Targeted Therapeutics, Department of Biomaterials Science and Technology, Technical Medical Centre, Faculty of Science and technology, University of Twente, Enschede, The Netherlands.
Nanotheranostics. 2020 Jan 1;4(1):26-39. doi: 10.7150/ntno.38092. eCollection 2020.
Pancreatic ductal adenocarcinoma (PDAC), characterized with abundant tumor stroma, is a highly malignant tumor with poor prognosis. The tumor stroma largely consists of cancer-associated fibroblasts (CAFs) and extracellular matrix (ECM), and is known to promote tumor growth and progression as well as acts as a barrier to chemotherapy. Inhibition of tumor stroma is highly crucial to induce the effect of chemotherapy. In this study, we delivered fibroblast growth factor 2 (FGF2) to human pancreatic stellate cells (hPSCs), the precursors of CAFs, using superparamagnetic iron oxide nanoparticles (SPIONs). FGF2 was covalently conjugated to functionalized PEGylated dextran-coated SPIONs. FGF2-SPIONs significantly reduced TGF-β induced hPSCs differentiation (α-SMA and collagen-1 expression) by inhibiting pSmad2/3 signaling and inducing ERK1/2 activity, as shown with western blot analysis. Then, we established a stroma-rich self-assembling 3D heterospheroid model by co-culturing PANC-1 and hPSCs in 3D environment. We found that FGF2-SPIONs treatment alone inhibited the tumor stroma-induced spheroid growth. In addition, they also potentiated the effect of gemcitabine, as shown by measuring the spheroid size and ATP content. These effects were attributed to the reduced expression of the hPSC activation and differentiation marker, α-SMA. Furthermore, to demonstrate an application of SPIONs, we applied an external magnetic field to spheroids while incubated with FGF2-SPIONs. This resulted in an enhanced effect of gemcitabine in our 3D model. In conclusion, this study presents a novel approach to target FGF2 to tumor stroma using SPIONs and thereby enhancing the effect of gemcitabine as demonstrated in the complex 3D tumor spheroid model.
胰腺导管腺癌（PDAC）以丰富的肿瘤基质为特征，是一种高度恶性肿瘤，预后不良。肿瘤基质主要由癌相关成纤维细胞（CAFs）和细胞外基质（ECM）组成，已知其促进肿瘤生长和进展，并充当化疗的屏障。抑制肿瘤基质对于诱导化疗效果至关重要。在这项研究中，我们使用超顺磁性氧化铁纳米粒子（SPIONs）将成纤维细胞生长因子 2（FGF2）递送到人胰腺星状细胞（hPSC），即 CAFs 的前体。FGF2 与功能化聚乙二醇化葡聚糖包覆的 SPIONs 共价偶联。FGF2-SPIONs 通过抑制 pSmad2/3 信号通路和诱导 ERK1/2 活性，显著减少 TGF-β诱导的 hPSC 分化（α-SMA 和胶原-1 表达），如 Western blot 分析所示。然后，我们通过在 3D 环境中共同培养 PANC-1 和 hPSC，建立了富含基质的自组装 3D 异质球体模型。我们发现，FGF2-SPIONs 单独处理即可抑制肿瘤基质诱导的球体生长。此外，如通过测量球体大小和 ATP 含量所示，它们还增强了吉西他滨的效果。这些作用归因于 hPSC 激活和分化标志物α-SMA 的表达减少。此外，为了证明 SPIONs 的应用，我们在孵育 FGF2-SPIONs 的同时，对球体施加外部磁场。这导致我们的 3D 模型中吉西他滨的效果增强。总之，这项研究提出了一种使用 SPIONs 靶向肿瘤基质的 FGF2 的新方法，并在复杂的 3D 肿瘤球体模型中证明了增强吉西他滨效果的方法。
