Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto, Japan.
Department of Bioanalytical Chemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan.
Anticancer Res. 2023 Feb;43(2):547-555. doi: 10.21873/anticanres.16191.
BACKGROUND/AIM: The prognosis of patients with multiple myeloma (MM) has recently improved due to the emergence of new molecular targeting agents. However, MM remains incurable because MM stem cells are resistant to these agents. Therefore, it is essential to develop strategies to eradicate MM stem cells. We have previously demonstrated that MM cells cultured under prolonged hypoxic conditions (1% O) (i.e., hypoxia-adapted MM cells; MM-HA cells) exhibited stem-cell-like characteristics. γδ T cells attack tumor cells by recognizing butyrophilin (BTN) 3A1 and BTN2A1, which are activated by the intracellular accumulation of isopentenyl pyrophosphate (IPP), an intermediate in the mevalonate pathway. In the present study, we investigated the cytotoxicity of γδ T cells against MM-HA stem-like cells.
We used a combination of flow cytometry, liquid chromatography-tandem mass spectrometry, and western blotting methods to investigate the cytotoxicity of γδ T cells against MM-HA cells and measured the amounts of IPP in MM-HA cells and their supernatants.
The cytotoxicity of γδ T cells against MM-HA cells was significantly lower than that against MM cells cultured under normoxic conditions (20% O; MM-Normo). Furthermore, the concentration of IPP in MM-HA cells was lower than that in MM-Normo cells. The expression of mevalonate decarboxylase and farnesyl diphosphate synthase proteins were decreased in MM-HA-cells.
The cytotoxicity of γδ T cells against MM-HA cells was suppressed by the reduced IPP accumulation by modulating the mevalonate pathway in MM-HA cells.
背景/目的：由于新的分子靶向药物的出现，多发性骨髓瘤（MM）患者的预后最近有所改善。然而，MM 仍然无法治愈，因为 MM 干细胞对这些药物具有抗性。因此，开发根除 MM 干细胞的策略至关重要。我们之前已经证明，在长时间低氧条件下（1% O）培养的 MM 细胞（即，适应低氧的 MM 细胞；MM-HA 细胞）表现出干细胞样特征。γδ T 细胞通过识别丁酰基转移酶 3A1 和 BTN2A1 攻击肿瘤细胞，BTN 3A1 和 BTN2A1 被异戊烯焦磷酸（IPP）的细胞内积累激活，IPP 是甲羟戊酸途径的中间产物。在本研究中，我们研究了 γδ T 细胞对 MM-HA 干细胞样细胞的细胞毒性。
我们使用流式细胞术、液相色谱-串联质谱和 Western blot 方法来研究 γδ T 细胞对 MM-HA 细胞的细胞毒性，并测量 MM-HA 细胞及其上清液中 IPP 的量。
γδ T 细胞对 MM-HA 细胞的细胞毒性明显低于在常氧条件（20% O；MM-Normo）下培养的 MM 细胞。此外，MM-HA 细胞中 IPP 的浓度低于 MM-Normo 细胞。Mevalonate 脱羧酶和法呢基二磷酸合酶蛋白的表达在 MM-HA 细胞中降低。
通过调节 MM-HA 细胞中的甲羟戊酸途径，降低 IPP 的积累抑制了 γδ T 细胞对 MM-HA 细胞的细胞毒性。
