Aberrant glycosylation patterns are a hallmark of the tumor phenotype. While highly variable in structure, many tumor-associated oligosaccharides share one important feature: they contain sialic acid residues. Indeed, the overexpression of sialic acid is highly correlated with the malignant phenotype in gastric, colon, pancreatic, liver, lung, prostate and breast cancers, as well as several types of leukemia. Consequently, new strategies for targeting cells on the basis of differential sialic acid expression levels may have widespread utility in the treatment and diagnosis of cancer. This proposal describes a chemicAL approach to the selective targeting of highly sialylated cells with therapeutic and diagnostic agents. The strategy is predicated on the remarkable tolerance of the sialic acid biosynthetic machinery for modified substrates. We have shown that a uniquely reactive functional group, the ketone, can be delivered to cell surface sialic acids by feeding the cells the unnatural metabolic precursor N-levulinoyl mannosamine (ManLev). The ketone provides the ideal mechanism for targeting cells in their native environment because it is chemically orthogonal to all other cell surface components, yet will react selectively with hydroxylamines and hydrazides under physiological conditions. Thus, in the context of the biological milieu, the ketone introduces a unique functional group which permits covalent targeting with molecules bearing complementary functionality. The objective of the proposed research is to explore the potential application of unnatural sialic acid biosynthesis to the selective delivery of therapeutic and diagnostic agents to human tumor cells. A positive correlation between sialic acid expression level and ManLev metabolism is critical for the proposed application, and will be established using tumor cell lines selected for defined sialic acid levels. Next, hydroxylamine-conjugated toxins, imaging reagents and small molecular antigens will be synthesized, and their selectivity for cells rich in sialic acid will be evaluated. As a prelude to future in vivo targeting studies, unnatural sialic acid biosynthesis in laboratory animals will be investigated. Finally, the biosynthetic pathway for cell surface fucosides will be explored as an alternative vehicle for the cell surface delivery of unique chemical targets. This project is the first phase of a long-term program focusing on applications of unnatural oligosaccharide biosynthesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM058867-03
Application #
6343067
Study Section
Bio-Organic and Natural Products Chemistry Study Section (BNP)
Program Officer
Jones, Warren
Project Start
1999-01-01
Project End
2005-04-30
Budget Start
2001-01-01
Budget End
2001-12-31
Support Year
3
Fiscal Year
2001
Total Cost
$252,499
Indirect Cost
Name
University of California Berkeley
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
094878337
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Rodriguez-Rivera, Frances P; Zhou, Xiaoxue; Theriot, Julie A et al. (2018) Acute Modulation of Mycobacterial Cell Envelope Biogenesis by Front-Line Tuberculosis Drugs. Angew Chem Int Ed Engl 57:5267-5272
Wan, Stephanie J; Sullivan, Aaron B; Shieh, Peyton et al. (2018) IL-1R and MyD88 Contribute to the Absence of a Bacterial Microbiome on the Healthy Murine Cornea. Front Microbiol 9:1117
Tomlin, Frederick M; Gordon, Chelsea G; Han, Yisu et al. (2018) Site-specific incorporation of quadricyclane into a protein and photocleavage of the quadricyclane ligation adduct. Bioorg Med Chem 26:5280-5290
Jolly, Amber L; Agarwal, Paresh; Metruccio, Matteo M E et al. (2017) Corneal surface glycosylation is modulated by IL-1R and Pseudomonas aeruginosa challenge but is insufficient for inhibiting bacterial binding. FASEB J 31:2393-2404
Rodriguez-Rivera, Frances P; Zhou, Xiaoxue; Theriot, Julie A et al. (2017) Visualization of mycobacterial membrane dynamics in live cells. J Am Chem Soc 139:3488-3495
Zhu, Xuejun; Shieh, Peyton; Su, Michael et al. (2016) A fluorogenic screening platform enables directed evolution of an alkyne biosynthetic tool. Chem Commun (Camb) 52:11239-42
Kim, Justin; Bertozzi, Carolyn R (2015) A Bioorthogonal Reaction of N-Oxide and Boron Reagents. Angew Chem Int Ed Engl 54:15777-81
Shieh, Peyton; Dien, Vivian T; Beahm, Brendan J et al. (2015) CalFluors: A Universal Motif for Fluorogenic Azide Probes across the Visible Spectrum. J Am Chem Soc 137:7145-51
Beahm, Brendan J; Dehnert, Karen W; Derr, Nicolas L et al. (2014) A visualizable chain-terminating inhibitor of glycosaminoglycan biosynthesis in developing zebrafish. Angew Chem Int Ed Engl 53:3347-52
Shieh, Peyton; Siegrist, M Sloan; Cullen, Andrew J et al. (2014) Imaging bacterial peptidoglycan with near-infrared fluorogenic azide probes. Proc Natl Acad Sci U S A 111:5456-61

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