Project description:In gastric cancer (GC), PIEZO1 was suggested to promote cell migration by interacting with Trefoil factor family 1 (TFF1) and serve as a therapeutic target against invasion and metastasis. In addition, PIEZO1 demonstrates abundant expression in most GC cell lines and primary samples and highly-expressed PIEZO1 is associated with poor disease-specific survival. As Yoda1 is known to be an agonist of PIEZO1, we try to explore the PIEZO1 function in GC by Yoda1 treatment.
Project description:In gastric cancer (GC), PIEZO1 was suggested to promote cell migration by interacting with Trefoil factor family 1 (TFF1) and serve as a therapeutic target against invasion and metastasis. In addition, PIEZO1 demonstrates abundant expression in most GC cell lines and primary samples and highly-expressed PIEZO1 is associated with poor disease-specific survival. Thus, we try to explore the PIEZO1 function in GC by knocking down assay.
Project description:Piezo1 is a mechanosensitive ion channel that has gained recognition for its role in regulating diverse physiological processes. However, the influence of Piezo1 in inflammatory disease, including infection and tumor-immunity, is not well-studied. We postulated that Piezo1 links physical forces to immune regulation in myeloid cells. We discovered signal transduction via Piezo1 in myeloid cells and established this channel as the primary sensor of mechanical stress in these cells. Global inhibition of Piezo1 was protective against both cancer and septic shock and resulted in a diminution in suppressive myeloid cells. Moreover, deletion of Piezo1 in myeloid cells protected against cancer and increased survival in poly-microbial sepsis. Mechanistically, we show that mechanical stimulation promotes Piezo1-dependent myeloid cell expansion by suppressing Rb. We further show Piezo1-mediated silencing of Rb is regulated via upregulation of HDAC2. Collectively, our work uncovers Piezo1 as a targetable immune checkpoint that drives immune-suppressive myelopoiesis in cancer and infectious disease.
Project description:PIEZO1 is a mechanically-activated ion channel that contributes to flow sensing in vascular endothelium. Moreover, deletion of endothelial PIEZO1 was recently found to suppress activation of Notch1 target genes in hepatic microvascular endothelium. Here, because of the liver’s dominant role in lipid regulation, we set out to test the novel hypothesis that endothelial PIEZO1 regulates hepatic lipid homeostasis. We performed bulk RNA sequencing on PIEZO1-deleted mice exposed to chow and high fat diets. Our transcriptomics analysis reveal unexpected relevance to lipid and glucose homeostasis.
Project description:To investigate the effect of Piezo1 in the apoptosis of anulus fibrous cells (AFCs) induced by mechanical stretch. We established AFCs in which Piezo1 channel has been knocked down by shRNA. We then performed gene expression profiling analysis using data obtained from RNA-seq of AFCs treated withpLVX-shRNA-Puro(Lv-Ctrl group) and AFCs treated with pLVX-shRNA-Puro-Piezo1(Lv-Piezo1 group).
Project description:Most cancer cells are exposed to extracellular environments, such as extracellular matrix, which commonly becomes stiffer along with transformation. It is conceivable that tumorous extracellular environments would be changing to affect tumor cell behavior. It has been reported that Hippo pathway responds to the extracellular environments and induces the nuclear localization of transcription activator, yes-associated protein (YAP), resulting in stimulating cell proliferation. Its pathway also regulates gene expression, but the precise molecule to meditate cell proliferating effect of Hippo pathway in oral squamous cell carcinoma (OSCC) is not well understood. Here, we examined the effects of YAP-mediated Hippo pathway in OSCC tumorigenesis. Loss-of-function experiments using siRNA or an inhibitor, and immunohistochemical analyses of tissue specimens obtained from OSCC specimens demonstrated that YAP-mediated Hippo pathway was involved in OSCC cell proliferation. We identified Piezo-type mechanosensitive ion channel component 1 (PIEZO1), a Ca2+ channel, as a downstream molecule of Hippo pathway and showed that elevated PIEZO1 expression was required for PIEZO1 agonist-dependent Ca2+ entry and cell proliferation in OSCC cells. Furthermore, the experiments using three-dimensional culture and suspension culture revealed that PIEZO1, of which expression was regulated by YAP-mediated Hippo pathway, was involved in OSCC cellular growth. Immunohistochemically, YAP overexpression with nucleus and/or cytoplasm was detected with both PIEZO1 and Ki-67 expression at high frequencies in tumor lesion, but not in non-tumor region, of OSCC specimens. These results suggest that the YAP-mediated Hippo/PIEZO1 axis, which might be activated by the tumorous extracellular environments, promotes OSCC tumor cell growth.
Project description:Gastric cancer is a global health concern. Molecular alterations in various signaling pathways have been implicated in the development and late-stage progression/metastasis of gastric cancer. Reports have suggested that Wnt signaling pathway might contribute to gastric carcinogenesis by stimulating migration and invasion of gastric cancer cells. This study aimed at analysing the proteome change upon CAMKK2 inhibition in gastric cancer cells using LC-MS/MS based quantitative proteomic approach. A TMT based quantitative approach was used to identify the significantly altered proteins upon CAMKK2 inhibition. Gene Ontology (GO) analysis and pathway analysis was done for the significantly altered proteins and was later validated by immunoblotting.
Project description:To investigate the effect of STAT3 activation on the expression of gastric cancer cells, expression profile was compared in MKN28 cells overexpressed with control vector vs mouse constitutively activated STAT3 mutant (STAT3c). MKN28 gastric cancer cells were transfected with pcDNA3.1 (vector control) or plasmid overexpressing STAT3c (treatment). Stable clones were selected for RNA extraction and expression microarray analysis (Agilent). Experiments were repeated twice.
Project description:The propeller-shaped blades of the PIEZO1 and PIEZO2 ion channels partition into the plasma membrane and respond to indentation or stretching of the lipid bilayer, thus converting mechanical forces into signals that can be interpreted by cells, in the form of calcium flux and changes in membrane potential. While PIEZO channels participate in diverse physiological processes, from sensing the shear stress of blood flow in the vasculature to detecting a light touch on the surface of the skin, the molecular details that enable these mechanosensors to tune their responses over a vast dynamic range of forces remain largely uncharacterized. To survey the molecular landscape surrounding PIEZO channels at the cell surface, we employed a mass spectrometry-based proteomic approach to capture and identify extracellularly exposed proteins in the vicinity of PIEZO1. This PIEZO1-proximal interactome was enriched in surface proteins localized to cell junctions and signaling hubs within the plasma membrane. Functional screening of these interaction candidates by calcium imaging and electrophysiology in an overexpression system identified the adhesion molecule CADM1/SynCAM that slows the inactivation kinetics of PIEZO1 with little effect on PIEZO2. Conversely, we found that CADM1 knockdown accelerates inactivation of endogenous PIEZO1 in Neuro-2a cells. Systematic deletion of CADM1 domains indicate that the transmembrane region is critical for the observed effects on PIEZO1, suggesting that modulation of inactivation is mediated by interactions in or near the lipid bilayer.