Integration of genetic and metabolic features related to sialic acid metabolism distinguishes human breast cell subtypes

• Published in: PloS one Vol. 13; no. 5; p. e0195812
• Main Authors: Saeui, Christopher T, Nairn, Alison V, Galizzi, Melina, Douville, Christopher, Gowda, Prateek, Park, Marian, Dharmarha, Vrinda, Shah, Sagar R, Clarke, Amelia, Austin, Melissa, Moremen, Kelley W, Yarema, Kevin J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30-05-2018; Public Library of Science (PLoS)
• Subjects: Abnormalities; Acid production; Acids; Alkynes; Analogs; Analysis; Biology and Life Sciences; Biomarkers, Tumor - genetics; Biomedical engineering; Biosynthesis; Brain research; Breast cancer; Breast Neoplasms - classification; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cancer; Cancer cells; Carbohydrates; Cell Proliferation; Cytotoxicity; Diagnosis; Dimensional analysis; Disease; Epimerase; Feedback inhibition; Female; Fluctuations; Flux; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genes; Genetic aspects; Genetic control; Genetic engineering; Glycosylation; Hexosamines - chemistry; Humans; Intracellular; Kinases; Mathematical analysis; Medical research; Medicine and Health Sciences; Metabolic flux; Metabolism; Metabolites; Metastasis; N-Acetylneuraminic Acid - metabolism; Physical Sciences; Profiling; Regulatory mechanisms (biology); Research and Analysis Methods; Sialic acids; Sugar; Supplementation; Supplements; Tissue engineering; Transcription; Tumor Cells, Cultured; Georgia; United States > US; Maryland; Baltimore Maryland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0195812

In this report we use 'high-flux' tributanoyl-modified N-acetylmannosamine (ManNAc) analogs with natural N-acetyl as well as non-natural azido- and alkyne N-acyl groups (specifically, 1,3,4-O-Bu3ManNAc, 1,3,4-O-Bu3ManNAz, and 1,3,4-O-Bu3ManNAl respectively) to probe intracellular sialic acid metabolism in the near-normal MCF10A human breast cell line in comparison with earlier stage T-47D and more advanced stage MDA-MB-231 breast cancer lines. An integrated view of sialic acid metabolism was gained by measuring intracellular sialic acid production in tandem with transcriptional profiling of genes linked to sialic acid metabolism. The transcriptional profiling showed several differences between the three lines in the absence of ManNAc analog supplementation that helps explain the different sialoglycan profiles naturally associated with cancer. Only minor changes in mRNA transcript levels occurred upon exposure to the compounds confirming that metabolic flux alone can be a key determinant of sialoglycoconjugate display in breast cancer cells; this result complements the well-established role of genetic control (e.g., the transcription of STs) of sialylation abnormalities ubiquitously associated with cancer. A notable result was that the different cell lines produced significantly different levels of sialic acid upon exogenous ManNAc supplementation, indicating that feedback inhibition of UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE)-generally regarded as the 'gatekeeper' enzyme for titering flux into sialic acid biosynthesis-is not the only regulatory mechanism that limits production of this sugar. A notable aspect of our metabolic glycoengineering approach is its ability to discriminate cell subtype based on intracellular metabolism by illuminating otherwise hidden cell type-specific features. We believe that this strategy combined with multi-dimensional analysis of sialic acid metabolism will ultimately provide novel insights into breast cancer subtypes and provide a foundation for new methods of diagnosis.