Piezo1 Mediates\nGlycolysis-Boosted Pancreatic Ductal\nAdenocarcinoma Chemoresistance within a Biomimetic Three-Dimensional\nMatrix Stiffness

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer\nwith\na very low 5-year survival rate, which is partially attributed to\nchemoresistance. Although the regulation of chemoresistance through\nbiochemical signaling is well-documented, the influence of three-dimensional\n(3D) matrix stiffness is poorly understood. In this study, gelatin\nmethacrylate (GelMA) hydrogels were reconstructed with stiffnesses\nspanning the range from normal to cancerous PDAC tissues, which are\ntermed as the soft group and stiff group. The PDAC cell lines (Mia-PaCa2\nand CFPAC-1) encapsulated in the stiff group displayed a chemoresistance\nphenotype and were prominent against gemcitabine. RNA-sequencing and\nbioinformatics analysis indicated that glycolysis was apparently enriched\nin the stiff group <i>versus</i> the soft group, which was\nalso validated through assays of glucose uptake, lactate production,\nand the expression of GLUT2, HK2, and LDHA. A rescue assay with 2-deoxy-d-glucose and <i>N</i>-acetylcysteine demonstrated\nthat glycolysis is involved in chemoresistance. Furthermore, the expression\nof Piezo1 and the content of Ca<sup>2+</sup> were elevated in the\nstiff group. The addition of Yoda1 (Piezo1 agonist) in the soft group\npromoted glycolysis, whereas in the stiff group, treatment with GsMTx4\n(Piezo1 inhibitor) inhibited glycolysis, which showcased that Piezo1\nparticipated in 3D matrix stiffness-induced glycolysis. Taken together,\nPiezo1-mediated glycolysis was involved in PDAC chemoresistance triggered\nby the 3D matrix stiffness. Our study sheds light on the mechanism\nunderlying chemoresistance in PDAC from the perspective of 3D mechanical\ncues.