EP1280771A2 - NOVEL PRODRUGS VON 6-HYDROXY-2,3-DIHYDRO-1H-INDOLES, 5-HYDROXY-1,2-DIHYDRO-3H-PYRROLO 3,2-E]INDOLES AND 5-HYDROXY-1,2-DIHYDRO-3H-BENZO(E)INDOLES AS WELL AS OF 6-HYDROXY-1,2,3,4-TETRAHYDRO-BENZO F]QUINOLINE DERIVATIVES FOR USE IN SELECTIVE CANCER THERAPY