High extent of O-GlcNAcylation in breast cancer cells correlates with the levels of HAS enzymes, accumulation of hyaluronan, and poor outcome.
Obesity and oversupply of glucose, e.g., due to nutritional factors may shape the tumor microenvironment favorable for tumor progression. O-GlcNAcylation, a reversible modification of intracellular proteins, influences on several cellular functions and is connected to many diseases including cancer. Glycosaminoglycan hyaluronan (HA) enhances tumor progression and in breast cancer HA accumulation associates strongly with poor outcome. In vitro studies have suggested that O-GlcNAcylation may enhance HA synthesis. The aim of this study was to investigate the correlations between O-GlcNAcylation, HA-related parameters, and disease outcome in a clinical breast cancer material consisting of 278 breast cancer cases.



In microscopic analyses, O-GlcNAc staining of the breast carcinoma cells was evaluated in several randomly picked high-power fields of each section. The extent of cytoplasmic O-GlcNAc staining was graded as either low or high according to the intensity of the staining and the percentage of stained cells. The extent of nuclear O-GlcNAc staining was categorized as either low or high according to the percentage of stained nuclei.



A high extent of both cytoplasmic and nuclear O-GlcNAcylation correlated with an increased relapse rate, development of distant metastases, and poor outcome. A high extent of cytoplasmic O-GlcNAcylation correlated also with the accumulation of all hyaluronan synthase (HAS1-3) proteins and with a large amount of HA in the tumor stroma. In addition, a high extent of nuclear O-GlcNAcylation associated with obesity.



The results suggest a mechanistic association between increased O-GlcNAcylation and HA synthesis, leading to a HA-rich microenvironment favorable for breast cancer progression.
Cancer Center, Kuopio University Hospital, P.O. Box 100, 70029, Kuopio, Finland. satu.tiainen@kuh.fi.|Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland. satu.tiainen@kuh.fi.
Satu
S
Tiainen
Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
Sanna
S
Oikari
Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
Markku
M
Tammi
Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
Kirsi
K
Rilla
Clinical Pathology and Forensic Medicine, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.|Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.|Clinical Pathology, Imaging Center, Kuopio University Hospital, P.O. Box 100, 70029, Kuopio, Finland.
Kirsi
K
Hämäläinen
Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
Raija
R
Tammi
Clinical Pathology and Forensic Medicine, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.|Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.|Clinical Pathology, Imaging Center, Kuopio University Hospital, P.O. Box 100, 70029, Kuopio, Finland.
Veli-Matti
VM
Kosma
Cancer Center, Kuopio University Hospital, P.O. Box 100, 70029, Kuopio, Finland.|Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
Päivi
P
Auvinen
D000117:Acetylglucosamine / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000401:mortality*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D006031:Glycosylation; D006801:Humans; D000076002:Hyaluronan Synthases / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000378:metabolism*; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009765:Obesity / Q000378:metabolism; D011379:Prognosis; D017154:Stromal Cells
D015415:Biomarkers; D006820:Hyaluronic Acid; D000076002:Hyaluronan Synthases; D000117:Acetylglucosamine
Breast cancer; Hyaluronan; Hyaluronan synthase; O-GlcNAcylation