Imaging Cell Signalling & Therapeutics Lab, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi Mumbai, 410210, India.
Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India.
J Exp Clin Cancer Res. 2024 Aug 10;43(1):222. doi: 10.1186/s13046-024-03147-z.
The mechanisms enabling dynamic shifts between drug-resistant and drug-sensitive states in cancer cells are still underexplored. This study investigated the role of targeted autophagic protein degradation in regulating ovarian cancer stem cell (CSC) fate decisions and chemo-resistance.
Autophagy levels were compared between CSC-enriched side population (SP) and non-SP cells (NSP) in multiple ovarian cancer cell lines using immunoblotting, immunofluorescence, and transmission electron microscopy. The impact of autophagy modulation on CSC markers and differentiation was assessed by flow cytometry, immunoblotting and qRT-PCR. In silico modeling and co-immunoprecipitation identified ID1 interacting proteins. Pharmacological and genetic approaches along with Annexin-PI assay, ChIP assay, western blotting, qRT-PCR and ICP-MS were used to evaluate effects on cisplatin sensitivity, apoptosis, SLC31A1 expression, promoter binding, and intracellular platinum accumulation in ID1 depleted backdrop. Patient-derived tumor spheroids were analyzed for autophagy and SLC31A1 levels.
Ovarian CSCs exhibited increased basal autophagy compared to non-CSCs. Further autophagy stimulation by serum-starvation and chemical modes triggered proteolysis of the stemness regulator ID1, driving the differentiation of chemo-resistant CSCs into chemo-sensitive non-CSCs. In silico modeling predicted TCF12 as a potent ID1 interactor, which was validated by co-immunoprecipitation. ID1 depletion freed TCF12 to transactivate the cisplatin influx transporter SLC31A1, increasing intracellular cisplatin levels and cytotoxicity. Patient-derived tumor spheroids exhibited a functional association between autophagy, ID1, SLC31A1, and platinum sensitivity.
This study reveals a novel autophagy-ID1-TCF12-SLC31A1 axis where targeted autophagic degradation of ID1 enables rapid remodeling of CSCs to reverse chemo-resistance. Modulating this pathway could counter drug resistance in ovarian cancer.
癌症细胞中使耐药性和敏感性状态之间发生动态转变的机制仍未得到充分探索。本研究探讨了靶向自噬蛋白降解在调节卵巢癌干细胞（CSC）命运决定和化疗耐药性中的作用。
使用免疫印迹、免疫荧光和透射电子显微镜比较了多个卵巢癌细胞系中 CSC 富集侧群（SP）和非侧群（NSP）细胞中的自噬水平。通过流式细胞术、免疫印迹和 qRT-PCR 评估自噬调节对 CSC 标志物和分化的影响。通过计算机建模和免疫共沉淀鉴定 ID1 相互作用蛋白。采用药理学和遗传学方法以及 Annexin-PI 测定、ChIP 测定、western blot、qRT-PCR 和 ICP-MS 评估在 ID1 耗尽背景下对顺铂敏感性、凋亡、SLC31A1 表达、启动子结合和细胞内铂积累的影响。分析了患者来源的肿瘤球体中的自噬和 SLC31A1 水平。
与非 CSCs 相比，卵巢 CSCs 表现出更高的基础自噬水平。通过血清饥饿和化学方式进一步刺激自噬会触发干性调节剂 ID1 的蛋白水解，从而促使化疗耐药性 CSCs 分化为化疗敏感性非 CSCs。计算机建模预测 TCF12 是 ID1 的一个潜在的强相互作用蛋白，通过免疫共沉淀得到了验证。ID1 的耗竭使 TCF12 释放出来，从而激活顺铂流入转运体 SLC31A1，增加细胞内顺铂水平和细胞毒性。患者来源的肿瘤球体表现出自噬、ID1、SLC31A1 和铂敏感性之间的功能关联。
本研究揭示了一个新的自噬-ID1-TCF12-SLC31A1 轴，其中靶向自噬降解 ID1 使 CSCs 能够快速重塑以逆转化疗耐药性。调节该途径可能有助于对抗卵巢癌的耐药性。
