Characterization of LEF1 High Expression and Novel Mutations in Adult Acute Lymphoblastic Leukemia.
Aberrant activation of the Wnt pathway plays a pathogenetic role in tumors and has been associated with adverse outcome in acute lymphoblastic leukemia (ALL). Lymphoid enhancer binding factor 1 (LEF1), a key mediator of Wnt signaling, has been linked to leukemic transformation, and LEF1 mutations have been identified in T-ALL. Here we found LEF1 is highly expressed in 25.0% adult ALL patients and LEF1 high expression was associated with high-risk leukemia factors (high WBC, Philadelphia chromosome positive, complex karyotype), shorter event-free survival (EFS), and high relapse rates in patients with B-ALL. LEF1 high expression is also associated with high mutation rate of Notch1 and JAK1 in T-ALL. We identified 2 novel LEF1 mutations (K86E and P106L) in 4 of 131 patients with ALL, and those patients with high-risk ALL (high WBC, complex karyotype). These results suggest a role for LEF1 mutations in leukemogenesis. We further explored the effect of the mutations on cell proliferation and found both mutations significantly promoted the proliferation of ALL cells. We also observed the effect of LEF1 and its mutations on the transcription of its targets, c-MYC and Cyclin D1. We found LEF1 increased the promoter activity of its targets c-MYC and Cyclin D1, and LEF1 K86E and P106L mutants further significantly enhanced this effect. We also observed that the c-MYC and Cyclin D1 mRNA levels were significantly increased in patients with LEF1 high expression compared with those with low expression. Taken together, our findings indicate high LEF1 expression and mutation are associated with high-risk leukemia and our results also revealed that LEF1 high expression and/or gain-of-function mutations are involved in leukemogenesis of ALL.
The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Department of Hematology, Nanjing, 210029, China.
Xing
X
Guo
The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Department of Hematology, Nanjing, 210029, China.
Run
R
Zhang
The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Department of Hematology, Nanjing, 210029, China.
Juan
J
Liu
The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Department of Hematology, Nanjing, 210029, China.
Min
M
Li
Pennsylvania State University Medical College, Department of Pediatrics, Hershey, 17033, PA, United States of America.
Chunhua
C
Song
Pennsylvania State University Medical College, Department of Pediatrics, Hershey, 17033, PA, United States of America.
Sinisa
S
Dovat
The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Department of Hematology, Nanjing, 210029, China.
Jianyong
J
Li
The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Department of Hematology, Nanjing, 210029, China; Pennsylvania State University Medical College, Department of Pediatrics, Hershey, 17033, PA, United States of America.
Zheng
Z
Ge
D000293:Adolescent; D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002869:Chromosome Aberrations; D019938:Cyclin D1 / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics; D012008:Recurrence; D014158:Transcription, Genetic; D055815:Young Adult
C497573:LEF1 protein, human; D051821:Lymphoid Enhancer-Binding Factor 1; D016271:Proto-Oncogene Proteins c-myc; D019938:Cyclin D1