naa a22 4500 510746497 CHVBK 20180411083048.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s12192-012-0367-x doi (NATIONALLICENCE)springer-10.1007/s12192-012-0367-x Downregulation of Hsp27 (HSPB1) in MCF-7 human breast cancer cells induces upregulation of PTEN [Elektronische Daten] [Niubys Cayado-Gutiérrez, Vera Moncalero, Eliana Rosales, Walter Berón, Edgardo Salvatierra, Daiana Alvarez-Olmedo, Martín Radrizzani, Daniel Ciocca] Hsp27 (HSPB1) is usually overexpressed in breast cancers affecting the disease outcome and the sensitivity of tumors to chemotherapy and radiotherapy. Hsp27 interacts with other proteins such as β-catenin, histone deacetylase HDAC6, transcription factor STAT2 and procaspase-3. Phosphatase and tensin homologue (PTEN) is a tumor suppressor gene that is deleted in many human tumors. The PI3K/Akt signaling pathway is negatively regulated by PTEN. Hsp27 is described as a key component of the Akt signaling cascade: Akt, BAD, Forkhead transcription factors, Hsp27, mitogen-activated protein kinase kinase-3 and -6. Here, we have examined whether the downregulation of Hsp27 by siHsp27 affects the PTEN levels in the MCF-7 human breast cancer cell line. PTEN was detected with two different antibodies using western blots and immunocytochemistry. p-Akt was also evaluated by western blot. In addition, Hsp27 and PTEN were immunoprecipitated to know whether these proteins interact. Intracellular colocalization studies were carried out by confocal microscopy. A significant reduction in the Hsp27 levels was noted in the siHsp27 transfected cells. These Hsp27 downregulated cells showed a significant increased expression of PTEN. The MW 76 and 55kDa PTEN forms were upregulated as revealed by two different antibodies. The phosphatase activity of PTEN seems to be active because p-Akt levels were reduced. Hsp27 immunoprecipitation was bringing PTEN and vice versa, these two proteins seem to interact at cytoplasmic level by FRET. Downregulation of Hsp27 stabilized PTEN protein levels. Chaperone-assisted E3 ligase C terminus of Hsc70-interacting protein (CHIP) levels were not significantly influenced by Hsp27 downregulation. In conclusion, we report a novel function of Hsp27 modulating the PTEN levels in human breast cancer cells suggesting an interaction between these two molecules. Cell Stress Society International, 2012 Hsp27 (HSPB1) nationallicence Human breast cancer cells nationallicence PTEN nationallicence Akt nationallicence Heat shock proteins nationallicence Cayado-Gutiérrez Niubys Laboratory of Oncology, IMBECU, CCT-CONICET, National Research Council, C.C. 855, Mendoza, Argentina aut Moncalero Vera Laboratorio de Neuro y Citogenética Molecular, Centro de Estudios de Salud y Medio Ambiente, UN de San Martín, CONICET, Buenos Aires, Argentina aut Rosales Eliana Instituto de Histología y Embriología, Facultad de Ciencias Médicas, UNCuyo, CONICET, Mendoza, Argentina aut Berón Walter Instituto de Histología y Embriología, Facultad de Ciencias Médicas, UNCuyo, CONICET, Mendoza, Argentina aut Salvatierra Edgardo Molecular and Cellular Therapy Laboratory, Instituto F. Leloir-IBBA-CONICET, Buenos Aires, Argentina aut Alvarez-Olmedo Daiana Laboratory of Oncology, IMBECU, CCT-CONICET, National Research Council, C.C. 855, Mendoza, Argentina aut Radrizzani Martín Laboratorio de Neuro y Citogenética Molecular, Centro de Estudios de Salud y Medio Ambiente, UN de San Martín, CONICET, Buenos Aires, Argentina aut Ciocca Daniel Laboratory of Oncology, IMBECU, CCT-CONICET, National Research Council, C.C. 855, Mendoza, Argentina aut Cell Stress and Chaperones Springer Netherlands 18/2(2013-03-01), 243-249 1355-8145 18:2<243 2013 18 12192 https://doi.org/10.1007/s12192-012-0367-x text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12192-012-0367-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cayado-Gutiérrez Niubys Laboratory of Oncology, IMBECU, CCT-CONICET, National Research Council, C.C. 855, Mendoza, Argentina aut NATIONALLICENCE 700 1- Moncalero Vera Laboratorio de Neuro y Citogenética Molecular, Centro de Estudios de Salud y Medio Ambiente, UN de San Martín, CONICET, Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Rosales Eliana Instituto de Histología y Embriología, Facultad de Ciencias Médicas, UNCuyo, CONICET, Mendoza, Argentina aut NATIONALLICENCE 700 1- Berón Walter Instituto de Histología y Embriología, Facultad de Ciencias Médicas, UNCuyo, CONICET, Mendoza, Argentina aut NATIONALLICENCE 700 1- Salvatierra Edgardo Molecular and Cellular Therapy Laboratory, Instituto F. Leloir-IBBA-CONICET, Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Alvarez-Olmedo Daiana Laboratory of Oncology, IMBECU, CCT-CONICET, National Research Council, C.C. 855, Mendoza, Argentina aut NATIONALLICENCE 700 1- Radrizzani Martín Laboratorio de Neuro y Citogenética Molecular, Centro de Estudios de Salud y Medio Ambiente, UN de San Martín, CONICET, Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Ciocca Daniel Laboratory of Oncology, IMBECU, CCT-CONICET, National Research Council, C.C. 855, Mendoza, Argentina aut NATIONALLICENCE 773 0- Cell Stress and Chaperones Springer Netherlands 18/2(2013-03-01), 243-249 1355-8145 18:2<243 2013 18 12192 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer