CD109 expression is upregulated in penile squamous cell carcinoma

Cluster of differentiation (CD) 109 is a glycosylphosphatidylinositol-anchored cell surface glycoprotein and a co-receptor for transforming growth factor β. The expression of CD109 has been detected in squamous cell carcinoma of the lung, esophagus, skin and gallbladder. The aim of the present study was to evaluate CD109 expression in penile squamous cell carcinoma (PSCC). CD109 expression in PSCC tumor and adjacent tissues from 45 specimens in tissue microarrays was examined by immunohistochemical analyses. In addition, 3 fresh surgical samples of PSCC were collected and examined for their CD109 mRNA and protein levels by reverse transcription-quantitative polymerase chain reaction, western blotting and immunofluorescence staining. CD109 transcription and expression were significantly higher in the PSCC tissues compared with adjacent normal penile tissues, and its expression was restricted to squamous cells. However, CD109 expression level was not associated with the PSCC differentiation grade. These results suggest that CD109 may be associated with the pathogenesis of PSCC, and may therefore be a potential therapeutic target.