UPK1A
Overview
UPK1A (Uroplakin 1A) encodes a member of the uroplakin family of transmembrane proteins, which form crystalline plaques on the apical surface of umbrella cells in the urothelium. In the expanded TCGA bladder cancer analysis, UPK1A is one of the defining high-expression markers of the luminal subtype, reflecting umbrella-cell-like differentiation.
Alterations observed in the corpus
- UPK1A is most highly expressed in the luminal subtype (6% of the 412-tumor expanded TCGA MIBC cohort), together with UPK2, KRT20, and SNX31, consistent with an umbrella-cell-like differentiated phenotype PMID:28988769.
Cancer types (linked)
- BLCA — highest expression in the luminal mRNA subtype among the five-subtype taxonomy (luminal-papillary, luminal-infiltrated, luminal, basal-squamous, neuronal); serves as a defining marker of umbrella-cell-like differentiation in muscle-invasive bladder cancer PMID:28988769.
Co-occurrence and mutual exclusivity
- High UPK1A expression co-occurs with UPK2, KRT20, and SNX31 overexpression as a set of umbrella-cell markers that collectively define the luminal subtype PMID:28988769.
Therapeutic relevance
- No direct targeted therapy reported in the corpus. UPK1A’s restriction to the luminal subtype positions it as a potential lineage marker for subtype-stratified treatment selection; optimal therapy for the luminal subtype is not yet defined PMID:28988769.
Open questions
- The optimal therapeutic strategy for the UPK1A-high luminal subtype is unresolved; the authors propose future trials comparing neoadjuvant chemotherapy vs mutation-targeted therapy in this low-frequency subtype PMID:28988769.
Sources
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