title: Clustered localization of STAT3 during the cell cycle detected by super-resolution fluorescence microscopy.
abstract: Signal transducer and activator of transcription 3 (STAT3) plays a key role in various cellular processes such as cell proliferation, differentiation, apoptosis and immune responses. In particular, STAT3 has emerged as a potential molecular target for cancer therapy. The functional role and standard activation mechanism of STAT3 have been well studied, however, the spatial distribution of STAT3 during the cell cycle is poorly known. Therefore, it is indispensable to study STAT3 spatial arrangement and nuclear-cytoplasimic localization at the different phase of cell cycle in cancer cells. By direct stochastic optical reconstruction microscopy imaging, we find that STAT3 forms various number and size of clusters at the different cell-cycle stage, which could not be clearly observed by conventional fluorescent microscopy. STAT3 clusters get more and larger gradually from G1 to G2 phase, during which time transcription and other related activities goes on consistently. The results suggest that there is an intimate relationship between the clustered characteristic of STAT3 and the cell-cycle behavior. Meanwhile, clustering would facilitate STAT3 rapid response to activating signals due to short distances between molecules. Our data might open a new door to develop an antitumor drug for inhibiting STAT3 signaling pathway by destroying its clusters.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.forename: Junling
authors.initials: J
authors.lastname: Chen
authors.forename: Mingjun
authors.initials: M
authors.lastname: Cai
authors.forename: Haijiao
authors.initials: H
authors.lastname: Xu
authors.forename: Junguang
authors.initials: J
authors.lastname: Jiang
authors.forename: Ti
authors.initials: T
authors.lastname: Tong
authors.forename: Hongda
authors.initials: H
authors.lastname: Wang
mesh_terms: D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism; D016000:Cluster Analysis; D003593:Cytoplasm / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D050796:STAT3 Transcription Factor / Q000378:metabolism*
chemical_list: D015850:Interleukin-6; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human