PGP9.5 expression in human tumors: A tissue microarray study on 13,920 tumors from 120 different tumor entities

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Protein gene product 9.5 (PGP9.5), also known as ubiquitin C-terminal hydrolase L1 (UCH-L1), is integral to the ubiquitination/deubiquitination system and axonal transport.
• Its role in neoplastic tissues remains incompletely understood.

Purpose of the Study:

• To comprehensively map the expression patterns of PGP9.5 across a wide spectrum of human cancers.
• To investigate the correlation between PGP9.5 expression and clinicopathological parameters and patient outcomes in various tumor types.

Main Methods:

• Immunohistochemistry (IHC) was employed on a large-scale tissue microarray comprising 13,920 samples from 120 tumor types and subtypes.
• Statistical analyses were performed to correlate PGP9.5 expression with tumor grade, stage, metastasis, and survival.

Main Results:

• PGP9.5 immunostaining was detected in 109 out of 120 tumor categories, with strong positivity in neuronal, neuroendocrine, germ cell neoplasms, sarcomas, and mesotheliomas.
• In clear cell renal cell carcinoma (RCC), strong PGP9.5 expression correlated with higher ISUP grade, advanced stage, metastasis, and poorer survival outcomes.
• In papillary RCC and urothelial carcinoma, PGP9.5 expression was linked to higher grade and muscle-invasion, respectively.

Conclusions:

• PGP9.5 is broadly expressed in human neoplasms, indicating its potential as a pan-cancer biomarker.
• PGP9.5 overexpression is significantly associated with adverse prognostic factors and outcomes in specific cancers like clear cell RCC.
• The clinical relevance of PGP9.5 expression varies across different tumor types, necessitating entity-specific evaluation.