Effect of High VEGF-C mRNA Expression on Achievement of Complete Remission in Adult Acute Myeloid Leukemia

Peptides Targeting Fms-Related Tyrosine Kinase-4 Activate the Function of Natural Killer Cells in Acute Myeloid Leukemia

Background and Objectives

The increased expression for the Fms-related tyrosine kinase-4 (FLT-4, known as VEGFR-3) is relevant to dysfunctional natural killer (NK) cells in acute myeloid leukemia (AML). MAZ51 (M), a VEGFR-3 inhibiting chemical, was effectively restored the function of NK cells via the high expression of interferon-gamma (IFN-γ) in NK cells, as shown in our previous study. Although tremendous amount of clinical data using peptides are currently available in real clinic, peptides targeting FLT-4 in modulating immune cells such as NK cells are not fully elucidated.

Methods and Results

In present study, we developed peptides targeting FLT-4 (P), which is inhibiting an affinity for AML-NK expressing FLT-4 in vitro and in vivo. Bone marrow (BM) and peripheral blood (PB) mononuclear cells (MNCs) from AML patients were treated with combinational cocktails of the three agents including P, M, ara-C (A) and FLT-4 expression and IFN-γ release were examined. In an AML mouse model, IFN-γ expression were examined in T and NK cells from mouse BM, spleen, and liver to address relevance between peptides and immune cell activation. We found that AML-NK cells both in human and mouse samples showed a gradual increase the IFN-γ levels compared to the controls. There was a trend toward a reduction in leukemic blasts in the BM, spleen, and liver from the AML mice, when we compared the effects of combinational treatments.

Conclusions

Our results suggest that the function of AML-NK cells was synergistically activated by P in combination with M or A.

7‑Difluoromethyl‑5,4'‑dimethoxygenistein exerts anti‑angiogenic effects on acute promyelocytic leukemia HL‑60 cells by inhibiting the TLR4/NF‑κB signaling pathway

Angiogenesis plays an important role in the development and metastasis of tumors, and anti-angiogenesis agents are used to treat tumors. For example, the acute promyelocytic leukemia (APL) may be treated with arsenic trioxide. Angiogenesis in APL is a multi-step dynamic equilibrium process coordinated by various angiogenic stimulators and inhibitors, which play key roles in the occurrence, progression and chemosensitivity of this disease. Our research group previously synthesized 7-difluoromethyl-5,4′-dimethoxygenistein (DFMG), and found that it inhibits angiogenesis during atherosclerotic plaque formation. In the present study, the effect and mechanism of DFMG in angiogenesis induced by APL HL-60 cells was investigated using a chick embryo chorioallantoic membrane model and Matrigel tubule formation assays. The results obtained revealed an anti-angiogenesis effect of DFMG towards HL-60 cells. When the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway was inhibited, the anti-angiogenic effect of DFMG was further enhanced. However, when the TLR4/NF-κB signaling pathway was activated, the anti-angiogenic effect of DFMG was attenuated. These results demonstrated that DFMG inhibits angiogenesis induced by APL HL-60 cells, and provides insights into the mechanism by which DFMG inhibits the TLR4/NF-κB signaling pathway. In conclusion, in the present study, the anti-angiogenesis effect of DFMG on APL has been reported, and the mechanism by which DFMG induced the anti-angiogenesis effect was explored. These findings have provided a potential new drug candidate for the treatment of patients with APL.