoroughly screened for selecting the ones meeting the inclusion criteria.

RESULT

Studies applying CellSearch® method demonstrated the risk ratios (RR) of 2.51 (95% CI: 1.78- 3.54), 3.98 (95% CI: 2.28- 6.95), 5.59 (95% CI: 3.29- 9.51), and 3.38 (95% CI: 1.88- 6.06) for death rate and relapse rates of 2.48 (95% CI: 1.89 - 3.26), 3.62 (95% CI: 2.37 - 5.51), 4.45 (95% CI: 2.94 - 6.73), and 2.88 (95 % CI: 1.99 - 4.17) at four CTC positive cut points (≥ 1, ≥ 2, ≥ 3, and ≥ 5 CTCs/7.5 ml). Two studies applying the AdnaTest® also documented increased death (RR: 1.38, 95 % CI: 0.42- 4.49) and relapse rates (RR: 2.97, 95 % CI: 1.23 - 7.18)).

CONCLUSION

Results of this meta-analysis allude CTCs as potent prognostic markers in primary breast cancers prior to any systemic therapy especially when it is studied via CellSearch® administration, considering that the more the CTCs, the greater the death and relapse rates.

Epithelial-Mesenchymal Plasticity in Circulating Tumor Cells, the Precursors of Metastasis

Circulating tumor cells offer an unprecedented window into the metastatic cascade, and to some extent can be considered as intermediates in the process of metastasis. They exhibit dynamic oscillations in epithelial to mesenchymal plasticity and provide important opportunities for prognosis, therapy response monitoring, and targeting of metastatic disease. In this manuscript, we review the involvement of epithelial-mesenchymal plasticity in the early steps of metastasis and what we have learned about its contribution to genomic instability and genetic diversity, tumor progression and therapeutic responses using cell culture, mouse models and circulating tumor cells enriched from patients.

Recent advances in gastric cancer early diagnosis

Gastric cancer (GC) remains an important cause of cancer death worldwide with a high mortality rate due to the fact that the majority of GC cases are diagnosed at an advanced stage when the prognosis is poor and the treatment options are limited. Unfortunately, the existing circulating biomarkers for GC diagnosis and prognosis display low sensitivity and specificity and the GC diagnosis is based only on the invasive procedures such as upper digestive endoscopy. There is a huge need for less invasive or non-invasive tests but also highly specific biomarkers in case of GC. Body fluids such as peripheral blood, urine or saliva, stomach wash/gastric juice could be a source of specific biomarkers, providing important data for screening and diagnosis in GC. This review summarized the recently discovered circulating molecules such as microRNAs, long non-coding RNAs, circular RNAs, which hold the promise to develop new strategies for early diagnosis of GC.

Expression of Proteolytic Enzymes by Small Cell Lung Cancer Circulating Tumor Cell Lines

Small cell lung cancer (SCLC) is an aggressive type of lung cancer which disseminates vigorously and has a dismal prognosis. Metastasis of SCLC is linked to an extremely high number of circulating tumor cells (CTCs), which form chemoresistant spheroids, termed tumorospheres. Intravasation and extravasation during tumor spread requires the activity of a number of proteases to disintegrate the stroma and vascular tissue. Generation of several permanent SCLC CTC lines allowed us to screen for the expression of 35 proteases using Western blot arrays. Cell culture supernatants of two CTC lines, namely BHGc7 and 10, were analyzed for secreted proteases, including matrix metalloproteinases (MMPs), ADAM/TS, cathepsins, kallikreins, and others, and compared to proteases expressed by SCLC cell lines (GLC14, GLC16, NCI-H526 and SCLC26A). In contrast to NCI-H526 and SCLC26A, MMP-9 was highly expressed in the two CTC lines and in GLC16 derived of a relapse. Furthermore, cathepsins (S, V, X/Z/P, A and D) were highly expressed in the CTC lines, whereas ADAM/TS and kallikreins were not detectable. In conclusion, SCLC CTCs express MMP-9 and a range of cathepsins for proteolysis and, aside from tissue degradation, these enzymes are involved in cell signaling, survival, and the chemoresistance of tumor cells.

Molecular detection of epithelial-mesenchymal transition markers in circulating tumor cells from pancreatic cancer patients: Potential role in clinical practice

AIM

To evaluate the clinical properties of three subpopulations of circulating tumor cells (CTCs) undergoing epithelial-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) patients.

METHODS

We identified CTCs for expression of the epithelial cell marker cytokeratin or epithelial cell adhesion molecule (EpCAM) (E-CTC), the mesenchymal cell markers vimentin and twist (M-CTC), or both (E/M-CTC) using the CanPatrol system. Between July 2014 and July 2016, 107 patients with PDAC were enrolled for CTC evaluation. CTC enumeration and classification were correlated with patient clinicopathological features and outcomes.

RESULTS

CTCs were detected in 78.5% of PDAC patients. The number of total CTCs ranged from 0 to 26 across all 107 patients, with a median value of six. CTC status correlated with lymph node metastasis, TNM stage, distant metastasis, blood lymphocyte counts, and neutrophil-to-lymphocyte ratio (NLR). Kaplan-Meier survival analysis showed that patients with ≥ 6 total CTCs had significantly decreased overall survival and progression-free survival compared with patients with < 6 total CTCs. The presence of M-CTCs was positively correlated with TNM stage (P < 0.01) and distant metastasis (P < 0.01). Additionally, lymphocyte counts and NLR in patients without CTCs were significantly different from those in patients testing positive for each CTC subpopulation (P < 0.01).

CONCLUSION

Classifying CTCs by EMT markers helps to identify the more aggressive CTC subpopulations and provides useful evidence for determining a suitable clinical approach.

Expression of immune-regulatory molecules in circulating tumor cells derived from patients with head and neck squamous cell carcinoma

OBJECTIVES

Circulating tumor cells (CTCs) are cells that have shed from tumor tissue into the bloodstream, and the detection and characterization of CTCs in head and neck squamous cell carcinoma (HNSCC) still remain a challenge.

MATERIALS AND METHODS

CTCs were isolated from 30 patients with HNSCC with recurrent and/or distant metastasis, via the depletion of CD45-positive cells with magnetic beads and the expression of multiple epithelial markers (CK19, EpCAM, EGFR, and c-Met) was analyzed by RT-qPCR with a low concentration of RNA from the CTC population. We next investigated the expression of the immune-regulatory molecules, PD-L1, PD-L2, and CD47, in CTC-positive patients and the PD-L1 expression in CTCs was compared with that in tumor tissues.

RESULTS

Twenty-four (80.0%) of the 30 patients were positive for at least one epithelial-related gene. Among the 24 CTC-positive patients, 19 (79.2%), 20 (83.3%), and 17 (70.8%) patients were positive for CD47, PD-L1, and PD-L2, respectively. Interestingly, the expression of these three immune-regulatory molecules was positively correlated to each other. As expected, PD-L1 expression in the tumor tissue did not correspond completely with that in the CTCs.

CONCLUSION

Although clinical application and/or characterization of CTCs are still developing, our findings suggest that the CTCs are rapidly becoming a powerful tool in cancer treatments that involve the use of immune checkpoint inhibitors.

Automatic detection of circulating tumor cells in darkfield microscopic images of unstained blood using boosting techniques

Circulating tumor cells (CTCs) are nowadays one of the most promising tumor biomarkers. It is well correlated with overall survival and progression-free survival in breast cancer, as well as in many other types of human cancer. In addition, enumeration and analysis of CTCs could be important for monitoring the response to different therapeutic agents, thus guiding the treatment of cancer patients and offering the promise of a more personalized approach. In this article, we present a new method that could be used for the automatic detection of CTC in blood, based on the microscopic appearance of unstained cells. The proposed method is based on the evaluation of image characteristics and boosting techniques. A dataset of 263 dark field microscopy images was constructed and used for our tests, containing blood spiked with three different types of tumor cells. An overall sensitivity of 92.87% and a specificity of 99.98% were obtained for the detection of CTC, performances which proved to be comparable to those obtained by human experts.

Circulating tumor cells as a potential biomarker for postoperative clinical outcome in HBV-related hepatocellular carcinoma

BACKGROUND

This study aimed to determine if the number of circulating tumor cells (CTCs) and changes in their numbers affected tumor recurrence and metastasis after surgical resection in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

METHODS

The primary endpoints were overall survival (OS) and progression-free survival (PFS). A total of 42 patients with HCC were selected from the First Affiliated Hospital of Guangxi Medical College from 2014 to 2017. CTCs were counted 1 day prior to and 30 days after surgical excision of HCC using the CanPatrol™ system.

RESULTS

Numbers of CTCs (> 2 CTCs and > 5 CTCs per 5 ml peripheral blood) were significantly associated with Edmondson stage in HBV-related HCC prior to surgery (P = 0.004 and 0.014, respectively). However there were no significant associations between other tested clinicopathological factors and CTC counts. Postoperative CTC counts (> 2 and > 5) and pre/postoperative change in CTC counts were significantly associated with PFS (P = 0.02, 0.009, and 0.001, respectively), but not with OS. Receiver operating characteristic curve analysis showed that pre/postoperative changes in the CTC count were a better predictor of performance than absolute count. The postoperative CTC count was also significantly associated with positive TP53 expression (P < 0.05).

CONCLUSION

These results demonstrate that postoperative CTC counts (> 2 and > 5) and changes in CTC counts may be independent prognostic indicators for PFS in patients with HBV-related HCC, with the change in number of CTCs showing better predictive performance.

Liquid biopsy of cancer: a multimodal diagnostic tool in clinical oncology

Over the last decades, the concept of precision medicine has dramatically renewed the field of medical oncology; the introduction of patient-tailored therapies has significantly improved all measurable outcomes. Liquid biopsy is a revolutionary technique that is opening previously unexpected perspectives. It consists of the detection and isolation of circulating tumor cells, circulating tumor DNA and exosomes, as a source of genomic and proteomic information in patients with cancer. Many technical hurdles have been resolved thanks to newly developed techniques and next-generation sequencing analyses, allowing a broad application of liquid biopsy in a wide range of settings. Initially correlated to prognosis, liquid biopsy data are now being studied for cancer diagnosis, hopefully including screenings, and most importantly for the prediction of response or resistance to given treatments. In particular, the identification of specific mutations in target genes can aid in therapeutic decisions, both in the appropriateness of treatment and in the advanced identification of secondary resistance, aiming to early diagnose disease progression. Still application is far from reality but ongoing research is leading the way to a new era in oncology. This review summarizes the main techniques and applications of liquid biopsy in cancer.

Contemporary role of liver biopsy in hepatocellular carcinoma

A correct diagnosis of hepatocellular carcinoma (HCC) in cirrhotic patients with focal liver lesions is one of the most important issues nowadays. Probably one of the oldest debates in the hepatology community is whether to perform liver biopsy (LB) in all cirrhotic patients with focal liver lesions. We now face a time when oncology is moving towards personalized medicine. According to the current European Association for the study of Liver diseases HCC guidelines, LB has only a minor role in the management of HCC. However, the current recommendations were made more than five years ago. As time has passed, the development of high-throughput molecular technologies has helped reveal the main molecular mechanism involved in HCC development and progression. Several subtypes of HCC, with both molecular and histological characterization, have been described. Importantly, some of these subtypes have prognostic impact. In the context of personalized treatment, the role of LB will be carefully reconsidered. Until then, it is mandatory to know the various techniques of LB, their performances, complications and limitations. The balance of risk and benefit defines many of the decisions that we make as providers of medical care. In this review, we discuss not only the risks associated with LB, but also the benefits of biopsy in various clinical scenarios. Not long from now, the role of LB will be reconsidered. It is possible that we will go back in time and once again use biopsy for HCC diagnosis. Then again, we may move back to the future to try to improve the use of liquid biopsy in the follow-up of HCC patients after various treatment modalities.

Liquid biopsy provides new insights into gastric cancer

Liquid biopsies have great promise for precision medicine as they provide information about primary and metastatic tumors via a minimally invasive method. In gastric cancer patients, a large number of blood-based biomarkers have been reported for their potential role in clinical practice for screening, early diagnosis, prognostic evaluation, recurrence monitoring and therapeutic efficiency follow-up. This current review focuses on blood liquid biopsies' role and their clinical implications in gastric cancer patients, with an emphasis on circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and circulating non-coding RNAs (ncRNAs). We also provide a brief discussion of the potential and limitations of liquid biopsies use and their future use in the routine clinical care of gastric cancer.

In Vitro Model-Systems to Understand the Biology and Clinical Significance of Circulating Tumor Cell Clusters

The isolation of clusters of circulating tumor cells (CTCs) from cancer patients has recently challenged the accepted view that the initiation of secondary tumors during metastasis involves the dissemination of individual cancer cells. As such clusters appear to be more aggressive than single tumor cells, CTC clusters are now considered a main player in the metastatic process, and many studies are exploring their diagnostic, prognostic, and clinical significance. However, several technical challenges limit advances in this area. Here, we suggest the use of established cancer cell lines that grow as cell clusters in suspension as a complementary approach that can help in understanding the biology of CTC clusters and their clinical significance. We argue that the many similarities between these "surrogate" clusters and the CTC clusters isolated from patients (e.g., in terms of size, morphology, heterogeneous expression of epithelial and mesenchymal markers, and type of cell-cell junctions) make these cell lines ideal systems for the development of strategies aimed at preventing or slowing down the metastatic process by targeting CTC clusters.

Liquid biopsy to monitor melanoma patients

During the last six years, several innovative, systemic therapies for the treatment of metastatic malignant melanoma (MM) have emerged. Conventional chemotherapy has been superseded by novel first-line therapies, including systemic immunotherapies (anti-CTLA4 and anti-PD1; authorization of anti-PDL1 is anticipated) and therapies targeting specific mutations (BRAF, NRAS, and c-KIT). Thus, treating physicians are confronted with new challenges, such as stratifying patients for appropriate treatments and monitoring long-term responders for progression. Consequently, reliable methods for monitoring disease progression or treatment resistance are necessary. Localized and advanced cancers may generate circulating tumor cells and circulating tumor DNA (ctDNA) that can be detected and quantified from peripheral blood samples (liquid biopsy). For melanoma patients, liquid biopsy results may be useful as novel predictive biomarkers to guide therapeutic decisions, particularly in the context of mutation-based targeted therapies. The challenges of using liquid biopsy include strict criteria for the phenotypic nature of circulating MM cells or their fragments and the instability of ctDNA in blood. The limitations of liquid biopsy in routine diagnostic testing are discussed in this review.

Modulation of the colon cancer cell phenotype by pro-inflammatory macrophages: A preclinical model of surgery-associated inflammation and tumor recurrence

Peritoneal infection after colorectal cancer surgery is associated with a higher rate of tumor relapse. We have recently proposed that soluble inflammatory factors released in response to a postoperative infection enhance tumor progression features in residual tumor cells. In an effort to set up models to study the mechanisms of residual tumor cell activation during surgery-associated inflammation, we have analyzed the phenotypic response of colon cancer cell lines to the paracrine effects of THP-1 and U937 differentiated human macrophages, which release an inflammatory medium characteristic of an innate immune response. The exposure of the colon cancer cell lines HT-29 and SW620 to conditioned media isolated from differentiated THP-1 and U937 macrophages induced a mesenchymal-like phenotypic shift, involving the activation of in vitro invasiveness. The inflammatory media activated the β-catenin/TCF4 transcriptional pathway and induced the expression of several mesenchymal (e.g., FN1 and VIM) and TCF4 target genes (e.g., MMP7, PTGS2, MET, and CCD1). Similarly, differential expression of some transcription factors involved in epithelial-to-mesenchymal transitions (i.e. ZEB1, SNAI1, and SNAI2) was variably observed in the colon cancer cell lines when exposed to the inflammatory media. THP-1 and U937 macrophages, which displayed characteristics of M1 differentiation, overexpressed some cytokines previously shown to be induced in colorectal cancer patients with increased rates of tumor recurrence associated with postoperative peritoneal infections, thus suggesting their pro-tumoral character. Therefore, the environment created by inflammatory M1 macrophages enhances features of epithelial-to-mesenchymal transition, and may be useful as a model to characterize pro-inflammatory cytokines as putative biomarkers of tumor recurrence risk.

Combined peripheral natural killer cell and circulating tumor cell enumeration enhance prognostic efficiency in patients with metastatic triple-negative breast cancer

Objective

Triple-negative breast cancer (TNBC) is a heterogeneous disease with poor prognosis. Circulating tumor cells (CTCs) are a promising predictor for breast cancer prognoses but their reliability regarding progression-free survival (PFS) is controversial. We aim to verify their predictive value in TNBC.

Methods

In present prospective cohort study, we used the Pep@MNPs method to enumerate CTCs in baseline blood samples from 75 patients with TNBC (taken at inclusion in this study) and analyzed correlations between CTC numbers and outcomes and other clinical parameters.

Results

Median PFS was 6.0 (range: 1.0-25.0) months for the entire cohort, in whom we found no correlations between baseline CTC status and initial tumor stage (P=0.167), tumor grade (P=0.783) or histological type (P=0.084). However, among those getting first-line treatment, baseline CTC status was positively correlated with ratio of peripheral natural killer (NK) cells (P=0.032), presence of lung metastasis (P=0.034) and number of visceral metastatic site (P=0.037). Baseline CTC status was predictive for PFS in first-line TNBC (P=0.033), but not for the cohort as a whole (P=0.118). This prognostic limitation of CTC could be ameliorated by combining CTC and NK cell enumeration (P=0.049).

Conclusions

Baseline CTC status was predictive of lung metastasis, peripheral NK cell ratio and PFS in TNBC patients undergoing first-line treatment. We have developed a combined CTC-NK enumeration strategy that allows us to predict PFS in TNBC without any preconditions.

Extracellular vesicles for personalized therapy decision support in advanced metastatic cancers and its potential impact for prostate cancer

The use of circulating tumor cells (CTCs) and circulating extracellular vesicles (EVs), such as exosomes, as liquid biopsy-derived biomarkers for cancers have been investigated. CTC enumeration using the CellSearch based platform provides an accurate insight on overall survival where higher CTC counts indicate poor prognosis for patients with advanced metastatic cancer. EVs provide information based on their lipid, protein, and nucleic acid content and can be isolated from biofluids and analyzed from a relatively small volume, providing a routine and non-invasive modality to monitor disease progression. Our pilot experiment by assessing the level of two subpopulations of small EVs, the CD9 positive and CD63 positive EVs, showed that the CD9 positive EV level is higher in plasma from patients with advanced metastatic prostate cancer with detectable CTCs. These data show the potential utility of a particular EV subpopulation to serve as biomarkers for advanced metastatic prostate cancer. EVs can potentially be utilized as biomarkers to provide accurate genotypic and phenotypic information for advanced prostate cancer, where new strategies to design a more personalized therapy is currently the focus of considerable investigation.

"Stealth dissemination" of macrophage-tumor cell fusions cultured from blood of patients with pancreatic ductal adenocarcinoma

Here we describe isolation and characterization of macrophage-tumor cell fusions (MTFs) from the blood of pancreatic ductal adenocarcinoma (PDAC) patients. The MTFs were generally aneuploidy, and immunophenotypic characterizations showed that the MTFs express markers characteristic of PDAC and stem cells, as well as M2-polarized macrophages. Single cell RNASeq analyses showed that the MTFs express many transcripts implicated in cancer progression, LINE1 retrotransposons, and very high levels of several long non-coding transcripts involved in metastasis (such as MALAT1). When cultured MTFs were transplanted orthotopically into mouse pancreas, they grew as obvious well-differentiated islands of cells, but they also disseminated widely throughout multiple tissues in "stealth" fashion. They were found distributed throughout multiple organs at 4, 8, or 12 weeks after transplantation (including liver, spleen, lung), occurring as single cells or small groups of cells, without formation of obvious tumors or any apparent progression over the 4 to 12 week period. We suggest that MTFs form continually during PDAC development, and that they disseminate early in cancer progression, forming "niches" at distant sites for subsequent colonization by metastasis-initiating cells.

Rapid and Sensitive Detection of Breast Cancer Cells in Patient Blood with Nuclease-Activated Probe Technology

A challenge for circulating tumor cell (CTC)-based diagnostics is the development of simple and inexpensive methods that reliably detect the diverse cells that make up CTCs. CTC-derived nucleases are one category of proteins that could be exploited to meet this challenge. Advantages of nucleases as CTC biomarkers include: (1) their elevated expression in many cancer cells, including cells implicated in metastasis that have undergone epithelial-to-mesenchymal transition; and (2) their enzymatic activity, which can be exploited for signal amplification in detection methods. Here, we describe a diagnostic assay based on quenched fluorescent nucleic acid probes that detect breast cancer CTCs via their nuclease activity. This assay exhibited robust performance in distinguishing breast cancer patients from healthy controls, and it is rapid, inexpensive, and easy to implement in most clinical labs. Given its broad applicability, this technology has the potential to have a substantive impact on the diagnosis and treatment of many cancers.

The prognostic and diagnostic value of circulating tumor cells in bladder cancer and upper tract urothelial carcinoma: a meta-analysis of 30 published studies

There are inconsistent conclusions in the association between circulating tumor cells (CTCs) and urothelial cancer (UC). We performed a meta-analysis to assess the prognostic and diagnostic value of CTCs in UC. We search Medline, Embase and Web of science for relevant studies. The study was set up according to the inclusion/exclusion criteria. 30 published studies with a total of 2161 urothelial cancer patients were included. Meta-analysis showed that CTC-positive was significantly associated with tumor stage (≤ II vs III, IV) (OR = 4.60, 95% CI: 2.34-9.03), histological grade (I, II vs III) (OR = 2.91, 95% CI: 1.92-4.40), metastasis (OR = 5.12, 95% CI: 3.47-7.55) and regional lymph node metastasis (OR = 2.47, 95% CI: 1.75-3.49). It was also significantly associated with poor overall survival (OS) (HR = 3.98, 95% CI: 2.20-7.21), progression/disease-free survival (PFS/DFS) (HR = 2.22, 95% CI: 1.80-2.73) and cancer-specific survival (CSS) (HR = 5.18, 95% CI: 2.21-12.13). Overall sensitivity and specificity of CTC detection assays were 0.35 (95% CI: 0.28-0.43) and 0.97 (95% CI: 0.92-0.99) respectively. In summary, our meta-analysis suggests that the presence of CTCs in the peripheral blood is an independent predictive indicator of poor outcomes for urothelial cancer patients. It can also be used as a noninvasive method for the confirmation of cancer diagnosis. More studies are required to further explore the role of this marker in clinical practice.

Circulating Tumor Cells: From Theory to Nanotechnology-Based Detection

Cancer stem cells with stem-cell properties are regarded as tumor initiating cells. Sharing stem-cell properties, circulating tumor cells (CTCs) are responsible for the development of metastasis, which significant affects CTC analysis in clinical practice. Due to their extremely low occurrence in blood, however, it is challenging to enumerate and analyze CTCs. Nanotechnology is able to address the problems of insufficient capture efficiency and low purity of CTCs owing to the unique structural and functional properties of nanomaterials, showing strong promise for CTC isolation and detection. In this review, we discuss the role of stem-like CTCs in metastases, provide insight into recent progress in CTC isolation and detection approaches using various nanoplatforms, and highlight the role of nanotechnology in the advancement of CTC research.

Identification of high independent prognostic value of nanotechnology based circulating tumor cell enumeration in first-line chemotherapy for metastatic breast cancer patients

Enumeration of circulating tumor cells (CTCs) is a promising tool in the management of metastatic breast cancer (MBC). This study investigated the capturing efficiency and prognostic value of our previously reported peptide-based nanomagnetic CTC isolation system (Pep@MNPs). We counted CTCs in blood samples taken at baseline (n = 102) and later at patients' first clinical evaluation after starting firstline chemotherapy (n = 72) in a cohort of women treated for MBC. Their median follow-up was 16.3 months (range: 9.0-31.0 months). The CTC detection rate was 69.6 % for the baseline samples. Patients with ≤2 CTC/2 ml at baseline had longer median progression-free survival (PFS) than did those with >2 CTC/2 ml (17.0 months vs. 8.0 months; P = 0.002). Patients with ≤2 CTC/2 ml both at baseline and first clinical evaluation had longest PFS (18.2 months) among all patient groups (P = 0.004). Particularly, among patients with stable disease (SD; per imaging evaluation) our assay could identify those with longer PFS (P < 0.001). Patients with >2 CTC/2 ml at baseline were also significantly more likely to suffer liver metastasis (P = 0.010). This study confirmed the prognostic value of Pep@MNPs assays for MBC patients who undergo firstline chemotherapy, and offered extra stratification regarding PFS for patients with SD, and a possible indicator for patients at risk for liver metastasis.

Fluid shear stress induces cancer stem cell-like phenotype in MCF7 breast cancer cell line without inducing epithelial to mesenchymal transition

Metastasis is the leading cause of cancer deaths due to the spread of cancer cells through the blood vessels and the subsequent formation of secondary tumors. Metastasizing cancer cells in the human vasculature are called circulating tumor cells (CTCs) and are characterized to express the epithelial cell adhesion molecule (EpCAM). They are further known to survive physiological fluid shear stress (FSS) conditions. However, the effect of FSS on CTC molecular phenotype, such as the epithelial to mesenchymal transition (EMT) and cancer stem cell (CSC) expression, has not been extensively studied. Here, CTCs in FSS are evaluated in an in vitro model system. MCF7 and MDA-MB-231 breast cancer cell lines were grown in adherent and suspension culture media. The cell lines were tested for EMT and CSC genetic and protein markers using qRT-PCR and flow cytometry, respectively. Suspension cells showed a significantly increased EMT signature compared to adherent cells (p<0.05), suggesting that they model cells detaching from primary tumors in vivo. Upon application of FSS, MCF7 and MDA-MB-231 cells did not show a significant change in EMT expression (p>0.05), but there was a statistically significant increase of the CSC population in MCF7 suspension cultures (p<0.05). These results with MCF7 suggest that CTCs can be modeled in vitro as non-adherent cancer cells in FSS and that they show an increased CSC-like signature during circulation, providing new insights to the importance of CSC-targeting strategies when treating metastatic patients.

Measurement of copy number variation in single cancer cells using rapid-emulsification digital droplet MDA

Uniform amplification of low input DNA is important for applications across biology, including single-cell genomics, forensic science, and microbial and viral sequencing. However, the requisite biochemical amplification methods are prone to bias, skewing sequence proportions and obscuring signals relating to copy number. Digital droplet multiple displacement amplification enables uniform amplification, but requires expert knowledge of microfluidics to generate monodisperse emulsions. In addition, existing microfluidic methods are tedious and labor intensive for preparing many samples. Here, we introduce rapid emulsification multiple displacement amplification, a method to generate monodisperse droplets with a hand-held syringe and hierarchical droplet splitter. While conventional microfluidic devices require >10 minutes to emulsify a sample, our system takes tens of seconds and yields data of equivalent quality. We demonstrate the approach by using it to accurately measure copy number variation in single cancer cells.

Evaluating blood levels of neuron specific enolase, chromogranin A, and circulating tumor cells as Merkel cell carcinoma biomarkers

Background

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin cancer. Although used to monitor MCC patients, the clinical utility of neuron-specific enolase (NSE) and chromogranin A (ChrA) blood levels is untested. EpCAM-positive circulating tumor cells (CTC) reflect disease status in several epithelial tumors. Here we investigate the use of NSE and ChrA blood levels and CTC counts as biomarkers for MCC disease behavior.

Methods

NSE and ChrA blood levels from 60 patients with MCC were retrospectively analyzed; 30 patients were additionally screened for CTC. Biomarker values were correlated to clinical parameters.

Results

Despite routine use by some physicians, NSE and ChrA blood levels did not correlate with progression free survival, disease specific survival, or MCC recurrence. We found CTC in 97% of tested MCC patients. CTC counts were elevated in patients with active disease, suggesting their potential use in monitoring MCC.

Conclusion

NSE and ChrA levels were not effective in predicting outcomes or detecting recurrences of MCC. In contrast, CTC counts have potential utility as a biomarker for MCC disease behavior.

Association of preoperative EpCAM Circulating Tumor Cells and peripheral Treg cell levels with early recurrence of hepatocellular carcinoma following radical hepatic resection

Background

This study was carried out to determine the prognostic significance of preoperative peripheral epithelial cell adhesion molecule- positive (EpCAM⁺) circulating tumor cell (CTC) and T regulatory (Treg) cell levels in hepatocellular carcinoma (HCC) patients for the prediction of postoperative recurrence following curative resection.

Methods

A total of 49 patients about to undergo curative resection for HCC were recruited into the study. PCR and FACS were used to detect the preoperative levels of EpCAM^mRNA+ CTCs and CD4⁺CD25⁺Foxp3⁺ Treg cells. The prognostic value of EpCAM^mRNA+ CTCs, CD4⁺CD25⁺Foxp3⁺ Treg cells, and other clinicopathological factors were analyzed by applying the Kaplan–Meier method and the multivariate Cox proportional hazards model.

Results

The number of EpCAM^mRNA+ CTCs and Treg/CD4⁺ cells showed significant correlation as prognostic factors of postoperative HCC recurrence: EpCAM^mRNA+ CTC ≥ 2.22 (P = 0.001) and Treg/CD4⁺ ≥ 5.07 (P = 0.045), with EpCAM^mRNA+ CTC ≥ 2.22 (P = 0.003, HR = 6.668) being the most important indicator. Patients with high CTC/Treg levels showed a significantly higher risk of developing postoperative HCC recurrence than those with low CTC/Treg levels (66.7 % vs. 10.3 %, P < 0.001). The high CTC/low Treg group also presented higher 1-year recurrence rates compared with the low CTC/low Treg level group (50.0 % vs. 10.3 %, P = 0.004).

Conclusions

Elevated EpCAM^mRNA+ CTC and Treg/CD4⁺ levels were associated with early recurrence of HCC, indicative of poor clinical outcome. The combined detection of EpCAM^mRNA+ CTC and Treg/CD4⁺ may therefore provide a novel prognostic predictor for HCC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2526-4) contains supplementary material, which is available to authorized users.

DNA alterations in the tumor genome and their associations with clinical outcome in prostate cancer

Although most prostate cancer (PCa) cases are not life-threatening, approximately 293 000 men worldwide die annually due to PCa. These lethal cases are thought to be caused by coordinated genomic alterations that accumulate over time. Recent genome-wide analyses of DNA from subjects with PCa have revealed most, if not all, genetic changes in both germline and PCa tumor genomes. In this article, I first review the major, somatically acquired genomic characteristics of various subtypes of PCa. I then recap key findings on the relationships between genomic alterations and clinical parameters, such as biochemical recurrence or clinical relapse, metastasis and cancer-specific mortality. Finally, I outline the need for, and challenges with, validation of recent findings in prospective studies for clinical utility. It is clearer now than ever before that the landscape of somatically acquired aberrations in PCa is highlighted by DNA copy number alterations (CNAs) and TMPRSS2-ERG fusion derived from complex rearrangements, numerous single nucleotide variations or mutations, tremendous heterogeneity, and continuously punctuated evolution. Genome-wide CNAs, PTEN loss, MYC gain in primary tumors, and TP53 loss/mutation and AR amplification/mutation in advanced metastatic PCa have consistently been associated with worse cancer prognosis. With this recently gained knowledge, it is now an opportune time to develop DNA-based tests that provide more accurate patient stratification for prediction of clinical outcome, which will ultimately lead to more personalized cancer care than is possible at present.

An improved CTC isolation scheme for pairing with downstream genomics: Demonstrating clinical utility in metastatic prostate, lung and pancreatic cancer

Improvements in technologies to yield purer circulating tumor cells (CTCs) will enable a broader range of clinical applications. We have previously demonstrated the use of a commercially available cell-adhesion matrix (CAM) assay to capture invasive CTCs (iCTCs). To improve the purity of the isolated iCTCs, here we used fluorescence-activated cell sorting (FACS) in combination with the CAM assay (CAM + FACS). Our results showed an increase of median purity from the CAM assay to CAM + FACS for the spiked-in cell lines and patient samples analyzed from three different metastatic cancer types: castration resistant prostate cancer (mCRPC), non-small cell lung cancer (mNSCLC) and pancreatic ductal adenocarcinoma cancer (mPDAC). Copy number profiles for spiked-in mCRPC cell line and mCRPC patient iCTCs were similar to expected mCRPC profiles and a matched biopsy. A somatic epidermal growth factor receptor (EGFR) mutation specific to mNSCLC was observed in the iCTCs recovered from EGFR(+) mNSCLC cell lines and patient samples. Next-generation sequencing (NGS) of spiked-in pancreatic cancer cell line and mPDAC patient iCTCs showed mPDAC common mutations. CAM + FACS iCTC enrichment enables multiple downstream genomic characterizations across different tumor types.

A Multiscale TiO2 Nanorod Array for Ultrasensitive Capture of Circulating Tumor Cells

In this work, a uniform multiscale TiO2 nanorod array is fabricated to provide a "multi-scale interacting platform" for cell capture, which exhibits excellent capture specificity and sensitivity of the target cells after modification with bovine serum albumin (BSA) and DNA aptamer. After studying the capture performance of the BSA-aptamer TiO2 nanorod substrates and other nanostructured substrates, we can conclude that the multisacle TiO2 nanorod substrates could indeed effectively enhance the capture yields of target cancer cells. The capture yield of artificial blood samples on the BSA-aptamer TiO2 nanorod substrates is up to 85%-95%, revealing the potential application of the TiO2 nanorods on efficient and sensitive capture of rare circulating tumor cells.

Circulating tumor cells in germ cell tumors: are those biomarkers of real prognostic value? A review

Analysis of circulating tumor cells from patients with different types of cancer is nowadays a fascinating new tool of research and their number is proven to be useful as a prognostic factor in metastatic breast, colon and prostate cancer patients. Studies are going beyond enumeration, exploring the circulating tumor cells to better understand the mechanisms of tumorigenesis, invasion and metastasis and their value for characterization, prognosis and tailoring of treatment. Few studies investigated the prognostic significance of circulating tumor cells in germ cell tumors. In this review, we examine the possible significance of the detection of circulating tumor cells in this setting.

Perioperative circulating tumor cell detection: Current perspectives

Primary cancer resections and in selected cases surgical metastasectomies significantly improve survival, however many patients develop recurrences. Circulating tumor cells (CTCs) function as an independent marker that could be used in the prognostication of different cancers. Sampling of blood and bone marrow compartments during cancer resections is a unique opportunity to increase individual tumor cell capture efficiency. This review will address the diagnostic and therapeutic potentials of perioperative tumor isolation and highlight the focus of future studies on characterization of single disseminated cancer cells to identify targets for molecular therapy and immune escape mechanisms.

Urinary Metabolite Risk Biomarkers of Lung Cancer: A Prospective Cohort Study

BACKGROUND

Lung cancer is a major health burden causing 160,000 and 1.6 million deaths annually in the United States and worldwide, respectively.

METHODS

While seeking to identify stable and reproducible biomarkers in noninvasively collected biofluids, we assessed whether previously identified metabolite urinary lung cancer biomarkers, creatine riboside (CR), N-acetylneuraminic acid (NANA), cortisol sulfate, and indeterminate metabolite 561+, were elevated in the urines of subjects prior to lung cancer diagnosis in a well-characterized prospective Southern Community Cohort Study (SCCS). Urine was examined from 178 patients and 351 nondiseased controls, confirming that one of four metabolites was associated with lung cancer risk in the overall case-control set, whereas two metabolites were associated with lung cancer risk in European-Americans.

RESULTS

OR of lung cancer associated with elevated CR levels, and adjusted for smoking and other potential confounders, was 2.0 [95% confidence interval (CI), 1.2-3.4; P= 0.01]. In European-Americans, both CR and NANA were significantly associated with lung cancer risk (OR = 5.3; 95% CI, 1.6-17.6; P= 0.006 and OR=3.5; 95% CI, 1.5-8.4; P= 0.004, respectively). However, race itself did not significantly modify the associations. ROC analysis showed that adding CR and NANA to a model containing previously established lung cancer risk factors led to a significantly improved classifier (P= 0.01). Increasing urinary levels of CR and NANA displayed a positive association with increasing tumor size, strengthening a previously established link to altered tumor metabolism.

CONCLUSION AND IMPACT

These replicated results provide evidence that identified urinary metabolite biomarkers have a potential utility as noninvasive, clinical screening tools for early diagnosis of lung cancer. Cancer Epidemiol Biomarkers Prev; 25(6); 978-86. ©2016 AACR.

Inflammasome-independent NLRP3 is required for epithelial-mesenchymal transition in colon cancer cells

Inflammasome NLRP3 plays a crucial role in the process of colitis and colitis--associated colon cancer. Even though much is known regarding the NLRP3 inflammasome that regulates pro-inflammatory cytokine release in innate immune cells, the role of NLRP3 in non-immune cells is still unclear. In this study, we showed that NLRP3 was highly expressed in mesenchymal-like colon cancer cells (SW620), and was upregulated by tumor necrosis factors-α (TNF-α) and transforming growth factor-β1 (TGF-β1) respectively, during EMT in colon cancer epithelial cells HCT116 and HT29. Knockdown of NLRP3 retained epithelial spindle-like morphology of HCT116 and HT29 cells and reversed the mesenchymal characteristic of SW620 cells, indicated by the decreased expression of vimentin and MMP9 and increased expression of E-cadherin. In addition, knockdown of NLRP3 in colorectal carcinoma cells displayed diminished cell migration and invasion. Interestingly, during the EMT process induced by TNF-α or TGF-β1, the cleaved caspase-1 and ASC speck were not detected, indicating that NLRP3 functions in an inflammasome-independent way. Further studies demonstrated that NLRP3 protein expression was regulated by NF-κB signaling in TNF-α or TGF-β1-induced EMT, as verified by the NF-κB inhibitor Bay 11-7082. Moreover, NLRP3 knockdown reduced the expression of Snail1, indicating that NLRP3 may promote EMT through regulating Snail1. In summary, our results showed that the NLRP3 expression, not the inflammasome activation, was required for EMT in colorectal cancer cells.

Glucose is a key driver for GLUT1-mediated nanoparticles internalization in breast cancer cells

The mesenchymal state in cancer is usually associated with poor prognosis due to the metastatic predisposition and the hyper-activated metabolism. Exploiting cell glucose metabolism we propose a new method to detect mesenchymal-like cancer cells. We demonstrate that the uptake of glucose-coated magnetic nanoparticles (MNPs) by mesenchymal-like cells remains constant when the glucose in the medium is increased from low (5.5 mM) to high (25 mM) concentration, while the MNPs uptake by epithelial-like cells is significantly reduced. These findings reveal that the glucose-shell of MNPs plays a major role in recognition of cells with high-metabolic activity. By selectively blocking the glucose transporter 1 channels we showed its involvement in the internalization process of glucose-coated MNPs. Our results suggest that glucose-coated MNPs can be used for metabolic-based assays aimed at detecting cancer cells and that can be used to selectively target cancer cells taking advantage, for instance, of the magnetic-thermotherapy.