PGP9.5 overexpression in esophageal squamous cell carcinoma.

Background/aims: PGP9.5 is a ubiquitin hydrolase widely expressed in neuronal tissue at all stages of neuronal differentiation and has been used as a neuroendocrine marker. Recently, it has been proved that PGP9.5 expression was highly observed in squamous cell carcinoma of lung cancer, suggesting that it might be a tumor marker for squamous cell carcinoma. To better characterize its role in digestive tract cancers, we examined PGP9.5 expression retrospectively in esophageal cancers.

Methodology: We examined PGP9.5 expression retrospectively in 40 resected esophageal cancers (squamous cell carcinoma) and 10 gastric cancers (adenocarcinoma) using immunohistochemistry.

Results: Of 40 esophageal cancer specimens, 19 (48%) exhibited positive staining with PGP9.5 in most tumor cells, while no PGP9.5 expression was observed in any of the 10 gastric cancers.

Conclusions: Although the precise mechanism underlying the effect of PGP9.5 on oncogenicity remains to be proven, it was confirmed that it may be a potential marker for esophageal squamous cell carcinoma.