title: NKL homeobox genes in leukemia.
abstract: NK-like (NKL) homeobox genes code for transcription factors, which can act as key regulators in fundamental cellular processes. NKL genes have been implicated in divergent types of cancer. In this review, we summarize the involvement of NKL genes in cancer and leukemia in particular. NKL genes can act as tumor-suppressor genes and as oncogenes, depending on tissue type. Aberrant expression of NKL genes is especially common in T-cell acute lymphoblastic leukemia (T-ALL). In T-ALL, 8 NKL genes have been reported to be highly expressed in specific T-ALL subgroups, and in ~30% of cases, high expression is caused by chromosomal rearrangement of 1 of 5 NKL genes. Most of these NKL genes are normally not expressed in T-cell development. We hypothesize that the NKL genes might share a similar downstream effect that promotes leukemogenesis, possibly due to mimicking a NKL gene that has a physiological role in early hematopoietic development, such as HHEX. All eight NKL genes posses a conserved Eh1 repressor motif, which has an important role in regulating downstream targets in hematopoiesis and possibly in leukemogenesis as well. Identification of a potential common leukemogenic NKL downstream pathway will provide a promising subject for future studies.
authors.affiliation: Department of Pediatric Oncology/Hematology, Erasmus MC/Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Homminga
authors.forename: R
authors.initials: R
authors.lastname: Pieters
authors.forename: J P P
authors.initials: JP
authors.lastname: Meijerink
mesh_terms: D051943:Antennapedia Homeodomain Protein / Q000235:genetics*; D005801:Genes, Homeobox / Q000502:physiology*; D016147:Genes, Tumor Suppressor; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000209:etiology / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics; D029961:Zebrafish Proteins
chemical_list: D051943:Antennapedia Homeodomain Protein; C078492:HHEX protein, human; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; C491178:NKX3-1 protein, human; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C489494:TLX3 protein, human; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D029961:Zebrafish Proteins; C071250:TLX1 protein, human