Revealing interactions between reactive plasma and cancer cell membranes

Cold atmospheric plasma (CAP) has the potential to be used in cancer treatments by generating reactive oxygen and nitrogen species (RONS) that can selectively target and kill cancer cells. Previous research has suggested that the membrane transport protein aquaporin (AQP), which is overexpressed in many cancer cells, may play a role, but the exact mechanism is unclear.

Cui et al. employed molecular dynamics simulations to observe the behavior of RONS with AQP overexpression. Their results could lead to a better understanding of the mechanisms underlying plasma-assisted apoptosis and more targeted cancer treatments.

“The key to inducing apoptosis of cancer cells without damaging normal cells under the action of plasma is precise regulation and optimization of plasma dose,” said author Tong Zhao. “Therefore, this study provided some understanding of the dose concentration of reactive species at the microscopic level.”

The team compared the differences between reactive oxygen and nitrogen species’ transmembrane behavior across lipid bilayers with and without AQP. They found that hydrophobic nitrogen species, such as NO and NO₂, tend to be transported through the phospholipid bilayer and the presence of AQP has little effect. Hydrophilic oxygen species, like H₂O₂, HO₂, and OH, rely on AQP for transmembrane transport and are most affected by its overexpression.

The authors plan to expand their analysis to incorporate more complex plasma interactions and further explore their effects on cancer cells.

“We will focus on the effects of oxidation of reactive species and plasma electric field effects on RONS transmembrane behavior, further explore the microscopic mechanism of selective apoptosis of cancer cells by plasma, and attempt to verify it experimentally,” said Zhao.

Source: “Molecular dynamics simulation of the effect of AQP1 on the transmembrane transport of plasma RONS across cancer cell membranes,” by Yanxiu Cui, Tong Zhao, Zichen Wang, Xiaolong Wang, Daohan Wang, and Yuantao T Zhang, Physics of Plasmas (2023). The article can be accessed at https://doi.org/10.1063/5.0145098 .