Volume 272, Number 46, Issue of November 14, 1997 pp. 29190-29199
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

Elevations in Cathepsin B Protein Content and Enzyme Activity Occur Independently of Glycosylation during Colorectal Tumor Progression

(Received for publication, August 6, 1997)

Christine A. Iacobuzio-Donahue , Sania Shuja ^§ , Jinguo Cai , Phyllis Peng and Mary Jo Murnane ^§¶

From the Departments of  Pathology and ^¶ Biochemistry, Boston University School of Medicine and the ^§ Mallory Institute of Pathology, Boston, Massachusetts 02118

Western blots, enzyme assays, protein glycosylation studies, and immunohistochemical staining were used to characterize cathepsin B expression at successive stages of colorectal tumor progression. In normal colon mucosa and premalignant adenomas, cathepsin B expression was predominantly due to mature two-chain protein detected on Western blots as the nonglycosylated 27-kDa form, with overexpression of this protein occurring in only 4 of 18 adenomas. Overexpression increased significantly in Dukes A and B carcinomas (26 of 37 cases), with cathepsin B protein generally detectable in carcinomas as a combination of both 27-kDa nonglycosylated and 28-kDa glycosylated mature two-chain forms. Glycosylated cathepsin B protein in carcinoma extracts was sensitive to PNGase F but resistant to Endo H, indicating a pattern consistent with complex rather than high mannose type glycosylation. When sorted by advancing tumor stage, peak expression of cathepsin B protein occurred in carcinomas involved in local invasion compared with adenomas or metastatic cancers. At all stages, cathepsin B activity correlated significantly with the levels of heavy chain mature cathepsin B protein (r = 0.6682, p < 0.0001) irrespective of glycosylation. Immunohistochemical staining of cathepsin B protein revealed fine diffuse cytoplasmic staining in both adenomas and carcinomas compared with coarse granular cytoplasmic staining (typical of lysosomes) seen in matched normal mucosa. Our results demonstrate several sequential, apparently independent changes in cathepsin B expression during colorectal tumor progression including early changes in subcellular localization, up-regulation of cathepsin B protein and activity in invasive cancers, and altered protein glycosylation detected in malignant tumors at all stages.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				T. Tsubokawa, I. Solaroglu, H. Yatsushige, J. Cahill, K. Yata, and J. H. Zhang Cathepsin and Calpain Inhibitor E64d Attenuates Matrix Metalloproteinase-9 Activity After Focal Cerebral Ischemia in Rats Stroke, July 1, 2006; 37(7): 1888 - 1894. [Abstract] [Full Text] [PDF]

				J. M. Hoffman Can Optical Molecular Imaging Techniques with Catheter-based Approaches Be Used for Disease Detection? Radiology, June 1, 2004; 231(3): 609 - 610. [Full Text] [PDF]

				P. K. Sengupta, E. M. Smith, K. Kim, M. J. Murnane, and B. D. Smith DNA Hypermethylation Near the Transcription Start Site of Collagen {alpha}2(I) Gene Occurs in Both Cancer Cell Lines and Primary Colorectal Cancers Cancer Res., April 15, 2003; 63(8): 1789 - 1797. [Abstract] [Full Text] [PDF]

				L. G. M. Hazen, F. E. Bleeker, B. Lauritzen, S. Bahns, J. Song, A. Jonker, B. E. M. Van Driel, H. Lyon, U. Hansen, A. Köhler, et al. Comparative Localization of Cathepsin B Protein and Activity in Colorectal Cancer J. Histochem. Cytochem., October 1, 2000; 48(10): 1421 - 1430. [Abstract] [Full Text]

				J. Kos, M. Krasovec, N. Cimerman, H. J. Nielsen, I. J. Christensen, and N. Brünner Cysteine Proteinase Inhibitors Stefin A, Stefin B, and Cystatin C in Sera from Patients with Colorectal Cancer: Relation to Prognosis Clin. Cancer Res., February 1, 2000; 6(2): 505 - 511. [Abstract] [Full Text]

				P. C. Almeida, I. L. Nantes, C. C. A. Rizzi, W. A. S. Judice, J. R. Chagas, L. Juliano, H. B. Nader, and I. L. S. Tersariol Cysteine Proteinase Activity Regulation. A POSSIBLE ROLE OF HEPARIN AND HEPARIN-LIKE GLYCOSAMINOGLYCANS J. Biol. Chem., October 22, 1999; 274(43): 30433 - 30438. [Abstract] [Full Text] [PDF]

				P. C. Almeida, I. L. Nantes, J. R. Chagas, C. C. A. Rizzi, A. Faljoni-Alario, E. Carmona, L. Juliano, H. B. Nader, and I. L. S. Tersariol Cathepsin B Activity Regulation. HEPARIN-LIKE GLYCOSAMINOGLYCANS PROTECT HUMAN CATHEPSIN B FROM ALKALINE pH-INDUCED INACTIVATION J. Biol. Chem., January 5, 2001; 276(2): 944 - 951. [Abstract] [Full Text] [PDF]