Changes in the Expression of Many Ets Family Transcription Factors and of Potential Target Genes in Normal Mammary Tissue and Tumors

McGill University, Montréal, Quebec, Canada
Journal of Biological Chemistry (Impact Factor: 4.57). 04/2004; 279(12):11281-92. DOI: 10.1074/jbc.M311887200
Source: PubMed


Interfering with Ets transcription factor function reverses multiple aspects of the transformed phenotype of mouse or human tumor cells. However, the unknown number of individual Ets factors expressed in any cellular context and the similar DNA binding specificities of Ets family members complicates the identification of those that mediate transformation. By utilizing quantitative PCR assays for 25 mouse Ets factors, we analyzed the expression of essentially the entire Ets family in normal mammary tissue, mammary-related cell lines, and mammary tumors. In normal mammary tissue, 24 Ets factors were expressed. Even clonal derived cell lines expressed 14-20 Ets members. The most abundant Ets factor mRNAs measured in normal mammary tissue were Elk4, Elf1, and Ets2. Subtractive analysis of mammary tissue identified which Ets factors were predominantly expressed in the myeloid/lymphoid or epithelial cell compartments. Comparison of Ets factor expression in normal mammary tissue and mammary tumors identified significantly elevated expression of Pse/PDEF, Ese2/Elf5, Ese3/Ehf, TEL/Etv6, and Elf2/NERF in mammary tumors and confirmed previously reported alterations in expression of Ese1/Elf3 and the PEA3 subfamily. Expression of 13 Ets target genes, implicated in various aspects of tumor progression, was also analyzed. Altered expression of particular Ets target genes was significantly correlated with particular Ets factors (e.g. maspin and Ese2), suggesting specific in vivo regulatory roles. Together, this comprehensive analysis revealed unexpectedly diverse Ets family gene expression, characterized novel Ets factor changes in mammary tumors, and implicated specific Ets factors in the regulation of multiple genes involved in mammary tumor progression.

Download full-text


Available from: Robert Glen Oshima, Oct 01, 2015
24 Reads
  • Source
    • "Transformation of immortalized mouse fibroblasts by RAS oncogenes provided a powerful assay for defining and characterizing the downstream signaling effectors of RAS, including ETS-family transcription factors [9], [19]–[22]. Previous work using dominant-negative approaches implicated ETS-family members as mediators of RAS transformation but were incapable of distinguishing which family members contributed to the transformed phenotype because multiple ETS family members with similar DNA binding properties are expressed in all cell lines and tissues [23], [24]. In the present work, we utilized null alleles of Ets1 and Ets2 to determine their function in HrasG12V transformation of immortalized MEFs. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The ETS-family transcription factors Ets1 and Ets2 are evolutionarily conserved effectors of the RAS/ERK signaling pathway, but their function in Ras cellular transformation and biology remains unclear. Taking advantage of Ets1 and Ets2 mouse models to generate Ets1/Ets2 double knockout mouse embryonic fibroblasts, we demonstrate that deletion of both Ets1 and Ets2 was necessary to inhibit HrasG12V induced transformation both in vitro and in vivo. HrasG12V expression in mouse embryonic fibroblasts increased ETS1 and ETS2 expression and binding to cis-regulatory elements on the c-Myc proximal promoter, and consequently induced a robust increase in MYC expression. The expression of the oncogenic microRNA 17-92 cluster was increased in HrasG12V transformed cells, but was significantly reduced when ETS1 and ETS2 were absent. MYC and ETS1 or ETS2 collaborated to increase expression of the oncogenic microRNA 17-92 cluster in HrasG12V transformed cells. Enforced expression of exogenous MYC or microRNA 17-92 rescued HrasG12V transformation in Ets1/Ets2-null cells, revealing a direct function for MYC and microRNA 17-92 in ETS1/ETS2-dependent HrasG12V transformation.
    PLoS ONE 06/2014; 9(6):e100693. DOI:10.1371/journal.pone.0100693 · 3.23 Impact Factor
  • Source
    • "The reaction mixtures were analyzed on an Applied Biosystems 7900HT Fast Real Time PCR System. Analysis of relative gene expression was performed as previously described (Galang et al., 2004). Briefly, for each experiment, a standard curve relating GAPDH cDNA concentration to threshold cycle (Ct) was generated using serial dilutions of cDNA with GAPDH primers. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The developing heart contains an inner tube of specialized endothelium known as endocardium, which performs multiple essential functions. In spite of the essential role of the endocardium in heart development and function, the transcriptional pathways that regulate its development remain largely undefined. GATA4 is a zinc finger transcription factor that is expressed in multiple cardiovascular lineages and is required for endocardial cushion development and embryonic viability, but the transcriptional pathways upstream of Gata4 in the endocardium and its derivatives in the endocardial cushions are unknown. Here, we describe a distal enhancer from the mouse Gata4 gene that is briefly active in multiple cardiac lineages early in cardiac development but restricts to the endocardium where it remains active through cardiogenesis. The activity of this Gata4 cardiac enhancer in transgenic embryos and in cultured aortic endothelial cells is dependent on four ETS sites. To identify which ETS transcription factors might be involved in Gata4 regulation via the ETS sites in the enhancer, we determined the expression profile of 24 distinct ETS factors in embryonic mouse hearts. Among multiple ETS transcripts present, ETS1, FLI1, ETV1, ETV5, ERG, and ETV6 were the most abundant in the early embryonic heart. We found that ETS1, FLI1, and ERG were strongly expressed in the heart at embryonic day 8.5 and that ETS1 and ERG bound to the endogenous Gata4 enhancer in cultured endothelial cells. Thus, these studies define the ETS expression profile in the early embryonic heart and identify an ETS-dependent enhancer from the Gata4 locus.
    Developmental Biology 10/2011; 361(2):439-49. DOI:10.1016/j.ydbio.2011.10.023 · 3.55 Impact Factor
  • Source
    • "Of note, ER81 transcriptional activity is dramatically enhanced upon Her2/Neu (a receptor tyrosine kinase and proto-oncoprotein especially associated with breast cancer) overexpression [8] [9]. Moreover, ER81 mRNA levels are increased in murine cell lines and tumors overexpressing Her2/Neu and also in many human breast cancer cell lines, which suggests that ER81 may contribute to breast tumorigenesis [10] [11] [12]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: ER81 is a transcription factor that may contribute to breast cancer; however, little known about the role of ER81 in breast carcinogenesis. To investigate the role of ER81 in breast carcinogenesis, we examined ER81 expression in IDC, DCIS, ADH, HUT, and normal breast tissues by immunohistochemical staining. We found that ER81 overexpression was detected in 25.7% (9/35) of HUT, 41.2% (7/17) of ADH, 54.5% (12/22) of DCIS, and 63.0% (51/81) of IDC. In 20 of breast cancer tissues combined with DCIS, ADH, and HUT, ER81 expression was found in 14/20 (70%) IDC. In these 14 cases all cases were ER81 positive expression in DCIS, 13 of 14 cases were positively expressed of ER81 in ADH and 8 of 14 were positive for ER81 in HUT components. A statistical significance was found between NBT and HUT (P < .05) and HUT and ADH (P < .05). Clinical-pathological features analysis of breast cancer revealed that ER81 expression was significantly associated with Her2 amplification and was negatively associated with ER and PR expression. Our results demonstrated that ER81 overexpression was present in the early stage of breast development that suggested that ER81 overexpression may play an important role in breast carcinogenesis.
    Pathology Research International 02/2011; 2011:980513. DOI:10.4061/2011/980513
Show more