Expression of Fas/APO-1 during the progression of astrocytomas.

Fas/APO-1 (CD95) is an apoptosis-signaling receptor molecule on the surface of cells. To investigate the possible role of Fas during malignant transformation of glial cells, we analyzed the expression of Fas mRNA by reverse transcription-PCR in human astrocytic brain tumors. Expression was found in 1 of 4 (25%) juvenile pilocytic astrocytomas (WHO grade I), 1 of 9 (11%) low-grade astrocytomas (WHO grade II), 6 of 12 (50%) anaplastic astrocytomas (WHO grade III), and all of 9 glioblastomas (WHO grade IV). Thus, the frequency of Fas expression appears to correlate with the malignancy grade of astrocytomas. The soluble form of the Fas mRNA lacking the transmembrane domain was detected in one anaplastic astrocytoma and in two glioblastomas.