Special Issue "Circulating Tumor Cells (CTCs)"

A special issue of Cancers (ISSN 2072-6694).

Deadline for manuscript submissions: closed (30 November 2018)

Special Issue Editor

Guest Editor
Prof. Dr. Dario Marchetti

Director, Biomarker Research Program, Houston Methodist Research Institute, Professor, Institute of Academic Medicine, Visiting Professor, Baylor College of Medicine, MS: R7-414, 6670 Bertner Avenue, Houston, TX 77030, USA
Website | E-Mail
Interests: the biology and therapeutic utility of circulating tumor cells (CTCs); liquid biopsies; mechanisms of brain metastasis and dormancy in breast and melanoma cancers; roles of heparanase in development and disease

Special Issue Information

Dear Colleagues,

The major cause of patient mortality in cancer is metastasis; however, understanding of the metastatic cascade and mechanisms underlying this complex set of events remain poorly understood. Cancer cells invade the surrounding tissue of primary or metastatic tumors, intravasate into lymphatic and blood vessels, disseminate to distant tissues, extravasate by adapting to the new microenvironment, and colonize these tissues. Because dissemination mostly occurs through the blood, circulating tumor cells (CTCs) are of paramount importance and one of the most promising areas of oncology research. CTCs might serve as “liquid biopsy” as a better way to diagnose cancer patients compared to painful biopsies of the primary tumor, and can represent a clinically useful tool to better reflect cancer progression and monitoring in the patient. The isolation, characterization, and interrogation of CTCs are hampered by their rarity and heterogeneity, either inherited from respective primary or metastatic tumors or as a result of CTC evolution in blood by genetic/epigenetic progression that may or may not lead to a fully metastatic-competent CTC. Significant technical challenges in the field also persist in regard to identifying and interrogating CTC heterogeneity, assessing CTC biomarkers of clinical utility, and comprehensively capturing these cells (usually, a ratio of one CTC per 106 leukocytes and 109 erythrocytes in one milliliter of blood). Finally, many studies have reported the clinical impact of enumerating CTCs, considering that CTC testing is being employed in over 300 clinical trials worldwide. However, much of the CTC biology needs to be discovered and many scientific/technical challenges must be overcome before their clinical promise as biomarkers and targets for improved therapies can be fulfilled. The objective of this Special Issue is to publish the latest findings in CTC research and clinical implementation. Contributions outlining CTC discoveries in biological and clinical settings, CTC theoretical and pre-clinical models, CTC technologies and methods for their detection, and clinical findings applying CTC concepts, are welcome.

Prof. Dr. Dario Marchetti
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Cancers is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (13 papers)

View options order results:
result details:
Displaying articles 1-13
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Detection and Prognostic Relevance of Circulating and Disseminated Tumour Cell in Dogs with Metastatic Mammary Carcinoma: A Pilot Study
Cancers 2019, 11(2), 163; https://doi.org/10.3390/cancers11020163
Received: 7 December 2018 / Revised: 23 January 2019 / Accepted: 24 January 2019 / Published: 1 February 2019
PDF Full-text (5768 KB) | HTML Full-text | XML Full-text
Abstract
In human breast cancer, both circulating tumour cells (CTCs) in peripheral blood and disseminated tumour cells (DTCs) in the bone marrow are predictive of short survival and may be used as liquid biopsy to guide therapy. Herein we investigate, for the first time, [...] Read more.
In human breast cancer, both circulating tumour cells (CTCs) in peripheral blood and disseminated tumour cells (DTCs) in the bone marrow are predictive of short survival and may be used as liquid biopsy to guide therapy. Herein we investigate, for the first time, the feasibility to quantify CTCs and DTCs in canine metastatic mammary carcinoma (MMC) with the automated CellSearch platform, which identifies tumour cells by immune-magnetic enrichment and fluorescent labelling. Using this approach before start of treatment, we could detect at least 1 CTC per 7.5 mL of peripheral blood in 12 out of 27 evaluable samples (44.4%) and at least 1 DTC per 1 mL of bone marrow in 11 out of 14 evaluable samples (78.6%). Conversely, we did not find any CTCs in the healthy, negative control dogs (n = 5) that we analysed in parallel. Interestingly, the levels of CTCs/DTCs and the prevalence of positive dogs closely resemble results obtained by CellSearch assay in metastatic breast cancer patients at diagnosis. Moreover, in the canine cohort, the presence of CTCs was significantly associated with poor outcome. These observations identify the first actionable marker in veterinarian oncology to guide treatment of canine MMC. Furthermore, our findings have important implications for human research, since it reinforce the value of canine MMC as model useful to speed up pharmacological studies with primary endpoint of overall survival, given the reduced life-span of the canine species. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Immunomagnetic-Enriched Subpopulations of Melanoma Circulating Tumour Cells (CTCs) Exhibit Distinct Transcriptome Profiles
Cancers 2019, 11(2), 157; https://doi.org/10.3390/cancers11020157
Received: 16 January 2019 / Accepted: 28 January 2019 / Published: 30 January 2019
PDF Full-text (1474 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Cutaneous melanoma circulating tumour cells (CTCs) are phenotypically and molecularly heterogeneous. We profiled the gene expression of CTC subpopulations immunomagnetic-captured by targeting either the melanoma-associated marker, MCSP, or the melanoma-initiating marker, ABCB5. Firstly, the expression of a subset of melanoma genes was investigated [...] Read more.
Cutaneous melanoma circulating tumour cells (CTCs) are phenotypically and molecularly heterogeneous. We profiled the gene expression of CTC subpopulations immunomagnetic-captured by targeting either the melanoma-associated marker, MCSP, or the melanoma-initiating marker, ABCB5. Firstly, the expression of a subset of melanoma genes was investigated by RT-PCR in MCSP-enriched and ABCB5-enriched CTCs isolated from a total of 59 blood draws from 39 melanoma cases. Of these, 6 MCSP- and 6 ABCB5-enriched CTC fractions were further analysed using a genome-wide gene expression microarray. The transcriptional programs of both CTC subtypes included cell survival maintenance, cell proliferation, and migration pathways. ABCB5-enriched CTCs were specifically characterised by up-regulation of genes involved in epithelial to mesenchymal transition (EMT), suggesting an invasive phenotype. These findings underscore the presence of at least two distinct melanoma CTC subpopulations with distinct transcriptional programs, which may have distinct roles in disease progression and response to therapy. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Expression of Proteolytic Enzymes by Small Cell Lung Cancer Circulating Tumor Cell Lines
Cancers 2019, 11(1), 114; https://doi.org/10.3390/cancers11010114
Received: 28 December 2018 / Revised: 16 January 2019 / Accepted: 17 January 2019 / Published: 19 January 2019
PDF Full-text (2525 KB) | HTML Full-text | XML Full-text
Abstract
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 [...] Read more.
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. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Spectrum of Epithelial-Mesenchymal Transition Phenotypes in Circulating Tumour Cells from Early Breast Cancer Patients
Received: 12 December 2018 / Revised: 30 December 2018 / Accepted: 2 January 2019 / Published: 9 January 2019
PDF Full-text (2432 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Circulating tumour cells (CTCs) can provide valuable prognostic information in a number of epithelial cancers. However, their detection is hampered due to their molecular heterogeneity, which can be induced by the epithelial-mesenchymal transition (EMT) process. Therefore, current knowledge about CTCs from clinical samples [...] Read more.
Circulating tumour cells (CTCs) can provide valuable prognostic information in a number of epithelial cancers. However, their detection is hampered due to their molecular heterogeneity, which can be induced by the epithelial-mesenchymal transition (EMT) process. Therefore, current knowledge about CTCs from clinical samples is often limited due to an inability to isolate wide spectrum of CTCs phenotypes. In the current work, we aimed at isolation and molecular characterization of CTCs with different EMT status in order to establish their clinical significance in early breast cancer patients. We have obtained CTCs-enriched blood fraction from 83 breast cancer patients in which we have tested the expression of epithelial, mesenchymal and general breast cancer CTCs markers (MGB1/HER2/CK19/CDH1/CDH2/VIM/PLS3), cancer stem cell markers (CD44, NANOG, ALDH1, OCT-4, CD133) and cluster formation gene (plakoglobin). We have shown that in the CTCs-positive patients, epithelial, epithelial-mesenchymal and mesenchymal CTCs markers were detected at a similar rate (in 28%, 24% and 24%, respectively). Mesenchymal CTCs were characterized by the most aggressive phenotype (significantly higher expression of CXCR4, uPAR, CD44, NANOG, p < 0.05 for all), presence of lymph node metastases (p = 0.043), larger tumour size (p = 0.023) and 7.33 higher risk of death in the multivariate analysis (95% CI 1.06–50.41, p = 0.04). Epithelial-mesenchymal subtype, believed to correspond to highly plastic and aggressive state, did not show significant impact on survival. Gene expression profile of samples with epithelial-mesenchymal CTCs group resembled pure epithelial or pure mesenchymal phenotypes, possibly underlining degree of EMT activation in particular patient’s sample. Molecular profiling of CTCs EMT phenotype provides more detailed and clinically informative results, proving the role of EMT in malignant cancer progression in early breast cancer. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Graphical abstract

Open AccessArticle Enumerating Circulating Tumor Cells with a Self-Assembled Cell Array (SACA) Chip: A Feasibility Study in Patients with Colorectal Cancer
Received: 30 November 2018 / Revised: 1 January 2019 / Accepted: 3 January 2019 / Published: 8 January 2019
PDF Full-text (2254 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide. Detecting and enumerating circulating tumor cells (CTCs) in patients with colorectal cancer emerged as an important prognostic tool which provides a direct estimate of metastatic potential. Improving the turnaround time [...] Read more.
Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide. Detecting and enumerating circulating tumor cells (CTCs) in patients with colorectal cancer emerged as an important prognostic tool which provides a direct estimate of metastatic potential. Improving the turnaround time and decreasing sample volume is critical for incorporating this liquid biopsy tool into routine practice. The objective of the current study was to validate the clinical feasibility of a self-assembled cell array (SACA) chip, a CTC counting platform with less than 4 h turnaround time, in patients with newly diagnosed colorectal cancers. In total, 179 patients with newly diagnosed colorectal cancers from a single institute were enrolled. Epithelial cell adhesion molecule positive (EpCAM(+)), cluster of differentiation 45 negative (CD45(−)) cells were isolated and enumerated from 2 mL of peripheral vein blood (PB) and inferior mesenteric vein blood (IMV) samples obtained during surgery. We found that the CTC count in PB but not IMV correlates with disease stages. Neoadjuvant chemotherapy did not lead to decreased CTC count in both types of blood samples. With cutoffs of four CTCs per 2 mL of blood, and serum carcinoembryonic antigen (CEA) level of 5 ng/mL, patients with non-metastatic disease were more likely to experience recurrence if they had high PB CTC count and high serum CEA concentration (odds ratio, 8.9). Our study demonstrates the feasibility of enumerating CTCs with a SACA chip in patients with colorectal cancer. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Frequency of Circulating Tumor Cells (CTC) in Patients with Brain Metastases: Implications as a Risk Assessment Marker in Oligo-Metastatic Disease
Cancers 2018, 10(12), 527; https://doi.org/10.3390/cancers10120527
Received: 5 November 2018 / Revised: 9 December 2018 / Accepted: 17 December 2018 / Published: 19 December 2018
PDF Full-text (1186 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Forty percent of non-small cell lung cancer (NSCLC) patients develop brain metastases, resulting in a dismal prognosis. However, patients in an oligo-metastatic brain disease setting seem to have better outcomes. Here, we investigate the possibility of using circulating tumor cells (CTCs) as biomarkers [...] Read more.
Forty percent of non-small cell lung cancer (NSCLC) patients develop brain metastases, resulting in a dismal prognosis. However, patients in an oligo-metastatic brain disease setting seem to have better outcomes. Here, we investigate the possibility of using circulating tumor cells (CTCs) as biomarkers to differentiate oligo-metastatic patients for better risk assessment. Using the CellSearch® system, few CTCs were detected among NSCLC patients with brain metastases (n = 52, 12.5% ≥ two and 8.9% ≥ five CTC/7.5 mL blood) and especially oligo-metastatic brain patients (n = 34, 5.9%, and 2.9%). Still, thresholds of both ≥ two and ≥ five CTCs were independent prognostic indicators for shorter overall survival time among all of the NSCLC patients (n = 90, two CTC ≥ HR: 1.629, p = 0.024, 95% CI: 1.137–6.465 and five CTC ≥ HR: 2.846, p = 0.0304, CI: 1.104–7.339), as well as among patients with brain metastases (two CTC ≥ HR: 4.694, p = 0.004, CI: 1.650–13.354, and five CTC ≥ HR: 4.963, p = 0.003, CI: 1.752–14.061). Also, oligo-brain NSCLC metastatic patients with CTCs had a very poor prognosis (p = 0.019). Similarly, in other tumor entities, only 9.6% of patients with brain metastases (n = 52) had detectable CTCs. Our data indicate that although patients with brain metastases more seldom harbor CTCs, they are still predictive for overall survival, and CTCs might be a useful biomarker to identify oligo-metastatic NSCLC patients who might benefit from a more intense therapy. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Circulating Tumor and Invasive Cell Gene Expression Profile Predicts Treatment Response and Survival in Pancreatic Adenocarcinoma
Cancers 2018, 10(12), 467; https://doi.org/10.3390/cancers10120467
Received: 5 September 2018 / Revised: 17 October 2018 / Accepted: 16 November 2018 / Published: 24 November 2018
PDF Full-text (1044 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Previous studies have shown that pharmacogenomic modeling of circulating tumor and invasive cells (CTICs) can predict response of pancreatic ductal adenocarcinoma (PDAC) to combination chemotherapy, predominantly 5-fluorouracil-based. We hypothesized that a similar approach could be developed to predict treatment response to standard frontline [...] Read more.
Previous studies have shown that pharmacogenomic modeling of circulating tumor and invasive cells (CTICs) can predict response of pancreatic ductal adenocarcinoma (PDAC) to combination chemotherapy, predominantly 5-fluorouracil-based. We hypothesized that a similar approach could be developed to predict treatment response to standard frontline gemcitabine with nab-paclitaxel (G/nab-P) chemotherapy. Gene expression profiles for responsiveness to G/nab-P were determined in cell lines and a test set of patient samples. A prospective clinical trial was conducted, enrolling 37 patients with advanced PDAC who received G/nab-P. Peripheral blood was collected prior to treatment, after two months of treatment, and at progression. The CTICs were isolated based on a phenotype of collagen invasion. The RNA was isolated, cDNA synthesized, and qPCR gene expression analyzed. Patients were most closely matched to one of three chemotherapy response templates. Circulating tumor and invasive cells’ SMAD4 expression was measured serially. The CTICs were reliably isolated and profiled from peripheral blood prior to and during chemotherapy treatment. Individual patients could be matched to distinct response templates predicting differential responses to G/nab-P treatment. Progression free survival was significantly correlated to response prediction and ΔSMAD4 was significantly associated with disease progression. These findings support phenotypic profiling and ΔSMAD4 of CTICs as promising clinical tools for choosing effective therapy in advanced PDAC, and for anticipating disease progression. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Scanning Electron Microscopy of Circulating Tumor Cells and Tumor-Derived Extracellular Vesicles
Cancers 2018, 10(11), 416; https://doi.org/10.3390/cancers10110416
Received: 13 August 2018 / Revised: 24 October 2018 / Accepted: 30 October 2018 / Published: 31 October 2018
Cited by 2 | PDF Full-text (7236 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
To explore morphological features of circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs), we developed a protocol for scanning electron microscopy (SEM) of CTCs and tdEVs. CTCs and tdEVs were isolated by immunomagnetic enrichment based on their Epithelial Cell Adhesion Molecule (EpCAM) [...] Read more.
To explore morphological features of circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs), we developed a protocol for scanning electron microscopy (SEM) of CTCs and tdEVs. CTCs and tdEVs were isolated by immunomagnetic enrichment based on their Epithelial Cell Adhesion Molecule (EpCAM) expression or by physical separation through 5 μm microsieves from 7.5 mL of blood from Castration-Resistant Prostate Cancer (CRPC) patients. Protocols were optimized using blood samples of healthy donors spiked with PC3 and LNCaP cell lines. CTCs and tdEVs were identified among the enriched cells by fluorescence microscopy. The positions of DNA+, CK+, CD45− CTCs and DNA−, CK+, CD45− tdEVs on the CellSearch cartridges and microsieves were recorded. After gradual dehydration and chemical drying, the regions of interest were imaged by SEM. CellSearch CTCs retained their morphology revealing various shapes, some of which were clearly associated with CTCs undergoing apoptosis. The ferrofluid was clearly distinguishable, shielding major portions of all isolated objects. CTCs and leukocytes on microsieves were clearly visible, but revealed physical damage attributed to the physical forces that cells exhibit while entering one or multiple pores. tdEVs could not be identified on the microsieves as they passed through the pores. Insights on the underlying mechanism of each isolation technique could be obtained. Complete detailed morphological characteristics of CTCs are, however, masked by both techniques. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle The Value of Monitoring the Behavior of Circulating Tumor Cells at the End of Endocrine Therapy in Breast Cancer Patients
Cancers 2018, 10(11), 407; https://doi.org/10.3390/cancers10110407
Received: 9 October 2018 / Accepted: 26 October 2018 / Published: 29 October 2018
PDF Full-text (2462 KB) | HTML Full-text | XML Full-text
Abstract
After five years of endocrine therapy, patients with ER+ (estrogen receptor positive) breast cancer face the question of the benefit of further treatment. Ten years of endocrine therapy has been demonstrated to improve survival compared to five years. However, the individual benefit of [...] Read more.
After five years of endocrine therapy, patients with ER+ (estrogen receptor positive) breast cancer face the question of the benefit of further treatment. Ten years of endocrine therapy has been demonstrated to improve survival compared to five years. However, the individual benefit of continuation remains unclear. Therefore, markers for predicting benefit from endocrine treatment and extended endocrine treatment are desperately needed. In this study the dynamics over time of the tumor cells circulating in peripheral blood of patients, circulating tumor cells/ circulating epithelial tumor cells (CTC/CETC), as the systemic part of the tumor were investigated in 36 patients with ER+ primary breast cancer. CTC/CETCs were monitored serially during and after endocrine therapy. After termination of endocrine therapy 12 patients showed an increase in CTC/CETCs, with 8 of 12 suffering relapse. No change or a reduction was observed in 24 patients, with 2 of 24 suffering relapse. Initial tumor size was marginally prognostic (p = 0.053) but not nodal status nor the mere number of CTC/CETCs. Only the trajectory of CTC/CETCs was a statistically significant predictor of relapse free survival (increasing cell numbers: mean = 940 days vs. stable/decreasing cell numbers mean not reached). Individual cases demonstrated that an increase of CTC/CETCs after discontinuation of tamoxifen therapy could be stopped by resuming the endocrine therapy. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Classification of Cells in CTC-Enriched Samples by Advanced Image Analysis
Cancers 2018, 10(10), 377; https://doi.org/10.3390/cancers10100377
Received: 21 August 2018 / Revised: 5 October 2018 / Accepted: 8 October 2018 / Published: 10 October 2018
Cited by 1 | PDF Full-text (2657 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In the CellSearch® system, blood is immunomagnetically enriched for epithelial cell adhesion molecule (EpCAM) expression and cells are stained with the nucleic acid dye 4′6-diamidino-2-phenylindole (DAPI), Cytokeratin-PE (CK), and CD45-APC. Only DAPI+/CK+ objects are presented to the operator to identify circulating tumor [...] Read more.
In the CellSearch® system, blood is immunomagnetically enriched for epithelial cell adhesion molecule (EpCAM) expression and cells are stained with the nucleic acid dye 4′6-diamidino-2-phenylindole (DAPI), Cytokeratin-PE (CK), and CD45-APC. Only DAPI+/CK+ objects are presented to the operator to identify circulating tumor cells (CTC) and the identity of all other cells and potential undetected CTC remains unrevealed. Here, we used the open source imaging program Automatic CTC Classification, Enumeration and PhenoTyping (ACCEPT) to analyze all DAPI+ nuclei in EpCAM-enriched blood samples obtained from 192 metastatic non-small cell lung cancer (NSCLC) patients and 162 controls. Significantly larger numbers of nuclei were detected in 300 patient samples with an average and standard deviation of 73,570 ± 74,948, as compared to 359 control samples with an average and standard deviation of 4191 ± 4463 (p < 0.001). In patients, only 18% ± 21% and in controls 23% ± 15% of the nuclei were identified as leukocytes or CTC. Adding CD16-PerCP for granulocyte staining, the use of an LED as the light source for CD45-APC excitation and plasma membrane staining obtained with wheat germ agglutinin significantly improved the classification of EpCAM-enriched cells, resulting in the identification of 94% ± 5% of the cells. However, especially in patients, the origin of the unidentified cells remains unknown. Further studies are needed to determine if undetected EpCAM+/DAPI+/CK-/CD45- CTC is present among these cells. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessArticle Assessment of the Mutational Status of NSCLC Using Hypermetabolic Circulating Tumor Cells
Cancers 2018, 10(8), 270; https://doi.org/10.3390/cancers10080270
Received: 28 May 2018 / Revised: 1 August 2018 / Accepted: 10 August 2018 / Published: 14 August 2018
Cited by 1 | PDF Full-text (3225 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Molecular characterization is currently a key step in NSCLC therapy selection. Circulating tumor cells (CTC) are excellent candidates for downstream analysis, but technology is still lagging behind. In this work, we show that the mutational status of NSCLC can be assessed on hypermetabolic [...] Read more.
Molecular characterization is currently a key step in NSCLC therapy selection. Circulating tumor cells (CTC) are excellent candidates for downstream analysis, but technology is still lagging behind. In this work, we show that the mutational status of NSCLC can be assessed on hypermetabolic CTC, detected by their increased glucose uptake. We validated the method in 30 Stage IV NSCLC patients: peripheral blood samples were incubated with a fluorescent glucose analog (2-NBDG) and analyzed by flow cytometry. Cells with the highest glucose uptake were sorted out. EGFR and KRAS mutations were detected by ddPCR. In sorted cells, mutated DNA was found in 85% of patients, finding an exact match with primary tumor in 70% of cases. Interestingly, in two patients multiple KRAS mutations were detected. Two patients displayed different mutations with respect to the primary tumor, and in two out of the four patients with a wild type primary tumor, new mutations were highlighted: EGFR p.746_750del and KRAS p.G12V. Hypermetabolic CTC can be enriched without the need of dedicated equipment and their mutational status can successfully be assessed by ddPCR. Finally, the finding of new mutations supports the possibility of probing tumor heterogeneity. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Graphical abstract

Review

Jump to: Research

Open AccessReview Profiling of Invasive Breast Carcinoma Circulating Tumour Cells—Are We Ready for the ‘Liquid’ Revolution?
Cancers 2019, 11(2), 143; https://doi.org/10.3390/cancers11020143
Received: 14 December 2018 / Revised: 21 January 2019 / Accepted: 22 January 2019 / Published: 25 January 2019
PDF Full-text (723 KB) | HTML Full-text | XML Full-text
Abstract
As dissemination through blood and lymph is the critical step of the metastatic cascade, circulating tumour cells (CTCs) have attracted wide attention as a potential surrogate marker to monitor progression into metastatic disease and response to therapy. In patients with invasive breast carcinoma [...] Read more.
As dissemination through blood and lymph is the critical step of the metastatic cascade, circulating tumour cells (CTCs) have attracted wide attention as a potential surrogate marker to monitor progression into metastatic disease and response to therapy. In patients with invasive breast carcinoma (IBC), CTCs are being considered nowadays as a valid counterpart for the assessment of known prognostic and predictive factors. Molecular characterization of CTCs using protein detection, genomic and transcriptomic panels allows to depict IBC biology. Such molecular profiling of circulating cells with increased metastatic abilities appears to be essential, especially after tumour resection, as well as in advanced disseminated disease, when information crucial for identification of therapeutic targets becomes unobtainable from the primary site. If CTCs are truly representative of primary tumours and metastases, characterization of the molecular profile of this easily accessible ‘biopsy’ might be of prime importance for clinical practice in IBC patients. This review summarizes available data on feasibility and documented benefits of monitoring of essential IBC biological features in CTCs, with special reference to multifactorial proteomic, genomic, and transcriptomic panels of known prognostic or predictive value. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Open AccessReview Circulating Tumor Cell-Derived Pre-Clinical Models for Personalized Medicine
Received: 3 December 2018 / Revised: 17 December 2018 / Accepted: 20 December 2018 / Published: 24 December 2018
Cited by 1 | PDF Full-text (616 KB) | HTML Full-text | XML Full-text
Abstract
The main cause of death from cancer is associated with the development of metastases, resulting from the inability of current therapies to cure patients at metastatic stages. Generating preclinical models to better characterize the evolution of the disease is thus of utmost importance, [...] Read more.
The main cause of death from cancer is associated with the development of metastases, resulting from the inability of current therapies to cure patients at metastatic stages. Generating preclinical models to better characterize the evolution of the disease is thus of utmost importance, in order to implement effective new cancer biomarkers and therapies. Circulating Tumor Cells (CTCs) are good candidates for generating preclinical models, making it possible to follow up the spatial and temporal heterogeneity of tumor tissues. This method is a non-invasive liquid biopsy that can be obtained at any stage of the disease. It partially summarizes the molecular heterogeneity of the corresponding tumors at a given time. Here, we discuss the CTC-derived models that have been generated so far, from simplified 2D cultures to the most complex CTC-derived explants (CDX models). We highlight the challenges and strengths of these preclinical tools, as well as some of the recent studies published using these models. Full article
(This article belongs to the Special Issue Circulating Tumor Cells (CTCs))
Figures

Figure 1

Cancers EISSN 2072-6694 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top