Université de Montréal, Département de Biochimie, Montréal, Canada

Correspondence to: G Ferbeyre, Université de Montréal, Département de Biochimie, E-515, CP 6128, Succ Centre-Ville, Montréal, Qc H3C 3J7, Canada; Fax: 514 343-2210

PML is the most frequent fusion partner of the RAR in the specific translocations associated with acute promyelocytic leukemia (APL). Models to explain the origin of this leukemia propose a block in cell differentiation due to aberrant repression of retinoic acid responsive genes and/or disruption of the function of the PML-containing nuclear bodies. Recently, PML has been identified as a regulator of replicative senescence and the premature senescence that occurs in response to oncogenic ras. This review discusses the idea that senescence is a general tumor suppressor mechanism related to terminal differentiation and disrupted during the establishment of APL and other cancers. According to this idea the PML-RAR fusion protein promotes leukemogenesis not only through repression of retinoic acid responsive genes, but also by way of interfering with several tumor suppressor proteins that cooperate to establish senescence. Retinoids and other drugs effective against APL do so by re-establishment of the senescence program, which also includes features of cell differentiation.

Leukemia (2002) 16, 1918-1926. doi:10.1038/sj.leu.2402722

senescence; PML; differentiation; retinoic acid; ras