Cirmtuzumab inhibits Wnt5a-induced Rac1 activation in chronic lymphocytic leukemia treated with ibrutinib.
Leukemia
; 31(6): 1333-1339, 2017 06.
Article
en En
| MEDLINE
| ID: mdl-27904138
ABSTRACT
Signaling via the B cell receptor (BCR) plays an important role in the pathogenesis and progression of chronic lymphocytic leukemia (CLL). This is underscored by the clinical effectiveness of ibrutinib, an inhibitor of Bruton's tyrosine kinase (BTK) that can block BCR-signaling. However, ibrutinib cannot induce complete responses (CR) or durable remissions without continued therapy, suggesting alternative pathways also contribute to CLL growth/survival that are independent of BCR-signaling. ROR1 is a receptor for Wnt5a, which can promote activation of Rac1 to enhance CLL-cell proliferation and survival. In this study, we found that CLL cells of patients treated with ibrutinib had activated Rac1. Moreover, Wnt5a could induce Rac1 activation and enhance proliferation of CLL cells treated with ibrutinib at concentrations that were effective in completely inhibiting BTK and BCR-signaling. Wnt5a-induced Rac1 activation could be blocked by cirmtuzumab (UC-961), an anti-ROR1 mAb. We found that treatment with cirmtuzumab and ibrutinib was significantly more effective than treatment with either agent alone in clearing leukemia cells in vivo. This study indicates that cirmtuzumab may enhance the activity of ibrutinib in the treatment of patients with CLL or other ROR1+ B-cell malignancies.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Pirazoles
/
Pirimidinas
/
Leucemia Linfocítica Crónica de Células B
/
Proteína de Unión al GTP rac1
/
Proteína Wnt-5a
/
Anticuerpos Monoclonales
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Leukemia
Asunto de la revista:
HEMATOLOGIA
/
NEOPLASIAS
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos