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CBX8, a polycomb group protein, is essential for MLL-AF9-induced leukemogenesis.

ABSTRACT: Chromosomal translocations involving the mixed lineage leukemia (MLL) gene lead to the development of acute leukemias. Constitutive HOX gene activation by MLL fusion proteins is required for MLL-mediated leukemogenesis; however, the underlying mechanisms remain elusive. Here, we show that chromobox homolog 8 (CBX8), a Polycomb Group protein that interacts with MLL-AF9 and TIP60, is required for MLL-AF9-induced transcriptional activation and leukemogenesis. Conversely, both CBX8 ablation and specific disruption of the CBX8 interaction by point mutations in MLL-AF9 abrogate HOX gene upregulation and abolish MLL-AF9 leukemic transformation. Surprisingly, Cbx8-deficient mice are viable and display no apparent hematopoietic defects. Together, our findings demonstrate that CBX8 plays an essential role in MLL-AF9 transcriptional regulation and leukemogenesis.

SUBMITTER: Tan J

PROVIDER: S-EPMC3220883 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature

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CBX8, a polycomb group protein, is essential for MLL-AF9-induced leukemogenesis.

Tan Jiaying J Jones Morgan M Koseki Haruhiko H Nakayama Manabu M Muntean Andrew G AG Maillard Ivan I Hess Jay L JL

Cancer cell 20111101 5

Chromosomal translocations involving the mixed lineage leukemia (MLL) gene lead to the development of acute leukemias. Constitutive HOX gene activation by MLL fusion proteins is required for MLL-mediated leukemogenesis; however, the underlying mechanisms remain elusive. Here, we show that chromobox homolog 8 (CBX8), a Polycomb Group protein that interacts with MLL-AF9 and TIP60, is required for MLL-AF9-induced transcriptional activation and leukemogenesis. Conversely, both CBX8 ablation and spec ...[more]

PMID: 22094252

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