Leukemogenic properties of NUP98-PMX1 are linked to NUP98 and homeodomain sequence functions but not to binding properties of PMX1 to serum response factor.
PMX1 is a member of a non-clustered homeobox gene family, not normally expressed in hematopoietic cells, and first identified for its role in enhancing the binding of the serum response factor (SRF) to the serum responsive element (SRE). PMX1 has never been linked to leukemia on its own, raising the possibility of unique mechanisms underlying the oncogenicity of NUP98-PMX1. To elucidate the leukemogenic potential of NUP98-PMX1, we compared the effects of PMX1 and NUP98-PMX1 and, through strategic mutations, the involvement of the SRE in NUP98-PMX1-mediated leukemia. NUP98-PMX1, but not PMX1, had potent ability to impair differentiation, promote proliferation of myeloid progenitors, induce lethal myeloproliferative disease and to activate a number of genes previously linked to leukemic stem cells. Similar to NUP98-HOX fusions, the transforming potential of NUP98-PMX1 required the NUP98 portion and DNA-binding capability of the PMX1 homeodomain and collaborated with Meis1 to induce more rapid onset myeloproliferative-like myeloid leukemia. The transforming activity of NUP98-PMX1 was independent of its ability to interact with SRF. These findings provide novel evidence of the contributory role of the NUP98 sequence in conferring leukemogenic properties on a partner gene and point to common leukemogenic pathways for NUP98-PMX1 and NUP98-clustered HOX fusions.
Hirose
K
K
Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
Abramovich
C
C
Argiropoulos
B
B
Humphries
R K
RK
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000502:physiology; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D007938:Leukemia / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D022423:Myeloid Cells / Q000378:metabolism / Q000502:physiology; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015514:Oncogene Proteins, Fusion / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary / Q000502:physiology; D026362:Serum Response Factor / Q000378:metabolism*; D014410:Tumor Stem Cell Assay
D018398:Homeodomain Proteins; C120274:NUP98-PMX1 fusion protein, human; D028861:Nuclear Pore Complex Proteins; C465451:Nup98 protein, human; D015514:Oncogene Proteins, Fusion; C082157:PRRX1 protein, human; D026362:Serum Response Factor