Single-cell analysis of lung adenocarcinoma cell lines reveals diverse expression patterns of individual cells invoked by a molecular target drug treatment.

Ayako Suzuki,Takashi Kohno,Yutaka Suzuki,Sumio Sugano,Koutatsu Matsushima,Katsuya Tsuchihara,Hideki Makinoshima

doi:10.1186/s13059-015-0636-y

Abstract

BackgroundTo understand the heterogeneous behaviors of individual cancer cells, it is essential to investigate gene expression levels as well as their divergence between different individual cells. Recent advances in next-generation sequencing-related technologies have enabled us to conduct a single-cell RNA-Seq analysis of a series of lung adenocarcinoma cell lines.ResultsWe analyze a total of 336 single-cell RNA-Seq libraries from seven cell lines. The results are highly robust regarding both average expression levels and the relative gene expression differences between individual cells. Gene expression diversity is characteristic depending on genes and pathways. Analyses of individual cells treated with the multi-tyrosine kinase inhibitor vandetanib reveal that, while the ribosomal genes and many other so-called house-keeping genes reduce their relative expression diversity during the drug treatment, the genes that are directly targeted by vandetanib, the EGFR and RET genes, remain constant. Rigid transcriptional control of these genes may not allow plastic changes of their expression with the drug treatment or during the cellular acquisition of drug resistance. Additionally, we find that the gene expression patterns of cancer-related genes are sometimes more diverse than expected based on the founder cells. Furthermore, we find that this diversity is occasionally latent in a normal state and initially becomes apparent after the drug treatment.ConclusionsCharacteristic patterns in gene expression divergence, which would not be revealed by transcriptome analysis of bulk cells, may also play important roles when cells acquire drug resistance, perhaps by providing a cellular reservoir for gene expression programs.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-015-0636-y) contains supplementary material, which is available to authorized users.

Highlights

To understand the heterogeneous behaviors of individual cancer cells, it is essential to investigate gene expression levels as well as their divergence between different individual cells
RNA-Seq analysis of individual cells of a lung adenocarcinoma cell line, LC2/ad To analyze gene expression levels and their variances between different individual cells, we constructed a series of single-cell RNA-Seq libraries from a human lung adenocarcinoma cell line, LC2/ad
When we considered the data for LC2/ad and LC2/ad-R cells treated with vandetanib, we found that the clusters were occasionally disordered across their originating cell types (Figure 6D; see Figure S17 in Additional file 1 for gene expression changes based on drug treatment)

Summary

Introduction

To understand the heterogeneous behaviors of individual cancer cells, it is essential to investigate gene expression levels as well as their divergence between different individual cells. Recent advances in next-generation sequencing-related technologies have enabled us to conduct a single-cell RNA-Seq analysis of a series of lung adenocarcinoma cell lines. Recent advances in next-generation sequencing analysis have enabled genome and transcriptome analysis of a large number of samples within a reasonable time and at a reasonable cost. Using microfluidics technology or cell sorters, commercial instruments support automatic separation of cells, which are subsequently used for template preparation for sequencing analysis in a seamless manner [8]. Taken together, these methods have opened the possibility to conduct genome or transcriptome analysis of a single cell in various biological systems [9]

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