Research Center on Tropical Diseases (CIET), Faculty of Microbiology, University of Costa Rica, San José 11501-2060, Costa Rica.
Research Center on Surgery and Cancer (CICICA), Campus Rodrigo Facio, University of Costa Rica, San José 11501-2060, Costa Rica.
Cells. 2023 Nov 8;12(22):2588. doi: 10.3390/cells12222588.
Tumor heterogeneity leads to drug resistance in cancer treatment with the crucial role of sphingolipids in cell fate and stress signaling. We analyzed sphingolipid metabolism and autophagic flux to study chemotherapeutic interactions on the A549 lung cancer model. Loaded cells with fluorescent sphingomyelin analog (BODIPY) and mCherry-EGFP-LC3B were used to track autophagic flux and assess cytotoxicity when cells are exposed to chemotherapy (epirubicin, cisplatin, and paclitaxel) together with sphingolipid pathway inhibitors and autophagy modulators. Our cell model approach employed fluorescent sphingolipid biosensors and a Gaussian Mixture Model of cell heterogeneity profiles to map the influence of chemotherapy on the sphingolipid pathway and infer potential synergistic interactions. Results showed significant synergy, especially when combining epirubicin with autophagy inducers (rapamycin and Torin), reducing cell viability. Cisplatin also synergized with a ceramidase inhibitor. However, paclitaxel often led to antagonistic effects. Our mapping model suggests that combining chemotherapies with autophagy inducers increases vesicle formation, possibly linked to ceramide accumulation, triggering cell death. However, the in silico model proposed ceramide accumulation in autophagosomes, and kinetic analysis provided evidence of sphingolipid colocalization in autophagosomes. Further research is needed to identify specific sphingolipids accumulating in autophagosomes. These findings offer insights into potential strategies for overcoming chemotherapy resistance by targeting the sphingolipid pathway.
肿瘤异质性导致癌症治疗中的药物耐药性，而鞘脂在细胞命运和应激信号中起着关键作用。我们分析了鞘脂代谢和自噬流，以研究 A549 肺癌模型中化疗的相互作用。用荧光鞘磷脂类似物（BODIPY）和 mCherry-EGFP-LC3B 负载细胞，以跟踪自噬流，并在细胞暴露于化疗（表柔比星、顺铂和紫杉醇）以及鞘脂途径抑制剂和自噬调节剂时评估细胞毒性。我们的细胞模型方法使用荧光鞘脂生物传感器和细胞异质性谱的高斯混合模型来绘制化疗对鞘脂途径的影响，并推断潜在的协同相互作用。结果表明存在显著的协同作用，尤其是当将表柔比星与自噬诱导剂（雷帕霉素和 Torin）联合使用时，细胞活力降低。顺铂也与神经酰胺酶抑制剂协同作用。然而，紫杉醇通常会产生拮抗作用。我们的映射模型表明，将化疗药物与自噬诱导剂联合使用会增加囊泡形成，这可能与神经酰胺积累有关，从而触发细胞死亡。然而，该模型提出了自噬体中神经酰胺的积累，并且动力学分析提供了鞘脂在自噬体中共定位的证据。需要进一步研究以确定自噬体中积累的特定鞘脂。这些发现为通过靶向鞘脂途径克服化疗耐药性提供了潜在策略的深入了解。
