Histone methylation defines an epigenetic entity in penile squamous cell carcinoma

Abstract

Purpose: Earlier studies indicate that epigenetics contribute to the pathogenesis of penile squamous cell carcinoma. Histone methylation patterns are frequently altered during carcinogenesis. Therefore, we investigated the methylation pattern of the histones H3K4, H3K9 and H3K27 in penile carcinoma and normal tissue.

Materials and methods: A tissue microarray was constructed with 65 penile carcinomas, 6 metastatic lesions and 30 control tissues. Global histone methylation was assessed using immunohistochemistry.

Results: Global levels of H3K4me1, H3K9me1, H3K9me2, H3K27me2 and H3K27me3 were decreased, whereas H3K9me3 was increased in penile carcinoma. Histone methylation levels defined an epigenetic entity that allowed accurate differentiation of cancer and normal samples. We observed no correlation of histone methylation levels with clinicopathological parameters or patient outcome.

Conclusions: The description of a definite epigenetic entity in penile carcinoma provides a rationale for testing epigenetic agents in patients with metastatic disease.