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 Geissler, F. Articles by Press, O. Search for Related Content PubMed PubMed Citation Articles by Geissler, F. Articles by Press, O.

Intracellular Catabolism of Radiolabeled Anti-µ Antibodies by Malignant B-Cells¹

Departments of Biological Structure [F. G., S. K. A., O. P.], Radiology (Division of Nuclear Medicine) [P. V.], and Medicine (Division of Oncology) [S. K. A., O. P.], University of Washington, Seattle, Washington 98195, and the Fred Hutchinson Cancer Research Center, Seattle, Washington 98104 [O. P.]

The endocytosis and degradation of ¹²⁵I-labeled anti-µ monoclonal antibody DA4-4 by a Burkitt's lymphoma cell line was investigated using biochemical, chromatographic, electrophoretic, radioautographic, and electron microscopic techniques. ¹²⁵I-DA4-4 was rapidly internalized by Ramos cells and routed from endosomes to lysosomes. Proteolysis of radiolabeled antibodies began in a late endosomal compartment, but lysosomes were primarily responsible for the terminal degradation of ¹²⁵I-DA4-4. Catabolism of ¹²⁵I-DA4-4 could be inhibited by 74–95% by blocking its delivery to late endosomes and lysosomes by incubation at 18°C, by neutralizing the pH in intracellular organelles with monensin or ammonium chloride, or by inhibiting lysosomal enzymes with leupeptin. Radiolabeled antibodies synthesized using the chloramine T or Iodo-Gen techniques were degraded three times faster than conjugates made using a nonmetabolizable ¹²⁵I-tyramine cellobiose adduct. Five major intermediate metabolites (M_r 48,000, 42,000, 25,000, 15,000, and 10,000) were generated during the intracellular catabolism of ¹²⁵I-DA4-4, but ¹²⁵I-tyrosine was responsible for 95% of the small-molecular-weight metabolites released by cells into the culture medium. We anticipate that a full comprehension of the catabolism of radiolabeled antibodies by tumor cells will make possible the development of clinical interventions which will enhance the retention of radioimmunoconjugates by hematologic malignancies and improve the efficacy of radioimmunotherapy.

¹ Supported in part by Department of Energy Grant DE-FG06-88ER60719 and NIH R01 CA55596-01. F. G. is the recipient of a W. M. Keck Foundation Bioimaging Research Fellowship.

² To whom correspondence should be addressed, at the University of Washington Cancer Center, Mailstop RC-08, Seattle, WA 98195.

Received 11/11/91. Accepted 3/11/92.

This article has been cited by other articles:

				Z. Cheng, L. Zhang, E. Graves, Z. Xiong, M. Dandekar, X. Chen, and S. S. Gambhir Small-Animal PET of Melanocortin 1 Receptor Expression Using a 18F-Labeled {alpha}-Melanocyte-Stimulating Hormone Analog J. Nucl. Med., June 1, 2007; 48(6): 987 - 994. [Abstract] [Full Text] [PDF]

				D. A. Vallera, M. W. Brechbiel, L. J. Burns, A. Panoskaltsis-Mortari, K. E. Dusenbery, D. R. Clohisy, and E. S. Vitetta Radioimmunotherapy of CD22-Expressing Daudi Tumors in Nude Mice with a 90Y-Labeled Anti-CD22 Monoclonal Antibody Clin. Cancer Res., November 1, 2005; 11(21): 7920 - 7928. [Abstract] [Full Text] [PDF]

				S. V. Govindan, G. L. Griffiths, R. Stein, P. Andrews, R. M. Sharkey, H. J. Hansen, I. D. Horak, and D. M. Goldenberg Clinical-Scale Radiolabeling of a Humanized Anticarcinoembryonic Antigen Monoclonal Antibody, hMN-14, with Residualizing 131I for Use in Radioimmunotherapy J. Nucl. Med., January 1, 2005; 46(1): 153 - 159. [Abstract] [Full Text] [PDF]

				T. Olafsen, G. J. Tan, C.-w. Cheung, P. J. Yazaki, J. M. Park, J. E. Shively, L. E. Williams, A. A. Raubitschek, M. F. Press, and A. M. Wu Characterization of engineered anti-p185HER-2 (scFv-CH3)2 antibody fragments (minibodies) for tumor targeting Protein Eng. Des. Sel., April 1, 2004; 17(4): 315 - 323. [Abstract] [Full Text] [PDF]

				Z. Cheng, J. Chen, T. P. Quinn, and S. S. Jurisson Radioiodination of Rhenium Cyclized {alpha}-Melanocyte-Stimulating Hormone Resulting in Enhanced Radioactivity Localization and Retention in Melanoma Cancer Res., February 15, 2004; 64(4): 1411 - 1418. [Abstract] [Full Text] [PDF]

				A. H. Brouwers, J. E.M. van Eerd, C. Frielink, E. Oosterwijk, W. J.G. Oyen, F. H.M. Corstens, and O. C. Boerman Optimization of Radioimmunotherapy of Renal Cell Carcinoma: Labeling of Monoclonal Antibody cG250 with 131I, 90Y, 177Lu, or 186Re J. Nucl. Med., February 1, 2004; 45(2): 327 - 337. [Abstract] [Full Text] [PDF]

				A. H. Brouwers, W. C. A. M. Buijs, E. Oosterwijk, O. C. Boerman, C. Mala, P. H. M. De Mulder, F. H. M. Corstens, P. F. A. Mulders, and W. J. G. Oyen Targeting of Metastatic Renal Cell Carcinoma with the Chimeric Monoclonal Antibody G250 Labeled with 131I or 111In: An Intrapatient Comparison Clin. Cancer Res., September 1, 2003; 9(10): 3953s - 3960s. [Abstract] [Full Text]

				S. Welt, G. Ritter, C. Williams Jr., L. S. Cohen, M. John, A. Jungbluth, E. A. Richards, L. J. Old, and N. E. Kemeny Phase I Study of Anticolon Cancer Humanized Antibody A33 Clin. Cancer Res., April 1, 2003; 9(4): 1338 - 1346. [Abstract] [Full Text] [PDF]

				G. L. DeNardo, S. J. DeNardo, D. L. Kukis, R. T. O'Donnell, S. Shen, G. R. Mirick, and C. F. Meares Metabolite Production in Patients with Lymphoma After Radiometal-Labeled Antibody Administration J. Nucl. Med., September 1, 2001; 42(9): 1324 - 1333. [Abstract] [Full Text] [PDF]

				R. Stein, S. V. Govindan, S. Chen, L. Reed, H. Richel, G. L. Griffiths, H. J. Hansen, and D. M. Goldenberg Radioimmunotherapy of a Human Lung Cancer Xenograft with Monoclonal Antibody RS7: Evaluation of 177Lu and Comparison of Its Efficacy with That of 90Y and Residualizing 131I J. Nucl. Med., June 1, 2001; 42(6): 967 - 974. [Abstract] [Full Text] [PDF]

				A. Bilge, C. V. Warner, and O. W. Press Translocation of Ricin A-chain into Proteoliposomes Reconstituted from Golgi and Endoplasmic Reticulum J. Biol. Chem., October 6, 1995; 270(40): 23720 - 23725. [Abstract] [Full Text] [PDF]