This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend 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 Soldatenkov, V. A. Articles by Dritschilo, A. Search for Related Content PubMed PubMed Citation Articles by Soldatenkov, V. A. Articles by Dritschilo, A.

Apoptosis of Ewing's Sarcoma Cells Is Accompanied by Accumulation of Ubiquitinated Proteins¹

Department of Radiation Medicine, Division of Radiation Research, Georgetown University Medical Center, Washington, D.C. 20007

Induction of apoptosis in Ewing's sarcoma cells by ionizing radiation is accompanied by accumulation of ubiquitinated proteins preferentially in the form of conjugates with M_r greater than 75,000. Furthermore, enhanced antiubiquitin immunofluorescence was detected only in cells that underwent radiation-induced apoptosis, suggesting that the observed alterations in protein ubiquitination are specific to the apoptotic process. To determine the role of the proteasome in apoptosis-associated accumulation of ubiquitin-protein conjugates, we used lactacystin, a highly selective inhibitor of proteasome proteolytic activity. Exposure of Ewing's sarcoma cells to lactacystin resulted in accumulation of ubiquitinated proteins and activation of a Bcl-2-sensitive apoptotic pathways. The latter led to proteolytic cleavage of poly(ADP-ribose) polymerase and fragmentation of nuclear DNA. These findings suggest that proteasome function is required for apoptosis-specific accumulation of ubiquitinated proteins and indicate that functional disorder of the ubiquitin-proteasome system may play an important role in the apoptotic cell death pathway.

¹ Supported in part by Grant #CA 74175 from the NIH (to A. D.) and Research Starter Grant Award from Georgetown University Medical Center (to V. A. S.).

² To whom correspondence should be addressed, at Department of Radiation Medicine, Georgetown University Medical Center, The Research Bldg., Room E-207A, 3970 Reservoir Road, Washington, D.C. 20007.

Received 7/15/97. Accepted 7/31/97.

This article has been cited by other articles:

				S. R. Rheingold, M. D. Hogarty, S. M. Blaney, J. A. Zwiebel, C. Sauk-Schubert, R. Chandula, M. D. Krailo, and P. C. Adamson Phase I Trial of G3139, a bcl-2 Antisense Oligonucleotide, Combined With Doxorubicin and Cyclophosphamide in Children With Relapsed Solid Tumors: A Children's Oncology Group Study J. Clin. Oncol., April 20, 2007; 25(12): 1512 - 1518. [Abstract] [Full Text] [PDF]

				C. Brignole, D. Marimpietri, F. Pastorino, B. Nico, D. Di Paolo, M. Cioni, F. Piccardi, M. Cilli, A. Pezzolo, M. V. Corrias, et al. Effect of bortezomib on human neuroblastoma cell growth, apoptosis, and angiogenesis. J Natl Cancer Inst, August 16, 2006; 98(16): 1142 - 1157. [Abstract] [Full Text] [PDF]

				S. M. Blaney, M. Bernstein, K. Neville, J. Ginsberg, B. Kitchen, T. Horton, S. L. Berg, M. Krailo, and P. C. Adamson Phase I Study of the Proteasome Inhibitor Bortezomib in Pediatric Patients With Refractory Solid Tumors: A Children's Oncology Group Study (ADVL0015) J. Clin. Oncol., December 1, 2004; 22(23): 4804 - 4809. [Abstract] [Full Text] [PDF]

				C. Adrain, E. M. Creagh, S. P. Cullen, and S. J. Martin Caspase-dependent Inactivation of Proteasome Function during Programmed Cell Death in Drosophila and Man J. Biol. Chem., August 27, 2004; 279(35): 36923 - 36930. [Abstract] [Full Text] [PDF]

				Q. Chen, K. L. Behar, T. Xu, C. Fan, and G. G. Haddad Expression of Drosophila Trehalose-Phosphate Synthase in HEK-293 Cells Increases Hypoxia Tolerance J. Biol. Chem., December 5, 2003; 278(49): 49113 - 49118. [Abstract] [Full Text] [PDF]

				D. Chauhan, G. Li, T. Hideshima, K. Podar, C. Mitsiades, N. Mitsiades, L. Catley, Y. T. Tai, T. Hayashi, R. Shringarpure, et al. Hsp27 inhibits release of mitochondrial protein Smac in multiple myeloma cells and confers dexamethasone resistance Blood, November 1, 2003; 102(9): 3379 - 3386. [Abstract] [Full Text] [PDF]

				C. Wojcik and G. N. DeMartino Analysis of Drosophila 26 S Proteasome Using RNA Interference J. Biol. Chem., February 15, 2002; 277(8): 6188 - 6197. [Abstract] [Full Text] [PDF]

				P. Masdehors, H. Merle-Beral, K. Maloum, S. Omura, H. Magdelenat, and J. Delic Deregulation of the ubiquitin system and p53 proteolysis modify the apoptotic response in B-CLL lymphocytes Blood, July 1, 2000; 96(1): 269 - 274. [Abstract] [Full Text] [PDF]

				J. H. Qiu, A. Asai, S. Chi, N. Saito, H. Hamada, and T. Kirino Proteasome Inhibitors Induce Cytochrome c-Caspase-3-Like Protease-Mediated Apoptosis in Cultured Cortical Neurons J. Neurosci., January 1, 2000; 20(1): 259 - 265. [Abstract] [Full Text] [PDF]

				J. Kikuchi, Y. Furukawa, N. Kubo, A. Tokura, N. Hayashi, M. Nakamura, M. Matsuda, and I. Sakurabayashi Induction of Ubiquitin-Conjugating Enzyme by Aggregated Low Density Lipoprotein in Human Macrophages and Its Implications for Atherosclerosis Arterioscler Thromb Vasc Biol, January 1, 2000; 20(1): 128 - 134. [Abstract] [Full Text] [PDF]

				V. A. Soldatenkov, A. Dritschilo, Z.'e. Ronai, and S. Y. Fuchs Inhibition of Homologue of Slimb (HOS) Function Sensitizes Human Melanoma Cells for Apoptosis Cancer Res., October 1, 1999; 59(20): 5085 - 5088. [Abstract] [Full Text] [PDF]

				L. Meng, B. H. B. Kwok, N. Sin, and C. M. Crews Eponemycin Exerts Its Antitumor Effect through the Inhibition of Proteasome Function Cancer Res., June 1, 1999; 59(12): 2798 - 2801. [Abstract] [Full Text] [PDF]

				J. Chandra, I. Niemer, J. Gilbreath, K.-O. Kliche, M. Andreeff, E. J. Freireich, M. Keating, and D. J. McConkey Proteasome Inhibitors Induce Apoptosis in Glucocorticoid-Resistant Chronic Lymphocytic Leukemic Lymphocytes Blood, December 1, 1998; 92(11): 4220 - 4229. [Abstract] [Full Text] [PDF]