PO.TB05.01 · 肿瘤生物学
细胞外黏度调控SMARCB1缺陷型脑肿瘤细胞的球体形成
Extracellular viscosity modulates spheroid formation in SMARCB1-deficient brain tumor cells
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：在发育中的儿童脑内，组织微环境的黏度随组织成熟而动态变化，提供了一种独特的机械微环境，可能通过机械转导影响细胞行为。SMARCB1缺陷导致最具侵袭性的儿童中枢神经系统恶性肿瘤，这些肿瘤具有高度组织特异性、发病极早、表观遗传失调和代谢状态改变等特点。尽管存在这一独特的生物学背景，但细胞外黏度是否与SMARCB1缺失相互作用以改变肿瘤细胞行为，此前从未被探索过。
方法：为研究细胞外黏度如何影响SMARCB1缺陷型脑肿瘤细胞，将结冷胶（GG）——一种生物相容性黏度调节剂——加入培养基中，以在37 °C下产生2.2（0%）、10（0.01%）和34（0.03%）mPa·s的黏度。将SMARCB1缺陷型Re1P6细胞（c.157>T突变，源自患者来源异种移植）与SMARCB1充足型胶质瘤细胞系（T98G）进行比较。将单细胞悬液接种于超低吸附板上，并在黏度递增的培养基中培养，以监测细胞生长和球体形成。还将预先形成的球体转移至不同黏度的培养基中，以评估球体的稳定性和分散性。在每种条件下进一步检查干性标志物和其他细胞表型的变化。
结果：我们发现，升高的细胞外黏度选择性地调控SMARCB1缺陷型Re1P6细胞的球体形成，但不影响SMARCB1充足型胶质瘤细胞。Re1P6对黏度表现出非线性反应，在10 mPa·s时形成最均匀的球体（直径约200 μm）并伴随细胞生长增加（约30倍），而在34 mPa·s时球体形成几乎被抑制且增殖保持不变。SMARCB1充足型胶质瘤细胞在相同黏度条件下的球体形成或细胞生长变化极小。预先形成的Re1P6球体在较高黏度下形成不规则边界，提示球体黏聚性存在黏度依赖性破坏。高黏度条件似乎还会降低SOX2并增加vimentin表达。总体而言，Re1P6细胞对黏度依赖性微环境表现出比SMARCB1充足型对照更大的表型调节。
结论：我们的初步发现提示细胞外黏度与儿童SMARCB1缺陷型肿瘤的恶性行为之间存在潜在联系。未来的工作将研究黏度依赖性反应是否与机械感应信号通路以及代谢-表观遗传变化相关联，从而为其组织特异性提供新的见解。
查看英文原文 English abstract
Background In the developing pediatric brain, the viscosity of the tissue microenvironment changes dynamically with tissue maturation, providing a unique mechanical microenvironment that may influence cellular behavior through mechanotransduction. SMARCB1 deficiency causes the most aggressive pediatric central nervous system malignancies, which have high tissue specificity, extremely early onset, epigenetic dysregulation, and altered metabolic states. Despite this unique biological context, whether extracellular viscosity interacts with SMARCB1 loss to alter tumor cell behavior has never been explored.
Methods To investigate how extracellular viscosity affects SMARCB1-deficient brain tumor cells, gellan gum (GG), a biocompatible viscosity modifier, was incorporated into culture medium to generate viscosities of 2.2 (0%), 10 (0.01%), and 34 (0.03%) mPa·s at 37 °C. SMARCB1-deficient Re1P6 cells (c.157>T mutation and established from a patient-derived xenograft) were compared with SMARCB1-proficient glioma cell lines (T98G). Single-cell suspensions were seeded on ultra-low attachment plates and cultured in media of increasing viscosities to monitor cell growth and spheroid formation. Pre-formed spheroids were also transferred into media with varying viscosities to evaluate spheroid stability and dispersion. Changes in stemness markers and other cellular phenotypes were further examined under each condition.
Results We found that elevated extracellular viscosity selectively modulates spheroid formation in SMARCB1-deficient Re1P6 cells but not in SMARCB1-proficient glioma cells. Re1P6 exhibited a nonlinear response to viscosity, forming the most uniform spheroids (~200 μm in diameter) with increased cell growth (~30-fold) at 10 mPa·s, whereas spheroid formation was almost suppressed and proliferation remained unchanged at 34 mPa·s. SMARCB1-proficient glioma cells showed minimal changes in spheroid formation or cell growth across the same viscosity conditions. Pre-formed Re1P6 spheroids developed irregular boundaries at higher viscosity, suggesting viscosity-dependent disruption of spheroid cohesion. High-viscosity conditions also appeared tp decrease SOX2 and increase vimentin expression. Overall, Re1P6 cells exhibited greater phenotypic modulation in response to viscosity-dependent microenvironments than SMARCB1-proficient controls.
Conclusion Our early findings suggest a potential link between extracellular viscosity and the malignant behavior of pediatric SMARCB1-deficient tumors. Future work will investigate whether the viscosity-dependent response is linked to mechanosensing signaling pathway and metabolic-epigenetic changes, providing new insights into their tissue-specificity.
利益披露 Disclosure
Y. Chen, None..
L. Lu, None..
Y. Lin, None.