胰腺癌组织重塑探索：机械力敏感通道Piezo1加速力稳态失衡促进肿瘤发生发展的研究

力稳态失衡影响胰腺癌发生发展，机制尚不明确。课题组发现，胰腺星状细胞与肿瘤细胞的交互作用是组织力学结构改变的主要原因，机械敏感型离子通道Piezo1能将胞外机械信号转变为胞内生物学信号，是组织力学结构重塑的枢纽分子。我们推测，Kras突变胰腺腺泡/肿瘤细胞高表达Piezo1，通过HSF1-TGFβ功能轴旁分泌活化胰腺星状细胞刺激其产生大量的细胞外基质改变胰腺组织力学微环境，进一步诱发实质细胞Piezo1激活形成级联放大正反馈环路，以组织结构重塑的方式促进胰腺癌发生发展。拟通过临床、体外、转基因小鼠三个层面，在分子生物学与机械力学两个维度，采用腺泡细胞体外3D培养、细胞共培养、激光捕获显微切割、表达谱测序、双荧光素酶报告基因系统等分子生物学技术，和组织弹性成像应力检测、原子力显微镜、荧光标记细胞膜表面张力探针检测等生物机械力学技术，揭示不同阶段组织力学结构的改变，为研究胰腺癌发展提供新思路。

With the initiation and development of pancreatic cancer, the parenchymal changes of pancreatic cancer are accompanied with the changes of tumor cells. Stroma induced tissue stiffness and mechanical strength change have significant regulatory activities on the development of many cancers including pancreatic cancer. Our previous study showed that the interaction between pancreatic stellace cells(PSC) and cancer cells may be the key factor for the change of tissue remodeling. Piezo1, as a mechanosensitive cation channel, could transform extracellular mechanical signals into intracellular biological signals, which may play an important role in tissue remodeling of pancreatic cancer. We hypothesized that with the k-ras mutation, Piezo1 expression was elevated in pancreatic acinar cells/ tumor cells. It could induce PSC activation through paracrine stimulation of Piezo1-HSF1-TGFβaxis. Activated PSC could produce a plenty of stromal components which account for mechanical remodeling of pancreatic tissue. The new mechanical strength may form a cascade and enlarge the positive feedback loop through reactivation of Piezo1, which is crucial on the progression of pancreatic cancer. The hypothesis could be verified through clinical specimen analysis, in vitro cell study and in vivo transgenetic mouse level through molecular biological detection and mechanical strength study. Different molecular biological technique could be applied including in vitro 3D culture of acinar cells, co-culture of pancreatic cancer cells and PSCs, laser capture microdissection, differential expression sequencing analysis, double luciferase reporter gene system and chromatin immunocoprecipitation technology. Moreover, as to the observation of mechanical strength alteration, tissue elastic imaging detection, atomic force microscopy, fluorescence labeled cell membrane surface tension probe detection technique could be applied. The study could reveal the changes of tissue mechanical structure in different stages, and provide new sight of theoretical basis for the study of the occurrence and development of pancreatic cancer.