Hypoxia enhances the malignant nature of bladder cancer cells and concomitantly antagonizes protein O-glycosylation extension

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Peixoto, A (Author) Other; Fernandes, E (Author) Other; Gaiteiro, C (Author) Other; Lima, L (Author) Other; Azevedo, R (Author) Other; Soares, J (Author) Other; Cotton, S (Author) Other; Parreira, B (Author) Other; Neves, M (Author) Other; Amaro, T (Author) Other; Tavares, A (Author) Other; Teixeira, F (Author) Other; Palmeira, C (Author) Other; Maria Rangel (Author) ICBAS; Silva, AMN (Author) Other; Celso Reis (Author) ICBAS; Santos, LL (Author) Other; Oliveira, MJ (Author) FMUP; Ferreira, JA (Author) Other

Journal

Title: Oncotarget

Vol. 7

Pages: 63138-63157

ISSN: 1949-2553

Publisher: Impact Journals

Indexing

ISI Web of Knowledge - 52 Citations

Scopus - 55 Citations

Other information

Authenticus ID: P-00M-6XP

DOI: 10.18632/oncotarget.11257

Abstract (EN): Invasive bladder tumours express the cell-surface Sialyl-Tn (STn) antigen, which stems from a premature stop in protein O-glycosylation. The STn antigen favours invasion, immune escape, and possibly chemotherapy resistance, making it attractive for target therapeutics. However, the events leading to such deregulation in protein glycosylation are mostly unknown. Since hypoxia is a salient feature of advanced stage tumours, we searched into how it influences bladder cancer cells glycophenotype, with emphasis on STn expression. Therefore, three bladder cancer cell lines with distinct genetic and molecular backgrounds (T24, 5637 and HT1376) were submitted to hypoxia. To disclose HIF-1 alpha-mediated events, experiments were also conducted in the presence of Deferoxamine Mesilate (Dfx), an inhibitor of HIF-1 alpha proteasomal degradation. In both conditions all cell lines overexpressed HIF-1 alpha and its transcriptionally-regulated protein CA-IX. This was accompanied by increased lactate biosynthesis, denoting a shift toward anaerobic metabolism. Concomitantly, T24 and 5637 cells acquired a more motile phenotype, consistent with their more mesenchymal characteristics. Moreover, hypoxia promoted STn antigen overexpression in all cell lines and enhanced the migration and invasion of those presenting more mesenchymal characteristics, in an HIF-1 alpha-dependent manner. These effects were reversed by reoxygenation, demonstrating that oxygen affects O-glycan extension. Glycoproteomics studies highlighted that STn was mainly present

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 20