Multiplexed Single-Cell Plasmonic Immunoassay of Intracellular Signaling Proteins Enables Non-Destructive Monitoring of Cell Fate

Abstract Background Fms-related tyrosine kinase 3 (FLT3) receptor serves as a prognostic marker and therapeutic target in acute myeloid leukemia (AML). Approximately one-third of AML patients carry mutation in FLT3, associated with unfavourable prognosis and high relapse rate. The multitargeted kinase inhibitor midostaurin (PKC412) in combination with standard chemotherapy (daunorubicin and cytarabine) was recently shown to increase overall survival of AML patients. For that reason, PKC412 has been approved for treatment of AML patients with FLT3-mutation. PKC412 synergizes with standard chemotherapy, but the mechanism involved is not fully understood and the risk of relapse is still highly problematic. Methods By utilizing the unique nature of mass cytometry for single cell multiparameter analysis, we have explored the proteomic effect and intracellular signaling response in individual leukemic cells with internal tandem duplication of FLT3 (FLT3-ITD) after midostaurin treatment in combination with daunorubicin or cytarabine. Results We have identified a synergistic inhibition of intracellular signaling proteins after PKC412 treatment in combination with daunorubicin. In contrast, cytarabine antagonized phosphorylation inhibition of PKC412. Moreover, we found elevated levels of FLT3 surface expression after cytarabine treatment. Interestingly, the surface localization of FLT3 receptor increased in vivo on the blast cell population of two AML patients during day 3 of induction therapy (daunorubicin; once/day from day 1–3 and cytarabine; twice/day from day 1–7). We found FLT3 receptor expression to correlate with intracellular cytarabine (AraC) response. AML cell line cultured with AraC with or without PKC412 had an antagonizing phosphorylation inhibition of pAKT (p = 0.042 and 0.0261, respectively) and pERK1/2 (0.0134 and 0.0096, respectively) in FLT3high compared to FLT3low expressing cell populations. Conclusions Our study provides insights into how conventional chemotherapy affects protein phosphorylation of vital signaling proteins in human leukemia cells. The results presented here support further investigation of novel strategies to treat FLT3-mutated AML patients with PKC412 in combination with chemotherapy agents and the potential development of novel treatment strategies.

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Single Cell Label-Free Probing of Chromatin Dynamics During B Lymphocyte Maturation

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.646616 ◽

2021 ◽

Vol 9 ◽

Author(s):

Rikke Morrish ◽

Kevin Ho Wai Yim ◽

Stefano Pagliara ◽

Francesca Palombo ◽

Richard Chahwan ◽

...

Keyword(s):

Single Cell ◽

Cell Fate ◽

B Lymphocytes ◽

Intracellular Signaling ◽

Large Scale ◽

B Lymphocyte ◽

Biological Effects ◽

Raman Microscopy ◽

Phenotypic Characterization ◽

Label Free

Large-scale intracellular signaling during developmental growth or in response to environmental alterations are largely orchestrated by chromatin within the cell nuclei. Chemical and conformational modifications of the chromatin architecture are critical steps in the regulation of differential gene expression and ultimately cell fate determination. Therefore, establishing chemical properties of the nucleus could provide key markers for phenotypic characterization of cellular processes on a scale of individual cells. Raman microscopy is a sensitive technique that is capable of probing single cell chemical composition—and sub-cellular regions—in a label-free optical manner. As such, it has great potential in both clinical and basic research. However, perceived limitations of Raman spectroscopy such as low signal intensity and the difficulty in linking alterations in vibrational signals directly with ensuing biological effects have hampered advances in the field. Here we use immune B lymphocyte development as a model to assess chromatin and transcriptional changes using confocal Raman microscopy in combination with microfluidic devices and correlative transcriptomics, thereby linking changes in chemical and structural properties to biological outcomes. Live B lymphocytes were assessed before and after maturation. Multivariate analysis was applied to distinguish cellular components within each cell. The spectral differences between non-activated and activated B lymphocytes were then identified, and their correlation with known intracellular biological changes were assessed in comparison to conventional RNA-seq analysis. Our data shows that spectral analysis provides a powerful tool to study gene activation that can complement conventional molecular biology techniques and opens the way for mapping the dynamics in the biochemical makeup of individual cells.

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Faculty Opinions recommendation of T cell fate and clonality inference from single-cell transcriptomes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726267567.793522648 ◽

2016 ◽

Author(s):

Andrew McKenzie

Keyword(s):

T Cell ◽

Single Cell ◽

Cell Fate

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Faculty Opinions recommendation of Single-Cell RNA Sequencing Analysis Reveals Sequential Cell Fate Transition during Human Spermatogenesis.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733883362.793555704 ◽

2019 ◽

Author(s):

Miles Wilkinson

Keyword(s):

Single Cell ◽

Rna Sequencing ◽

Cell Fate ◽

Sequencing Analysis ◽

Single Cell Rna Sequencing ◽

Human Spermatogenesis

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Melanoma Single-Cell Biology in Experimental and Clinical Settings

Journal of Clinical Medicine ◽

10.3390/jcm10030506 ◽

2021 ◽

Vol 10 (3) ◽

pp. 506

Author(s):

Hans Binder ◽

Maria Schmidt ◽

Henry Loeffler-Wirth ◽

Lena Suenke Mortensen ◽

Manfred Kunz

Keyword(s):

T Cell ◽

Single Cell ◽

Intracellular Signaling ◽

Cell Biology ◽

Immune Cell ◽

Malignant Tumors ◽

Checkpoint Inhibitor ◽

Treatment Resistance ◽

Resistance Mechanisms ◽

Cellular Heterogeneity

Cellular heterogeneity is regarded as a major factor for treatment response and resistance in a variety of malignant tumors, including malignant melanoma. More recent developments of single-cell sequencing technology provided deeper insights into this phenomenon. Single-cell data were used to identify prognostic subtypes of melanoma tumors, with a special emphasis on immune cells and fibroblasts in the tumor microenvironment. Moreover, treatment resistance to checkpoint inhibitor therapy has been shown to be associated with a set of differentially expressed immune cell signatures unraveling new targetable intracellular signaling pathways. Characterization of T cell states under checkpoint inhibitor treatment showed that exhausted CD8+ T cell types in melanoma lesions still have a high proliferative index. Other studies identified treatment resistance mechanisms to targeted treatment against the mutated BRAF serine/threonine protein kinase including repression of the melanoma differentiation gene microphthalmia-associated transcription factor (MITF) and induction of AXL receptor tyrosine kinase. Interestingly, treatment resistance mechanisms not only included selection processes of pre-existing subclones but also transition between different states of gene expression. Taken together, single-cell technology has provided deeper insights into melanoma biology and has put forward our understanding of the role of tumor heterogeneity and transcriptional plasticity, which may impact on innovative clinical trial designs and experimental approaches.

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Single-Cell Transcriptome Analysis as a Promising Tool to Study Pluripotent Stem Cell Reprogramming

International Journal of Molecular Sciences ◽

10.3390/ijms22115988 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5988

Author(s):

Hyun Kyu Kim ◽

Tae Won Ha ◽

Man Ryul Lee

Keyword(s):

Stem Cells ◽

Single Cell ◽

Cell Fate ◽

Human Cell ◽

Transcriptome Analysis ◽

Single Cell Analysis ◽

Embryonic Stem ◽

Single Cell Level ◽

Cell Analysis ◽

Cell Level

Cells are the basic units of all organisms and are involved in all vital activities, such as proliferation, differentiation, senescence, and apoptosis. A human body consists of more than 30 trillion cells generated through repeated division and differentiation from a single-cell fertilized egg in a highly organized programmatic fashion. Since the recent formation of the Human Cell Atlas consortium, establishing the Human Cell Atlas at the single-cell level has been an ongoing activity with the goal of understanding the mechanisms underlying diseases and vital cellular activities at the level of the single cell. In particular, transcriptome analysis of embryonic stem cells at the single-cell level is of great importance, as these cells are responsible for determining cell fate. Here, we review single-cell analysis techniques that have been actively used in recent years, introduce the single-cell analysis studies currently in progress in pluripotent stem cells and reprogramming, and forecast future studies.

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