Combination ambient gas plasma treatment and chemotherapy

Abstract

Summary form only given. Despite its expense and harmful side effects, chemotherapy remains a standard part of breast cancer treatment. Combining chemotherapy with ambient gas plasma offers a way to reduce the dose of chemotherapeutics without reducing treatment efficacy. Ambient gas plasmas are cytotoxic to cancer cells. In vitro plasma treatment of MCF7 breast cancer cells by indirect dielectric barrier discharge and subsequent flow cytometry and fluorescence microscopy shows that the cytotoxicity correlates with increased intracellular reactive oxygen species. Ambient plasmas generate cocktails of reactive oxygen and nitrogen species, known to be involved in the mechanisms of many chemotherapeutics [1]. It has been previously shown that NO-donating compounds can sensitize cancer cells to some chemotherapeutics believed to have redox mechanisms [2]. We show that plasma treatment synergistically sensitizes MCF7 cells to cyclophosphamide and methotrexate doses orders of magnitude below the measured IC50s. The synergistic effect depends on order of treatment and concentration of chemotherapeutic used. The low concentration effect suggests potential clinical applications in treating drug resistant breast cancers with ambient plasmas.Despite its expense and harmful side effects, chemotherapy remains a standard part of breast cancer treatment. Combining chemotherapy with ambient gas plasma offers a way to reduce the dose of chemotherapeutics without reducing treatment efficacy. Ambient gas plasmas are cytotoxic to cancer cells. In vitro plasma treatment of MCF7 breast cancer cells by indirect dielectric barrier discharge and subsequent flow cytometry and fluorescence microscopy shows that the cytotoxicity correlates with increased intracellular reactive oxygen species. Ambient plasmas generate cocktails of reactive oxygen and nitrogen species, known to be involved in the mechanisms of many chemotherapeutics [1]. It has been previously shown that NO-donating compounds can sensitize cancer cells to some chemotherapeutics believed to have redox mechanisms [2]. We show that plasma treatment synergistically sensitizes MCF7 cells to cyclophosphamide and methotrexate doses orders of magnitude below the measured IC50s. The synergistic effect depends on order of treatment and concentration of chemotherapeutic used. The low concentration effect suggests potential clinical applications in treating drug resistant breast cancers with ambient plasmas.