Leukemia L1210Leukemia P388Leukemia Virus, MurineLeukemia, ExperimentalMoloney murine leukemia virusLeukemia L5178LeukemiaCell LineTrimetrexateTumor Cells, CulturedPteroylpolyglutamic AcidsCell Line, TumorLeukemia, Myeloid, AcuteFolic Acid AntagonistsAKR murine leukemia virusFriend murine leukemia virusHL-60 CellsDrug ResistanceAbelson murine leukemia virusMethotrexateAntineoplastic AgentsCell DivisionCell SurvivalLeukemia, LymphoidLeukemia, MyeloidLeukemia, Lymphocytic, Chronic, B-CellBase SequenceMolecular Sequence DataDoxorubicinRetroviridae InfectionsLeukemia, Myelogenous, Chronic, BCR-ABL PositiveLeukemia, Monocytic, AcuteCell Line, TransformedApoptosisK562 CellsRNA, MessengerRauscher VirusCell DifferentiationGene Expression Regulation, LeukemicLeukemia, T-CellStructure-Activity RelationshipTransfectionMice, Inbred AKRRetroviridaeNeoplasm ProteinsPrecursor Cell Lymphoblastic Leukemia-LymphomaLeukemia, Promyelocytic, AcuteMice, Inbred BALB CDNA, NeoplasmCell Transformation, NeoplasticLeukemia, B-CellLeukemia, Megakaryoblastic, AcuteCell ProliferationTumor Necrosis Factor-alphaAmino Acid SequenceMutationMice, Inbred StrainsLymphomaFlow CytometryXenotropic murine leukemia virus-related virusTumor Markers, BiologicalCells, CulturedDNA, ViralMink Cell Focus-Inducing VirusesDrug Screening Assays, Antitumor