Peyer's patch follicle-associated epithelium (FAE) regulates intestinal antigen access to the immune system in part through the action of microfold (M) cells which mediate transcytosis of antigens and microorganisms. Studies on M cells have been limited by the difficulties in isolating purified cells, so we applied TOGA mRNA expression profiling to identify genes associated with the in vitro induction of M cell-like features in Caco-2 cells and tested them against normal Peyer's patch tissue for their expression in FAE. Among the genes identified by this method, laminin beta3, a matrix metalloproteinase and a tetraspan family member, showed enriched expression in FAE of mouse Peyer's patches. Moreover, the C. perfringens enterotoxin receptor (CPE-R) appeared to be expressed more strongly by UEA-1(+) M cells relative to neighboring FAE. Expression of the tetraspan TM4SF3 gene and CPE-R was also confirmed in human Peyer's patch FAE. Our results suggest that while the Caco-2 differentiation model is associated with some functional features of M cells, the genes induced may instead reflect the acquisition of a more general FAE phenotype, sharing only select features with the M cell subset.
We report a microfluidic assay to select active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral particles (VPs), which were defined as intact particles with an accessible angiotensin-converting enzyme 2 receptor binding domain (RBD) on the spike (S) protein, from clinical samples. Affinity selection of SARS-CoV-2 particles was carried out using injection molded microfluidic chips, which allow for high-scale production to accommodate large-scale screening. The microfluidic contained a surface-bound aptamer directed against the virus’s S protein RBD to affinity select SARS-CoV-2 VPs. Following selection (~94% recovery), the VPs were released from the chip’s surface using a blue light light-emitting diode (89% efficiency). Selected SARS-CoV-2 VP enumeration was carried out using reverse transcription quantitative polymerase chain reaction. The VP selection assay successfully identified healthy donors (clinical specificity = 100%) and 19 of 20 patients with coronavirus disease 2019 (COVID-19) (95% sensitivity). In 15 patients with COVID-19, the presence of active SARS-CoV-2 VPs was found. The chip can be reprogrammed for any VP or exosomes by simply changing the affinity agent.
Objective: To evaluate a microfluidics-based positive selection technology for isolating circulating trophoblasts (CTs) from peripheral blood of women whose pregnancies are affected by aneuploidy and to evaluate fetal karyotype using fluorescence in situ hybridization (FISH).Method: Ten 18-ml samples of peripheral blood were collected consecutively from pregnant women whose fetus was affected by aneuploidy. A preservation buffer was added, and the specimens were shipped overnight to the testing laboratory at ambient temperature. The specimen was infused into the fully automated microfluidics-based LiquidScan ® instrument without pre-processing. This instrument contains microfluidic chips, which are coated with antibodies (anti-huEpCAM and a proprietary antibody mixture) specific to CT surface epitopes. FISH analysis was performed on the enriched cells.Results: Fetal aneuploidy evaluated included trisomy 21 (n = 3), trisomy 18 (n = 1), trisomy 13 (n = 1), monosomy X (n = 3), and triploidy (n = 1). CTs for analysis by FISH were identified in all samples. The average number of mononucleate cells per 1 ml of whole blood was 2.11 (range 0.38-4.63) overall and was 2.67 (range 1.13-4.63) using the proprietary combination of antibodies. FISH results were concordant with the aneuploidy based on other testing in all cases. Multinucleate cells were searched for and identified in the last seven samples (average number: 0.84/1 ml). Conclusions:Our study demonstrates that the LiquidScan ® , a high-sensitivity microfluidic platform, can enrich circulating trophoblasts (mononucleate and multinucleate). FISH can then be used to detect fetal aneuploidy. Key pointsWhat is already known about this topic? � Fetal trophoblasts are found in maternal circulation during pregnancy � Existing methods used to enrich circulating trophoblasts are time-intensive and expensive
Circulating tumor cells (CTCs) are rare cells found in peripheral blood or other body fluids of cancer patients. Single-cell multi-omics analysis of CTCs can provide critical information and insights for tumor heterogeneity, early detection, residual disease, recurrence, and response and resistance to therapies. However, the adoption of single cell analysis in a clinical setting has been challenging due to complicated and lengthy workflows, lack of automation, low throughput, cell loss, inefficient cell picking, and nucleic acid degradation. To overcome these challenges, we have developed the fully automated LiquidScan liquid biopsy platform as a solution for CTC enrichment and single cell isolation. Whole blood samples were collected from breast, prostate, and lung cancer patients using BioFluidica blood collection tubes. CTCs were enriched with LiquidScan platform coupled with microfluidic affinity selection of rare cells with antibodies against cancer specific surface markers. Cell eluates released from microfluidic chips were further sorted and individual cells were placed into individual wells of PCR plates. The isolated single cells were processed with either whole genome amplification for DNA analysis or pre-amplification of RNA for transcriptome profiling. Cell viability and RNA integrity were assessed for enriched cells post LiquidScan processing. Whole blood samples were directly loaded to microfluidic chips and processed (capture, wash, release and elute) using Hamilton robot for automated processing with no require to red blood cell lysis. The sample processing time was approximately 3 hours with up to 8 samples processed simultaneously. Enriched cells were 70% viable on average post LiquidScan sample processing. The RNA RIN score for the enriched cells was 6 on average. Success rate of DNA amplifications and RNA pre-Amplifications were both over 90% across all samples processed. The LiquidScan platform provides a solution for fast, automated single viable cell isolation making downstream molecular analysis possible in a clinical setting. Protocols for RNA pre-amplification and DNA sequencing including copy number analysis and targeted resequencing have been developed. Single cell DNA methylation and proteomics assay development is in progress. Citation Format: Janet Dickerson, Dylan Dufek, Robbie Huff, Stephenie Jones, Jennifer Barber-Singh, Christopher Brandt, Judy Muller-Cohn, Rolf Muller, Yipeng Wang. Automated viable circulating tumor cell (CTC) isolation enables efficient single-cell multi-omics analysis in a clinical setting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB179.
e13016 Background: Overexpression of HER2 serves as an oncogenic driver in breast cancer which can result in tumor progression and distant metastases. Amplification or overexpression of HER2 occurs in approximately 15–30% of breast cancers and serves as a therapeutic, prognostic and predictive biomarker. There have been tremendous advances in HER2+ breast cancer management and there is an need to identify patients with HER2+ early breast cancer who may benefit from de-escalation or escalation of treatment. In addition, selection of HER2 therapies beyond the 2nd line setting for HER2+ metastatic breast cancer is currently unclear. Therefore, rapid monitoring tests for treatment response are needed. Liquid biopsy may provide a cost effective, sensitive, and non-invasive approach to monitor response. Methods: Whole blood (8ml) from 20 consenting patients with confirmed stage 3 or 4 metastatic breast cancer with clinical Her2 status identified by solid tissue biopsy (10 HER2+ and 10 HER2-) were collected. Circulating tumor cells were isolated on the LiquidScan system, were probed by HER2 FISH, analyzed using automated and visual microscopy. Results: Protocols were optimized to obtain morphology and cellularity of the tumor cells allowing conclusive HER2 identification for all samples. All samples from patients identified as Her2+ by standard invasive solid tumor biopsies could be identified (100% concordance), whereas for one sample that was reported as HER2-, cells were identified with the liquid biopsy having HER2+ FISH morphology. Further molecular analysis on this patient is under way. Conclusions: We were able to demonstrate that non-invasive liquid biopsy with the LiquidScan identifies HER2 status. The method has high concordance with conventional solid biopsy approach and may be a promising for patient monitoring. We will expand to larger sample sets to explore the full capacity of liquid biopsy to monitor and diagnose HER2 related diseases.
e13047 Background: HER2 targeted therapies, such as HER2 monoclonal antibodies, HER2 tyrosine kinase inhibitors, and HER2 antibody drug conjugates, are approved for the treatment of HER2-positive breast, gastric and colorectal cancers. However, inter- and intra-tumoral heterogeneity in HER2 status presented a significant challenge in identifying patients that may benefit from HER2-targeted therapies. Detection of ERBB2 amplification in Circulating Tumor Cells (CTCs) may circumvent tissue heterogeneity issues and effectively predict the response of patients to anti-HER2 agents as a non-invasive alternative approach. Methods: A twenty-four patient pilot study was designed to compare HER2 status of traditional needle biopsies to high sensitivity CTC based liquid biopsies. HER2 status was determined using immunohistochemistry (IHC) and Fluorescence in Situ Hybridization (FISH) for tissue samples and FISH analysis for CTCs. Currently 21 patient samples have been compared in this study. Results: CTCs with HER2 amplified signals were found in patients with stages 2, 3, or 4 breast cancers. Based on the biopsies of the primary tumor or metastatic disease, 6 patients (29%) had HER2-overexpressing as defined by either HER2 IHC 3+ or HER2 FISH amplified. Analysis of CTCs showed 100% concordance (HER2 amplification detected in CTCs) in these patients with HER2-overexpressing breast cancer. Furthermore, an additional 4 (19%) patients had HER2 amplification by CTC analysis but not on needle biopsy. Conclusions: Our finding demonstrates that LiquidScan can be used as a rapid analysis tool to evaluate HER2 amplification in CTCs. This approach can potentially help identify additional cohort of patients (HER2 non-amplified tumor / HER2 amplified CTCs) who may benefit from the new generation of HER2 targeted therapies. Studies are ongoing to include an expanded cohort of patients with early stage disease, as well as HER2-low disease, in order to evaluating dynamics of ERBB2 gene amplification, expression, and pathway activation while on active systemic therapy.
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