OUTLINE: Patients receive decitabine IV for 6 hours every 12 hr for 5 days. Peripheral blood stem cells (PBSC) are administered 5 days after last dose of decitabine. Donors receive filgrastim subcutaneously (SQ) daily every 12 hours starting 2-4 days prior to first PBSC collection. If insufficient number of cells are collected, bone marrow can be harvested for supplementation. Donor cells should be collected prior to decitabine infusion. Patients receive filgrastim SQ administered daily starting 1 day after PBSC infusion until blood counts recover. For GVHD prophylaxis, patients receive cyclosporine IV daily on day -2, then orally once dose is tolerable. Dose of decitabine is escalated in cohorts of 3-6 patients. If dose limiting toxicity occurs in 2 of 6 patients at a given dose level, then that dose is declared the maximum tolerated dose. Patients are followed weekly. If none of the first 5 patients survive in remission for more than 100 days, the study will be terminated.