We conclude that the expression pattern of OCT2, SSX2-4, and SAGE1 supports the origin of SS from spermatogonia and provides new evidence for heterogeneity of this tumour, potentially linked either to the cellular origin of SS or to partial differentiation during tumour progression, including a hitherto unknown OCT2-positive variant of the tumour likely derived from A(dark) spermatogonia.
Pyrosequencing assays were utilized to assess the DNA methylation of the tumors, and SAGE libraries were constructed and sequenced to determine the gene expression profiles of the tumors.
SAGE and HAGE are recently isolated genes, which were thought to be expressed tumour-specifically, and are potentially coding for tumour-specific antigens recognized by T lymphocytes.