Gene silencing of Rac1 with RNA interference mediated by ultrasound and microbubbles in human LoVo cells: evaluation of cell invasion inhibition and metastatic

Abstract

Objective: The objective of this study was to assess the change of cytoskeleton and cell cycle in LoVo (human colorectal cancer) cell via gene silencing of Rac1 with RNA interference mediated by microbubble (SonoVue) and ultrasound (US).

Methods: The compound of plasmid Rac1-shRNA, LoVo cells, and SonoVue was exposed to US (1 MHz, 2 W/cm², 5 min). The expression of Rac1 mRNA and Rac1 protein was detected by RT-PCR and Western blot. Cytoskeleton was taken by confocal microscope in a random fashion. Cell invasion was assayed using modified Boyden chambers, and cell cycle and apoptosis were analyzed by flow cytometry in LoVo cells.

Results: Rac1 gene is overexpressed in human colorectal cancer cells, gene silencing of Rac1 with RNA interference mediated by microbubble and US strongly inhibited lamellipodia formation, cell invasion, and delayed cell cycle, as well as enhanced cell apoptosis of LoVo cells in vitro.

Conclusion: Silencing Rac1 gene mediated by microbubble and US may become a new treatment option for the inhibition of the invasion and metastasis of colorectal cancer cells.

• Actin cytoskeleton
• invasion colorectal cancer
• microbubble and ultrasound
• Rac1
• RNA interference

Acknowledgements

We would like to thank digestive laboratory of Nanfang Hospital affiliated Southern Medical University (Guangzhou, China) for providing colorectal cancer cell lines.

Declaration of interest

The authors report no declarations of interest. This work is supported in part by Grant 1010RJZA128 from Natural Science Research fund plan of Gansu, China.