Elevated MGMT and apurinic endonuclease activity accompanies glial tumorigenesis

- Silber, J.R., Bobola, M.S., Ghatan, S., Blank, A., Kolstoe, D.D. and Berger, M.S. O6-methyl-guanine-DNA methyltransferase activity in adult gliomas: Relation to patient and tumor characteristics. Cancer Res. 58: 1068-1073, 1998
- Silber, J.R., Bobola, M.S., Blank, A., Berger, M.S., Stevens, B.A. and Silber, J.R. Apurinic/apyrimidinic endonuclease activity is elevated in human adult gliomas. Clin. Cancer Res. 7: 3510-3518, 2000

Ratio of MGMT (left) and Ap endo (right) activities in paired gliomas and adjacent normal brain. Analysis of MGMT activity in 105 tumor/normal pairs revealed a 1.2- to 144-fold elevation of tumor activity relative to adjacent normal tissue in 75% of pairs. Analysis of Ap endo activity in 58 tumor/normal pairs revealed a 1.2- to 85-fold elevation of tumor activity in 93% of tissue pairs. A clinically important consequence of elevated MGMT and Ap endo activities may be enhanced resistance to alkylating agent-based chemotherapy. Bold crosses, mean elevation of tumor activity. Astro, astrocytoma; AA, anaplastic astrocytoma; GBM, glioblastoma; oligo, oligodendroglioma; O-A, mixed oligodendroglioma-astrocytoma