Development of In Vitro Model to Elucidate the Mechanism of Cancer Development by Mechano-stress Induced by Sonic Stimulation

Cancers are considered to be affected by mechano-stress caused by sonic stimulation such as vibration and vocalization during their development and malignant transformation, but no device has been available to enable such an investigation. We have developed an in vitro cell culture model that can reproduce mechano-stress by sonic stimulation. The device is fabricated by micro-stereolithography and can reproduce the 3D shape of the target tissue with a modeling resolution of 50 µm. Cells are cultured on a 50-µm-thick poly-dimethylpolysiloxane (PDMS) sheet, and sonic stimulation is applied directly through a micro-speaker set on the bottom of the device. To verify the function of this device, the HepG2 cancer cell line was cultured while being stimulated with vibrations from the micro-speaker. The results showed a significant change in ACTa1 gene expression, which is a gene with variable expression in various types of cancer. There are currently no reports on ACTa1 gene expression increasing only by the vibration stimulation of cancer cell lines. This result is the first data showing that mechano-stress induced by sonic stimulation may be involved in changes in the malignant potential of cancer.