Detection of circulating tumor cells with a novel microfluidic system in malignant pleural mesothelioma

Application and prospect of microfluidic devices for rapid assay of cell activities in the tumor microenvironment

The global impact of cancer on human health has raised significant concern. In this context, the tumor microenvironment (TME) plays a pivotal role in the tumorigenesis and malignant progression. In order to enhance the accuracy and efficacy of therapeutic outcomes, there is an imminent requirement for in vitro models that can accurately replicate the intricate characteristics and constituents of TME. Microfluidic devices exhibit notable advantages in investigating the progression and treatment of tumors and have the potential to become a novel methodology for evaluating immune cell activities in TME and assist clinicians in assessing the prognosis of patients. In addition, it shows great advantages compared to traditional cell experiments. Therefore, the review first outlines the applications and advantages of microfluidic chips in facilitating tumor cell culture, constructing TME and investigating immune cell activities. Second, the roles of microfluidic devices in the analysis of circulating tumor cells, tumor prognosis, and drug screening have also been mentioned. Moreover, a forward-looking perspective is discussed, anticipating the widespread clinical adoption of microfluidic devices in the future.

Novel insights into biomarkers of progression in Desmoid tumor

Desmoid tumor (DT) is a rare neoplasm characterized by the proliferation of myofibroblastic cells that infiltrates and invades adjacent tissues. Due to its locally aggressive and recurrent nature, DT often causes local symptoms and can be challenging to manage clinically. Therefore, identifying biomarkers that can predict the progression of DT and guide treatment decisions is critical. This review summarizes several biomarkers that have been implicated in active surveillance (AS) and the prediction of postoperative recurrence and attempts to elucidate their underlying mechanisms. Some of these novel markers could provide prognostic value for clinicians, and ultimately help facilitate optimal and accurate therapeutic decisions for DT.

Recent advances in micro-/nanostructure array integrated microfluidic devices for efficient separation of circulating tumor cells

Circulating tumor cells (CTCs) released from the primary tumor to peripheral blood are promising targets for liquid biopsies. Their biological information is vital for early cancer detection, efficacy assessment, and prognostic monitoring. Despite the tremendous clinical applications of CTCs, development of effective separation techniques are still demanding. Traditional separation methods usually use batch processing for enrichment, which inevitably destroy cell integrity and affect the complete information acquisition. Considering the rarity and heterogeneity of CTCs, it is urgent to develop effective separation methods. Microfluidic chips with precise fluid control at the micron level are promising devices for CTC separation. Their further combination with micro-/nanostructure arrays adds more biomolecule binding sites and exhibit unique fluid barrier effect, which significantly improve the CTC capture efficiency, purity, and sensitivity. This review summarized the recent advances in micro-/nanostructure array integrated microfluidic devices for CTC separation, including microrods, nanowires, and 3D micro-/nanostructures. The mechanisms by which these structures contribute to improved capture efficiency are discussed. Two major categories of separation methods, based on the physical and biological properties of CTCs, are discussed separately. Physical separation includes the design and preparation of micro-/nanostructure arrays, while chemical separation additionally involves the selection and modification of specific capture probes. These emerging technologies are expected to become powerful tools for disease diagnosis in the future.

Roles of Podoplanin in Malignant Progression of Tumor

Podoplanin (PDPN) is a cell-surface mucin-like glycoprotein that plays a critical role in tumor development and normal development of the lung, kidney, and lymphatic vascular systems. PDPN is overexpressed in several tumors and is involved in their malignancy. PDPN induces platelet aggregation through binding to platelet receptor C-type lectin-like receptor 2. Furthermore, PDPN modulates signal transductions that regulate cell proliferation, differentiation, migration, invasion, epithelial-to-mesenchymal transition, and stemness, all of which are crucial for the malignant progression of tumor. In the tumor microenvironment (TME), PDPN expression is upregulated in the tumor stroma, including cancer-associated fibroblasts (CAFs) and immune cells. CAFs play significant roles in the extracellular matrix remodeling and the development of immunosuppressive TME. Additionally, PDPN functions as a co-inhibitory molecule on T cells, indicating its involvement with immune evasion. In this review, we describe the mechanistic basis and diverse roles of PDPN in the malignant progression of tumors and discuss the possibility of the clinical application of PDPN-targeted cancer therapy, including cancer-specific monoclonal antibodies, and chimeric antigen receptor T technologies.

Prognostic impact of circulating tumor cells detected with the microfluidic "Universal CTC-chip" for primary lung cancer

Detecting rare circulating tumor cells (CTCs) in the bloodstream is extremely challenging. We had previously developed a novel polymeric microfluidic device, "CTC-chip," for capturing CTCs and have shown high capture efficiency in lung cancer cell lines by conjugating antibodies against epithelial cell adhesion molecules (EpCAM). This study aimed to optimize the EpCAM-chip and clarify the prognostic impact of CTCs in lung cancer patients. Of the 123 patients with pathologically proven lung cancer, both progression-free survival (p = 0.037) and cancer-specific survival (p = 0.0041) were predominantly poor when CTCs were detected before treatment. After classification into surgical and chemotherapy groups, progression-free survival was worse in CTC-positive patients in both groups (surgery, p = 0.115; chemotherapy, p = 0.012), indicating that the detection of baseline CTCs is a risk factor for recurrence and progression. Furthermore, we demonstrated that captured CTCs can be recovered using micromanipulators and performed mutation analysis using PCR. Thus, the EpCAM-chip is a highly sensitive system for detecting CTCs that contributes to the prediction of recurrence and progression and enables genetic analysis of captured CTCs, which may open new diagnostic, therapeutic, and prognostic options for lung cancer patients.

Novel circulating tumor cell-detection chip combining conventional podoplanin and EGFR antibodies for all histological malignant pleural mesothelioma

In our previous study, a microfluidic system was developed based on podoplanin detection for capturing circulating tumor cells (CTCs), derived from malignant pleural mesothelioma (MPM). However, non-epithelioid MPM shows low podoplanin protein expression compared with that in epithelioid MPM; thus, some CTC populations may be missed. To overcome this limitation, a new CTC-detection chip was developed by combining the conventional podoplanin antibody (clone: NZ-1.2) with an epidermal growth factor receptor (EGFR)-targeted antibody (cetuximab). The cell-capture efficiency of the Cocktail-chip reached 100% in all the histological MPM cell lines. The median CTC-counts from 19 patients with MPM (epithelioid/non-epithelioid: 10/9) with the NZ-1.2- and Cocktail-chips were 1 and 3 (P=0.311) in 1 ml peripheral blood, 1.5 and 2 (P=0.332) in epithelioid MPM, and 1 and 3 (P=0.106) in non-epithelioid MPM, respectively. Overall, the Cocktail-chip showed an improved ability to detect more CTCs in patients with non-epithelioid MPM compared with that in the conventional NZ-1.2-chip, showing non-significant, but higher CTC detection. Furthermore, CTC-counts, determined using the Cocktail-chip were significantly correlated with the clinical stage of non-epithelioid MPM. In epithelioid MPM, the Cocktail-chip achieved a CTC-detection efficiency equivalent to that in the conventional NZ-1.2-chip. The Cocktail-chip enabled sensitive CTC detection of all histological MPM, including the non-epithelioid subtype, which may provide a foundation for the diagnosis, treatment, and prognosis of MPM progression.

Circulating biomarkers in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive tumor strictly connected to asbestos exposure. Prognosis is dismal as diagnosis commonly occurs in advanced stage. Radiological screenings have not proven to be effective and also pathological diagnosis may be challenging. In the era of precision oncology, validation of robust non-invasive biomarkers for screening of asbestos-exposed individuals, assessment of prognosis and prediction of response to treatments remains an important unmet clinical need. This review provides an overview on current understanding and possible applications of liquid biopsy in MPM, mostly focused on the utility as diagnostic and prognostic test.

Kaneko M, Kato Y, Tanaka F. Detection of Circulating Tumor Cells (CTCs) in Malignant Pleural Mesothelioma (MPM) with the "Universal" CTC-Chip and An Anti-Podoplanin Antibody NZ-1.2

Circulating tumor cell (CTC) is a potentially useful surrogate of micro-metastasis, but detection of rare tumor cells contaminated in a vast majority of normal hematologic cells remains technical challenges. To achieve effective detection of a variety of CTCs, we have developed a novel microfluidic system (CTC-chip) in which any antibody to capture CTCs is easily conjugated. In previous studies, we employed an antibody (clone E-1) against podoplanin that was strongly expressed on mesothelioma cells. The CTC-chip coated by the E-1 antibody (E1-chip) provided a modest sensitivity in detection of CTCs in malignant pleural mesothelioma (MPM). Here, to achieve a higher sensitivity, we employed a novel anti-podoplanin antibody (clone NZ-1.2). In an experimental model, MPM cells with high podoplanin expression were effectively captured with the CTC-chip coated by the NZ-1.2 antibody (NZ1.2-chip). Next, we evaluated CTCs in the peripheral blood sampled from 22 MPM patients using the NZ1.2-chip and the E1-chip. One or more CTCs were detected in 15 patients (68.2%) with the NZ1.2-chip, whereas only in 10 patients (45.5%) with the E1-chip. Of noted, in most (92.3%, 12/13) patients with epithelioid MPM subtype, CTCs were positive with the NZ1.2-chip. The CTC-count detected with the NZ1.2-chip was significantly higher than that with the E1-chip (p = 0.034). The clinical implications of CTCs detected with the NZ1.2-chip will be examined in a future study.

7-lncRNA Assessment Model for Monitoring and Prognosis of Breast Cancer Patients: Based on Cox Regression and Co-expression Analysis

Background: Breast cancer is one of the deadliest malignant tumors worldwide. Due to its complex molecular and cellular heterogeneity, the efficacy of existing breast cancer risk prediction models is unsatisfactory. In this study, we developed a new lncRNA model to predict the prognosis of patients with BRCA.

Methods: BRCA-related differentially-expressed long non-coding RNA were screened from the Cancer Genome Atlas database. A novel lncRNA model was developed by univariate and multivariate analyses to predict the prognosis of patients with BRCA. The efficacy of the model was verified by TCGA-based breast cancer samples. Identified lncRNA-related mRNA based on the co-expression method.

Results: We constructed a 7-lncRNA breast cancer prediction model including LINC00377, LINC00536, LINC01224, LINC00668, LINC01234, LINC02037, and LINC01456. The breast cancer samples were divided into high-risk and low-risk groups based on the model, which verified the specificity and sensitivity of the model. The Area Under Curve (AUC) of the 3- and 5-year Receiver Operating Characteristic curve were 0.711 and 0.734, respectively, indicating that the model has good performance.

Conclusion: We constructed a 7-lncRNA model to predict the prognosis of patients with BRCA, and suggest that these lncRNAs may play a specific role in the carcinogenesis of BRCA.

Liquid Biopsy in Malignant Pleural Mesothelioma: State of the Art, Pitfalls, and Perspectives

Malignant pleural mesothelioma (MPM) is an aggressive tumor linked to asbestos exposure. Although the risk factors for MPM are well-known, the majority of MPM patients are diagnosed at an advanced stage and have a very poor prognosis. Circulating biomarkers for early diagnosis remain to be identified, and the current standard for MPM diagnosis relies on pleural biopsies. Robust non-invasive tests for the screening of asbestos-exposed subjects are therefore an important unmet clinical need. This review provides a critical summary of recent liquid biopsy-based studies aimed at discovering novel blood-based circulating biomarkers for the early diagnosis and prognostic stratification of MPM patients.

Detection of circulating tumor cells with a novel microfluidic system in malignant pleural mesothelioma

Detection of rare tumor cells circulating in the blood (CTCs) presents technical challenges. CellSearch, the only approved system for clinical use, fails to capture epithelial cell adhesion molecule‐negative CTCs such as malignant pleural mesothelioma (MPM). We have developed a novel microfluidic device (CTC‐chip) in which any Ab to capture CTCs is conjugated. The CTC‐chip was coated with an Ab against podoplanin that is abundantly expressed on MPM. Circulating tumor cell‐detection performance was evaluated in experimental models in which MPM cells were spiked in blood sampled from a healthy volunteer and in clinical samples drawn from MPM patients. The CTC‐chip showed superior CTC‐detection performance over CellSearch in experimental models (sensitivity, 63.3%‐64.5% vs 0%‐1.1%; P < .001) and in clinical samples (CTC‐positivity, 68.8% vs 6.3%; P < .001). A receiver operating characteristic (ROC) analysis showed that the CTC test provided a significant diagnostic performance in discrimination of unresectable disease from resectable disease (area under the ROC curve, 0.851; P = .003). The higher CTC count (≥2 cells/mL) was significantly associated with a poor prognosis (P = .030). The novel CTC‐chip enabled sensitive detection of CTCs, which provided significant diagnostic and prognostic information in MPM.