Orthopedic Research Institute/Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Guangzhou, China.
The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, China; Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, China.
Acta Biomater. 2021 Sep 1;131:326-340. doi: 10.1016/j.actbio.2021.07.009. Epub 2021 Jul 8.
Besides molecular and phenotypic variations observed in cancer cells, intratumoral heterogeneity also occurs in the tumor microenvironment. Correlative stiffness maps of different intratumor locations in breast tumor biopsies show that stiffness increases from core to periphery. However, how different local ECM stiffness regulates key functions of cancer cells in tumor progression remains unclear. Although increased tissue stiffness is an established driver of breast cancer progression, conclusions from 2D cultures do not correspond with newer data from cancer cells in 3D environments. Many past studies of breast cancer in 3D culture fail to recapitulate the stiffness of a real breast tumor or the various local stiffnesses present in a tumor microenvironment. In this study, we developed a series of collagen/alginate hybrid hydrogels with adjustable stiffness to match the core, middle, and peripheral zones of a breast tumor. We used this hydrogel system to investigate effects of different local stiffness on morphology, proliferation, and migration of breast cancer cells. RNA sequencing of cells in hydrogels with different stiffness revealed changes in multiple cellular processes underlying cancer progression, including angiogenesis and metabolism. We discovered that tumor cells in a soft environment enriched YAP1 and AP1 signaling related genes, whereas tumor cells in a stiff environment became more pro-angiogenic by upregulating fibronectin 1 (FN1) and matrix metalloproteinase 9 (MMP9) expression. This systematic study defines how the range of environmental stiffnesses present in a breast tumor regulates cancer cells, providing new insights into tumorigenesis and disease progression at the tumor-stroma interface. STATEMENT OF SIGNIFICANCE: Applied a well-defined hybrid hydrogel system to mimic the tumor microenvironment with heterogeneous local stiffness. Breast cancer cells tended to proliferate in soft core environment while migrate in stiff peripheral environment. Breast cancer cells shift from glycolysis to OXPHOS and fatty acid metabolism responding to stiff matrix microenvironment. The transcriptomic profile of breast cancer cells altered due to microenvironmental stiffness changes.
除了癌细胞中观察到的分子和表型变化外，肿瘤微环境中也存在肿瘤内异质性。乳腺肿瘤活检中不同肿瘤内位置的相关性硬度图谱表明，硬度从核心向边缘增加。然而，不同局部 ECM 硬度如何调节肿瘤进展中癌细胞的关键功能仍不清楚。尽管组织硬度增加是乳腺癌进展的一个既定驱动因素，但来自 2D 培养物的结论与来自 3D 环境中癌细胞的最新数据不一致。许多过去关于 3D 培养乳腺癌的研究未能重现真实乳腺肿瘤的硬度或肿瘤微环境中存在的各种局部硬度。在这项研究中，我们开发了一系列具有可调节硬度的胶原/藻酸盐杂化水凝胶，以匹配乳腺肿瘤的核心、中间和外围区域。我们使用这种水凝胶系统研究了不同局部硬度对乳腺癌细胞形态、增殖和迁移的影响。不同硬度水凝胶中细胞的 RNA 测序揭示了癌症进展中多个细胞过程的变化，包括血管生成和代谢。我们发现，在软环境中的肿瘤细胞富集了 YAP1 和 AP1 信号相关基因，而在硬环境中的肿瘤细胞通过上调纤连蛋白 1 (FN1) 和基质金属蛋白酶 9 (MMP9) 的表达变得更具血管生成能力。这项系统研究定义了乳腺肿瘤中存在的环境硬度范围如何调节癌细胞，为肿瘤-基质界面的肿瘤发生和疾病进展提供了新的见解。
应用了定义明确的杂化水凝胶系统来模拟具有异质局部硬度的肿瘤微环境。乳腺癌细胞在软核心环境中倾向于增殖，而在硬外围环境中迁移。乳腺癌细胞响应硬基质微环境从糖酵解转变为 OXPHOS 和脂肪酸代谢。由于微环境刚度变化，乳腺癌细胞的转录组特征发生改变。
