Plexiform neurofibromas (PNs) occur in about a half of neurofibromatosis type 1 (NF1) patients and have garnered significant research attention due to their capacity for growth and potential for malignant transformation. NF1 plexiform neurofibroma (pNF1) is a complex tumor composed of Schwann cell-derived tumor cells (Nf1−/−) and the tumor microenvironment (TME). Although it has been widely demonstrated that the TME is involved in the formation of neurofibromas, little is known about the effects of the TME on the subsequent progression of human pNF1. Elucidating the molecular interactions between tumor cells and the TME may provide new therapeutic targets to reduce the progression of pNF1. In the present study, we focused on the contributions of fibroblasts, the most abundant cell types in the TME, to the growth of pNF1. To simulate the TME, we used a three-dimensional (3D) coculture model of immortalized pNF1 tumor cells (Nf1−/−) and primary fibroblasts (Nf1+/−) derived from pNF1 patients. We performed live-cell imaging of 3D/4D (3D in real-time) cultures through confocal microscopy followed by 3D quantitative analyses using advanced imaging software. The growth of pNF1 spheroids in 3D cocultures with fibroblasts was significantly greater than that of pNF1 spheroids in 3D monocultures. An increase in the growth of pNF1 spheroids also occurred when they were cultured with conditioned media (CM) from fibroblasts. Moreover, fibroblast-derived CM increased the invasive outgrowth and further local invasion of pNF1 spheroids. Interestingly, when small extracellular vesicles (sEVs) were depleted from the fibroblast-derived CM, the stimulation of the growth of pNF1 spheroids was lost. Our results suggest that fibroblast-derived sEVs are a therapeutic target for reducing the growth of pNF1.
丛状神经纤维瘤（PNs）约发生于半数1型神经纤维瘤病（NF1）患者中，因其生长潜能和恶性转化可能性而受到广泛研究关注。NF1丛状神经纤维瘤（pNF1）是由雪旺细胞来源的肿瘤细胞（Nf1−/−）与肿瘤微环境（TME）构成的复杂肿瘤。尽管已有充分证据表明TME参与神经纤维瘤的形成，但关于TME对人类pNF1后续进展的影响尚不明确。阐明肿瘤细胞与TME之间的分子相互作用，可能为抑制pNF1进展提供新的治疗靶点。本研究聚焦于TME中最丰富的细胞类型——成纤维细胞对pNF1生长的促进作用。为模拟TME，我们采用源自pNF1患者的永生化pNF1肿瘤细胞（Nf1−/−）与原代成纤维细胞（Nf1+/−）构建三维共培养模型。通过共聚焦显微镜对三维/四维（实时三维）培养体系进行活细胞成像，并运用先进成像软件进行三维定量分析。结果显示：与成纤维细胞共培养的pNF1球体生长速度显著快于单独培养的pNF1球体；使用成纤维细胞条件培养基（CM）培养时，pNF1球体生长同样加速。此外，成纤维细胞来源的CM还能促进pNF1球体的侵袭性生长及局部浸润。值得注意的是，当去除成纤维细胞CM中的小型细胞外囊泡（sEVs）后，其对pNF1球体生长的刺激作用随之消失。本研究结果表明，成纤维细胞来源的sEVs可作为抑制pNF1生长的潜在治疗靶点。
肿瘤(癌症)患者之家