Abstract A122: Molecular barcoding and single cell approaches to investigate drug tolerance in EGFRmutNSCLC

Author(s):  
Jennifer L. Cotton ◽  
Viveksagar KrishnamurthyRadhakrishna ◽  
Julie Chen ◽  
Michelle Piquet ◽  
Joel Wagner ◽  
...  
Author(s):  
Jennifer L. Cotton ◽  
Viveksagar Krisnamurthy Radhakrishna ◽  
Javier Estrada Diez ◽  
David A. Ruddy ◽  
Kathleen Sprouffske ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yapeng Su ◽  
Melissa E. Ko ◽  
Hanjun Cheng ◽  
Ronghui Zhu ◽  
Min Xue ◽  
...  

2018 ◽  
Author(s):  
Clare Rebbeck ◽  
Florian Raths ◽  
Bassem Ben Cheik ◽  
Kenneth Gouin ◽  
Gregory J. Hannon ◽  
...  

AbstractMolecular barcoding has provided means to link genotype to phenotype, to individuate cells in single-cell analyses, to enable the tracking of evolving lineages, and to facilitate the analysis of complex mixtures containing phenotypically distinct lineages. To date, all existing approaches enable retrospective associations to be made between characteristics and the lineage harbouring them, but provide no path toward isolating or manipulating those lineages within the complex mixture. Here, we describe a strategy for creating functionalized barcodes that enable straightforward manipulation of lineages within complex populations of cells, either marking and retrieval of selected lineages, or modification of their phenotype within the population, including their elimination. These “SmartCodes” rely on a simple CRISPR-based, molecular barcode reader that can switch measurable, or selectable markers, on or off in a binary fashion. While this approach could have broad impact, we envision initial approaches to the study of tumour heterogeneity, focused on issues of tumour progression, metastasis, and drug resistance.


2020 ◽  
Vol 1874 (2) ◽  
pp. 188440 ◽  
Author(s):  
Domenico Liguoro ◽  
Luigi Fattore ◽  
Rita Mancini ◽  
Gennaro Ciliberto

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexandre F. Aissa ◽  
Abul B. M. M. K. Islam ◽  
Majd M. Ariss ◽  
Cammille C. Go ◽  
Alexandra E. Rader ◽  
...  

AbstractTyrosine kinase inhibitors were found to be clinically effective for treatment of patients with certain subsets of cancers carrying somatic mutations in receptor tyrosine kinases. However, the duration of clinical response is often limited, and patients ultimately develop drug resistance. Here, we use single-cell RNA sequencing to demonstrate the existence of multiple cancer cell subpopulations within cell lines, xenograft tumors and patient tumors. These subpopulations exhibit epigenetic changes and differential therapeutic sensitivity. Recurrently overrepresented ontologies in genes that are differentially expressed between drug tolerant cell populations and drug sensitive cells include epithelial-to-mesenchymal transition, epithelium development, vesicle mediated transport, drug metabolism and cholesterol homeostasis. We show analysis of identified markers using the LINCS database to predict and functionally validate small molecules that target selected drug tolerant cell populations. In combination with EGFR inhibitors, crizotinib inhibits the emergence of a defined subset of EGFR inhibitor-tolerant clones. In this study, we describe the spectrum of changes associated with drug tolerance and inhibition of specific tolerant cell subpopulations with combination agents.


2020 ◽  
Vol 117 (9) ◽  
pp. 4693-4700 ◽  
Author(s):  
Wenlong Zuo ◽  
Yilin Wu

Population expansion in space, or range expansion, is widespread in nature and in clinical settings. Space competition among heterogeneous subpopulations during range expansion is essential to population ecology, and it may involve the interplay of multiple factors, primarily growth and motility of individuals. Structured microbial communities provide model systems to study space competition during range expansion. Here we use bacterial swarms to investigate how single-cell motility contributes to space competition among heterogeneous bacterial populations during range expansion. Our results revealed that motility heterogeneity can promote the spatial segregation of subpopulations via a dynamic motility selection process. The dynamic motility selection is enabled by speed-dependent persistence time bias of single-cell motion, which presumably arises from physical interaction between cells in a densely packed swarm. We further showed that the dynamic motility selection may contribute to collective drug tolerance of swarming colonies by segregating subpopulations with transient drug tolerance to the colony edge. Our results illustrate that motility heterogeneity, or “motility fitness,” can play a greater role than growth rate fitness in determining the short-term spatial structure of expanding populations.


2018 ◽  
Author(s):  
Xingqi Chen ◽  
Ulrike M. Litzenburger ◽  
Yuning Wei ◽  
Alicia N. Schep ◽  
Edward L. LaGory ◽  
...  

AbstractHere we introduce Protein-indexed Assay of Transposase Accessible Chromatin with sequencing (Pi-ATAC) that combines single-cell chromatin and proteomic profiling. In conjunction with DNA transposition, the levels of multiple cell surface or intracellular protein epitopes are recorded by index flow cytometry and positions in arrayed microwells, and then subject to molecular barcoding for subsequent pooled analysis. Pi-ATAC simultaneously identifies the epigenomic and proteomic heterogeneity in individual cells. Pi-ATAC reveals a casual link between transcription factor abundance and DNA motif access, and deconvolute cell types and states in the tumor microenvironmentin vivo. We identify a dominant role for hypoxia, marked by HIF1α protein, in the tumor microvenvironment for shaping the regulome in a subset of epithelial tumor cells.


2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Samira Massahi ◽  
Van Bettauer ◽  
Sanny Khurdia ◽  
Nasim Khosravi ◽  
Shawn Simpson ◽  
...  

Background For Candida albicans and Candidiasis, drug resistance is sometimes due to the pre-existence of genetic polymorphisms that bypass the mode of action of the drug, thus conferring a long-term survival benefit. In other cases, resistance is acquired via the evolution of de novo genetic polymorphisms. There is evidence that C. albicans possess a drug tolerance response which “buys time” for individuals to evolve beneficial mutations. Our goal here is to characterize this poorly understood epigenetic cytoprotective program at the single cell molecular level. Methods We developed a nano-litre droplet based Candida single cell sequencing platform capable of transcriptionally profiling several thousand individual cells in an efficient manner. We exploit this platform to profile both untreated and drug exposed (incl. fluconazole, caspofungin and nystatin) populations at early time points post-treatment (tolerance) and late time points (resistance) in order to understand survival trajectories. The profile are compared with the matched sequenced genomes. Results We show that untreated Candida populations exhibit “bet hedging”, stochastically expressing cytoprotective transcriptional programs, and drug tolerant individuals partition into distinct subpopulations, each with a unique survival strategy involving different transcriptional programs. We observe a burst of chromosomal aberrations at two days post-treatment that differ between survivor subpopulation. Discussion Our single cell approach highlights that survivor subpopulations pass through a tolerance phase that involves a multivariate transcriptional response including upregulation of efflux pumps, chaperones and transport mechanisms, and cell wall maintenance. Together this suggests that targeting the tolerance response concomitantly with standard therapies could represent an efficient approach to ablating clinical persistence.


Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2876
Author(s):  
Yang Xiang ◽  
Ryohichi Sugimura

Hematopoietic stem cells (HSCs) play a core role in blood development. The ability to efficiently produce HSCs from various pluripotent stem cell sources is the Holy Grail in the hematology field. However, in vitro or in vivo HSC production remains low, which may be attributable to the lack of understanding of hematopoiesis. Here, we review the recent progress in this area and introduce advanced technologies, such as single-cell RNA-seq, spatial transcriptomics, and molecular barcoding, which may help to acquire missing information about HSC generation. We finally discuss unresolved questions, the answers to which may be conducive to HSC production, providing a promising path toward HSC-based immunotherapies.


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