SIGNIFICANCE: These results demonstrate the efficacy of ABT-199 <i>in vivo</i> and provide encouraging preclinical data of Bcl-2 as a potential target for the treatment of hypodiploid B-ALL.
Early intervention strategies by rational combination of Bcl-2 blockage may constitute a promising new treatment option to GC-resistant ALL and significantly improving the chances of treating poor prednisone responders.
Other new strategies include the incorporation of tyrosine kinase inhibitor-based therapy for patients with Philadelphia chromosome-like ALL and the use of DOT inhibitors and bcl-2/bcl-xl inhibitors in R/R disease.
Here, we investigated the activity of the BCL-2 inhibitor venetoclax (VEN, ABT-199) in B-cell precursor acute lymphoblastic leukemia and found heterogeneous sensitivities in BCP-ALL cell lines and in a series of patient-derived primografts.
Wnt5a and ROR1 activate non-canonical Wnt signaling via RhoA in TCF3-PBX1 acute lymphoblastic leukemia and highlight new treatment strategies via Bcl-2 co-targeting.
The anti-apoptotic factors Mcl-1, Bcl-2, and Bcl-xL were also found to be over-expressed in acute myeloid leukemia (AML) (Kaufmann et al., 2016) and acute lymphocytic leukemia (ALL) (Findley, Gu, Yeager, & Zhou, 1997), suggesting that dis-regulated apoptotic processes could be a factor in the instigation of leukemia and/or its relapse.
Evaluation of BAX and BCL-2 Gene Expression and Apoptosis Induction in Acute Lymphoblastic Leukemia Cell Line CCRFCEM after High- Dose Prednisolone Treatment
The studied parameters, BCL-2 protein (p less than 0.001), TOS (p less than 0.001) and LDH (p less than 0.001) were significantly elevated in the ALL group compared to the normal group (N-group).
circPVT1 was highly expressed in ALL compared with normal bone marrow samples. circPVT1 expression was also significantly higher in ALL cell lines. circPVT1 knockdown inhibited cell proliferation and induced cell apoptosis through suppression of its neighbor gene c-Myc, and antiapoptotic Bcl-2 protein expression.
As the role of RBP2 in regulating apoptosis was confirmed, RBP2 overexpression and activation of BCL2 might play important roles in ALL development and progression.
In both AML and ALL groups, beclin-1 and MAB1LC3B expressions were significantly down-regulated (p < 0.001), while HIF-1α (p < 0.01) and Bcl-2 (p < 0.001) expressions were significantly up-regulated compared to the control group.
These data demonstrate the role of miR-17~92 in regulation of apoptosis, and identify BCL2 as a therapeutic target of particular relevance in BCR-ABL-positive ALL.
Our results suggest that BCL2-938C > A genotyping may be beneficial for therapy response prediction in ALL patients, and warrant examination in a larger cohort to validate its usefulness for treatment stratification of pediatric ALL patients.
The Bcl-2/Bcl-xL/Bax and the Ras/Raf/MEK/ERK (MAPK) pathways are often deregulated in many human cancers and especially in acute lymphoblastic leukemia and acute myeloid leukemia.
We characterized in vitro sensitivity to the pan-antiapoptotic BCL-2 family inhibitor obatoclax mesylate in diagnostic leukemia cells from 54 infants with ALL/bilineal acute leukemia because of the role of prosurvival BCL-2 proteins in resistance, their imbalanced expression in infant ALL, and evidence of obatoclax activity with a favorable toxicity profile in early adult leukemia trials.
High expression of MDR1 and BCL-2 in AML and MRP1 gene in ALL was associated with response to induction chemotherapy (p=0.001, p=0.02 and p=0.007 respectively).