title: Raman spectral dynamics of single cells in the early stages of growth factor stimulation.
abstract: Cell fates change dynamically in response to various extracellular signals, including growth factors that stimulate differentiation and proliferation. The processes underlying cell-fate decisions are complex and often include large cell-to-cell variations, even within a clonal population in the same environment. To understand the origins of these cell-to-cell variations, we must detect the internal dynamics of single cells that reflect their changing chemical milieu. In this study, we used the Raman spectra of single cells to trace their internal dynamics during the early stages of growth factor stimulation. This method allows nondestructive and inclusive time-series analyses of chemical compositions of the same single cells. Applying a Gaussian mixture model to the major principal components of the single-cell Raman spectra, we detected the dynamics of the chemical states in MCF-7 cancer-derived cells in the absence and presence of differentiation and proliferation factors. The dynamics displayed characteristic variations according to the functions of the growth factors. In the differentiation pathway, the chemical composition changed directionally between multiple states, including both reversible and irreversible state transitions. In contrast, in the proliferation pathway, the chemical composition was homogenized into a single state. The differentiation factor also stimulated fluctuations in the chemical composition, whereas the proliferation factor did not.
authors.affiliation: Cellular Informatics Laboratory, RIKEN, Wako, Japan; Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Japan.
authors.forename: Sota
authors.initials: S
authors.lastname: Takanezawa
authors.affiliation: Cellular Informatics Laboratory, RIKEN, Wako, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Morita
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Ozaki
authors.affiliation: Cellular Informatics Laboratory, RIKEN, Wako, Japan. Electronic address: sako@riken.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sako
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D061986:MCF-7 Cells; D051379:Mice; D008954:Models, Biological; D020880:Neuregulins / Q000494:pharmacology*; D059010:Single-Cell Analysis / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D020880:Neuregulins; D007334:Insulin-Like Growth Factor I