Ji Kyungmin, Schwenkel George J
Department of Neurology, Henry Ford Health, Detroit, MI 48202, USA.
Department of Pharmacology, Wayne State University, Detroit, MI 48201, USA.
Cells. 2025 Aug 18;14(16):1276. doi: 10.3390/cells14161276.
Plexiform neurofibromas (hereafter called pNF1) are often diagnosed in early childhood and occur in about 30% of neurofibromatosis type 1 (NF1) patients. pNF1 exhibits aggressive growth along a nerve in the body and has substantial potential for progression to malignant peripheral nerve sheath tumors that are rarely curable. There are two recently FDA-approved drugs, selumetinib and mirdametinib, for pNF1 patients who have symptomatic and inoperable plexiform neurofibromas; however, these treatments achieve only approximately 30% tumor shrinkage. Fibroblasts, the most abundant cell types within the pNF1 tumor microenvironment, are implicated in pNF1 growth and invasion; however, how fibroblasts affect a drug response of pNF1 remains poorly understood. In the present study, we focused on contributions of fibroblasts to the drug resistance in pNF1 via their secretome. We employed our established three-dimensional (3D) culture system incorporating human pNF1 tumor cells () and primary fibroblasts () grown in our patented microfluidic culture chips for monocultures and parallel cocultures in which 3D pNF1 structures and fibroblasts share their secretome without direct cell-to-cell contact. Three-dimensional pNF1 structures in 3D parallel cocultures with fibroblasts exhibited greater drug resistance than ones in monocultures. We found that pNF1 tumor cells showed increased P-glycoprotein expression when incubated with fibroblast-derived conditioned media or parallel cocultured with fibroblasts, compared to control conditions. Pharmacological inhibition of P-glycoprotein partially restored drug sensitivity. Additionally, fibroblasts showed higher resistance to selumetinib and mirdametinib than pNF1 tumor structures, likely due to elevated P-glycoprotein levels. This study is the first to define precise roles of fibroblasts in pNF1 drug resistance, emphasizing the potential of fibroblast-targeted therapies as a promising approach to improve pNF1 treatment outcomes.
丛状神经纤维瘤（以下简称pNF1）常在儿童早期被诊断出来，约30%的1型神经纤维瘤病（NF1）患者会出现。pNF1沿体内神经呈侵袭性生长，具有发展为恶性外周神经鞘瘤的巨大潜力，而恶性外周神经鞘瘤很少能治愈。最近有两种药物已获美国食品药品监督管理局（FDA）批准，即司美替尼和米哚妥林，用于治疗有症状且无法手术切除的丛状神经纤维瘤的pNF1患者；然而，这些治疗仅能使肿瘤缩小约30%。成纤维细胞是pNF1肿瘤微环境中最丰富的细胞类型，与pNF1的生长和侵袭有关；然而，成纤维细胞如何影响pNF1的药物反应仍知之甚少。在本研究中，我们聚焦于成纤维细胞通过其分泌组对pNF1耐药性的影响。我们采用了已建立的三维（3D）培养系统，该系统将人pNF1肿瘤细胞（）和原代成纤维细胞（）培养在我们获得专利的微流控培养芯片中，用于单培养和平行共培养，其中3D pNF1结构和成纤维细胞在不直接细胞间接触的情况下共享其分泌组。与成纤维细胞进行3D平行共培养的3D pNF1结构比单培养的表现出更高的耐药性。我们发现，与对照条件相比，pNF1肿瘤细胞在与成纤维细胞衍生的条件培养基孵育或与成纤维细胞平行共培养时，P-糖蛋白表达增加。对P-糖蛋白的药理抑制部分恢复了药物敏感性。此外，成纤维细胞对司美替尼和米哚妥林的耐药性高于pNF1肿瘤结构，这可能是由于P-糖蛋白水平升高所致。本研究首次明确了成纤维细胞在pNF1耐药性中的精确作用，强调了靶向成纤维细胞治疗作为改善pNF1治疗效果的一种有前景方法的潜力。
