SETBP1 overexpression is a novel leukemogenic mechanism that predicts adverse outcome in elderly patients with acute myeloid leukemia.
Acute myeloid leukemias (AMLs) result from multiple genetic alterations in hematopoietic stem cells. We describe a novel t(12;18)(p13;q12) involving ETV6 in a patient with AML. The translocation resulted in overexpression of SETBP1 (18q12), located close to the breakpoint. Overexpression of SETBP1 through retroviral insertion has been reported to confer growth advantage in hematopoietic progenitor cells. We show that SETBP1 overexpression protects SET from protease cleavage, increasing the amount of full-length SET protein and leading to the formation of a SETBP1-SET-PP2A complex that results in PP2A inhibition, promoting proliferation of the leukemic cells. The prevalence of SETBP1 overexpression in AML at diagnosis (n = 192) was 27.6% and was associated with unfavorable cytogenetic prognostic group, monosomy 7, and EVI1 overexpression (P < .01). Patients with SETBP1 overexpression had a significantly shorter overall survival, and the prognosis impact was remarkably poor in patients older than 60 years in both overall survival (P = .015) and event-free survival (P = .015). In summary, our data show a novel leukemogenic mechanism through SETBP1 overexpression; moreover, multivariate analysis confirms the negative prognostic impact of SETBP1 overexpression in AML, especially in elderly patients, where it could be used as a predictive factor in any future clinical trials with PP2A activators.
Cristóbal
Ion
I
Division of Oncology, Center for Applied Medical Research, Spain.
Blanco
Francisco J
FJ
Garcia-Orti
Laura
L
Marcotegui
Nerea
N
Vicente
Carmen
C
Rifon
José
J
Novo
Francisco J
FJ
Bandres
Eva
E
Calasanz
María J
MJ
Bernabeu
Carmelo
C
Odero
María D
MD
D000368:Aged; D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D002478:Cells, Cultured; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D020014:K562 Cells; D015470:Leukemia, Myeloid, Acute / Q000175:diagnosis* / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D011379:Prognosis; D015854:Up-Regulation
D002352:Carrier Proteins; D009687:Nuclear Proteins; C425066:SETBP1 protein, human