Ordaz-Ramos Alejandro, Diaz-Blancas Jorge, Martínez-Cruz Aketzalli, Castro-Oropeza Rosario, Zampedri Cecilia, Romero-Rodríguez Damaris P, Rodriguez-Dorantes Mauricio, Melendez-Zajgla Jorge, Maldonado Vilma, Vazquez-Santillan Karla
Innovation and Precision Medicine Laboratory, Instituto Nacional de Medicina Genómica, Periférico Sur No.4809, Col Arenal Tepepan, Tlalpan, Mexico City C.P. 14610, Mexico; Posgrado en Ciencias Biológicas, Unidad de Posgrado, Edificio D, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, Mexico City C.P. 04510, Mexico.
Epigenetics Laboratory, Instituto Nacional de Medicina Genómica, Periférico Sur No.4809, Col Arenal Tepepan, Tlalpan, Mexico City C.P. 14610, Mexico.
Biochim Biophys Acta Mol Cell Res. 2025 Feb;1872(2):119888. doi: 10.1016/j.bbamcr.2024.119888. Epub 2024 Dec 9.
Breast cancer stem cells (BCSC) are a subpopulation responsible for cancer resistance and relapse. The receptor activator of nuclear factor kappa-Β ligand (RANKL) is a cytokine capable of activating RANK and LGR4 receptors. RANKL/RANK signaling maintains the self-renewal of BCSCs, however, the effect of RANKL via LGR4 remains unclear. Evidence from osteoclasts suggests that RANKL/LGR4 axis disrupts RANK signaling, leading to opposing cellular responses. Anti-RANKL inhibitors are potential agents for eradicating CSCs, but their effect on RANKL/LGR4 signal has not been demonstrated.
This project aimed to elucidate the role of RANKL in regulating stemness depending on the expression of its receptors.
We use in vitro and in vivo approaches to evaluate the effects of RANKL inhibition in stemness in low or high-LGR4 expressing cells. Furthermore, we analyze the effects of RANKL stimulation on the stemness of LGR4 or RANK overexpressing cells. Additionally, we evaluated the impact of RANKL/LGR4 signaling in the activity of Wnt/β-catenin and NF-κB signaling pathways.
Our findings indicated that elevated RANKL expression is related to a favorable prognosis in patients with high LGR4 levels. Furthermore, RANKL inhibition decreased BCSC properties in LGR4-low cell lines, while it promoted migration in LGR4-high cells. Additionally, the RANKL/RANK axis activated NF-κB signaling and enhanced BCSCs in RANK-overexpressing cells. In contrast, in LGR4-overexpressing cells, RANKL failed to activate NF-κB but instead inhibited the Wnt/β-catenin pathway, leading to a reduction in BCSCs.
Our findings suggest that RANKL exerts different responses according to the expression of its receptors.
乳腺癌干细胞（BCSC）是导致癌症耐药和复发的一个亚群。核因子κB受体激活剂配体（RANKL）是一种能够激活RANK和LGR4受体的细胞因子。RANKL/RANK信号传导维持BCSC的自我更新，然而，RANKL通过LGR4产生的作用仍不清楚。来自破骨细胞的证据表明，RANKL/LGR4轴破坏RANK信号传导，导致相反的细胞反应。抗RANKL抑制剂是根除癌症干细胞的潜在药物，但其对RANKL/LGR4信号的作用尚未得到证实。
本项目旨在阐明RANKL根据其受体表达在调节干性方面的作用。
我们采用体外和体内方法评估RANKL抑制对低LGR4表达或高LGR4表达细胞干性的影响。此外，我们分析RANKL刺激对LGR4或RANK过表达细胞干性的影响。另外，我们评估了RANKL/LGR4信号传导对Wnt/β-连环蛋白和NF-κB信号通路活性的影响。
我们的研究结果表明，RANKL表达升高与LGR4水平高的患者的良好预后相关。此外，RANKL抑制降低了LGR4低表达细胞系中的BCSC特性，而在LGR4高表达细胞中促进了迁移。此外，RANKL/RANK轴激活了NF-κB信号传导，并增强了RANK过表达细胞中的BCSC。相反，在LGR4过表达细胞中，RANKL未能激活NF-κB，反而抑制了Wnt/β-连环蛋白通路，导致BCSC减少。
我们的研究结果表明，RANKL根据其受体的表达产生不同的反应。
