Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, China.
Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, China.
Biomater Adv. 2024 Oct;163:213936. doi: 10.1016/j.bioadv.2024.213936. Epub 2024 Jul 1.
Matrix stiffening is one of the major risk factors for hepatocellular carcinoma (HCC) and drives tumor progression. The extracellular matrix (ECM) stiffness of HCC displays mechanical heterogeneity, with stiffness increasing from the core to the invasive frontier. The distribution of liver cancer stem cells (CSCs) is related to this mechanical property. However, it is not sufficiently understood how heterogeneous matrix stiffness regulates the stemness of CSCs. In this study, we developed an adjustable gelatin/alginate hydrogel to investigate the effect of various matrix stiffnesses on CSC stemness under three-dimensional culture conditions. Gelatin/alginate hydrogel with the stiffness of soft (5 kPa), medium (16 kPa), and stiff (81 kPa) were prepared by altering the concentration of calcium ions. It was found that a stiffer matrix promoted stemness-associated gene expression, reduced drug sensitivity, enhanced sphere-forming and clonogenic ability, and tumorigenic potential. Mechanistically, matrix stiffening facilitates CSC stemness by increasing Yes-associated protein (YAP) activity and inhibiting Bcl-2 modifying factor (BMF) expression. Knockdown of YAP or overexpression of BMF significantly attenuated matrix stiffening-induced stemness, suggesting the involvement of YAP and BMF in this process. Together, our results unravel the regulatory mechanism of heterogeneous matrix stiffness on CSC stemness and also provide a novel therapeutic strategy for eradicating CSCs and improving the efficiency of HCC treatment.
基质变硬是肝细胞癌（HCC）的主要风险因素之一，可驱动肿瘤进展。HCC 的细胞外基质（ECM）硬度表现出机械异质性，其硬度从核心向侵袭前沿增加。肝癌干细胞（CSC）的分布与这种机械特性有关。然而，对于基质硬度的异质性如何调节 CSC 的干性，目前还了解不足。在这项研究中，我们开发了一种可调节的明胶/海藻酸盐水凝胶，以在三维培养条件下研究不同基质硬度对 CSC 干性的影响。通过改变钙离子浓度来制备具有软（5 kPa）、中（16 kPa）和硬（81 kPa）硬度的明胶/海藻酸盐水凝胶。结果发现，更硬的基质促进了与干性相关的基因表达，降低了药物敏感性，增强了球体形成和克隆形成能力以及致瘤潜能。在机制上，基质变硬通过增加 Yes 相关蛋白（YAP）活性和抑制 Bcl-2 修饰因子（BMF）表达来促进 CSC 干性。YAP 的敲低或 BMF 的过表达显著减弱了基质变硬诱导的干性，表明 YAP 和 BMF 参与了这一过程。总之，我们的研究结果揭示了异质基质硬度对 CSC 干性的调控机制，并为根除 CSC 和提高 HCC 治疗效率提供了一种新的治疗策略。
