RESUMEN

Non-small cell lung cancer (NSCLC) has a poor prognosis. Targeted therapy and immunotherapy in recent years has significantly improved NSCLC patient outcome. In this study, we employed cell-by-cell immune and cancer marker profiling of the primary tumor cells to investigate possible signatures that might predict the presence or absence of circulating tumor cells (CTCs). We performed a comprehensive study on 10 NSCLC patient tissue samples with paired blood samples. The solid tissue biopsy samples were dissociated into single cells by non-enzymatic tissue homogenization and stained with a total 25 immune, cancer markers and DNA content dye and analyzed with high-parameter flow cytometry. CTCs were isolated and analyzed from the paired peripheral blood. We investigated a total of 74 biomarkers for their correlation with CTC number. Strong correlations were observed between CTC number and the frequency of immune checkpoint marker expressing lymphocytes (CTLA-4, LAG3, TIM3, PD-1), within the CD103+CD4+ T lymphocyte subset. CTC number is also correlated with the frequency of PD-L1 expressing cancer cells and cancer cell DNA content. In contrast, CTC number inversely correlated to the frequency of CD44+E-cadherin- cancer cells. Unsupervised clustering analysis based on the biomarker analysis separated the CTC negative patients from the CTC positive patients. Profiling multiple immune and cancer markers on cancer samples with multi-parametric flow cytometry allowed us to obtain protein expression information at the single cell level. Clustering analysis of the proteomic data revealed a signature driven by checkpoint marker expression on CD103+CD4+ T cells that could potentially be predictive of CTCs and targets of therapy.

RESUMEN

Molecular analysis of circulating tumor cells (CTCs) is hindered by low sensitivity and high level of background leukocytes of currently available CTC enrichment technologies. We have developed a novel device to enrich and retrieve CTCs from blood samples by using a microfluidic chip. The Celsee PREP100 device captures CTCs with high sensitivity and allows the captured CTCs to be retrieved for molecular analysis. It uses the microfluidic chip which has approximately 56,320 capture chambers. Based on differences in cell size and deformability, each chamber ensures that small blood escape while larger CTCs of varying sizes are trapped and isolated in the chambers. In this report, we used the Celsee PREP100 to capture cancer cells spiked into normal donor blood samples. We were able to show that the device can capture as low as 10 cells with high reproducibility. The captured CTCs were retrieved from the microfluidic chip. The cell recovery rate of this back-flow procedure is 100% and the level of remaining background leukocytes is very low (about 300-400 cells). RNA from the retrieved cells are extracted and converted to cDNA, and gene expression analysis of selected cancer markers can be carried out by using RT-PCR assays. The sensitive and easy-to-use Celsee PREP100 system represents a promising technology for capturing and molecular characterization of CTCs.

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RESUMEN

Current analysis of circulating tumor cells (CTCs) is hindered by sub-optimal sensitivity and specificity of devices or assays as well as lack of capability of characterization of CTCs with clinical biomarkers. Here, we validate a novel technology to enrich and characterize CTCs from blood samples of patients with metastatic breast, prostate and colorectal cancers using a microfluidic chip which is processed by using an automated staining and scanning system from sample preparation to image processing. The Celsee system allowed for the detection of CTCs with apparent high sensitivity and specificity (94% sensitivity and 100% specificity). Moreover, the system facilitated rapid capture of CTCs from blood samples and also allowed for downstream characterization of the captured cells by immunohistochemistry, DNA and mRNA fluorescence in-situ hybridization (FISH). In a subset of patients with prostate cancer we compared the technology with a FDA-approved CTC device, CellSearch and found a higher degree of sensitivity with the Celsee instrument. In conclusion, the integrated Celsee system represents a promising CTC technology for enumeration and molecular characterization.

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RESUMEN

Circulating tumor cells (CTCs) have been shown in many studies as a possible biomarker for metastasis and may be instrumental for the spread of the disease. Despite advances in CTC capturing technologies, the low frequency of CTCs in cancer patients and the heterogeneity of the CTCs have limited the wide application of the technology in clinic. In this study, we investigated a novel microfluidic technology that uses a size- and deformability-based capture system to characterize CTCs. This unique platform not only allows flexibility in the selection of antibody markers but also segregates the CTCs in their own chambers, thus, enabling morphological, immunological and genetic characterization of each CTC at the single cell level. In this study, different breast cancer cell lines including MCF7, MDA-MB-231 and SKBR3, as well as a panel of breast cancer biomarkers were used to test the device. The technology can capture a wide range of cells with high reproducibility. The capturing efficiency of the cells is greater than 80%. In addition, the background of leukocytes is minimized because individual cells are segregated in their own chambers. The device captured both epithelial cancer cells such as MCF7 and SKBR3 and mesenchymal cells such as MDA-MB-231. Immunostaining of the captured cells on the microchannel device suggests that a panel of breast cancer biomarkers can be used to further characterize differential expression of the captured cells.

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