The Antitumor Effects of Plasma-Activated Saline on Muscle-Invasive Bladder Cancer Cells In Vitro and In Vivo Demonstrate Its Feasibility as a Potential Therapeutic Approach

SIMPLE SUMMARY: Bladder cancer is the most common urinary system carcinoma, with more than 430,000 new cases diagnosed every year. More than 25% of patients are classed as having muscle-invasive bladder cancer (MIBC). MIBC is a serious clinical problem and is fatal for the majority of patients. In this work, we focus on the feasibility of plasma-activated saline (PAS) as a potential therapeutic approach for the treatment of MIBC. For this purpose, we evaluated the anticancer effect of PAS on two human bladder cancer cell lines (T24 and J82) in vitro and in vivo. Our initial results demonstrated that the PAS can provide a novel and valuable therapeutic effect for the local treatment of MIBC. We believe that the results presented in this paper will be of interest to many scientists in the field of bladder cancer treatment and plasma biomedicine. ABSTRACT: Muscle-invasive bladder cancer (MIBC) is a fast-growing and aggressive malignant tumor in urinary system. Since chemotherapy and immunotherapy are only useable with a few MIBC patients, the clinical treatment of MIBC still faces challenges. Here, we examined the feasibility of plasma-activated saline (PAS) as a fledgling therapeutic strategy for MIBC treatment. Our data showed that plasma irradiation could generate a variety of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in saline. In vivo tests revealed that pericarcinomatous tissue injection with PAS was effective at preventing subcutaneous bladder tumor growth, with no side effects to the visceral organs after long-term administration, as well as having no obvious influence on the various biochemistry indices of the blood in mice. The in vitro studies indicated that adding 30% PAS in cell culture media causes oxidative damage to the bladder transitional cells T24 and J82 through enhancing the intracellular ROS level, and eventually induces cancer cells’ apoptosis by activating the ROS-mediated Fas/CD95 pathway. Therefore, for an intracavity tumor, these initial observations suggest that the soaking of the tumor tissue with PAS by intravesical perfusion may be a novel treatment option for bladder cancer.