Oncotarget

Research Papers:

NKL homeobox gene MSX1 acts like a tumor suppressor in NK-cell leukemia

Stefan Nagel _, Claudia Pommerenke, Corinna Meyer, Maren Kaufmann, Roderick A.F. MacLeod and Hans G. Drexler

PDF  |  HTML  |  Supplementary Files  |  How to cite  |  Order a Reprint

Oncotarget. 2017; 8:66815-66832. https://doi.org/10.18632/oncotarget.18609

Metrics: PDF 703 views  |   HTML 1335 views  |   ?  


Abstract

Stefan Nagel1, Claudia Pommerenke1, Corinna Meyer1, Maren Kaufmann1, Roderick A.F. MacLeod1 and Hans G. Drexler1

1Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ, Braunschweig, Germany

Correspondence to:

Stefan Nagel, email: sna@dsmz.de

Keywords: homeobox, NKL-code, T-ALL

Received: March 24, 2017    Accepted: May 29, 2017    Published: June 21, 2017

ABSTRACT

NKL homeobox gene MSX1 is physiologically expressed in lymphoid progenitors and subsequently downregulated in developing T- and B-cells. In contrast, elevated expression levels of MSX1 persist in mature natural killer (NK)-cells, indicating a functional role in this compartment. While T-cell acute lymphoblastic leukemia (T-ALL) subsets exhibit aberrant overexpression of MSX1, we show here that in malignant NK-cells the level of MSX1 transcripts is aberrantly downregulated. Chromosomal deletions at 4p16 hosting the MSX1 locus have been described in NK-cell leukemia patients. However, NK-cell lines analyzed here showed normal MSX1 gene configurations, indicating that this aberration might be uncommon. To identify alternative MSX1 regulatory mechanisms we compared expression profiling data of primary normal NK-cells and malignant NK-cell lines. This procedure revealed several deregulated genes including overexpressed IRF4, MIR155HG and MIR17HG and downregulated AUTS2, EP300, GATA3 and HHEX. As shown recently, chromatin-modulator AUTS2 is overexpressed in T-ALL subsets where it mediates aberrant transcriptional activation of MSX1. Here, our data demonstrate that in malignant NK-cell lines AUTS2 performed MSX1 activation as well, but in accordance with downregulated MSX1 transcription therein we detected reduced AUTS2 expression, a small genomic deletion at 7q11 removing exons 3 and 4, and truncating mutations in exon 1. Moreover, genomic profiling and chromosomal analyses of NK-cell lines demonstrated amplification of IRF4 at 6p25 and deletion of PRDM1 at 6q21, highlighting their potential oncogenic impact. Functional analyses performed via knockdown or forced expression of these genes revealed regulatory network disturbances effecting downregulation of MSX1 which may underlie malignant development in NK-cells.


Creative Commons License All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.
PII: 18609