Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Mainz, Germany.
Julius Maximilian University, Institute of Pathology, Würzburg, Germany.
Cancer Genomics Proteomics. 2022 Sep-Oct;19(5):540-555. doi: 10.21873/cgp.20339.
BACKGROUND/AIM: Multiple myeloma (MM) is characterized by accumulation of a malignant clone of plasma cells in the bone marrow. Curative treatments are not yet available. Therefore, we undertook a drug repurposing approach to identify possible candidates from a chemical library of 1,230 FDA-approved drugs by virtual drug screening. As a target, we have chosen the non-receptor Bruton's tyrosine kinase (BTK) which is one of the main regulators of the MM biomarker CD38.
In silico virtual screening was performed by using PyRx. Flow cytometry was applied for cell cycle and apoptosis analysis. Furthermore, protein and gene expression was determined by western blotting and microarray hybridization. Lipid raft staining was observed by confocal microscopy.
The in silico identified lipid-lowering lomitapide presented with the strongest cytotoxicity among the top 10 drug candidates. This drug arrested the cell cycle in the G/M phase and induced apoptosis in MM cells. Western blot analyses revealed that treatment with lomitapide induced cleavage of the apoptosis regulator PARP and reduced the expression of CD38, an integral part of lipid rafts. Using confocal microscopy, we further observed that lipid raft microdomain formation in MM cells was inhibited by lomitapide. In four MM cell lines (KMS-12-BM, NCI-H929, RPMI-8226, and MOLP-8) treated with lomitapide, microarray analyses showed not only that the expression of CD38 and BTK was down-regulated, but also that the tumor suppressor gene TP53 and the oncogene c-MYC were among the top deregulated genes. Further analysis of these data by Ingenuity pathway analysis (IPA) suggested that lomitapide interferes with the cross-talk of CD38 and BTK and apoptosis-regulating genes via TP53 and c-MYC.
Lomitapide treatment led to disruption of lipid raft domains and induction of pro-apoptotic factors and might, therefore, be considered as a potential therapeutic agent in MM.
背景/目的：多发性骨髓瘤（MM）的特征是骨髓中恶性浆细胞克隆的积累。目前尚无治愈方法。因此，我们通过虚拟药物筛选，从 1230 种已获美国食品和药物管理局批准的药物的化学库中进行药物再利用，以确定可能的候选药物。作为靶点，我们选择了非受体布鲁顿酪氨酸激酶（BTK），它是 MM 生物标志物 CD38 的主要调节剂之一。
通过 PyRx 进行计算机虚拟筛选。流式细胞术用于细胞周期和细胞凋亡分析。此外，通过 Western blot 和微阵列杂交确定蛋白质和基因表达。通过共聚焦显微镜观察脂筏染色。
计算机鉴定的降血脂药物洛美他派在 10 种候选药物中显示出最强的细胞毒性。该药物使 MM 细胞的细胞周期停滞在 G/M 期，并诱导细胞凋亡。Western blot 分析显示，洛美他派处理诱导凋亡调节剂 PARP 的切割，并降低 CD38 的表达，CD38 是脂筏的组成部分。使用共聚焦显微镜，我们进一步观察到洛美他派抑制了 MM 细胞中脂筏微区的形成。在洛美他派处理的四种 MM 细胞系（KMS-12-BM、NCI-H929、RPMI-8226 和 MOLP-8）中，微阵列分析不仅显示 CD38 和 BTK 的表达下调，而且肿瘤抑制基因 TP53 和癌基因 c-MYC 也是上调基因。通过 IPA 对这些数据进行进一步分析表明，洛美他派通过 TP53 和 c-MYC 干扰 CD38 和 BTK 以及凋亡调节基因的相互作用。
洛美他派治疗导致脂筏结构域的破坏和促凋亡因子的诱导，因此可被视为 MM 的潜在治疗药物。
