This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gehrmann, M. Articles by Multhoff, G. Search for Related Content PubMed PubMed Citation Articles by Gehrmann, M. Articles by Multhoff, G.

Differential Up-Regulation of Cytosolic and Membrane-Bound Heat Shock Protein 70 in Tumor Cells by Anti-Inflammatory Drugs

Departments of ¹ Hematology and Oncology and ² Surgery, University Hospital Regensburg, Regensburg, Germany, and ³ Institute of Molecular Immunology, GSF National Research Center for the Environment and Health, Munich, Germany

ABSTRACT

Purpose: Modulation of the heat shock protein (HSP) response affects sensitivity to therapeutic agents in cancer. Here, drugs with anti-inflammatory potential (cyclooxygenase 1/2 inhibitors) and peroxidase proliferator-activated receptor- agonists were analyzed for their capacity to affect Hsp70 expression in human cancer cells with a divergent Hsp70 membrane expression pattern.

Experimental Design: In dose kinetics, the nonlethal concentration of acetyl-salicyl acid, celecoxib, rofecoxib, and the insulin-sensitizer pioglitazone was identified for the human adenocarcinoma cell line CX–. With the exception of CLX, which was diluted in DMSO, all reagents were dissolved in water. After treatment with the different compounds at nontoxic concentrations for 6 h, followed by a 1-h recovery period, the cytosolic Hsp70 levels were measured in CX-2 and CX– tumor cells by Western blot analysis. Fold increase was calculated in relation to the housekeeping protein tubulin. Membrane-bound Hsp70 was analyzed by flow cytometry using a FITC-labeled Hsp70-specific monoclonal antibody. Untreated cells and cells incubated with equivalent amounts of the diluting agents served as controls. The immunological function was tested in granzyme B apoptosis assays, standard ⁵¹Cr release assays, and antibody blocking studies.

Results: Compared with aqua dest, the cytoplasmic amount of Hsp70 was equally enhanced in CX-2 and CX– cells by all compounds. An increase in membrane-bound Hsp70, detected selectively in CX– cells, corresponded to an enhanced sensitivity to granzyme B- and natural killer cell-mediated kill that was blockable by using a Hsp70-specific antibody.

Conclusions: Although increase in cytosolic Hsp70 levels conferred resistance to further stress, membrane-bound Hsp70 rendered tumor cells more sensitive to the immunological attack mediated by granzyme B and natural killer cells. Our data provide a biological rational for combining anti-inflammatory drugs with immunotherapy in cancer therapy.

This article has been cited by other articles:

				L. Zamai, C. Ponti, P. Mirandola, G. Gobbi, S. Papa, L. Galeotti, L. Cocco, and M. Vitale NK Cells and Cancer J. Immunol., April 1, 2007; 178(7): 4011 - 4016. [Abstract] [Full Text] [PDF]

				E. Schmitt, M. Gehrmann, M. Brunet, G. Multhoff, and C. Garrido Intracellular and extracellular functions of heat shock proteins: repercussions in cancer therapy J. Leukoc. Biol., January 1, 2007; 81(1): 15 - 27. [Abstract] [Full Text] [PDF]

				M. Aburaya, K.-I. Tanaka, T. Hoshino, S. Tsutsumi, K. Suzuki, M. Makise, R. Akagi, and T. Mizushima Heme Oxygenase-1 Protects Gastric Mucosal Cells against Non-steroidal Anti-inflammatory Drugs J. Biol. Chem., November 3, 2006; 281(44): 33422 - 33432. [Abstract] [Full Text] [PDF]

				G. Li, I. S. Ali, and R. W. Currie Insulin induces myocardial protection and Hsp70 localization to plasma membranes in rat hearts Am J Physiol Heart Circ Physiol, October 1, 2006; 291(4): H1709 - H1721. [Abstract] [Full Text] [PDF]

				F. Lechin, B. van der Dijs, A. E. Lechin, G. Multhoff, K. Pfister, I. Hromadnikova, and D. Zlacka Natural Killer Cells Activity and Neuroimmunological Treatment of Cancer Clin. Cancer Res., December 1, 2004; 10(23): 8120 - 8121. [Full Text] [PDF]