Division of Hematology and Oncology, Department of Internal Medicine, Iwate Medical University School of Medicine, Yahaba, Japan.
Division of Hematology and Oncology, Department of Internal Medicine, Iwate Medical University School of Medicine, Yahaba, Japan
Anticancer Res. 2023 May;43(5):1901-1908. doi: 10.21873/anticanres.16349.
BACKGROUND/AIM: Adult T-cell leukemia (ATL) is a peripheral T-lymphocytic malignancy influenced by human T-cell leukemia virus type 1 (HTLV-1) infection. Aggressive ATL has a poor prognosis, therefore newer agents are desperately needed. We revealed that dimethyl fumarate (DMF) causes ATL cell death via inhibition of nuclear factor-kappa B (NF-B) and signal transducer and activator of transcription 3 signaling. Here, we evaluated the specific mechanism of DMF effects on NF-B signaling in MT-2 HTLV-1-infected T-cells.
We examined the effects of DMF on the caspase recruitment domain family member 11 (CARD11)-BCL10 immune signaling adaptor (BCL10)-mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) (CBM) complex and upstream signaling molecules which are critical for NF-B signaling in MT-2 cells by immunoblotting. We also explored its effects on cell-cycle distribution. Furthermore, we assessed whether the BCL2 apoptosis regulator (BCL2)/BCL2-like 1 (BCL-xL) inhibitor navitoclax promoted the inhibitory effect of DMF on cell proliferation and apoptosis-associated proteins by trypan blue exclusion test and immunoblotting, respectively.
DMF inhibited constitutive phosphorylation of CARD11 followed by suppression of inhibitory-B kinase α/β phosphorylation at serine in a dose-dependent fashion in MT-2 cells. Furthermore, DMF inhibited MALT1 and BCL10 expression in the same fashion. However, DMF did not prevent the phosphorylation of protein kinase C-β, an upstream signaling molecule of CARD11. Cell-cycle analysis highlighted that DMF treatment at 75 μM resulted in the accumulation of cells at the sub-G and G/M phases. Navitoclax modestly promoted DMF-induced suppression of MT-2 cells via inhibition of cellular inhibitor of apoptosis protein-2 expression and c-JUN N-terminal kinase phosphorylation.
The suppression of MT-2 cell proliferation by DMF makes its further evaluation as an innovative agent for therapy of ATL worthwhile.
背景/目的：成人 T 细胞白血病（ATL）是一种受人类 T 细胞白血病病毒 1（HTLV-1）感染影响的外周 T 淋巴细胞恶性肿瘤。侵袭性 ATL 的预后较差，因此急需新的药物。我们发现富马酸二甲酯（DMF）通过抑制核因子-κB（NF-κB）和信号转导及转录激活因子 3 信号通路导致 ATL 细胞死亡。在此，我们评估了 DMF 对 MT-2 HTLV-1 感染 T 细胞中 NF-κB 信号通路的具体作用机制。
我们通过免疫印迹法检测 DMF 对 caspase 募集结构域家族成员 11（CARD11）-BCL10 免疫信号衔接子（BCL10）-黏膜相关淋巴组织淋巴瘤易位蛋白 1（MALT1）（CBM）复合物以及对 NF-κB 信号通路至关重要的上游信号分子的影响。我们还研究了其对细胞周期分布的影响。此外，我们评估了 BCL2 凋亡调节因子（BCL2）/BCL2 样 1（BCL-xL）抑制剂 navitoclax 是否通过台盼蓝排除试验和免疫印迹法分别促进 DMF 对细胞增殖和凋亡相关蛋白的抑制作用。
DMF 以剂量依赖的方式抑制 MT-2 细胞中 CARD11 的组成性磷酸化，随后抑制抑制性-B 激酶α/β在丝氨酸上的磷酸化。此外，DMF 以相同的方式抑制 MALT1 和 BCL10 的表达。然而，DMF 并没有阻止蛋白激酶 C-β的磷酸化，蛋白激酶 C-β是 CARD11 的上游信号分子。细胞周期分析强调，DMF 以 75μM 的浓度处理会导致细胞在亚 G1 和 G/M 期积累。navitoclax 通过抑制细胞凋亡抑制蛋白-2 的表达和 c-JUN N 末端激酶磷酸化，适度促进 DMF 诱导的 MT-2 细胞抑制。
DMF 抑制 MT-2 细胞增殖，值得进一步评估其作为治疗 ATL 的创新药物。
