Dynamically softened substrate regulates malignancy of breast tumor cells

动态硬度降低基底调控肿瘤细胞恶性的研究

It has long been hypothesized that an increase in the extracellular matrix(ECM)stiffness mechanoactivates malignant phenotypes of breast tumor cells by regulating an array of processes underlying cancer biology.Although the contribution of substrate stiffening to drive malignant phenotype traits and other biological functions of a tumor is increasingly understood,the functional role of substrate softening on breast cancer cellular responses has rarely been investigated.Herein,we employed matrix metalloproteinase(MMP)-sensitive film to perform assays to explore the consequences of lowering stiffness on the biological behaviors of breast cancer cell MDA-MB-231.We demonstrated that cells underwent dramatic changes in migration,cellular conjunction,and expression of malignance-associated proteins and genes when the substrate stiffness decreased.Based on RNA sequencing and analysis,we found that hub genes including TP53,CCND1,MYC,CTNNB1,and YAP were validated to play central parts in regulating stiffness-dependent cellular manner change.Moreover,through visualization of differentially expressed genes(DEGs),cells on dynamically softened substrate appeared less influenced by transfer to tissue culture polystyrene(TCPS).These results suggest substrates with decreasing stiffness could normalize breast tumor malignant phenotype and help cells store the mechanical memory of the consequential weaker malignance.

肿瘤的发生发展伴随着细胞外基质的重塑和硬化.目前,尽管细胞外基质的硬度已经成为一种强有力的肿瘤细胞行为调节器,但基底硬度动态下降对乳腺癌细胞行为的影响却鲜有研究.在此,我们采用基质金属蛋白酶敏感的聚电解质多层膜进行分析,探讨硬度的降低对乳腺癌细胞MDA-MB-231生物学行为的影响.结果表明,与在静态高硬度基底上培养的细胞相比,在硬度动态降低的基底上培养时,细胞的迁移、粘附及恶性相关蛋白和基因表达水平发生了显著变化,肿瘤恶性降低.根据蛋白质相互作用PPI网络分析结果,中枢节点基因TP53,CCND1,MYC,CTNNB1和YAP被认为在硬度依赖性细胞行为变化中起着核心作用.此外,将在动态软化基底上培养的细胞转移到高硬度材料上之后,细胞仍保持较弱的恶性,表现出一定的记忆性.