title: Expression and distribution of HSP27 in response to G418 in different human breast cancer cell lines.
abstract: Heat shock proteins (HSPs) play an important role in folding, intracellular localization and degradation of cellular proteins. However, the cellular role of HSP27 is not completely understood. The conflicting results have been reported regarding stress-induced nuclear translocation of HSP27. In this study, human breast cancer cells transiently and stably expressing HSP27-EGFP chimera were utilized to observe the intracellular localization of HSP27. The data show that the transient and stable expression of HSP27-EGFP displayed distinguishingly cellular localization. The nuclear translocalization of HSP27-EGFP was correlated with the presence of G418. Experiments carried out with different human breast cancer cell lines revealed clearly different distribution patterns of endogenous HSP27. The subcellular distribution of endogenous HSP27 appeared diffuse throughout the cytoplasm in MDA435 cells. In MCF-7 and SKBR3 cells, the accumulation of the protein was distinctly seen along the cell membrane and around nucleus. Moreover, the nuclear translocation of endogenous HSP27 was stimulated by G418 only in MDA435 cells, but not in MCF-7 and SKBR3 cells. Overexpression of HSP27 has been associated with resistance to cisplatin and doxorubicin. The correlation of the expression pattern of HSP27 with the drug resistance may need to be investigated. Further studies on the intracellular function of HSP27 may take into account its interaction proteins in the cells. It may provide useful information for the identification of sensitivity of carcinoma cells to the chemotherapeutic drugs and development of more specific agents to circumvent HSP27.
authors.affiliation: Department of Cellular Immunology, Institute of Basic Medical Sciences, Taiping Road 27, Beijing 100850, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Qian
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Shi
authors.forename: Ming
authors.initials: M
authors.lastname: Yu
authors.forename: Meiru
authors.initials: M
authors.lastname: Hu
authors.forename: Qing
authors.initials: Q
authors.lastname: Xia
authors.forename: Beifen
authors.initials: B
authors.lastname: Shen
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D005260:Female; D005839:Gentamicins / Q000494:pharmacology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D021381:Protein Transport; D014162:Transfection
chemical_list: D005839:Gentamicins; D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C010680:antibiotic G 418