Imaging endogenous mRNAs in live animals is technically challenging. Here, we describe an MS2-based signal amplification with the Suntag system that enables live-cell RNA imaging of high temporal resolution and with 8xMS2 stem-loops, which overcomes the obstacle of inserting a 1300 nt 24xMS2 into the genome for the imaging of endogenous mRNAs. Using this tool, we were able to image the activation of gene expression and the dynamics of endogenous mRNAs in the epidermis of live C. elegans.

Pancreatic ductal adenocarcinoma (PDAC) continues to show no improvement in survival rates. One aspect of PDAC is elevated ATP levels, pointing to the purinergic axis as a potential attractive therapeutic target. Mediated in part by highly druggable extracellular proteins, this axis plays essential roles in fibrosis, inflammation response and immune function. Analysing the main members of the PDAC extracellular purinome using publicly available databases discerned which members may impact patient survival. P2RY2 presents as the purinergic gene with the strongest association with hypoxia, the highest cancer cell-specific expression and the strongest impact on overall survival. Invasion assays using a 3D spheroid model revealed P2Y₂ to be critical in facilitating invasion driven by extracellular ATP. Using genetic modification and pharmacological strategies we demonstrate mechanistically that this ATP-driven invasion requires direct protein-protein interactions between P2Y₂ and αV integrins. DNA-PAINT super-resolution fluorescence microscopy reveals that P2Y₂ regulates the amount and distribution of integrin αV in the plasma membrane. Moreover, receptor-integrin interactions were required for effective downstream signalling, leading to cancer cell invasion. This work elucidates a novel GPCR-integrin interaction in cancer invasion, highlighting its potential for therapeutic targeting.