Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida.
Sheila and David Fuente Graduate Program in Cancer Biology, University of Miami Miller School of Medicine, Miami, Florida.
Cancer Res. 2024 Jul 2;84(13):2141-2154. doi: 10.1158/0008-5472.CAN-23-2926.
Clear cell renal cell carcinoma (ccRCC), the most common type of kidney cancer, is largely incurable in the metastatic setting. ccRCC is characterized by excessive lipid accumulation that protects cells from stress and promotes tumor growth, suggesting that the underlying regulators of lipid storage could represent potential therapeutic targets. Here, we evaluated the regulatory roles of GPR1 and CMKLR1, two G protein-coupled receptors of the protumorigenic adipokine chemerin that is involved in ccRCC lipid metabolism. Both genetic and pharmacologic suppression of either receptor suppressed lipid formation and induced multiple forms of cell death, including apoptosis, ferroptosis, and autophagy, thereby significantly impeding ccRCC growth in cell lines and patient-derived xenograft models. Comprehensive lipidomic and transcriptomic profiling of receptor competent and depleted cells revealed overlapping and unique signaling of the receptors granting control over triglyceride synthesis, ceramide production, and fatty acid saturation and class production. Mechanistically, both receptors enforced suppression of adipose triglyceride lipase, but each receptor also demonstrated distinct functions, such as the unique ability of CMKLR1 to control lipid uptake through regulation of sterol regulatory element-binding protein 1c and the CD36 scavenger receptor. Treating patient-derived xenograft models with the CMKLR1-targeting small molecule 2-(α-naphthoyl) ethyltrimethylammonium iodide (α-NETA) led to a dramatic reduction in tumor growth, lipid storage, and clear-cell morphology. Together, these findings provide mechanistic insights into lipid regulation in ccRCC and identify a targetable axis at the core of the histologic definition of this tumor that could be exploited therapeutically. Significance: Extracellular control of lipid accumulation via G protein receptor-mediated cell signaling is a metabolic vulnerability in clear cell renal cell carcinoma, which depends on lipid storage to avoid oxidative toxicity.
透明细胞肾细胞癌(ccRCC)是最常见的肾癌类型,在转移环境中基本无法治愈。ccRCC 的特征是脂质积累过多,从而保护细胞免受应激并促进肿瘤生长,这表明潜在的脂质储存调节因子可能代表潜在的治疗靶点。在这里,我们评估了 G 蛋白偶联受体 GPR1 和 CMKLR1 的调节作用,这两种受体是参与 ccRCC 脂质代谢的促肿瘤脂肪因子 chemerin 的受体。两种受体的遗传和药物抑制均抑制了脂质的形成并诱导了多种细胞死亡形式,包括细胞凋亡、铁死亡和自噬,从而显著阻碍了细胞系和患者来源的异种移植模型中的 ccRCC 生长。对受体功能正常和耗尽的细胞进行全面的脂质组学和转录组学分析,揭示了两种受体的重叠和独特信号,赋予了对甘油三酯合成、神经酰胺产生以及脂肪酸饱和度和分类产生的控制。从机制上讲,两种受体都强制抑制脂肪甘油三酯酶,但每种受体也具有独特的功能,例如 CMKLR1 控制通过固醇调节元件结合蛋白 1c 和 CD36 清道夫受体调节脂质摄取的独特能力。用 CMKLR1 靶向小分子 2-(α-萘酰基)乙基三甲基氯化铵(α-NETA)治疗患者来源的异种移植模型,导致肿瘤生长、脂质储存和透明细胞形态明显减少。总之,这些发现为 ccRCC 中的脂质调节提供了机制上的见解,并确定了可作为该肿瘤组织学定义核心的可靶向轴,可用于治疗。意义:通过 G 蛋白受体介导的细胞信号转导对脂质积累的细胞外控制是透明细胞肾细胞癌的代谢脆弱性,该肿瘤依赖于脂质储存来避免氧化毒性。