RATIONALE: Drugs used in chemotherapy, such as temozolomide, work in different ways to stop
the growth of tumor cells, either by killing the cells or by stopping them from dividing.
O6-benzylguanine may help temozolomide work better by making tumor cells more sensitive to
the drug. Giving genetically modified peripheral blood stem cells during or after treatment
may prevent side effects caused by chemotherapy.
PURPOSE: This clinical trial studies O6-benzylguanine and temozolomide in combination with
genetically modified peripheral blood stem cells in treating patients with newly diagnosed
glioblastoma multiforme.