Abstract
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 55 kDa 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.
This is a preview of subscription content, log in via an institution to check access.
References
Ahmed SF, Deb S, Paul I, Chatterjee A, Mandal T, Chatterjee U, Ghosh MK (2012) The chaperone-assisted E3 ligase C terminus of Hsc70-interacting protein (CHIP) targets PTEN for proteasomal degradation. J Biol Chem 287(19):15996–16006
Bausero MA, Bharti A, Page DT, Perez KD, Eng JW, Ordonez SL, Asea EE, Jantschitsch C, Kindas-Muegge I, Ciocca D, Asea A (2006) Silencing the hsp25 gene eliminates migration capability of the highly metastatic murine 4T1 breast adenocarcinoma cell. Tumour Biol 27:17–26
Cantley LC, Neel BG (1999) New insights into tumor suppression: PTEN suppresses tumor formation by restraining the phosphoinositide 3-kinase/AKT pathway. Proc Natl Acad Sci USA 96:4240–4245
Ciocca DR, Calderwood SK (2005) Heat shock proteins in cancer: diagnostic, prognostic, predictive and treatment implications. Cell Stress Chaperones 10:86–103
Ciocca DR, Fanelli MA, Cuello-Carrión FD, Castro GN (2010) Small stress proteins, biomarkers of cancer. In: Simon S, Arrigo A-P (eds) Small stress proteins and human diseases. Nova Sciences, New York, pp 327–351, ISBN 978-1-61668-198-2
Fanelli MA, Montt-Guevara M, Diblasi AM, Gago FE, Tello O, Cuello-Carrión FD, Callegary E, Bausero MA, Ciocca DR (2008) P-cadherin and -catenin are useful prognostic markers in breast cancer patients; β-catenin interacts with heat shock protein Hsp27. Cell Stress Chaperones 13:207–220
Garrido C, Brunet M, Didelot C, Zermati Y, Schmitt E, Kroemer G (2006) Heat shock proteins 27 and 70. Anti-apoptotic proteins with tumorigenic properties. Cell Cycle 5:2592–2601
Gibert B, Eckel B, Fasquelle L, Moulin M, Bouhallier F, Gonin V, Mellier G, Simon S, Kretz-Remy C, Arrigo A-P, Diaz-Latoud C (2012) Knock down of heat shock protein 27 (HspB1) induces degradation of several putative client proteins. PLoS One 7(1):e29719, Epub 2012 Jan 4
Hafsi S, Pezzino FM, Candido S, Ligresti G, Spandidos DA, Soua Z, McCubrey JA, Travali S, Libra M (2012) Gene alterations in the PI3K/PTEN/AKT pathway as a mechanism of drug-resistance (review). Int J Oncol 40:639–644
Hayashi N, Peacock JW, Beraldi E, Zoubeidi A, Gleave ME, Ong CJ (2011) Hsp27 silencing coordinately inhibits proliferation and promotes Fas-induced apoptosis by regulating the PEA-15 molecular switch. Cell Death Differ. doi:10.1038/cdd.2011.184 [Epub ahead of print]
Jomary C, Cullen J, Jones SE (2006) Inactivation of the Akt survival pathway during photoreceptor apoptosis in the retinal degeneration mouse. Invest Ophthalmol Vis Sci 47:1620–1629
Kenworthy AK (2001) Imaging protein–protein interactions using fluorescence resonance energy transfer microscopy. Methods 24:289–296
Lelj-Garolla B, Mauk AG (2012) Roles of the N- and C-terminal sequences in Hsp27 self-association and chaperone activity. Protein Sci 21:122–133
Moncalero VL, Costanzo RV, Perandones C, Radrizzani M (2011) Different conformations of phosphatase and tensin homolog, deleted on chromosome 10 (PTEN) protein within the nucleus and cytoplasm of neurons. PLoS One 6:e18857
Nagaraja GM, Kaur P, Neumann W, Asea EE, Bausero MA, Multhoff G, Asea A (2012) Silencing Hsp25/Hsp27 gene expression augments proteasome activity and increases CD8+ T-cell-mediated tumor killing and memory responses. Cancer Prev Res (Phila) 5:122–1237
Naguib A, Cooke JC, Happerfield L, Kerr L, Gay LJ, Luben RN, Ball RY, Mitrou PN, McTaggart A, Arends MJ (2011) Alterations in PTEN and PIK3CA in colorectal cancers in the EPIC Norfolk study: associations with clinicopathological and dietary factors. BMC Cancer 11:123–133
Noh EM, Lee YR, Chay KO, Chung EY, Jung SH, Kim JS, Youn HJ (2011) Estrogen receptor α induces down-regulation of PTEN through PI3-kinase activation in breast cancer cells. Mol Med Report 4:215–219
O’Callaghan-Sunol C, Gabai VL, Sherman MY (2007) Hsp27 modulates p53 signaling and suppresses cellular senescence. Cancer Res 67:11779–11788
Paul C, Simon S, Gibert B, Virot S, Manero F, Arrigo AP (2010) Dynamic processes that reflect anti-apoptotic strategies set up by HspB1 (Hsp27). Exp Cell Res 316:1535–1552
Perandones C, Costanzo RV, Kowaljow V, Pivetta OH, Carminatti H, Radrizzani M (2004) Correlation between synaptogenesis and the PTEN phosphatase expression in dendrites during postnatal brain development. Brain Res Mol Brain Res 128:8–19
Schultz CR, Golembieski WA, King DA, Brown SL, Brodie C, Rempel SA (2012) Inhibition of HSP27 alone or in combination with pAKT inhibition as therapeutic approaches to target SPARC-induced glioma cell survival. Mol Cancer 11:20
Vargas-Roig LM, Gago FE, Tello O, Aznar JC, Ciocca DR (1998) Heat shock protein expression and drug resistance in breast cancer patients treated with induction chemotherapy. Int J Cancer (Pred Oncol) 79:468–475
Wang XH, Meng XW, Sun X, Du YJ, Zhao J, Fan YJ (2011) Wnt/b-catenin signaling pathway affects the protein expressions of caspase-3, XIAP and Grp-78 in hepatocellular carcinoma. Zhonghua Gan Zang Bing Za Zhi 19:599–602
Whitesell L, Lin NU (2012) HSP90 as a platform for the assembly of more effective cancer chemotherapy. Biochim Biophys Acta 1823:756–766
Xu D, Yao Y, Jiang X, Lu L, Dai W (2010) Regulation of PTEN stability and activity by Plk3. J Biol Chem 285:39935–39942
Acknowledgments
DRC was supported by the Agencia Nacional de Promoción Científica y Tecnológica (PICT 1047, 2007, BID), CONICET (PIP 2428), and the Argentina Foundation for Cancer Research. We thank Andrea F. Gil (Physiopathology Department, IMBECU, CONICET, Mendoza, Argentina) for plasmid purification.
Author information
Authors and Affiliations
Corresponding author
Additional information
N. Cayado-Gutierrez and VL Moncalero contributed equally to this work.
Rights and permissions
About this article
Cite this article
Cayado-Gutiérrez, N., Moncalero, V.L., Rosales, E.M. et al. Downregulation of Hsp27 (HSPB1) in MCF-7 human breast cancer cells induces upregulation of PTEN. Cell Stress and Chaperones 18, 243–249 (2013). https://doi.org/10.1007/s12192-012-0367-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12192-012-0367-x