Amofa Kwasi Yeboa, Patterson Katherine Michelle, Ortiz Jessica, Kumar Sanjay
Department of Bioengineering, University of California, Berkeley, California 94720, USA.
APL Bioeng. 2024 Jun 13;8(2):026125. doi: 10.1063/5.0203213. eCollection 2024 Jun.
Glioma stem cells (GSCs) contribute to rapid cellular invasion in glioblastoma (GBM). Transforming growth factor-β (TGF-β) has been strongly implicated in supporting key GSC functions, including stemness, immunosuppression, and resistance. Although TGF-β is well-known as a driver of cancer invasion, how TGF-β supports the invasion of GSCs is not well understood. Progress in understanding mechanisms of TGF-β-driven invasion in GSC-derived tumors has been limited by an absence of three-dimensional (3D) culture systems that support TGF-β-stimulated invasion. Here, we show that 3D hyaluronic acid (HA) matrices can address this need. We perform bioinformatic analysis of human glioma datasets, which reveals progressive enrichment of TGF-β-related gene expression with increasingly aggressive glioma grade and GBM subtype. We then experimentally screen the invasion of a panel of human GSC spheroids through a set of 3D matrix systems, including collagen I, Matrigel, and HA, and find that only HA recapitulates TGF-β-induced invasion. We then show that GSCs differ in their ability to invade HA in a way that can be predicted from TGF-β receptor 2 expression and SMAD2 phosphorylation. GSC spheroid invasion depends strongly on the presence of RGD peptides on the HA backbone but is surprisingly independent of matrix metalloprotease degradability. Finally, we demonstrate that TGF-β stimulates invasion through SMAD-dependent signaling, consistent with recent observations that TGF-β/SMAD signals drive tumor microtube formation and invasion. Our work supports further development of HA as a matrix platform for dissecting contributions of TGF-β and other cytokines to GBM invasion and screening of cytokine-dependent invasion in human tumors.
胶质瘤干细胞（GSCs）促使胶质母细胞瘤（GBM）发生快速的细胞侵袭。转化生长因子-β（TGF-β）与支持GSC的关键功能密切相关，包括干性、免疫抑制和耐药性。尽管TGF-β作为癌症侵袭的驱动因子广为人知，但TGF-β如何支持GSCs的侵袭尚不清楚。由于缺乏支持TGF-β刺激侵袭的三维（3D）培养系统，在理解TGF-β驱动GSC衍生肿瘤侵袭机制方面的进展有限。在此，我们表明3D透明质酸（HA）基质可以满足这一需求。我们对人类胶质瘤数据集进行了生物信息学分析，结果显示随着胶质瘤分级和GBM亚型侵袭性的增加，TGF-β相关基因表达逐渐富集。然后，我们通过一组3D基质系统，包括I型胶原、基质胶和HA，对一组人类GSC球体的侵袭进行了实验筛选，发现只有HA能够重现TGF-β诱导的侵袭。然后我们表明，GSCs在侵袭HA的能力上存在差异，这种差异可以从TGF-β受体2的表达和SMAD2磷酸化情况预测出来。GSC球体的侵袭强烈依赖于HA主链上RGD肽的存在，但令人惊讶的是，它与基质金属蛋白酶的降解能力无关。最后，我们证明TGF-β通过SMAD依赖的信号传导刺激侵袭，这与最近的观察结果一致，即TGF-β/SMAD信号驱动肿瘤微管形成和侵袭。我们的工作支持将HA进一步开发为一个基质平台，用于剖析TGF-β和其他细胞因子对GBM侵袭的作用，以及筛选人类肿瘤中细胞因子依赖性侵袭。
