Characterization of CD44s glycoproteoforms in bladder tumours and bladder cancer cell culture models
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ABSTRACT: Bladder cancer (BC) is a major health concern retaining high mortality rates when diagnosed at advanced stages. In this context, the clinical management of BC requires the introduction of new biomarkers and molecular targets capable to elicit precision medicine therapeutical approaches. A promising candidate is cluster of differentiation 44 (CD44), a multifunctional and heavily glycosylated transmembrane protein, involved in cell-cell and cell-matrix adhesion, and a transducer of several oncogenic signalling cascades. CD44 has been widely explored as a marker of BC aggressiveness and cancer stem cells (CSC), but this is a highly heterogenic protein and the lack of molecular tools for precise molecular characterization has led to conflicting results, delaying clinical application. CD44 molecular variability results from the number of proteoforms arising from alternative splicing. The human CD44 gene consists of 17 exons, and while the exons 1-5 are constitutively expressed, exons 6-14 are subjected to alternative splicing, generating a myriad of different variants whose functional implications are yet to be fully understood. Furthermore, this number of proteoforms is greatly amplified by O-GalNAc glycosylation, which is predicted to mostly occur in the protein variable regions. This microheterogeneity and its relevance for BC can only be addressed by obtaining a comprehensive characterization at the protein level. Herein, we devised a strategy, combining transcriptomics, glycomics and mass spectrometry based proteomics data, to interrogate CD44 proteoform expression in a series of BC cell culture models showing different aggressiveness (5637 and T24) and a sample pool from formalin fixed paraffin embedded (FFPE) tumours. Glycoengeneered T24 cells expressing the Tn antigen (T24 C1GALT1 knockout (KO)) were also analysed.
INSTRUMENT(S): LTQ Orbitrap, Q Exactive
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Urinary Bladder Urothelium
DISEASE(S): Urinary Bladder Cancer
SUBMITTER: André Silva
LAB HEAD: José Alexandre Ferreira
PROVIDER: PXD028307 | Pride | 2022-05-19
REPOSITORIES: pride
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