Peripheral T-lymphocytes express WNT7A and its restoration in leukemia-derived lymphoblasts inhibits cell proliferation.
BACKGROUND
WNT7a, a member of the Wnt ligand family implicated in several developmental processes, has also been reported to be dysregulated in some types of tumors; however, its function and implication in oncogenesis is poorly understood. Moreover, the expression of this gene and the role that it plays in the biology of blood cells remains unclear. In addition to determining the expression of the WNT7A gene in blood cells, in leukemia-derived cell lines, and in samples of patients with leukemia, the aim of this study was to seek the effect of this gene in proliferation.


METHODS
We analyzed peripheral blood mononuclear cells, sorted CD3 and CD19 cells, four leukemia-derived cell lines, and blood samples from 14 patients with Acute lymphoblastic leukemia (ALL), and 19 clinically healthy subjects. Reverse transcription followed by quantitative Real-time Polymerase chain reaction (qRT-PCR) analysis were performed to determine relative WNT7A expression. Restoration of WNT7a was done employing a lentiviral system and by using a recombinant human protein. Cell proliferation was measured by addition of WST-1 to cell cultures.


RESULTS
WNT7a is mainly produced by CD3 T-lymphocytes, its expression decreases upon activation, and it is severely reduced in leukemia-derived cell lines, as well as in the blood samples of patients with ALL when compared with healthy controls (p ≤0.001). By restoring WNT7A expression in leukemia-derived cells, we were able to demonstrate that WNT7a inhibits cell growth. A similar effect was observed when a recombinant human WNT7a protein was used. Interestingly, restoration of WNT7A expression in Jurkat cells did not activate the canonical Wnt/β-catenin pathway.


CONCLUSIONS
To our knowledge, this is the first report evidencing quantitatively decreased WNT7A levels in leukemia-derived cells and that WNT7A restoration in T-lymphocytes inhibits cell proliferation. In addition, our results also support the possible function of WNT7A as a tumor suppressor gene as well as a therapeutic tool.
División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico.
Alejandra B
AB
Ochoa-Hernández
Moisés
M
Ramos-Solano
Ivan D
ID
Meza-Canales
Beatriz
B
García-Castro
Mónica A
MA
Rosales-Reynoso
Judith A
JA
Rosales-Aviña
Esperanza
E
Barrera-Chairez
Pablo C
PC
Ortíz-Lazareno
Georgina
G
Hernández-Flores
Alejandro
A
Bravo-Cuellar
Luis F
LF
Jave-Suarez
Patricio
P
Barros-Núñez
Adriana
A
Aguilar-Lemarroy
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D018941:Antigens, CD19 / Q000276:immunology; D015153:Blotting, Western; D017252:CD3 Complex / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D019169:Jurkat Cells / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
D018941:Antigens, CD19; D017252:CD3 Complex; D011994:Recombinant Proteins; C092778:WNT7A protein, human; D051153:Wnt Proteins