Expression of CD97 across glioma grades.

Frozen tumor specimens histologically confirmed as low grade astrocytoma (n = 3), anaplastic astrocytoma (n = 3), and GBM (n = 3) were homogenized analyzed by Western blot. CD97 was expressed in the GBM specimens, but not low grade or anaplastic astrocytomas (A). Quantitative PCR was performed using these specimens and demonstrated a significant increase in CD97 expression among GBMs compared to low grade and anaplastic astrocytomas when normalized to normal brain (B). PCR using primers flanking the variably spliced regions of the CD97 transcript demonstrate the EGF(1,2,5) and EGF(1,2,3,5) in all GBM specimens and a single anaplastic astrocytoma, but not in the low grade or remaining anaplastic astrocytomas (C).