Fluid shear stress facilitates prostate cancer metastasis through Piezo1-Src-YAP axis

Mechanical forces surrounding solid tumors are pervasive in the tumor microenvironment (TME) and abnormally altered as solid tumors progress. Although it has been reported that biomechanical forces, including wall shear stress (WSS), enhance the metastatic features of cancer cells, its mechanism remains unknown. Here, we investigate how cancer cells sense mechanical stress and propagate signals in the TME.

Using a microfluidic device, interstitial fluid-mimicking flow (0.05 dyne cm^-2) was applied to the human prostate cancer cell line PC3. Piezo1 siRNA and shRNA lentivirus were applied to PC3 cells to ablate Piezo1 expression. PC3-Luc2 cells expressing control shRNA or shPiezo1 lentivirus were administered into the prostate of BALB/c mice for orthotopic injection.

Here, we show that Piezo1, a mechanosensitive ion channel, is activated by WSS in microfluidic channels. Moreover, Yoda1, a Piezo1 agonist, synergistically potentiates cancer cell motility and nuclear retention of YAP/TAZ via WSS. Also, Piezo1 increases Src phosphorylation, which activates YAP. Conversely, silencing Piezo1 significantly reduces cell motility and YAP/TAZ activity induced by WSS, and finally retards tumor growth and metastasis of administered PC3 cells in BALB/c mice.

Taken together, these results demonstrate that Piezo1 allows cancer cells to sense mechanical stimuli by altering the microenvironment during tumor progression and is a critical player in modulating cancer metastasis through the Piezo1-Src-YAP axis.