Targeted O-glycoproteomics explored increased sialylation and identified MUC16 as a poor prognosis biomarker in advanced-stage bladder tumours.
Bladder carcinogenesis and tumour progression is accompanied by profound alterations in protein glycosylation on the cell surface, which may be explored for improving disease management. In a search for prognosis biomarkers and novel therapeutic targets we have screened, using immunohistochemistry, a series of bladder tumours with differing clinicopathology for short-chain O-glycans commonly found in glycoproteins of human solid tumours. These included the Tn and T antigens and their sialylated counterparts sialyl-Tn(STn) and sialyl-T(ST), which are generally associated with poor prognosis. We have also explored the nature of T antigen sialylation, namely the sialyl-3-T(S3T) and sialyl-6-T(S6T) sialoforms, based on combinations of enzymatic treatments. We observed a predominance of sialoglycans over neutral glycoforms (Tn and T antigens) in bladder tumours. In particular, the STn antigen was associated with high-grade disease and muscle invasion, in accordance with our previous observations. The S3T and S6T antigens were detected for the first time in bladder tumours, but not in healthy urothelia, highlighting their cancer-specific nature. These glycans were also overexpressed in advanced lesions, especially in cases showing muscle invasion. Glycoproteomic analyses of advanced bladder tumours based on enzymatic treatments, Vicia villosa lectin-affinity chromatography enrichment and nanoLC-ESI-MS/MS analysis resulted in the identification of several key cancer-associated glycoproteins (MUC16, CD44, integrins) carrying altered glycosylation. Of particular interest were MUC16 STn+-glycoforms, characteristic of ovarian cancers, which were found in a subset of advanced-stage bladder tumours facing the worst prognosis. In summary, significant alterations in the O-glycome and O-glycoproteome of bladder tumours hold promise for the development of novel noninvasive diagnostic tools and targeted therapeutics. Furthermore, abnormal MUC16 glycoforms hold potential as surrogate biomarkers of poor prognosis and unique molecular signatures for designing highly specific targeted therapeutics.
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.
Sofia
S
Cotton
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Institute of Biomedical Sciences Abel Salazar, University of Porto, Portugal.
Rita
R
Azevedo
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.
Cristiana
C
Gaiteiro
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.
Dylan
D
Ferreira
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.
Luís
L
Lima
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Institute of Biomedical Sciences Abel Salazar, University of Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.
Andreia
A
Peixoto
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Institute of Biomedical Sciences Abel Salazar, University of Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.
Elisabete
E
Fernandes
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.
Manuel
M
Neves
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.
Diogo
D
Neves
Department of Pathology, Hospital Pedro Hispano, Matosinhos, Portugal.
Teresina
T
Amaro
Department of Urology, Portuguese Institute of Oncology of Porto, Portugal.
Ricardo
R
Cruz
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Department of Pathology, Portuguese Institute of Oncology of Porto, Portugal.
Ana
A
Tavares
UCIBIO-REQUIMTE, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Portugal.
Maria
M
Rangel
UCIBIO-REQUIMTE/Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Portugal.
André M N
AMN
Silva
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Health School of University Fernando Pessoa, Porto, Portugal.|Department of Surgical Oncology, Portuguese Institute of Oncology, Porto, Portugal.
Lúcio Lara
LL
Santos
Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal.|Institute of Biomedical Sciences Abel Salazar, University of Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.|Porto Comprehensive Cancer Center (P.ccc), Portugal.
José Alexandre
0000-0002-0097-6148
JA
Ferreira
D000368:Aged; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D009367:Neoplasm Staging; D040901:Proteomics; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology
D006023:Glycoproteins; D009363:Neoplasm Proteins; D019158:N-Acetylneuraminic Acid
MUC16; bladder cancer; glycoproteomics; glycosylation; precision medicine; sialic acids