A Hashing-Based Framework for Enhancing Cluster Delineation of High-Dimensional Single-Cell Profiles

Although many methods have been developed to explore the function of cells by clustering high-dimensional(HD)single-cell omics data,the inconspicuously differential expressions of biomarkers of proteins or genes across all cells disturb the cell cluster delineation and downstream analysis.Here,we introduce a hashing-based framework to improve the delineation of cell clusters,which is based on the hypothesis that one variable with no significant differences can be decomposed into more diversely latent variables to distinguish cells.By projecting the original data into a sparse HD space,fly and densefly hashing preprocessing retain the local structure of data,and improve the cluster delineation of existing clustering methods,such as PhenoGraph.Moreover,the analyses on mass cytometry dataset show that our hashing-based framework manages to unveil new hidden heterogeneities in cell clusters.The proposed framework promotes the utilization of cell biomarkers and enriches the biological findings by introducing more latent variables.

Integrated microfluidic single-cell immunoblotting chip enables high-throughput isolation,enrichment and direct protein analysis of circulating tumor cells

Effective capture and analysis of a single circulating tumor cell(CTC)is instrumental for early diagnosis and personalized therapy of tumors.However,due to their extremely low abundance and susceptibility to interference from other cells,high-throughput isolation,enrichment,and single-cell-level functional protein analysis of CTCs within one integrated system remains a major challenge.Herein,we present an integrated multifunctional microfluidic system for highly efficient and label-free CTC isolation,CTC enrichment,and single-cell immunoblotting(ieSCI).The ieSCI-chip is a multilayer microfluidic system that combines an inertia force-based cell sorter with a membrane filter for label-free CTC separation and enrichment and a thin layer of a photoactive polyacrylamide gel with microwell arrays at the bottom of the chamber for single-cell immunoblotting.The ieSCI-chip successfully identified a subgroup of apoptosis-negative(Bax-negative)cells,which traditional bulk analysis did not detect,from cisplatin-treated cells.Furthermore,we demonstrated the clinical application of the ieSCI-chip with blood samples from breast cancer patients for personalized CTC epithelial-to-mesenchymal transition(EMT)analysis.The expression level of a tumor cell marker(EpCAM)can be directly determined in isolated CTCs at the single-cell level,and the therapeutic response to anticancer drugs can be simultaneously monitored.Therefore,the ieSCI-chip provides a promising clinical translational tool for clinical drug response monitoring and personalized regimen development.