Motahari Zahra, Lepe Javier J, Bautista Malia R, Hoerig Clay, Plant-Fox Ashley S, Das Bhaskar, Fowler Christie D, Magge Suresh N, Bota Daniela A
CHOC Neuroscience Institute, Children's Hospital of Orange County, Orange, CA, USA.
Department of Pediatrics, University of Irvine, CA, USA.
bioRxiv. 2024 Mar 3:2024.02.29.582709. doi: 10.1101/2024.02.29.582709.
Medulloblastoma, the most common pediatric brain malignancy, has Sonic Hedgehog (SHH) and non-SHH group3 subtypes. MAGMAS (Mitochondrial Associated Granulocyte Macrophage colony-stimulating factor Signaling molecules) encode for mitochondrial import inner membrane translocase subunit and is responsible for translocation of matrix proteins across the inner membrane. We previously reported that a small molecule MAGMAS inhibitor, BT9, decreases cell proliferation, migration, and oxidative phosphorylation in adult glioblastoma cell lines. The aim of our study was to investigate whether the chemotherapeutic effect of BT9 can be extended to pediatric medulloblastoma.
Multiple in vitro assays were performed using human DAOY (SHH activated tp53 mutant) and D425 (non-SHH group 3) cells. The impact of BT9 on cellular growth, death, migration, invasion, and metabolic activity were quantified using MTT assay, TUNEL staining, scratch wound assay, Matrigel invasion chambers, and seahorse assay, respectively. Survival following 50mg/kg BT9 treatment was assessed in immunodeficient mice intracranially implanted with D425 cells.
Compared to control, BT9 treatment led to a significant reduction in medulloblastoma cell growth (DAOY, 24hrs IC50: 3.6uM, 48hrs IC50: 2.3uM, 72hrs IC50: 2.1uM; D425 24hrs IC50: 3.4uM, 48hrs IC50: 2.2uM, 72hrs IC50: 2.1uM) and a significant increase in cell death (DAOY, 24hrs p=0.0004, 48hrs p<0.0001; D425, 24hrs p=0.0001, 48hrs p=0.02). In DAOY cells, 3uM BT9 delayed migration, and significantly decreased DAOY and D425 cells invasion (p < 0.0001). Our study, however, did not extend survival in xenograft mouse model of group3 medulloblastoma compared to vehicle-treated controls.
Our data showed BT9 antitumor efficacy in DAOY and D425 cell lines suggesting that BT9 may represent a promising targeted therapeutic in pediatric medulloblastoma. These data, however, need to be further validated in animal models.
髓母细胞瘤是最常见的小儿脑恶性肿瘤，有音猬因子（SHH）和非SHH第3组亚型。MAGMAS（线粒体相关粒细胞巨噬细胞集落刺激因子信号分子）编码线粒体输入内膜转位酶亚基，负责基质蛋白穿过内膜的转位。我们之前报道过一种小分子MAGMAS抑制剂BT9可降低成人间变性星形细胞瘤细胞系的细胞增殖、迁移和氧化磷酸化。我们研究的目的是调查BT9的化疗效果是否能扩展到小儿髓母细胞瘤。
使用人DAOY（SHH激活的tp53突变体）和D425（非SHH第3组）细胞进行了多种体外试验。分别使用MTT试验、TUNEL染色、划痕试验、基质胶侵袭小室试验和海马试验定量分析BT9对细胞生长、死亡、迁移、侵袭和代谢活性的影响。对颅内植入D425细胞的免疫缺陷小鼠评估50mg/kg BT9治疗后的生存期。
与对照组相比，BT9治疗导致髓母细胞瘤细胞生长显著减少（DAOY，24小时半数抑制浓度：3.6μM，48小时半数抑制浓度：2.3μM，72小时半数抑制浓度：2.1μM；D425，24小时半数抑制浓度：3.4μM，48小时半数抑制浓度：2.2μM，72小时半数抑制浓度：2.1μM），细胞死亡显著增加（DAOY，24小时p = 0.0004，48小时p < 0.0001；D425，24小时p = 0.0001，48小时p = 0.02）。在DAOY细胞中，3μM BT9延迟迁移，并显著降低DAOY和D425细胞的侵袭（p < 0.0001）。然而，与载体处理的对照组相比，我们的研究并未延长第3组髓母细胞瘤异种移植小鼠模型的生存期。
我们的数据显示BT9在DAOY和D425细胞系中具有抗肿瘤功效，表明BT9可能是小儿髓母细胞瘤一种有前景的靶向治疗药物。然而，这些数据需要在动物模型中进一步验证。
