The results showed significantly increased frequencies of the FoxO1/rs2297626 AA genotype and A allele in AAU patients with AS (AA genotype: P = 6.23 × 10(-5), odds ratio [OR] = 1.86; A allele: P = 2.17 × 10(-4), OR = 1.53).
In conclusion, Ik6, the upstream factor of Akt-FoxO1 pathway, can protect ALL cells against daunorubicin-induced apoptosis and can potentially be explored as a therapeutic target in the treatment of patients with ALL.
Gata1 mutant cells that overexpress ERG with hyperactive AKT are characterized by diminished FOXO1/3a expression and an increased dependency on the c-Jun pathway similar to that seen in acute megakaryoblastic leukemia (AMKL) cell lines, acute myeloid leukemia (AML) with knockdown of FOXO3a, or AML with expression of myristoylated Akt.
In line with this finding, we observed increased phosphorylation of forkhead box protein O1 (FoxO1), and suppression of its nuclear retention, along with the relative enrichment of promyelocytic leukemia zinc finger (PLZF) -positive cells.
Furthermore, the use of the FDA-approved drug trifluoperazine hydrochloride (TFP), which has been shown to inhibit FOXO1 nuclear export, restored sensitivity to AKT-driven erlotinib resistance through modulation of the KLF6/FOXO1 signaling cascade in both cell culture and xenograft models of lung adenocarcinoma.
The FOXO1a protein, which is increased by wild-type APC expression, induces caveolin-1 promoter-reporter activity and binds directly to a FKHR consensus binding sequence in the caveolin-1 promoter.
While FOXO3 expression remained unchanged in ACCs, FOXO1 expression was found to be significantly downregulated in 19/20 ACAs and 9/10 ACCs (p<0.0001 and p<0.05, respectively), suggesting a global role for FOXO1 suppression in promoting and maintaining adrenocortical dedifferentiation.
In conclusion, Ik6, the upstream factor of Akt-FoxO1 pathway, can protect ALL cells against daunorubicin-induced apoptosis and can potentially be explored as a therapeutic target in the treatment of patients with ALL.
Interestingly, we found that overactivation of FOXO1 also induces growth inhibition in BL cell lines, indicating the importance of a tight regulation of FOXO1 activity in BL.
Using genome editing in human and mouse lymphomas in which MYC and PI3K cooperate synergistically in tumor development, we demonstrate proproliferative and antiapoptotic activity of FOXO1 in BL and identify its nuclear localization as an oncogenic event in GC B-cell-derived lymphomagenesis.
B cell malignancies, with exception of classical Hodgkin lymphoma, maintain expression of FOXO1 at levels characteristic for their non-malignant counterparts.