Ruiz-Malagón Antonio Jesús, Rodríguez-Sojo María Jesús, García-García Jorge, Ho-Plagaro Ailec, García Federico, Vezza Teresa, Redondo-Cerezo Eduardo, Griñán-Lisón Carmen, Marchal Juan Antonio, Rodríguez-Cabezas María Elena, Rodríguez-Nogales Alba, Gálvez Julio
Department of Pharmacology, Center for Biomedical Research (CIBM), University of Granada, 18071, Granada, Spain.
Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590, Málaga, Spain.
Acta Pharmacol Sin. 2025 Sep 12. doi: 10.1038/s41401-025-01629-0.
Cancer stem cells (CSCs) play a key role in the progression of colorectal cancer (CRC). The high heterogeneity of CSCs has hindered the clinical application of CSC-targeting therapies. Tetracyclines are drugs with therapeutic potentials beyond their antibiotic activity. We previously demonstrated the efficacy of tigecycline, a third-generation tetracycline, against a model of colitis-associated colorectal cancer, primarily focusing on its immunomodulatory role with a preliminary assessment of its impact on stemness. In this study we characterize the effects of tigecycline on colon CSCs in vitro and in a CRC xenograft model, with special attention on the signaling pathways involved and the modulation of the gut microbiota. We generated secondary colonospheres from two colon tumor cell lines HCT116 and CMT93, and evaluated the effect of tigecycline on CSCs properties. We showed that tigecycline (25, 50 μM) effectively reduced colon CD133CD44LGR5ALDH subpopulations and their viability, self-renewal and migratory capacity. Moreover, tigecycline treatment hindered epithelial-mesenchymal transition (EMT) process through targeting SNAI1 and β-catenin, resulting in an upregulation of epithelial markers (E-cadherin) and a downregulation of pluripotency and mesenchymal ones (Vimentin, N-cadherin, SOX2, NANOG, MIR155, MIR146). This effect was confirmed in two independent CRC-xenograft murine models in which tigecycline administration led to a reduction in tumor volume. Finally, CRC samples were taken from HCT116 xenograft model mice for analysis of CSCs-related signaling pathways and stools were collected for gut microbiome metagenomic analysis. We found that the antibiotic modulated gut dysbiosis by increasing the abundance of beneficial bacterial species such as Parabacteroides sp., which were involved in metabolic pathways that hindered SNAI1-Wnt-β-catenin signaling. These results reinforce the new role of tigecycline in the therapy of CRC and demonstrate for the first time the effect of tigecycline on colon CSCs and their malignancies.
癌症干细胞（CSCs）在结直肠癌（CRC）的进展中起关键作用。CSCs的高度异质性阻碍了针对CSC的治疗方法在临床上的应用。四环素类药物具有超出其抗生素活性的治疗潜力。我们之前证明了第三代四环素替加环素对结肠炎相关结直肠癌模型的疗效，主要关注其免疫调节作用，并初步评估了其对干性的影响。在本研究中，我们在体外和CRC异种移植模型中表征了替加环素对结肠CSCs的影响，特别关注其中涉及的信号通路以及肠道微生物群的调节。我们从两种结肠肿瘤细胞系HCT116和CMT93中生成了次级结肠球，并评估了替加环素对CSCs特性的影响。我们发现替加环素（25、50μM）有效减少了结肠CD133⁺CD44⁺LGR5⁺ALDH⁺亚群及其活力、自我更新和迁移能力。此外，替加环素治疗通过靶向SNAI1和β-连环蛋白阻碍上皮-间质转化（EMT）过程，导致上皮标志物（E-钙黏蛋白）上调，多能性和间质标志物（波形蛋白、N-钙黏蛋白、SOX2、NANOG、MIR155、MIR146）下调。在两个独立的CRC异种移植小鼠模型中证实了这种效果，其中给予替加环素导致肿瘤体积减小。最后，从HCT116异种移植模型小鼠中采集CRC样本用于分析与CSCs相关的信号通路，并收集粪便用于肠道微生物群宏基因组分析。我们发现该抗生素通过增加有益细菌种类如副拟杆菌属的丰度来调节肠道生态失调，这些有益细菌参与了阻碍SNAI1-Wnt-β-连环蛋白信号传导的代谢途径。这些结果强化了替加环素在CRC治疗中的新作用，并首次证明了替加环素对结肠CSCs及其恶性肿瘤的影响。
