Mahatma Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth (Deemed to-be University), Puducherry 607 403, India.
Department of Biotechnology, Jeppiaar Engineering College, Chennai 600 119, India.
Life Sci. 2022 Jul 15;301:120609. doi: 10.1016/j.lfs.2022.120609. Epub 2022 May 6.
Malignant gliomas constitute one of the deadly brain tumors with high degeneration rate. Though temozolomide (TMZ) is the first-line drug for glioma, its efficacy has decreased due to chemo-resistance. Repurposing synthetic and natural compounds have gained increasing interest in glioma. Hence, we combined chloroquine (CHL) a synthetic drug, naringenin (NAR) and phloroglucinol (PGL) (natural derivatives), to investigate whether the apoptotic effect of these drugs both alone and in combination, enhances the anti-tumor effects of TMZ in an in vitro and in vivo orthotopic xenograft glioma model.
The cytotoxic effect of the drugs was assessed in C6 (murine) glioma cells, U-87 MG and LN229 (human) glioblastoma cells, primary astrocytes (isolated from rat brain tissues) and HEK-293 T cells. Mitochondrial depolarization and alterations in the cell cycle was determined by confocal imaging and flow cytometry. The expression of angiogenic and apoptotic markers was evaluated using qRT-PCR and ELISA. The efficacy of the combinatorial treatment was assessed in an orthotopic xenograft model using U-87 MG cells.
The combinatorial treatment inhibited cell proliferation, induced apoptosis and contributed to cell cycle arrest in glioma cells. The quadruple combinatorial cocktail down-regulated BCL-2 with a concomitant decrease in VEGF. As observed in vitro, the quadruple combinatorial treatment enhanced the median survival of glioma-induced rats with lower cellularity rate.
The combination of CHL, NAR and PGL synergistically potentiated the efficacy of TMZ on glioma in vitro and in vivo. Hence, this combination may characterize an advanced strategy for glioma treatment, thereby providing a possible translation to clinical trial.
恶性脑胶质瘤是一种高退化率的致命脑肿瘤。替莫唑胺（TMZ）是脑胶质瘤的一线药物，但由于化疗耐药性，其疗效已降低。重新利用合成和天然化合物已成为脑胶质瘤研究的热点。因此，我们将氯喹（CHL）一种合成药物、柚皮苷（NAR）和根皮苷（PGL）（天然衍生物）结合起来，研究这些药物单独使用和联合使用是否能增强 TMZ 在体外和体内原位异种移植脑胶质瘤模型中的抗肿瘤作用。
在 C6（鼠）神经胶质瘤细胞、U-87 MG 和 LN229（人）神经母细胞瘤细胞、原代星形胶质细胞（从大鼠脑组织中分离）和 HEK-293T 细胞中评估药物的细胞毒性作用。通过共聚焦成像和流式细胞术测定线粒体去极化和细胞周期改变。使用 qRT-PCR 和 ELISA 评估血管生成和凋亡标志物的表达。使用 U-87 MG 细胞在原位异种移植模型中评估联合治疗的疗效。
联合治疗抑制神经胶质瘤细胞的增殖，诱导细胞凋亡，并导致细胞周期停滞。四元组合鸡尾酒下调 BCL-2，同时降低 VEGF。正如在体外观察到的，四元组合治疗增强了 TMZ 对胶质瘤诱导大鼠的中位生存时间，同时降低了细胞数量。
CHL、NAR 和 PGL 的联合使用协同增强了 TMZ 在体外和体内对神经胶质瘤的疗效。因此，这种联合可能是治疗脑胶质瘤的一种先进策略，从而为临床试验提供了可能的转化。
