Microbubble-Mediated Cavitation Promotes Apoptosis and Suppresses Invasion in AsPC-1 Cells

This study aimed to identify the potential and mechanisms of microbubble-mediated cavitation in promoting apoptosis and suppressing invasion in cancer cells. AsPC-1 cells were used and divided into four groups: control group, microbubble-only (MB) group, ultrasound-only (US) group, and ultrasound combined with microbubbles (US+MB) group. Pulse ultrasound was used with a frequency of 360 kHz and an intensity of 0.7 W/cm2 for 1 min (duty rate=50%). Then cells in four groups were cultured for 24 h. Cell counting kit-8 illustrated that US+MB could decrease cell viability. Western blot confirmed that US+MB increased cleaved Caspase-3, Bcl-2-associated X protein (BAX), and decreased the B-cell lymphoma-2 (Bcl-2) levels. Besides, US+MB increased intracellular calcium ions and down-regulated cleaved Caspase-8. For proliferation ability, cells in US+MB group had a lower expression of Ki67 and the weakened colony formation ability. The transwell invasion assay showed that US+MB could decrease invasion ability in AsPC-1 cells. Further evidence showed that cells conducted with US+MB had the lower level of hypoxia-inducible factor-1 (HIF-1) and Vimentin and the higher expression of E-cadherin than the other three groups. Finally, cells conducted with US+MB had less invadopodia formation. In conclusion, these results suggested that microbubble-mediated cavitation promoted apoptosis and suppressed invasion in AsPC-1 cells. SignificanceCancer cells have a high rate of cell division and a high rate of cell division can speed up the development of hypoxia which lead to promote cancer invasion and metastasis. Here we used microbubble-mediated cavitation to generate a mechanical shock wave which could effectively kill cancer cells through physical damage and intrinsic signaling pathway. Furthermore, effective killing of cancer cells could restrain the development of hypoxia and prevent invasion ability of cancer cells.