April 1991

Ubiquitin Hybrid Protein Gene Expression During Human Colon Cancer Progression

Author Affiliations

From the Department of Surgery, New England Deaconess Hospital (Drs Mafune, Staniunas, Ravikumar, and Steele) and the Division of Cellular and Molecular Biology, Dana-Farber Cancer Institute (Drs Mafune, Wong, Lu, and Chen), Harvard Medical School, Boston, Mass. Drs Mafune and Ravikumar are currently with the Department of Surgery, Yale University School of Medicine, New Haven, Conn, and Dr Wong is with the Department of Internal Medicine, National Taiwan University Hospital, Taipei.

Arch Surg. 1991;126(4):462-466. doi:10.1001/archsurg.1991.01410280064009

• Ubiquitin is involved in cell-cycle control and DNA replication through a specific proteolytic pathway. Our previous studies demonstrated selected higher expression of a gene encoding ubiquitin-ribosomal protein S27a in poorly differentiated colon carcinoma cell lines. In this study, we evaluated this ubiquitin hybrid protein gene expression in surgical specimens of colon cancers. Northern blot analysis showed that ubiquitin hybrid protein messenger RNA was overexpressed in primary colon cancers compared with adjacent normal colon mucosae in 17 of 20 patients. Dot blot analysis of RNA of 27 tumor samples revealed significantly greater expression in higher Dukes' stage primary colon tumors and liver metastases. These data imply that protein translation machinery is highly activated during progression and metastasis of colon tumors, and that ubiquitin hybrid protein may be useful as a marker of biological aggressiveness.

(Arch Surg. 1991;126:462-466)