Linke Charlotte, Freitag Thomas, Riess Christin, Scheffler Jana Vanessa, Del Moral Katharina, Schoenwaelder Nina, Fiedler Tomas, Fiebig Adina, Kaps Philipp, Dubinski Daniel, Schneider Björn, Bergmann Wendy, Classen Carl Friedrich, Maletzki Claudia
Department of Medicine Clinic III-Hematology, Oncology, Palliative Medicine, Rostock University Medical Center, Ernst-Heydemann-Str. 6, 18057, Rostock, Germany.
University Children's Hospital, Rostock University Medical Center, Ernst-Heydemann-Straße 8, 18057, Rostock, Germany.
Cancer Cell Int. 2023 Feb 27;23(1):38. doi: 10.1186/s12935-023-02873-2.
Arginine auxotrophy constitutes a shortcoming for ~ 30% of glioblastoma multiforme (GBM). Indeed, arginine-depleting therapy using arginine deiminase from Streptococcus pyogenes (SpyADI) has proven activity against GBM in preclinical studies. The good safety profile of SpyADI renders this agent an ideal combination partner for cytostatic therapy.
In this study, we combined the antineoplastic antibiotic Mithramycin A (MitA) with SpyADI to boost single-agent activity and analyzed underlying response mechanisms in-depth.
MitA monotherapy induced a time- and dose-dependent cytotoxicity in eight patient-derived GBM cell lines and had a radiosensitizing effect in all but one cell line. Combination treatment boosted the effects of the monotherapy in 2D- and 3D models. The simultaneous approach was superior to the sequential application and significantly impaired colony formation after repetitive treatment. MitA monotherapy significantly inhibited GBM invasiveness. However, this effect was not enhanced in the combination. Functional analysis identified SpyADI-triggered senescence induction accompanied by increased mitochondrial membrane polarization upon mono- and combination therapy. In HROG63, induction of lysosomes was seen after both monotherapies, indicative of autophagy. These cells seemed swollen and had a more pronounced cortically formed cytoskeleton. Also, cytochrome C and endoplasmatic reticulum-stress-associated proteins ATF4 and Calnexin were enhanced in the combination, contributing to apoptosis. Notably, no significant increases in glioma-stemness marker were seen.
Therapeutic utilization of a metabolic defect in GBM along with cytostatic therapy provides a novel combination approach. Whether this SpyADI/MitA regimen will provide a safe alternative to combat GBM, will have to be addressed in subsequent (pre-)clinical trials.
精氨酸营养缺陷是约30%的多形性胶质母细胞瘤（GBM）的一个缺点。事实上，在临床前研究中，使用化脓性链球菌精氨酸脱亚氨酶（SpyADI）的精氨酸消耗疗法已被证明对GBM有活性。SpyADI良好的安全性使其成为细胞抑制疗法的理想联合伙伴。
在本研究中，我们将抗肿瘤抗生素光神霉素A（MitA）与SpyADI联合使用以增强单药活性，并深入分析潜在的反应机制。
MitA单药治疗在8种患者来源的GBM细胞系中诱导了时间和剂量依赖性细胞毒性，并且在除一种细胞系外的所有细胞系中都有放射增敏作用。联合治疗在二维和三维模型中增强了单药治疗的效果。同时给药方法优于序贯给药，并且在重复治疗后显著损害集落形成。MitA单药治疗显著抑制GBM侵袭性。然而，联合治疗中这种作用并未增强。功能分析发现，单药治疗和联合治疗均有SpyADI触发的衰老诱导，同时伴有线粒体膜极化增加。在HROG63中，两种单药治疗后均可见溶酶体诱导，表明存在自噬。这些细胞似乎肿胀，并且有更明显的皮质形成的细胞骨架。此外，联合治疗中细胞色素C和内质网应激相关蛋白ATF4和钙连接蛋白增加，促进细胞凋亡。值得注意的是，胶质瘤干性标志物未见显著增加。
利用GBM中的代谢缺陷进行治疗并结合细胞抑制疗法提供了一种新的联合治疗方法。这种SpyADI/MitA方案是否会为对抗GBM提供一种安全的替代方案，将必须在后续的（临床前）临床试验中解决。
