ETS-related gene ERG expression in AML patients is significantly associated with NPM1 mutation status

Molecular mechanisms of ETS transcription factor-mediated tumorigenesis

The E26 transformation-specific (ETS) family of transcription factors is critical for development, differentiation, proliferation and also has a role in apoptosis and tissue remodeling. Changes in expression of ETS proteins therefore have a significant impact on normal physiology of the cell. Transcriptional consequences of ETS protein deregulation by overexpression, gene fusion, and modulation by RAS/MAPK signaling are linked to alterations in normal cell functions, and lead to unlimited increased proliferation, sustained angiogenesis, invasion and metastasis. Existing data show that ETS proteins control pathways in epithelial cells as well as stromal compartments, and the crosstalk between the two is essential for normal development and cancer. In this review, we have focused on ETS factors with a known contribution in cancer development. Instead of focusing on a prototype, we address cancer associated ETS proteins and have highlighted the diverse mechanisms by which they affect carcinogenesis. Finally, we discuss strategies for ETS factor targeting as a potential means for cancer therapeutics.

Presence of FLT3-ITD and high BAALC expression are independent prognostic markers in childhood acute myeloid leukemia

Mutation status of FLT3, NPM1, CEBPA, and WT1 genes and gene expression levels of ERG, MN1, BAALC, FLT3, and WT1 have been identified as possible prognostic markers in acute myeloid leukemia (AML). We have performed a thorough prognostic evaluation of these genetic markers in patients with pediatric AML enrolled in the Nordic Society of Pediatric Hematology and Oncology (NOPHO) 1993 or NOPHO 2004 protocols. Mutation status and expression levels were analyzed in 185 and 149 patients, respectively. Presence of FLT3-internal tandem duplication (ITD) was associated with significantly inferior event-free survival (EFS), whereas presence of an NPM1 mutation in the absence of FLT3-ITD correlated with significantly improved EFS. Furthermore, high levels of ERG and BAALC transcripts were associated with inferior EFS. No significant correlation with survival was seen for mutations in CEBPA and WT1 or with gene expression levels of MN1, FLT3, and WT1. In multivariate analysis, the presence of FLT3-ITD and high BAALC expression were identified as independent prognostic markers of inferior EFS. We conclude that analysis of the mutational status of FLT3 and NPM1 at diagnosis is important for prognostic stratification of patients with pediatric AML and that determination of the BAALC gene expression level can add valuable information.

Acute myeloid leukemia: a central role for the ETS factor ERG

Acute myeloid leukemia is a cancer of the myeloid lineage, characterized by the rapid proliferation of immature progenitor cells which accumulate in the bone marrow and interfere with the production of normal blood cells. Aberrant regulation of E-twenty-six (ETS) specific transcription factors such as PU.1 (SPI1) is thought to play a major role in this type of leukemia. The importance of these factors in normal blood development is highlighted by the fact that numerous studies showed a direct link between hematopoietic defects and aberrant regulation of ETS factor expression or expression of mutant forms. Apart from PU.1, another ETS factor, ERG, has emerged as a key player in normal hematopoiesis. Here, the role of this protein in normal and aberrant blood development will be discussed as well as the possibilities to therapeutically target this ETS factor.